Hub Gears: no need to scoffjaw the warranty

[Andre Jute]

A concurrent thread on a big gear range made me wonder what width one
could achieve in hub gears by ignoring the recommended chainring/
sprocket ratio, which for Rohloff appears to be a fraction under 2.5
and for the Shimano Nexus 8-speed hub is specifically given as from
2.0 to 2.1. I have no idea how long the hubs would survive under
abusive handling as in some of the examples below. All numbers in gear
inches.

With a 37-622 tyre and 46-16 gears, the Rohloff Speed Hub would give a
range from a notch or two below many mountain bikes to pretty well
beyond what most people could manage on the flat. Fourteen gears in
gear inches developed:

22
25
28
32
37
42
47
54
61
70
79
90
102
116

Just for comparison, here are the gear inches for the 14 gears of the
Rohloff with a more reasonable, and possibly permitted (I've seen it
several times), 42-16 setup. Still a very respectable spread, and
probably more pleasurable to use:

20
23
26
29
33
38
43
49
56
64
72
82
93
106

Adding the Schlumpf Speed Drive to a Rohloff Speed Hub seems
unnecessary: it will add only four useful gears at most, the rest
being duplicated.

Okay, let's look at the Shimano Nexus 8-speed hub.

With a 37-622 tyre and the same 46-16 gears as inour first example,
but in this case even more abusive, the Shimano Nexus 8-speed hub
combined with the Schlumpf Mountain Drive would give an even wider
useful spread, 14 unique gears out of 16 covering from a Himalayan low
gear to 127in to pose with in cafe society. (This covers the entirely
unreasonable 18 to 123in someone asked for in a concurrent thread, and
a bit more.)

Gear Direct SMD
1 42 17
2 51 20
3 59 24
4 67 27
5 79 32
6 97 39
7 112 45
8 127 51

I was speaking to a guy in the parts department at Volvo in Gothenburg
a few years ago, and when he heard I planted a Chevy mouse motor in
one of their estates and was now supercharging it and looking to use a
few gennie Volvo parts, he said thickly, "Doncha tell Warranty. Inna
flash Warranty turn your ash to grash." (On a tip from this colourful
fellow I ordered the parts I wanted a lot cheaper from Rolls-Royce
than from Volvo; they bought them the same place but the Volvo markup
was higher...) I imagine Shimano will turn one's warranty, and one's
ass, to grass in a flash if they hear about a 46-16 FR tooth ratio on
one of their Nexus hubs, when they went to the trouble of printing the
ratio warning on the cover of the spec sheet.

So let's try 38-18, which at 2.11 recurring is arguably within the
permitted ratio, and can be built with Shimano's goodlooking and
reasonably priced own-brand parts intended for the hub gear bikes.
With the Schlumpf Mountain Drive, that gives 14 unique gears that
covers everything from loaded goatherding to pretty fast touring:

31 12
37 15
43 17
49 20
58 23
71 28
82 33
94 37

It does look like iconoclasm and scoffjawing the warranty is
unnecessary. With either the Rohloff or the Nexus/Schlumpf combination
you can get nicely spaced gear ratios over a very wide operating band.
The designers of those hubs and geared bottom bracket got it right.

In fact, riding daily in the low rolling hills of West Cork, I find
38-19 sets of teeth just right on the Nexus gear hub without the need
for the Schlumpf geared bottom bracket; it gives me the following gear
inch development for the 8 gears, perfect for day rides on my
particular countryside without ever having to push:

29
35
41
47
55
67
78
89

Sprockets with any number of teeth you can want are readily available,
so for another use, say loaded alpine touring, I would not hesitate to
change the sprocket to give a ratio that is not permitted. I think the
Nexus hub is a lot sturdier than Shimano lets on, and it is widely
known that the Rohloff hub is panzer.

Andre Jute
Libertarian: a conservative who talks up a good liberal line.

 

[Clive George]

"Andre Jute" <[email protected]> wrote in message
news:[email protected]...
>A concurrent thread on a big gear range made me wonder what width one
> could achieve in hub gears by ignoring the recommended chainring/
> sprocket ratio, which for Rohloff appears to be a fraction under 2.5
> and for the Shimano Nexus 8-speed hub is specifically given as from
> 2.0 to 2.1. I have no idea how long the hubs would survive under
> abusive handling as in some of the examples below. All numbers in gear
> inches.

It's a pity you don't understand the simple rules about permitted gearing.

They specify a minimum gearing, ie on a rohloff, 40/17, 38/16, 36/15,
32/13t, or 40/16 etc for 100kg+ riders and tandems. Put a smaller chainring
than recommended, and you'll be putting more force on the hub than it's
designed for. (actually, you can push it, but that's not relevant for the
purposes of this discussion).

So, the 46/16 you claim is not permissible is in fact entirely legit - it's
rather easier on the hub than the minimum permissible gearing.

Ditto 42/16.

Not abusive at all.

32/16 would be abusive.

>With a 37-622 tyre and the same 46-16 gears as inour first example,
>but in this case even more abusive, the Shimano Nexus 8-speed hub
>combined with the Schlumpf Mountain Drive would give an even wider
>useful spread, 14 unique gears out of 16 covering from a Himalayan low
>gear to 127in to pose with in cafe society. (This covers the entirely
>unreasonable 18 to 123in someone asked for in a concurrent thread, and
>a bit more.)

You'll have that nice range, but using the mountain drive will break it. The
mountain drive gives the equivalent of a 18t chainring with your 46. The
minimum with a 16t sprocket on the nexus if your 2.1 is correct is a 32t,
though I've seen people using 29/17ish gearing.

And of course the wheel size makes no difference to the permitted gearing -
it does however make a difference to the effective gearing you end up with.
If you stick a Rohloff in a small wheel, you can get some pretty small
gears.

http://www.kinetics.org.uk/html/k_gear.shtml

is quite cool though.

clive

 

[[email protected]]

On Thu, 31 Jan 2008 03:43:46 -0000, "Clive George"
<[email protected]> wrote:

>"Andre Jute" <[email protected]> wrote in message
>news:[email protected]...
>>A concurrent thread on a big gear range made me wonder what width one
>> could achieve in hub gears by ignoring the recommended chainring/
>> sprocket ratio, which for Rohloff appears to be a fraction under 2.5
>> and for the Shimano Nexus 8-speed hub is specifically given as from
>> 2.0 to 2.1. I have no idea how long the hubs would survive under
>> abusive handling as in some of the examples below. All numbers in gear
>> inches.
>
>It's a pity you don't understand the simple rules about permitted gearing.
>
>They specify a minimum gearing, ie on a rohloff, 40/17, 38/16, 36/15,
>32/13t, or 40/16 etc for 100kg+ riders and tandems. Put a smaller chainring
>than recommended, and you'll be putting more force on the hub than it's
>designed for. (actually, you can push it, but that's not relevant for the
>purposes of this discussion).
>
>So, the 46/16 you claim is not permissible is in fact entirely legit - it's
>rather easier on the hub than the minimum permissible gearing.
>
>Ditto 42/16.
>
>Not abusive at all.
>
>32/16 would be abusive.
>
>>With a 37-622 tyre and the same 46-16 gears as inour first example,
>>but in this case even more abusive, the Shimano Nexus 8-speed hub
>>combined with the Schlumpf Mountain Drive would give an even wider
>>useful spread, 14 unique gears out of 16 covering from a Himalayan low
>>gear to 127in to pose with in cafe society. (This covers the entirely
>>unreasonable 18 to 123in someone asked for in a concurrent thread, and
>>a bit more.)
>
>You'll have that nice range, but using the mountain drive will break it. The
>mountain drive gives the equivalent of a 18t chainring with your 46. The
>minimum with a 16t sprocket on the nexus if your 2.1 is correct is a 32t,
>though I've seen people using 29/17ish gearing.
>
>And of course the wheel size makes no difference to the permitted gearing -
>it does however make a difference to the effective gearing you end up with.
>If you stick a Rohloff in a small wheel, you can get some pretty small
>gears.
>
>http://www.kinetics.org.uk/html/k_gear.shtml
>
>is quite cool though.
>
>clive

Dear Clive,

For those curious about the details . . .

