Bottom Bracket Hub Gear

[blacktom]

Is it possible to build a hub gear into a custom bottom bracket?

Imagine the possibilities:

-No derailleurs to get damaged and a short chain line

-Change gear when you are stationary

-Outrageous gear ratios

-Up to 196 speeds for gear freeks(Rohloff 14 x 14!)

-Or 42 for regular folk (3 x 14)

Has it been done?

Brian.

 

[Werehatrack]

On 16 Dec 2003 16:32:40 +1050, blacktom
<[email protected]> may have said:

>Has it been done?

Yes.

Heavy, expensive, and not as efficient mechanically as a derailleur, but they exist.

--
My email address is antispammed; pull WEEDS if replying via e-mail.
Yes, I have a killfile. If I don't respond to something,
it's also possible that I'm busy.
Words processed in a facility that contains nuts.

 

[Matt O'Toole]

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

> On 16 Dec 2003 16:32:40 +1050, blacktom <[email protected]> may have said:
>
> >Has it been done?
>
> Yes.
>
> Heavy, expensive, and not as efficient mechanically as a derailleur, but they exist.

Indeed they do:

http://www.sheldonbrown.com/harris/schlumpf.html

Matt O.

 

[Jeff Wills]

"Matt O'Toole" <[email protected]> wrote in message news:<[email protected]>...
> "Werehatrack" <[email protected]> wrote in message
> news:[email protected]...
>
> > On 16 Dec 2003 16:32:40 +1050, blacktom <[email protected]> may have said:
> >
> > >Has it been done?
> >
> > Yes.
> >
> > Heavy, expensive, and not as efficient mechanically as a derailleur, but they exist.
>
> Indeed they do:
>
> http://www.sheldonbrown.com/harris/schlumpf.html
>
> Matt O.

Go to the source: http://www.schlumpf.ch/hsd_engl.htm

A common use for these is on 20" wheel bikes- folders and recumbents. The step-up gear is useful to
get reasonable gearing with standard size chainrings.

I recall that Shimano offered a 5-speed crank mounted transmission a couple years back- but that's a
fuzzy memory, and it was Japan-market-only. I have no idea whether it was ever sold anywhere else.

Jeff

 

[Russ Price]

Jeff Wills <[email protected]> wrote:
>
> I recall that Shimano offered a 5-speed crank mounted transmission a couple years back- but
> that's a fuzzy memory, and it was Japan-market-only. I have no idea whether it was ever sold
> anywhere else.
>

Also, back in the 1970s there was a 3-speed crank/transmission setup that was made by Dana (better
known for car/truck differentials). It had a large cast aluminum housing and a very small chainring,
and two cables for the twist shifter. My father put one on my rescued-from-the-trash Schwinn
Stingray. It worked well, but it was definitely not for weight weenies.

When I outgrew it, I continued the weird drivetrain kick with a 1977 Schwinn Caliente (Positron II
rear derailleur and front freewheeling).

Now, instead of weird drivetrains, I've graduated to weird frames (recumbents).

--
Russ [email protected] the wabbit to despam "The Segway: revolutionizing
the way people get hit by cars." -Robert Canon

 

[Kirby James]

In this month's Velo Vision (http://www.velovision.co.uk/ excellent magazine
btw) there is a picture of a MTB with a Rohloff mounted just above the
standard bottom bracket (see http://www.g-boxx.org ) - amazing!

Kirby

 

[Tim McNamara]

"Kirby James" <[email protected]> writes:

> In this month's Velo Vision (http://www.velovision.co.uk/ excellent magazine btw) there is a
> picture of a MTB with a Rohloff mounted just above the standard bottom bracket (see http://www.g-
> boxx.org )
> - amazing!

There's also an article about a Canadian-made FWS recumbent with a Schlumpf drive- normally used in
the BB- which was adapted to be a step-up gear in a direct drive setting. The builder machined a
front hub with the internal dimensions of a bottom bracket shell, with a pawl to make the unit drive
the shell directly.

 

[meb]

Originally posted by blacktom
Is it possible to build a hub gear into a custom bottom bracket?

Imagine the possibilities:

-No derailleurs to get damaged and a short chain line

-Change gear when you are stationary

-Outrageous gear ratios

-Up to 196 speeds for gear freeks(Rohloff 14 x 14!)

-Or 42 for regular folk (3 x 14)

Has it been done?

Brian.

Sclumpf with Rohloff gets you 28 without derailleur.

Rohloff 14X 14 pairing is only 27 distinct ratios amongst those 196 gears-lots of repeats (169). You get 13 identical flavors of your 2 middle ratios (distributed like Pascal’s Triangle).

Pairing a Rohloff with a differing ratio interval S7 or Nexus 7 gets you more distinct derailuer free ratios at lower price & weight.

Easy to get a 2 chainring Schlumpf with 3X9 dual drive gets you 104 speeds but you’ve got the f/r derailleurs).

There is someone in Michigan in the Guiness Book of Records with a 1500+ speed bike.

There were some recent threads on liquid drive and “Continuously variable" electric transmission electric transmission which effectively give you infinite ratios without deraileurs.

