Question about White Industries MTB hubs



T

Trevor Jeffrey

Guest
Chalo wrote in message <[email protected]>...
Perhaps the lightest cartridge hubs used titanium axles.
What was their weight, and how do they compare to Campag Record with
titanium axles(c1980)? Compare like with like here. Exlude skewers off
all.

>So to you, a mallet is a "special tool"? My oldest wheel has its
>original bearing cartridges in it. At about 35,000 miles it is
>beginning to exhibit wear and a bit of roughness in the bearing
>surfaces, but no more so than the average _brand new_ cup & cone hub.
>

That is admirable that you still have a serviceable unit using original
cartridge bearings after 35,000miles. Are they sealed cartridge?
What is the exact type of bearing , dimensions and fit?
What is the make/model of hub, cost and when?
So how do you know a mallet is all it would take to exchange these bearings?
Has it seen water?
Actual service life is important, but how well does it roll compared to an
equivalently priced cup&cone model of the same period.
That bit of roughness shows the bearing surface has failed.

OK for some people tub's may be inappropriate due to the lack of
availability of wide off the peg models. At a guess I think you would need
35mm section in a tub a little more with wired-on.


Motorcycle - Nice big motor with plenty of reserve power, large wheel
bearings large stiff rear fork/front fork thick solid axles.
Power of motorcycle typically160 000watts
Power of cyclist 120watts
priority of cyclist - develop a little bit of power, make it go, make it
stop, make it turn, pare weight
priority of motorcyclist - Develop plenty of power, make it go, make it
stop, make it turn, protect components

>
>There are such bearing cartridges as you describe, but they are not
>generally used in bicycles. The usual kind are "double sealed deep
>groove radial contact" bearings, with two contact points per ball.


This type of bearing, has a high degree of osculation and much sliding
takes place, so is intolerant to contaminent and must be highly protected
against ingress so upping the cost of the hub. The slow and stop conditions
of a bicycle make this the quickest wearing choice of rolling bearing .
Without renewal of lubricant alongside removal of wear debris, this will
make it the first to fail through fatigue. It is almost not a rolling
bearing.
What milage do the bearing surfaces of this type typacally fail at? And at
what size are they?
I feel it woul be more apprpriate to use taper rollers with an oil feed.
This requires adjustment but I don't think is available in the small sizes
required for hubs and pedals antway.

What you infer is that for the inexpert or forgetful mechanic, sealed
cartridges are more suitable. I say, if it drips oil, a cup and cone
bearing will outlive you.
I think that your assessment of c&c bearings being poor is based on
experience with incorrectly lubricated units. Ideally the balls should roll
in an oil bath.
TJ
 
T

Trevor Jeffrey

Guest
[email protected] wrote in message ...
>I'm not quite clear whether you mean that your hill includes
>the 1 in 3 hairpin, or 33% grade, or if you mean that the
>hairpin is in the other hill, but either way it seems
>unlikely that anyone does 60 mph through a hairpin.
>

The old road contains the hairpin. The new road is declared a trunk road.
>What would you say the grade is on the section where you
>exceed 60 mph?

10% maybe less, have to check by map.
>
>Is this the mountain bike trail that I see on the internet
>when I google for bwlch, or is it a road? That is, are we
>talking about a ski-resort dirt-descent specialty-downhill
>or a paved road?

Single carriageway trunk road. Scares the **** outa some.
Motorcyclists coming towards you at 100mph+ dont always return to their
nearside, I guess so they can see around the bend which of course I want to
cut. The lead rider must keep their head up for this reason.
It takes three or four riders riding close to get past 100kmh
TJ Now stop it!
 
On Tue, 3 Aug 2004 02:54:19 +0100, "Trevor Jeffrey"
<[email protected]> wrote:

>
>[email protected] wrote in message ...
>>I'm not quite clear whether you mean that your hill includes
>>the 1 in 3 hairpin, or 33% grade, or if you mean that the
>>hairpin is in the other hill, but either way it seems
>>unlikely that anyone does 60 mph through a hairpin.
>>

>The old road contains the hairpin. The new road is declared a trunk road.
>>What would you say the grade is on the section where you
>>exceed 60 mph?