Here's the short but clear Rohloff page that explains that it's the
ratio between front chainring and rear sprocket that matters to the
hub, not the wheel size:

http://www.rohloff.de/en/info/faq/faq_detail/article/kettenblattzaehnezahl//bp/289/index.html

And here's the Rohloff page that explains the specific number of
front/rear teeth with the lowest front/rear sprocket ratio (not
overall gearing including wheel size) that they think wise:

http://www.rohloff.de/en/info/faq/f...der-rohloff-speedhub-50014//bp/289/index.html

As the page explains, the 2.35:1 front/rear ratio is the minimum
acceptable ratio for normal use, a 40/17 (2.35:1) being as low a ratio
as Rohloff thinks a normal rider should use. For a heavier rider
(100kg+) or a tandem, Rohloff warns that the minimum should be raised
to 40/16 (2.50:1).

Increasing the size of the front chain-ring is okay. That is, 40/16 is
2.50:1, so adding eight teeth for 48:16 (3.00:1) is fine.

In other words, you can gear a Rohloff's exposed front/rear up higher
and higher--it's fine to use the high-speed 52x12 (4.33:1) instead of
the 39x13 (3.00:1). That's a selling point for small-rear-wheel bikes
that need higher gearing.

But you don't want to go the other way and gear down in hopes of low
mountain-bike gearing--a 39 front and a 28 rear (1.39:1) would be a
bad thing, well below the recommended 2.35:1.

What confuses people is that it's a matter of how the front/rear
sprocket combination feeds into the Rohloff's many hidden internal
gears, not a matter of the simple front/rear sprocket of an exposed
derailleur.

Cheers,

Carl Fogel

 

[Tom Sherman]

Andre Jute wrote:
> A concurrent thread on a big gear range made me wonder what width one
> could achieve in hub gears by ignoring the recommended chainring/
> sprocket ratio, which for Rohloff appears to be a fraction under 2.5
> and for the Shimano Nexus 8-speed hub is specifically given as from
> 2.0 to 2.1. I have no idea how long the hubs would survive under
> abusive handling as in some of the examples below. All numbers in gear
> inches.
>
> With a 37-622 tyre and 46-16 gears, the Rohloff Speed Hub would give a
> range from a notch or two below many mountain bikes to pretty well
> beyond what most people could manage on the flat. Fourteen gears in
> gear inches developed:
>
> 22
> 25
> 28
> 32
> 37
> 42
> 47
> 54
> 61
> 70
> 79
> 90
> 102
> 116
>
> Just for comparison, here are the gear inches for the 14 gears of the
> Rohloff with a more reasonable, and possibly permitted (I've seen it
> several times), 42-16 setup. Still a very respectable spread, and
> probably more pleasurable to use:
>
> 20
> 23
> 26
> 29
> 33
> 38
> 43
> 49
> 56
> 64
> 72
> 82
> 93
> 106
>
> Adding the Schlumpf Speed Drive to a Rohloff Speed Hub seems
> unnecessary: it will add only four useful gears at most, the rest
> being duplicated.
>
Why not consider the Schlumpf High Speed Drive [1] that offers a 2.5:1
step-up, as compared to the 1.65:1 step-up of the Speed Drive?

> Okay, let's look at the Shimano Nexus 8-speed hub.
>
> With a 37-622 tyre and the same 46-16 gears as inour first example,
> but in this case even more abusive, the Shimano Nexus 8-speed hub
> combined with the Schlumpf Mountain Drive would give an even wider
> useful spread, 14 unique gears out of 16 covering from a Himalayan low
> gear to 127in to pose with in cafe society. (This covers the entirely
> unreasonable 18 to 123in someone asked for in a concurrent thread, and
> a bit more.)
>
Unreasonable for an upright bicycle, yes.

However, for a recumbent bicycle, that wide gearing range is not at all
unreasonable, but nearer to a necessity. The proper climbing technique
on a recumbent bicycle is unlike that for an upright bicycle, where the
preferred climbing technique of many is to stand and pedal at a
relatively low cadence, while pulling on the handlebars to increase
one's "effective" weight.

Conversely, the proper climbing technique on a recumbent is to use a
very high cadence (e.g. 120 RPM) and to pull back [2] as much as
possible. Trying to use the upright climbing technique will result in
excess lactic acid buildup with the rider then needing to stop or slow
severely to recover.

The (performance oriented) recumbent will also descend faster (where
tight corners or rough surfaces do not limit speed too severely) than
the upright. In particular, on a frontally or fully faired recumbent,
the rider can pedal without increasing drag, so a very high gear can be
used while going downhill.

I have a couple of lowracer bicycles with gear inch range of 19-120
(achieved with a step-up jack-shaft) and a "bodysock" faired long wheel
base recumbent with a range of 15-125 gear inches (achieved with a
triple crank and 3x7 hub). I have found both the lowest and highest gear
ratios on these bicycles useful.

> Gear Direct SMD
> 1 42 17
> 2 51 20
> 3 59 24
> 4 67 27
> 5 79 32
> 6 97 39
> 7 112 45
> 8 127 51
>
> I was speaking to a guy in the parts department at Volvo in Gothenburg
> a few years ago, and when he heard I planted a Chevy mouse motor in
> one of their estates and was now supercharging it and looking to use a
> few gennie Volvo parts, he said thickly, "Doncha tell Warranty. Inna
> flash Warranty turn your ash to grash." (On a tip from this colourful
> fellow I ordered the parts I wanted a lot cheaper from Rolls-Royce
> than from Volvo; they bought them the same place but the Volvo markup
> was higher...) I imagine Shimano will turn one's warranty, and one's
> ass, to grass in a flash if they hear about a 46-16 FR tooth ratio on
> one of their Nexus hubs, when they went to the trouble of printing the
> ratio warning on the cover of the spec sheet.
>
> So let's try 38-18, which at 2.11 recurring is arguably within the
> permitted ratio, and can be built with Shimano's goodlooking and
> reasonably priced own-brand parts intended for the hub gear bikes.
> With the Schlumpf Mountain Drive, that gives 14 unique gears that
> covers everything from loaded goatherding to pretty fast touring:
>
> 31 12
> 37 15
> 43 17
> 49 20
> 58 23
> 71 28
> 82 33
> 94 37
>
> It does look like iconoclasm and scoffjawing the warranty is
> unnecessary. With either the Rohloff or the Nexus/Schlumpf combination
> you can get nicely spaced gear ratios over a very wide operating band.
> The designers of those hubs and geared bottom bracket got it right.
>
> In fact, riding daily in the low rolling hills of West Cork, I find
> 38-19 sets of teeth just right on the Nexus gear hub without the need
> for the Schlumpf geared bottom bracket; it gives me the following gear
> inch development for the 8 gears, perfect for day rides on my
> particular countryside without ever having to push:
>
> 29
> 35
> 41
> 47
> 55
> 67
> 78
> 89
>
Would not a higher gear be useful when drafting trucks downhill?