 

[Rick Onanian]

On 16 Dec 2003 16:32:40 +1050, blacktom
<[email protected]> wrote:
>Is it possible to build a hub gear into a custom bottom bracket?

Schlumpf.

>-Outrageous gear ratios -Up to 196 speeds for gear freeks(Rohloff 14 x 14!) -Or 42 for regular folk
>(3 x 14) Has it been done?

Sheldon Brown did it. I can't find it now, but he has hundreds of speeds, with a Schlumpf, a triple
crank, a 7 speed rear (now he could use a ten speed!), and a Rohloff.

With the ten speed rear, 840 speeds.

Cram that Rohloff into the front where the Schlumpf goes, and get 5,880 speeds.

>Brian.
--
Rick Onanian

 

[Jeff Wills]

blacktom <[email protected]> wrote in message
news:<[email protected]>... <snip>
>
> -Or 42 for regular folk (3 x 14)
>
> Has it been done?
>
> Brian.

Triple chainrings combined with SRAM 3x7 (3x8, 3x9) DualDrive hubs are somewhat common in the
recumbent community. 63 (72, 81) gears.

Jeff

 

[Jeff Wills]

Rick Onanian <[email protected]> wrote in message
news:<[email protected]>... <snip>
> Sheldon Brown did it. I can't find it now, but he has hundreds of speeds, with a Schlumpf, a
> triple crank, a 7 speed rear (now he could use a ten speed!), and a Rohloff.
>
> With the ten speed rear, 840 speeds.
>
> Cram that Rohloff into the front where the Schlumpf goes, and get 5,880 speeds.
>
> >Brian.

Sheldon better watch it. Put that in high gear and he'll exceed the speed of light. Then he'll go
backwards in time and get his beard back.

Jeff

 

[John Barbrook]

Pashley Cycles in the UK have specced a bike for the british police force with hub gears and a
deraillier. In a interesting phone call I just went 'what!' and my mouth opened and shut.

Its random, but Its allegadly very durable!

/Mr Ferret

"blacktom" <[email protected]> wrote in message
news:[email protected]...
> Is it possible to build a hub gear into a custom bottom bracket?
>
> Imagine the possibilities:
>
> -No derailleurs to get damaged and a short chain line
>
> -Change gear when you are stationary
>
> -Outrageous gear ratios
>
> -Up to 196 speeds for gear freeks(Rohloff 14 x 14!)
>
> -Or 42 for regular folk (3 x 14)
>
> Has it been done?
>
> Brian.
>
>
>
> --

 

[blacktom]

Thanks for all your replies. I was not aware of the Schlumpf 2 speed bottom bracket. And although I had read much of Sheldon Brown's excellent site, I had missed his article on hub gears. Using his gear table (which includes ratios for Rohloff hub gears) I find that with a Schlumpf/Rohloff combination the gear inches go from 10" to 132" in the low Schlumpf to 23" to 177" in the high with a 50 tooth and 45 tooth chainrings respectively. However, as MEB previously stated most of the ratios are duplicated apart from the highs and lows.

Brian.

 

[meb]

Originally posted by blacktom
Thanks for all your replies. I was not aware of the Schlumpf 2 speed bottom bracket. And although I had read much of Sheldon Brown's excellent site, I had missed his article on hub gears. Using his gear table (which includes ratios for Rohloff hub gears) I find that with a Schlumpf/Rohloff combination the gear inches go from 10" to 132" in the low Schlumpf to 23" to 177" in the high with a 50 tooth and 45 tooth chainrings respectively. However, as MEB previously stated most of the ratios are duplicated apart from the highs and lows.

Brian.

Since 23/10 =2.3 while 177/132 =1.45, you've got at least one math error.

f you go with a mountain drive (2.5: reduction) with bigger chainring(s) rather than a speed drive (1.65: 1 overdrive), you get broader range and less quasi duplication.

 

[Tom Sherman]

Tim McNamara wrote:
>
> There's also an article about a Canadian-made FWS recumbent with a Schlumpf drive- normally used
> in the BB- which was adapted to be a step-up gear in a direct drive setting. The builder machined
> a front hub with the internal dimensions of a bottom bracket shell, with a pawl to make the unit
> drive the shell directly.

A FWD FWS recumbent that uses a Schlumpf BB as a jackshaft/step-up. <http://www.barcroftcycles.com/images/oregon-
web.jpg>.

Tom Sherman - 41½ N, 90½ W

 

[meb]

Originally posted by Tom Sherman
Tim McNamara wrote:
>
> There's also an article about a Canadian-made FWS recumbent with a Schlumpf drive- normally used
> in the BB- which was adapted to be a step-up gear in a direct drive setting. The builder machined
> a front hub with the internal dimensions of a bottom bracket shell, with a pawl to make the unit
> drive the shell directly.

A FWD FWS recumbent that uses a Schlumpf BB as a jackshaft/step-up. <http://www.barcroftcycles.com/images/oregon-
web.jpg>.

Tom Sherman - 41½ N, 90½ W

Is this a stepup with the internal gears or only the shell/bearings of a tandem Schlumpf BB with all stepup throught the chainrings/sprockets?

On a competition lowracer, it seems unlikely one would add the 5% efficiency loss of epicyclic gears in the BB.