>10% maybe less, have to check by map.
>>
>>Is this the mountain bike trail that I see on the internet
>>when I google for bwlch, or is it a road? That is, are we
>>talking about a ski-resort dirt-descent specialty-downhill
>>or a paved road?

>Single carriageway trunk road. Scares the **** outa some.
>Motorcyclists coming towards you at 100mph+ dont always return to their
>nearside, I guess so they can see around the bend which of course I want to
>cut. The lead rider must keep their head up for this reason.
>It takes three or four riders riding close to get past 100kmh
>TJ Now stop it!
>


Dear Trevor,

If you reveal marvels like this, you can hardly expect
people to stop asking for explanations. (I will, however,
skip the raised eyebrows about motorcycles routinely
climbing such grades at over 100 mph.)

For a typical bicycle rider's weight and profile, a long
stretch of extremelly rare 15.4% grade is required to reach
60 mph.

Heavier riders with improved tucks can do better. Chalo
Colina, for example, may be able to reach 60 mph on a mere
6.6% slope, since he enjoys considerably increased force
(over 400 pounds with bicycle) without a corresponding
increase in wind drag.

Pedalling, of course, is unlikely to be of any value. Over
157 rpm is required to pedal 60 mph on a 700c 53x11 and
would involve losing more to increased wind drag than could
be made up.

Perhaps you could check the details again with the other two
or three riders involved and persuade them to favor us with
a post or two about the maximum recorded on their
speedometers?

Meanwhile, you might enjoy plugging a few figures into this
speed calculator:

http://www.analyticcycling.com/ForcesSpeed_Page.html

Set the power to 0 watts and the slope to -0.154 and you'll
produce a speed of about 60 mph for a 75kg rider and
bicycle. Plug in Chalo's 182kg and the result converts to
93.5 mph.

I never trust my conversions, so I like to check them here:

http://members.aol.com/javawizard/speed.html

You can reduce various factors to increase speed, but you'll
have to keep them believable. A 10% slope with the defaults
produces only 48 mph. Increasing this 25% would be
impressive.

You may also have some explaining to do in order to convince
people that a peloton coasts downhill faster than a single
coasting rider. As I understand it, the lead rider works
like a dog and those who follow enjoy the reduced wind drag
available just behind him.

There are regular discussions here about whether the leader
benefits slightly from someone filling in his slipstream,
but I can't recall anyone claiming an improvement of more
than a mile per hour.

People do maintain sites reporting impressive climbs and
descents for bicyles, so you might want to look into getting
your local route listed if it turns out to have a
significant stretch of 10% grade.

Here are two links to places that list notable climbs:

http://www.ulb.ac.be/di/ssd/ldoyen/e/v.html

http://www.cyclos-cyclotes.org/altigraph.html

Cheers,

Carl Fogel
 
C

Chalo

Guest
"Trevor Jeffrey" <[email protected]> wrote:
>
> Perhaps the lightest cartridge hubs used titanium axles.
> What was their weight, and how do they compare to Campag Record with
> titanium axles(c1980)? Compare like with like here. Exlude skewers off
> all.


Consult Damon Rinard's component weights:
http://www.geocities.com/kwanseng/weight.html#fronthubs

These are out of date, but informative. Note that the hubs are
arranged in order of ascending weight, that the measured front hubs
begin at 64 grams, and that the first cup & cone hub on the list
weighs 115g. The lightest cup & cone hub on the list that I know to
have a steel axle weighs 128g.

I am certain that all of the very lightest hubs use aluminum axles,
made feasible by large diameters and smooth outer surfaces.

Other verified weight lists show examples down to 52g. There are more
data here, but nothing by Campagnolo on this list:
http://weightweenies.starbike.com/listings/components.php?type=hubs

> That is admirable that you still have a serviceable unit using original
> cartridge bearings after 35,000miles. Are they sealed cartridge?
> What is the exact type of bearing , dimensions and fit?
> What is the make/model of hub, cost and when?