> Sprockets with any number of teeth you can want are readily available,
> so for another use, say loaded alpine touring, I would not hesitate to
> change the sprocket to give a ratio that is not permitted. I think the
> Nexus hub is a lot sturdier than Shimano lets on, and it is widely
> known that the Rohloff hub is panzer.
>
Of course, one can obtain very low gearing when the Rohloff is used in a
small drive wheel, without violating Rohloff's restrictions. Lacing the
large flange Rohloff hub into an ISO 349-mm hub would be challenging, if
one were to use it on a bicycle such as the Tri-Sled Nitro [3].

[1] <http://www.schlumpf.ch/hsd_engl.htm>.
[2] Clipless pedals with good retention are mandatory.
[3] <http://www.trisled.com.au/nitro.html>.

--
Tom Sherman - Holstein-Friesland Bovinia
"And never forget, life ultimately makes failures of all people."
- A. Derleth

 

[Nick Payne]

Seeing that Rohloff are quite happy for their hub to be used on a tandem
with the recommended 2.4:1 front/rear ratio, I had no scruple using a lower
ratio on my own bike when I took it to Switzerland for two months in 2004. I
used 38/16 with 38x622 tyres, which gave a bottom gear that I found pretty
useful for comfortably climbing grades up to about 25% with a loaded bike.
That ratio gave gears from a low of 18 up to about 95 inches.

If you look at the actual hub specs, it nominates a maximum torque of 250Nm
at the crank with the recommended 2.4:1 ratio. With 170mm cranks that's
about 150Kgf on the pedal.

Nick

"Andre Jute" <[email protected]> wrote in message
news:[email protected]...
>A concurrent thread on a big gear range made me wonder what width one
> could achieve in hub gears by ignoring the recommended chainring/
> sprocket ratio, which for Rohloff appears to be a fraction under 2.5
> and for the Shimano Nexus 8-speed hub is specifically given as from
> 2.0 to 2.1. I have no idea how long the hubs would survive under
> abusive handling as in some of the examples below. All numbers in gear
> inches.
>
> With a 37-622 tyre and 46-16 gears, the Rohloff Speed Hub would give a
> range from a notch or two below many mountain bikes to pretty well
> beyond what most people could manage on the flat. Fourteen gears in
> gear inches developed:
>
> 22
> 25
> 28
> 32
> 37
> 42
> 47
> 54
> 61
> 70
> 79
> 90
> 102
> 116
>
> Just for comparison, here are the gear inches for the 14 gears of the
> Rohloff with a more reasonable, and possibly permitted (I've seen it
> several times), 42-16 setup. Still a very respectable spread, and
> probably more pleasurable to use:
>
> 20
> 23
> 26
> 29
> 33
> 38
> 43
> 49
> 56
> 64
> 72
> 82
> 93
> 106
>
> Adding the Schlumpf Speed Drive to a Rohloff Speed Hub seems
> unnecessary: it will add only four useful gears at most, the rest
> being duplicated.
>
> Okay, let's look at the Shimano Nexus 8-speed hub.
>
> With a 37-622 tyre and the same 46-16 gears as inour first example,
> but in this case even more abusive, the Shimano Nexus 8-speed hub
> combined with the Schlumpf Mountain Drive would give an even wider
> useful spread, 14 unique gears out of 16 covering from a Himalayan low
> gear to 127in to pose with in cafe society. (This covers the entirely
> unreasonable 18 to 123in someone asked for in a concurrent thread, and
> a bit more.)
>
> Gear Direct SMD
> 1 42 17
> 2 51 20
> 3 59 24
> 4 67 27
> 5 79 32
> 6 97 39
> 7 112 45
> 8 127 51
>
> I was speaking to a guy in the parts department at Volvo in Gothenburg
> a few years ago, and when he heard I planted a Chevy mouse motor in
> one of their estates and was now supercharging it and looking to use a
> few gennie Volvo parts, he said thickly, "Doncha tell Warranty. Inna
> flash Warranty turn your ash to grash." (On a tip from this colourful
> fellow I ordered the parts I wanted a lot cheaper from Rolls-Royce
> than from Volvo; they bought them the same place but the Volvo markup
> was higher...) I imagine Shimano will turn one's warranty, and one's
> ass, to grass in a flash if they hear about a 46-16 FR tooth ratio on
> one of their Nexus hubs, when they went to the trouble of printing the
> ratio warning on the cover of the spec sheet.
>
> So let's try 38-18, which at 2.11 recurring is arguably within the
> permitted ratio, and can be built with Shimano's goodlooking and
> reasonably priced own-brand parts intended for the hub gear bikes.
> With the Schlumpf Mountain Drive, that gives 14 unique gears that
> covers everything from loaded goatherding to pretty fast touring:
>
> 31 12
> 37 15
> 43 17
> 49 20
> 58 23
> 71 28
> 82 33
> 94 37
>
> It does look like iconoclasm and scoffjawing the warranty is
> unnecessary. With either the Rohloff or the Nexus/Schlumpf combination
> you can get nicely spaced gear ratios over a very wide operating band.
> The designers of those hubs and geared bottom bracket got it right.
>
> In fact, riding daily in the low rolling hills of West Cork, I find
> 38-19 sets of teeth just right on the Nexus gear hub without the need
> for the Schlumpf geared bottom bracket; it gives me the following gear
> inch development for the 8 gears, perfect for day rides on my
> particular countryside without ever having to push:
>
> 29
> 35
> 41
> 47
> 55
> 67
> 78
> 89
>
> Sprockets with any number of teeth you can want are readily available,
> so for another use, say loaded alpine touring, I would not hesitate to
> change the sprocket to give a ratio that is not permitted. I think the
> Nexus hub is a lot sturdier than Shimano lets on, and it is widely
> known that the Rohloff hub is panzer.
>
> Andre Jute
> Libertarian: a conservative who talks up a good liberal line.
>

 

[Clive George]

"Tom Sherman" <[email protected]> wrote in message
news:[email protected]...

> Why not consider the Schlumpf High Speed Drive [1] that offers a 2.5:1
> step-up, as compared to the 1.65:1 step-up of the Speed Drive?

You do need a modified version if you want to keep within warranty - the
high speed drive comes with quite a small chainwheel. But yes, it would give
an amusingly insane range of gears when combined with a rohloff

cheers,
clive

 

[[email protected]]

On Jan 31, 1:18 am, Tom Sherman <[email protected]>
wrote:

> However, for a recumbent bicycle, that wide gearing range is not at all
> unreasonable, but nearer to a necessity.

Bents and climbing don't mix well, in other words.

> The proper climbing technique
> on a recumbent bicycle is unlike that for an upright bicycle, where the
> preferred climbing technique of many is to stand and pedal at a
> relatively low cadence, while pulling on the handlebars to increase
> one's "effective" weight.

Nice try. Upright riders can sit or stand and easily switch back and
forth. Bent riders can't.

> The (performance oriented) recumbent will also descend faster (snip)

"Also"? Where did "also" come from? 120rpm in a 15" gear? Isn't that
right about stall speed for you guys?

> (where
> tight corners or rough surfaces do not limit speed too severely) than
> the upright.

I agree that in the real world, on real streets with potholes and
tight corners, uprights are safer to ride than bents (just sending a
little rhetoric back at you, there).

> In particular, on a frontally or fully faired recumbent,
> the rider can pedal without increasing drag, so a very high gear can be
> used while going downhill.

The proselytizing gets old, Tom.

We all know about wind resistance and bents and all that stuff. OK?
Oh, and "comfort". Well, I've tried a bent, I didn't feel very
comfortable <g>. Sure enough, the next guy had to go around the
parking lot a little faster to show me up, and he crashed. Whoops!
Truth be told, that was on a short-wheelbase prototype (lots of
prototypes in the bent world, from my brief lookings, btw).

We had a semi-regular bent rider on the Wednesday night "Tour of the
Inner Loop" in Houston (Planetary Bicycles, 6:00) and two or three
others who were occasionals. No problems here, but no thanks, either.
Not for riding on real roads, anyhow.

BTW, from what I've seen, the problem with mixing bents and bicycles
isn't wheelbase or profile (or slowing down on hills), it wobbling.
Does everyone wobble, or just the three or four guys I've ridden with?

(Don't get me wrong dept.): If you haven't "heard" me say before,
"there's a bent in everyone's future"-- kind of a parallel to your
"failure" thing in your sig. But, at 58-1/2 (three quarters,
actually), with a bad back, arthritis in the hands, and a difficulty
with one of the saddle contact areas (doing much better, thanks), I'm
not there yet.

Few bents are seen here in Austin, compared to bicycles. As in, you go
to a larger group ride, non-racer groups such as the esteemed ACA
weekend rides, you don't see a bent very often at all.

Well... Houston is flat, Austin is hilly. Bingo! --D-y

 

[Andre Jute]

Dear Carl:

Congratulations on finding your niche in life, googling support for
your betters. I'm sure it will bring you happiness.

In ten years or so of dilligent googlebugging you might even earn
rehabilitation from your crimes. Patience is also a virtue.

You may gofer coffee now.

Andre Jute
St Andre of the Infinite Mercy (in consultation with St Edward Dolan
the Excruciating)

<[email protected]> wrote:

> For those curious about the details . . .
>
> Here's the short but clear Rohloff page that explains that it's the
> ratio between front chainring and rear sprocket that matters to the
> hub, not the wheel size:
>
> http://www.rohloff.de/en/info/faq/faq_detail/article/kettenblattzaehnezahl//bp/289/index.html
>
> And here's the Rohloff page that explains the specific number of
> front/rear teeth with the lowest front/rear sprocket ratio (not
> overall gearing including wheel size) that they think wise:
>
> http://www.rohloff.de/en/info/faq/f...der-rohloff-speedhub-50014//bp/289/index.html
>
> As the page explains, the 2.35:1 front/rear ratio is the minimum
> acceptable ratio for normal use, a 40/17 (2.35:1) being as low a ratio
> as Rohloff thinks a normal rider should use. For a heavier rider
> (100kg+) or a tandem, Rohloff warns that the minimum should be raised
> to 40/16 (2.50:1).
>
> Increasing the size of the front chain-ring is okay. That is, 40/16 is
> 2.50:1, so adding eight teeth for 48:16 (3.00:1) is fine.
>
> In other words, you can gear a Rohloff's exposed front/rear up higher
> and higher--it's fine to use the high-speed 52x12 (4.33:1) instead of
> the 39x13 (3.00:1). That's a selling point for small-rear-wheel bikes
> that need higher gearing.
>
> But you don't want to go the other way and gear down in hopes of low
> mountain-bike gearing--a 39 front and a 28 rear (1.39:1) would be a
> bad thing, well below the recommended 2.35:1.
>
> What confuses people is that it's a matter of how the front/rear
> sprocket combination feeds into the Rohloff's many hidden internal
> gears, not a matter of the simple front/rear sprocket of an exposed
> derailleur.
>
> Cheers,
>
> Carl Fogel

 

[Andre Jute]

Tom Sherman <[email protected]> wrote:

> Andre Jute wrote:
> > A concurrent thread on a big gear range made me wonder what width one
> > could achieve in hub gears by ignoring the recommended chainring/
> > sprocket ratio, which for Rohloff appears to be a fraction under 2.5
> > and for the Shimano Nexus 8-speed hub is specifically given as from
> > 2.0 to 2.1. I have no idea how long the hubs would survive under
> > abusive handling as in some of the examples below. All numbers in gear
> > inches.
> >
> > With a 37-622 tyre and 46-16 gears, the Rohloff Speed Hub would give a
> > range from a notch or two below many mountain bikes to pretty well
> > beyond what most people could manage on the flat. Fourteen gears in
> > gear inches developed:
> >
> > 22
> > 25
> > 28
> > 32
> > 37
> > 42
> > 47
> > 54
> > 61
> > 70
> > 79
> > 90
> > 102
> > 116
> >
> > Just for comparison, here are the gear inches for the 14 gears of the
> > Rohloff with a more reasonable, and possibly permitted (I've seen it
> > several times), 42-16 setup. Still a very respectable spread, and
> > probably more pleasurable to use:
> >
> > 20
> > 23
> > 26
> > 29
> > 33
> > 38
> > 43
> > 49
> > 56
> > 64
> > 72
> > 82
> > 93
> > 106
> >
> > Adding the Schlumpf Speed Drive to a Rohloff Speed Hub seems
> > unnecessary: it will add only four useful gears at most, the rest
> > being duplicated.
> >
> Why not consider the Schlumpf High Speed Drive [1] that offers a 2.5:1
> step-up, as compared to the 1.65:1 step-up of the Speed Drive?

How many extra unique *and* useful gears would one get on a) an
upright bike and b) a recumbent? Seems to me that you're paying for a
lot of wasted gears. On hand of experience with the Nexus hub, on
admittedly none-too-challenging terrain, I've concluded that the 307
per cent range of the Nexus 8-speed is pretty useful, with the
Schlumpf drive required only for bicycling goatherds and/or Olympic
speed maniacs; if required, the improvement the Schlumpf brings to the
Nexus is pretty reasonably priced because it is a large effective
improvement. But the Rohloff strikes me as pretty near perfect just
the way it is, with the marginal improvement that is possible with the
Schlumpf drive (of any description) costing way out of proportion.