The wheel in question uses a front Specialized hub (made by Suzue
IIRC) that has a traditional-looking shell, adjusters and locknuts.
Under a set of cosmetic dustcaps, it hides 6000-2RS double sealed
made-in-Japan cartridges, which measure 10x26x8mm. I bought it in
1989; I don't remember how much it cost except that it was a little
cheaper than Deore XT at the time.

> So how do you know a mallet is all it would take to exchange these bearings?


This particular hub requires cone wrenches to remove the locknuts and
adjusters from one side, after which a tap to the axle end drives out
the other side.

> Has it seen water?


Yes. It lived out its days on a daily rider in Austin, TX, where rain
arrives infrequently but usually in God's Own Buckets. So the hub
didn't get wet often, but it got plenty wet.

> That bit of roughness shows the bearing surface has failed.


Yes, those bearings are done. They still don't have much more end
play than they ever did, but their former glassy smoothness is gone.
I don't use that wheel anymore so I haven't bothered to replace the
cartridges.

> I feel it woul be more apprpriate to use taper rollers with an oil feed.
> This requires adjustment but I don't think is available in the small sizes
> required for hubs and pedals antway.


Well, yes they are, but at a cost that would make components with such
bearings prohibitively expensive.

> I say, if it drips oil, a cup and cone bearing will outlive you.

....
> I think that your assessment of c&c bearings being poor is based on
> experience with incorrectly lubricated units. Ideally the balls should
> roll in an oil bath.


I have to admit that in my years of bike wrenching and bike building,
I have never knowingly met a cyclist who packed hub bearings in
anything other than some kind of grease. I have heard the hub center
drillings on Nuovo Record hubs referred to as "oil holes" but have
never seen them used in that way.

It sounds like a good way to keep a bearing clean and a bike filthy.
I suppose the thing gets "washed" often enough in Old Blighty.

Chalo Colina
 
G

Gary Young

Guest
[email protected] (Chalo) wrote in message news:<[email protected]>...
> "Trevor Jeffrey" <[email protected]> wrote:
>
> > You should have used something better than this. Correctly designed
> > cartridge hubs have a weight penalty to bear due to the requirement of a
> > stiffer axle and hubshell than cup &cone.

>
> Tell me then why _all_ of the lightest hubs ever made available have
> used cartridge bearings (e.g. Tune, TNT, Hershey, etc.)

<snip>

Are there any cartridge bearing hubs currently in production that
don't cost an arm and a leg? I know you recommend the JuJu hub, but it
seems to be available only in a 32-hole version, not 36.
 
D

Dave Lehnen

Guest
[email protected] wrote:
<snip>
> Dear Trevor,
>
> If you reveal marvels like this, you can hardly expect
> people to stop asking for explanations. (I will, however,
> skip the raised eyebrows about motorcycles routinely
> climbing such grades at over 100 mph.)
>

< snip on-topic information>
>
> Cheers,
>
> Carl Fogel


Oh, go ahead and raise your eyebrows. Many modern sport bikes
have the power-to-weigh to climb very steep grades at very
high speeds.

For example, a current open-class bike would weigh less than
450 lb, full of gas, oil, etc, and would have far over 100
rear-wheel horsepower when in the powerband. A rider in full
racer-wannabe gear might be another 200 lb.

Even if the rider isn't tucked at all, much less than 40 hp
is required to overcome aerodynamic drag and rolling resistance
at 100 mph. With 650 lb total weight, climbing a 33% grade at
100 mph takes an additional 55 hp. Even at this extreme slope,
high speeds are possible. With only a 10% grade, it takes just
over 17 hp to overcome gravity at 100 mph.

Motorcyclists' uphill speeds are more limited by corners, sanity
or lack therof, and fear of legal consequences than by grade.

Dave Lehnen
 
D

Dave Lehnen

Guest
[email protected] wrote:
<snip>
> Dear Trevor,
>
> If you reveal marvels like this, you can hardly expect
> people to stop asking for explanations. (I will, however,
> skip the raised eyebrows about motorcycles routinely
> climbing such grades at over 100 mph.)
>

< snip on-topic information>
>
> Cheers,
>
> Carl Fogel


Oh, go ahead and raise your eyebrows. Many modern sport bikes
have the power-to-weigh to climb very steep grades at very
high speeds.