> > Okay, let's look at the Shimano Nexus 8-speed hub.
> >
> > With a 37-622 tyre and the same 46-16 gears as in our first example,
> > but in this case even more abusive, the Shimano Nexus 8-speed hub
> > combined with the Schlumpf Mountain Drive would give an even wider
> > useful spread, 14 unique gears out of 16 covering from a Himalayan low
> > gear to 127in to pose with in cafe society. (This covers the entirely
> > unreasonable 18 to 123in someone asked for in a concurrent thread, and
> > a bit more.)
> >
> Unreasonable for an upright bicycle, yes.

See what I replied to Clive George about viewpoints in my original
post. I hadn't thought of recumbents... Okay, add recumbents and
stipulate that a bent rider might find 16-127 gear inches on the road
useful.

> However, for a recumbent bicycle, that wide gearing range is not at all
> unreasonable, but nearer to a necessity. The proper climbing technique
> on a recumbent bicycle is unlike that for an upright bicycle, where the
> preferred climbing technique of many is to stand and pedal at a
> relatively low cadence, while pulling on the handlebars to increase
> one's "effective" weight.
>
> Conversely, the proper climbing technique on a recumbent is to use a
> very high cadence (e.g. 120 RPM) and to pull back [2] as much as
> possible. Trying to use the upright climbing technique will result in
> excess lactic acid buildup with the rider then needing to stop or slow
> severely to recover.

Those of high blood pressure, a tendency to foam at the mouth. an
inability to think for themselves or outside the box, or who have ever
been insulted by Edward de Bono, should skip this paragraph. Now! Are
you gone?
Okay. //////////////////////////////////////////////////////////////////////
I don't bother with cadence, Tom. That's stuff for athletes, nothing
to do with me. My purpose in cycling is different. I get my heart rate
up to 80 per cent of max and then pedal slower or faster to keep it
there, counting on my Shimano Cyber Nexus automatic gearbox to keep
the box in the optimum gear for the road inclination. It works a
treat. Your friends on the recumbent newsgroup to which you
crossposted this can see my automatic hub gears and adaptive
suspension and the associated computerized control elements at:
http://members.lycos.co.uk/fiultra/BICYCLE Trek Navigator L700 Smover.html
May The Force be with the recumbent riders too.

> The (performance oriented) recumbent will also descend faster (where
> tight corners or rough surfaces do not limit speed too severely) than
> the upright. In particular, on a frontally or fully faired recumbent,
> the rider can pedal without increasing drag, so a very high gear can be
> used while going downhill.

We might when we exhaust this topic discuss aerodynamics and their
quantification.

> I have a couple of lowracer bicycles with gear inch range of 19-120
> (achieved with a step-up jack-shaft) and a "bodysock" faired long wheel
> base recumbent with a range of 15-125 gear inches (achieved with a
> triple crank and 3x7 hub). I have found both the lowest and highest gear
> ratios on these bicycles useful.

But is it also true that most recumbent riders do not have such
extreme requirements? Or are you making a case that 15-125 should be a
norm for recumbents?

> > Gear Direct SMD
> > 1 42 17
> > 2 51 20
> > 3 59 24
> > 4 67 27
> > 5 79 32
> > 6 97 39
> > 7 112 45
> > 8 127 51
> >
> > I was speaking to a guy in the parts department at Volvo in Gothenburg
> > a few years ago, and when he heard I planted a Chevy mouse motor in
> > one of their estates and was now supercharging it and looking to use a
> > few gennie Volvo parts, he said thickly, "Doncha tell Warranty. Inna
> > flash Warranty turn your ash to grash." (On a tip from this colourful
> > fellow I ordered the parts I wanted a lot cheaper from Rolls-Royce
> > than from Volvo; they bought them the same place but the Volvo markup
> > was higher...) I imagine Shimano will turn one's warranty, and one's
> > ass, to grass in a flash if they hear about a 46-16 FR tooth ratio on
> > one of their Nexus hubs, when they went to the trouble of printing the
> > ratio warning on the cover of the spec sheet.
> >
> > So let's try 38-18, which at 2.11 recurring is arguably within the
> > permitted ratio, and can be built with Shimano's goodlooking and
> > reasonably priced own-brand parts intended for the hub gear bikes.
> > With the Schlumpf Mountain Drive, that gives 14 unique gears that
> > covers everything from loaded goatherding to pretty fast touring:
> >
> > 31 12
> > 37 15
> > 43 17
> > 49 20
> > 58 23
> > 71 28
> > 82 33
> > 94 37
> >
> > It does look like iconoclasm and scoffjawing the warranty is
> > unnecessary. With either the Rohloff or the Nexus/Schlumpf combination
> > you can get nicely spaced gear ratios over a very wide operating band.
> > The designers of those hubs and geared bottom bracket got it right.
> >
> > In fact, riding daily in the low rolling hills of West Cork, I find
> > 38-19 sets of teeth just right on the Nexus gear hub without the need
> > for the Schlumpf geared bottom bracket; it gives me the following gear
> > inch development for the 8 gears, perfect for day rides on my
> > particular countryside without ever having to push:
> >
> > 29
> > 35
> > 41
> > 47
> > 55
> > 67
> > 78
> > 89
> >
> Would not a higher gear be useful when drafting trucks downhill?

You're wicked, Tom. Even better than drafting and pedalling like mad
is being towed and not pedalling at all.

> > Sprockets with any number of teeth you can want are readily available,
> > so for another use, say loaded alpine touring, I would not hesitate to
> > change the sprocket to give a ratio that is not permitted. I think the
> > Nexus hub is a lot sturdier than Shimano lets on, and it is widely
> > known that the Rohloff hub is panzer.
> >
> Of course, one can obtain very low gearing when the Rohloff is used in a
> small drive wheel, without violating Rohloff's restrictions. Lacing the
> large flange Rohloff hub into an ISO 349-mm hub would be challenging, if
> one were to use it on a bicycle such as the Tri-Sled Nitro [3].
>
> [1] <http://www.schlumpf.ch/hsd_engl.htm>.
> [2] Clipless pedals with good retention are mandatory.
> [3] <http://www.trisled.com.au/nitro.html>.

I wouldn't go on a public road in a Nitro without first arranging
blocking cars front and rear with big signs reading "SLOW! Madman on
the road." That thing makes you invisible to housewives in big SUVs
who are a danger even to fluorescently visible cyclists.

Andre Jute
http://members.lycos.co.uk/fiultra/BICYCLE & CYCLING.html

 

[Andre Jute]

Nick Payne <[email protected]> wrote:

> Seeing that Rohloff are quite happy for their hub to be used on a tandem
> with the recommended 2.4:1 front/rear ratio, I had no scruple using a lower
> ratio on my own bike when I took it to Switzerland for two months in 2004. I
> used 38/16 with 38x622 tyres, which gave a bottom gear that I found pretty
> useful for comfortably climbing grades up to about 25% with a loaded bike.
> That ratio gave gears from a low of 18 up to about 95 inches.
>
> If you look at the actual hub specs, it nominates a maximum torque of 250Nm
> at the crank with the recommended 2.4:1 ratio. With 170mm cranks that's
> about 150Kgf on the pedal.
>
> Nick

Yeah, that's why I mentioned loaded alpine touring, 'cos I couldn't
instantly think of another example.

Never mind the gear, how do you keep your balance going up a 25% grade
with a loaded bike? Sounds like an argument for credit card touring...

Andre Jute
I wish I were young and reckless enough to try that!

>
> "Andre Jute" <[email protected]> wrote in message
> news:[email protected]...
> >A concurrent thread on a big gear range made me wonder what width one
> > could achieve in hub gears by ignoring the recommended chainring/
> > sprocket ratio, which for Rohloff appears to be a fraction under 2.5
> > and for the Shimano Nexus 8-speed hub is specifically given as from
> > 2.0 to 2.1. I have no idea how long the hubs would survive under
> > abusive handling as in some of the examples below. All numbers in gear
> > inches.
> >
> > With a 37-622 tyre and 46-16 gears, the Rohloff Speed Hub would give a
> > range from a notch or two below many mountain bikes to pretty well
> > beyond what most people could manage on the flat. Fourteen gears in
> > gear inches developed:
> >
> > 22
> > 25
> > 28
> > 32
> > 37
> > 42
> > 47
> > 54
> > 61
> > 70
> > 79
> > 90
> > 102
> > 116
> >
> > Just for comparison, here are the gear inches for the 14 gears of the
> > Rohloff with a more reasonable, and possibly permitted (I've seen it
> > several times), 42-16 setup. Still a very respectable spread, and
> > probably more pleasurable to use:
> >
> > 20
> > 23
> > 26
> > 29
> > 33
> > 38
> > 43
> > 49
> > 56
> > 64
> > 72
> > 82
> > 93
> > 106
> >
> > Adding the Schlumpf Speed Drive to a Rohloff Speed Hub seems
> > unnecessary: it will add only four useful gears at most, the rest
> > being duplicated.
> >
> > Okay, let's look at the Shimano Nexus 8-speed hub.
> >
> > With a 37-622 tyre and the same 46-16 gears as inour first example,
> > but in this case even more abusive, the Shimano Nexus 8-speed hub
> > combined with the Schlumpf Mountain Drive would give an even wider
> > useful spread, 14 unique gears out of 16 covering from a Himalayan low
> > gear to 127in to pose with in cafe society. (This covers the entirely
> > unreasonable 18 to 123in someone asked for in a concurrent thread, and
> > a bit more.)
> >
> > Gear Direct SMD
> > 1 42 17
> > 2 51 20
> > 3 59 24
> > 4 67 27
> > 5 79 32
> > 6 97 39
> > 7 112 45
> > 8 127 51
> >
> > I was speaking to a guy in the parts department at Volvo in Gothenburg
> > a few years ago, and when he heard I planted a Chevy mouse motor in
> > one of their estates and was now supercharging it and looking to use a
> > few gennie Volvo parts, he said thickly, "Doncha tell Warranty. Inna
> > flash Warranty turn your ash to grash." (On a tip from this colourful
> > fellow I ordered the parts I wanted a lot cheaper from Rolls-Royce
> > than from Volvo; they bought them the same place but the Volvo markup
> > was higher...) I imagine Shimano will turn one's warranty, and one's
> > ass, to grass in a flash if they hear about a 46-16 FR tooth ratio on
> > one of their Nexus hubs, when they went to the trouble of printing the
> > ratio warning on the cover of the spec sheet.
> >
> > So let's try 38-18, which at 2.11 recurring is arguably within the
> > permitted ratio, and can be built with Shimano's goodlooking and
> > reasonably priced own-brand parts intended for the hub gear bikes.
> > With the Schlumpf Mountain Drive, that gives 14 unique gears that
> > covers everything from loaded goatherding to pretty fast touring:
> >
> > 31 12
> > 37 15
> > 43 17
> > 49 20
> > 58 23
> > 71 28
> > 82 33
> > 94 37
> >
> > It does look like iconoclasm and scoffjawing the warranty is
> > unnecessary. With either the Rohloff or the Nexus/Schlumpf combination
> > you can get nicely spaced gear ratios over a very wide operating band.
> > The designers of those hubs and geared bottom bracket got it right.
> >
> > In fact, riding daily in the low rolling hills of West Cork, I find
> > 38-19 sets of teeth just right on the Nexus gear hub without the need
> > for the Schlumpf geared bottom bracket; it gives me the following gear
> > inch development for the 8 gears, perfect for day rides on my
> > particular countryside without ever having to push:
> >
> > 29
> > 35
> > 41
> > 47
> > 55
> > 67
> > 78
> > 89
> >
> > Sprockets with any number of teeth you can want are readily available,
> > so for another use, say loaded alpine touring, I would not hesitate to
> > change the sprocket to give a ratio that is not permitted. I think the
> > Nexus hub is a lot sturdier than Shimano lets on, and it is widely
> > known that the Rohloff hub is panzer.
> >
> > Andre Jute
> > Libertarian: a conservative who talks up a good liberal line.
> >

 

[Clive George]

"Andre Jute" <[email protected]> wrote in message
news:8a046a70-5db0-4529-b83a-6cb808de5f0e@n20g2000hsh.googlegroups.com...
>
>> So, the 46/16 you claim is not permissible is in fact entirely legit -
>> it's
>> rather easier on the hub than the minimum permissible gearing.
>
> Certainly to the engineer it is legitimate, but to the manufacturer it
> is not permissible because he has stated both an upper and a lower
> range. I say again, check the viewpoint from which I make a particular
> statement.

That'll be the viewpoint which completely ignores what the manufacturer
says, would it? Rohloff don't specify maximum gearing.

You screwed up, admit it, move on.

clive

 

[Tom Sherman]

Former Normal person "[email protected]" wrote:
> On Jan 31, 1:18 am, Tom Sherman <[email protected]>
> wrote:
>
>> However, for a recumbent bicycle, that wide gearing range is not at all
>> unreasonable, but nearer to a necessity.
>
> Bents and climbing don't mix well, in other words.
>
Ever seen a state of the are recumbent with a properly trained rider?
(The answer is almost certainly not.) Do not compare apples to oranges.

>> The proper climbing technique
>> on a recumbent bicycle is unlike that for an upright bicycle, where the
>> preferred climbing technique of many is to stand and pedal at a
>> relatively low cadence, while pulling on the handlebars to increase
>> one's "effective" weight.
>
> Nice try. Upright riders can sit or stand and easily switch back and
> forth. Bent riders can't.
>
Where was the claim otherwise stated up-thread?

>> The (performance oriented) recumbent will also descend faster (snip)
>
> "Also"? Where did "also" come from? 120rpm in a 15" gear? Isn't that
> right about stall speed for you guys?
>
"Also" in comparison to climbing on a recumbent, not to upright
bicycles. That should have been obvious from the context

>> (where
>> tight corners or rough surfaces do not limit speed too severely) than
>> the upright.
>
> I agree that in the real world, on real streets with potholes and
> tight corners, uprights are safer to ride than bents (just sending a
> little rhetoric back at you, there).
>
Except that major injury is much more likely in a minor fall from an
upright than from a recumbent, since there is little change of landing
on one's head or shoulder with much force while crashing a recumbent,
unlike the upright.

>> In particular, on a frontally or fully faired recumbent,
>> the rider can pedal without increasing drag, so a very high gear can be
>> used while going downhill.
>
> The proselytizing gets old, Tom.
>
If you think this was intended to proselytize, your comprehension is off.

"dustoyevsky" is the one trying to start a flame war here, not me. I was
merely commenting on a technical point made by Andre Jute in regards to
usable gearing range.

> We all know about wind resistance and bents and all that stuff. OK?
> Oh, and "comfort". Well, I've tried a bent, I didn't feel very
> comfortable <g>. Sure enough, the next guy had to go around the
> parking lot a little faster to show me up, and he crashed. Whoops!
> Truth be told, that was on a short-wheelbase prototype (lots of
> prototypes in the bent world, from my brief lookings, btw).
>
Who brought up comfort? Was not me.

> We had a semi-regular bent rider on the Wednesday night "Tour of the
> Inner Loop" in Houston (Planetary Bicycles, 6:00) and two or three
> others who were occasionals. No problems here, but no thanks, either.
> Not for riding on real roads, anyhow.
>
> BTW, from what I've seen, the problem with mixing bents and bicycles
> isn't wheelbase or profile (or slowing down on hills), it wobbling.
> Does everyone wobble, or just the three or four guys I've ridden with?
>
Probably just the guys you ride with. Lots of upright riders wobble also.

> (Don't get me wrong dept.): If you haven't "heard" me say before,
> "there's a bent in everyone's future"-- kind of a parallel to your
> "failure" thing in your sig. But, at 58-1/2 (three quarters,
> actually), with a bad back, arthritis in the hands, and a difficulty
> with one of the saddle contact areas (doing much better, thanks), I'm
> not there yet.
>
You must be confusing me with Doug Cimper.

> Few bents are seen here in Austin, compared to bicycles. As in, you go
> to a larger group ride, non-racer groups such as the esteemed ACA
> weekend rides, you don't see a bent very often at all.
>
Chalo Colina is sure to get a recumbent any day! [rec.bicycles.tech
inside joke]

> Well... Houston is flat, Austin is hilly. Bingo! --D-y
>
What was the prize?

--
Tom Sherman - Holstein-Friesland Bovinia
"And never forget, life ultimately makes failures of all people."
- A. Derleth

 

[Clive George]

"Andre Jute" <[email protected]> wrote in message
news:0450d910-e7a6-493b-b4a6-cbd3ed3cba5a@s37g2000prg.googlegroups.com...

> Never mind the gear, how do you keep your balance going up a 25% grade
> with a loaded bike?

Same way as at higher speed, only potentially with rather larger movements.

 

[Tom Sherman]

Andre Jute wrote:
> Tom Sherman <[email protected]> wrote:
>
>> Andre Jute wrote:
>>> ...
>>> Okay, let's look at the Shimano Nexus 8-speed hub.
>>>
>>> With a 37-622 tyre and the same 46-16 gears as in our first example,
>>> but in this case even more abusive, the Shimano Nexus 8-speed hub
>>> combined with the Schlumpf Mountain Drive would give an even wider
>>> useful spread, 14 unique gears out of 16 covering from a Himalayan low
>>> gear to 127in to pose with in cafe society. (This covers the entirely
>>> unreasonable 18 to 123in someone asked for in a concurrent thread, and
>>> a bit more.)
>>>
>> Unreasonable for an upright bicycle, yes.
>
> See what I replied to Clive George about viewpoints in my original
> post. I hadn't thought of recumbents... Okay, add recumbents and
> stipulate that a bent rider might find 16-127 gear inches on the road
> useful.
>
I have approximately that range on a recumbent bicycle, and have found
both the highest and lowest gear useful (on different sides of the same
hill on several occasions).

>> However, for a recumbent bicycle, that wide gearing range is not at all
>> unreasonable, but nearer to a necessity. The proper climbing technique
>> on a recumbent bicycle is unlike that for an upright bicycle, where the
>> preferred climbing technique of many is to stand and pedal at a
>> relatively low cadence, while pulling on the handlebars to increase
>> one's "effective" weight.
>>
>> Conversely, the proper climbing technique on a recumbent is to use a
>> very high cadence (e.g. 120 RPM) and to pull back [2] as much as
>> possible. Trying to use the upright climbing technique will result in
>> excess lactic acid buildup with the rider then needing to stop or slow
>> severely to recover.
>
> Those of high blood pressure, a tendency to foam at the mouth. an
> inability to think for themselves or outside the box, or who have ever
> been insulted by Edward de Bono, should skip this paragraph. Now! Are
> you gone?
> Okay. //////////////////////////////////////////////////////////////////////
> I don't bother with cadence, Tom. That's stuff for athletes, nothing
> to do with me. My purpose in cycling is different. I get my heart rate
> up to 80 per cent of max and then pedal slower or faster to keep it
> there, counting on my Shimano Cyber Nexus automatic gearbox to keep
> the box in the optimum gear for the road inclination. It works a
> treat. Your friends on the recumbent newsgroup to which you
> crossposted this can see my automatic hub gears and adaptive
> suspension and the associated computerized control elements at:
> http://members.lycos.co.uk/fiultra/BICYCLE Trek Navigator L700 Smover.html
> May The Force be with the recumbent riders too.
>
I do not have a fixation on cadence by any means, but I believe that
much of the poor climbing reputation recumbent have is due to three factors:
1 - Non-optimum bicycle design. The DF upright frame has been optimized
since WW1, with the only real improvements coming from better materials.
Conversely, the recumbent is still in an evolutionary stage towards
improved designs.

2 - Trying to climb like an upright rider, using relatively high gears
and low cadence and mashing more than pulling on the pedals. Most stock
recumbents (and many stock uprights for that matter) are geared too high
overall for most riders.

3 - Most recumbents are being ridden by older and/or less fit riders. On
invitational rides, upright riders walking the steeper uphill sections
is not too uncommon of a sight, but in that case observers judge the
riders to be unfit and do not condemn the bicycle design. Instead, the
upright's climbing ability is judged by those ridden by racers and very
fit riders.

>> The (performance oriented) recumbent will also descend faster (where
>> tight corners or rough surfaces do not limit speed too severely) than
>> the upright. In particular, on a frontally or fully faired recumbent,
>> the rider can pedal without increasing drag, so a very high gear can be
>> used while going downhill.
>
> We might when we exhaust this topic discuss aerodynamics and their
> quantification.
>
On my un-faired recumbents, a noticeable speed decrease occurs when
descending if I switch from coasting to pedaling either backwards or
forwards too slowly to apply power to the wheel.

>> I have a couple of lowracer bicycles with gear inch range of 19-120
>> (achieved with a step-up jack-shaft) and a "bodysock" faired long wheel
>> base recumbent with a range of 15-125 gear inches (achieved with a
>> triple crank and 3x7 hub). I have found both the lowest and highest gear
>> ratios on these bicycles useful.
>
> But is it also true that most recumbent riders do not have such
> extreme requirements? Or are you making a case that 15-125 should be a
> norm for recumbents?
>
On an un-faired recumbent, the higher gears could be sacrificed with
little loss, but the lower ones should not be.

> ...
>>> In fact, riding daily in the low rolling hills of West Cork, I find
>>> 38-19 sets of teeth just right on the Nexus gear hub without the need
>>> for the Schlumpf geared bottom bracket; it gives me the following gear
>>> inch development for the 8 gears, perfect for day rides on my
>>> particular countryside without ever having to push:
>>>
>>> 29
>>> 35
>>> 41
>>> 47
>>> 55
>>> 67
>>> 78
>>> 89
>>>
>> Would not a higher gear be useful when drafting trucks downhill?
>
> You're wicked, Tom. Even better than drafting and pedalling like mad
> is being towed and not pedalling at all.
>
It never hurts to stir the pot.

> ...
>> [3] <http://www.trisled.com.au/nitro.html>.
>
> I wouldn't go on a public road in a Nitro without first arranging
> blocking cars front and rear with big signs reading "SLOW! Madman on
> the road." That thing makes you invisible to housewives in big SUVs
> who are a danger even to fluorescently visible cyclists.
>
I have ridden a bicycle that low in Chicago traffic, and some in Chicago
ride even lower bicycles:
<http://www.wisil.recumbents.com/home.asp?URL=wisil/main.asp>. I have
seen these bicycles being ridden on public roads. (As an aside, I
purchased a bicycle from Barb, which can be adjusted to fit both of us,
despite my being 0.3 meter taller than her.)

--
Tom Sherman - Holstein-Friesland Bovinia
"And never forget, life ultimately makes failures of all people."
- A. Derleth

 

[Andre Jute]

On Feb 1, 12:19 am, "Clive George" <[email protected]> wrote:
> "Andre Jute" <[email protected]> wrote in message
>
> news:8a046a70-5db0-4529-b83a-6cb808de5f0e@n20g2000hsh.googlegroups.com...
>
>
>
> >> So, the 46/16 you claim is not permissible is in fact entirely legit -
> >> it's
> >> rather easier on the hub than the minimum permissible gearing.
>
> > Certainly to the engineer it is legitimate, but to the manufacturer it
> > is not permissible because he has stated both an upper and a lower
> > range. I say again, check the viewpoint from which I make a particular
> > statement.
>
> That'll be the viewpoint which completely ignores what the manufacturer
> says, would it?

That's not right, Clive. I ignored what Rohloff *didn't* say:

>Rohloff don't specify maximum gearing.

Exactly. I apologized for confusing you with Shimano's superfluous but
positive statement of maximum gearing juxtaposed with my failure to
report Rohloff's strangely absent statement. No one else was confused
except Carl Fogel -- which is hardly surprising, is it now?

> You screwed up, admit it, move on.

Not at all. You'll see, when I screw up -- may you live so long as to
see it -- and you discover me doing it (for which you will need that
sensitivity-enhancing woman in place), I shall immediate put forward
your name to the Palace for a well-deserved knighthood. How would "for
services to sado-masochism, using a bicycle as his instrument of
flagellation" strike you as an encomium?

> clive

Lighten up, pal. Bicycling is only a hobby.

Andre Jute
Heretic

 

[Tom Sherman]

Andre Jute wrote:
> ...
> Never mind the gear, how do you keep your balance going up a 25% grade
> with a loaded bike? Sounds like an argument for credit card touring...
> ...
Or the addition of a third wheel.

--
Tom Sherman - Holstein-Friesland Bovinia
"And never forget, life ultimately makes failures of all people."
- A. Derleth

 

[Dan Burkhart]

On Feb 1, 12:19*am,> That'll be the viewpoint which completely ignores what the manufacturer
> says, would it?[/color]

That's not right, Clive. I ignored what Rohloff *didn't* say:

>Rohloff don't specify maximum gearing.


Andre Jute
Heretic

Actually, Rohloff does state there is no maximum.
http://www.rohloff.de/fileadmin/rohloffde/download/beschreibung/speedhub/handbuch/benutzerinfo_2.13.en.pdf
Page 13, left column near the bottom.
"Larger chainrings can be used without exceptions"
I've seen it elsewhere on their web site, but I can't find it right now.
Dan

 

[[email protected]]

On Fri, 1 Feb 2008 13:35:02 +1100, Dan Burkhart
<[email protected]> wrote:

>
>Andre Jute Wrote:
>> On Feb 1, 12:19*am,> That'll be the viewpoint which completely ignores
>> what the manufacturer
>> > says, would it?
>>
>> That's not right, Clive. I ignored what Rohloff *didn't* say:
>>
>> >Rohloff don't specify maximum gearing.
>>
>>
>> Andre Jute
>> Heretic
>
>Actually, Rohloff does state there is no maximum.
>http://www.rohloff.de/fileadmin/roh...ng/speedhub/handbuch/benutzerinfo_2.13.en.pdf
>Page 13, left column near the bottom.
>"Larger chainrings can be used without exceptions"
>I've seen it elsewhere on their web site, but I can't find it right
>now.
>Dan[/color]

Dear Dan,

Probably this:

"Of course, the use of larger chainrings is completely allowed, this
increases the primary force and the entry force at the same time for
the hub to reduce."

http://www.rohloff.de/en/info/faq/faq_detail/article/kettenblattzaehnezahl//bp/289/index.html

It's worth belaboring the point, since otherwise someone might
mistakenly swap in a _smaller_ chainring and destroy an expensive hub.

Rohloff sets a _minimum_ front:rear sprocket ratio.

A 40:17 (2.35:1) is the minimum ratio for normal riders.

A 40:16 (2.50:1) is the minimum ratio for heavier riders and tandems.

The 40-tooth front in the example can be increased to any size--the
front:rear ratio just gets bigger. Switching to 42-tooth or 72-tooth
is fine.

But he 40-tooth front in the example should not be reduced--the
front:rear ratio would fall below the minimum, and Rohloff expects
that the increased force inside the hub would damage its gears.

For example, replacing the 40-tooth front with a smaller 32-tooth
would be begging for trouble, since 32:16 is only 2.00:1, well below
the 2.35:1 minimum front/rear sprocket ratio.

Again, the rear wheel doesn't matter because the problem occurs in the
tiny gears inside the hub.

Cheers,

Carl Fogel

 

[Ozark Bicycle]

On Jan 31, 6:41 pm, Tom Sherman <[email protected]>
asked:


> What was the prize?
>

First Prize: a one night stay at Chateau de Smarm in Pueblo, Colorado,
with your host Carl "top dung beetle" Fogel.

Second Prize is, of course, a two-week stay at Chateau de Smarm.

 

[Andre Jute]

On Feb 1, 2:35 am, Dan Burkhart <Dan.Burkhart.342...@no-
mx.forums.cyclingforums.com> wrote:
> Andre Jute Wrote:
>
> > On Feb 1, 12:19*am,> That'll be the viewpoint which completely ignores
> > what the manufacturer
> > > says, would it?
>
> > That's not right, Clive. I ignored what Rohloff *didn't* say:
>
> > >Rohloff don't specify maximum gearing.
>
> > Andre Jute
> > Heretic
>
> Actually, Rohloff does state there is no maximum.http://www.rohloff.de/fileadmin/rohloffde/download/beschreibung/speed...
> Page 13, left column near the bottom.
> "Larger chainrings can be used without exceptions"
> I've seen it elsewhere on their web site, but I can't find it right
> now.
> Dan
>
> --
> Dan Burkhart[/color]

In that case it looks like I'll have to drop the palace a line. "Your
Majesty, My cat and i would be pleased indeed If you would graciously
confer an honour on Mr Clive George for promoting the product of a
German manufacturer."

Andre Jute