For example, a current open-class bike would weigh less than
450 lb, full of gas, oil, etc, and would have far over 100
rear-wheel horsepower when in the powerband. A rider in full
racer-wannabe gear might be another 200 lb.

Even if the rider isn't tucked at all, much less than 40 hp
is required to overcome aerodynamic drag and rolling resistance
at 100 mph. With 650 lb total weight, climbing a 33% grade at
100 mph takes an additional 55 hp. Even at this extreme slope,
high speeds are possible. With only a 10% grade, it takes just
over 17 hp to overcome gravity at 100 mph.

Motorcyclists' uphill speeds are more limited by corners, sanity
or lack therof, and fear of legal consequences than by grade.

Dave Lehnen
 
On Tue, 03 Aug 2004 18:51:46 GMT, Dave Lehnen
<[email protected]> wrote:

>[email protected] wrote:
><snip>
>> Dear Trevor,
>>
>> If you reveal marvels like this, you can hardly expect
>> people to stop asking for explanations. (I will, however,
>> skip the raised eyebrows about motorcycles routinely
>> climbing such grades at over 100 mph.)
>>

>< snip on-topic information>
> >
>> Cheers,
>>
>> Carl Fogel

>
>Oh, go ahead and raise your eyebrows. Many modern sport bikes
>have the power-to-weigh to climb very steep grades at very
>high speeds.
>
>For example, a current open-class bike would weigh less than
>450 lb, full of gas, oil, etc, and would have far over 100
>rear-wheel horsepower when in the powerband. A rider in full
>racer-wannabe gear might be another 200 lb.
>
>Even if the rider isn't tucked at all, much less than 40 hp
>is required to overcome aerodynamic drag and rolling resistance
>at 100 mph. With 650 lb total weight, climbing a 33% grade at
>100 mph takes an additional 55 hp. Even at this extreme slope,
>high speeds are possible. With only a 10% grade, it takes just
>over 17 hp to overcome gravity at 100 mph.
>
>Motorcyclists' uphill speeds are more limited by corners, sanity
>or lack therof, and fear of legal consequences than by grade.
>
>Dave Lehnen


Dear Dave,

True, modern motorcycles can exceed 100 mph uphill.

My eyebrows were lifting at the notion that this is a common
enough occurrence on an alleged 10% grade in Wales that
bicyclists allegedly descending at over 60 mph must keep a
wary eye out for motorcycles cornering on the wrong side of
the road at closing speeds exceeding 160 mph.

Perhaps I should have made my skepticism concerning the
original poster's ability to judge speeds clearer?

The original poster could be right about exceeding 60 mph on
his descent--an impressive tailwind, a much steeper grade
than he thinks, drafting trucks, or an unusually heavy build
might let him roll a mile a minute downhill.

He could also be right about motorcycles zooming up toward
him on the wrong side of corners at over 100 mph so often
that he has to keep an eye out for them.

But poor judgement of speed is at least as likely an
explanation. Few of us have much demonstrable skill at
judging our own speed at such high rates, much less the
speed of oncoming traffic. And generally we claim higher
than actual speeds (until the police pull us over).

Even at bicycling speeds, snap judgements of oncoming speeds
can be ludicrous. A defense witness once accused me of doing
well over 30 mph on a bicycle trail. I was tempted to let
the accusation stand in exchange for a copy of the court
record to hang on my wall to impress Lance, but honesty
compelled me to point out that my best efforts produce only
19 mph on the speedometer on that gentle uphill.

Carl Fogel
 
T

Trevor Jeffrey

Guest
The small group decent was required as crank revs of est. 180rpm where
attained. I think this may have been using 52x12 on 27" wheel. The bicycle
descent speed recordings where done using cycle computers, and as we could
overhaul cars I do not disbelieve the max speed recordings. Personally I
was able to attain pedal revs in excess of 200rpm on the road for short
periods. This was acheived by daily training for five weeks of round pedal
action using light gears with acceleration bursts upwards of 10 seconds.
All training was kept easy. The use of a cadence meter useful as I would
push a bit harder at each burst through a ride.
TJ
 
C

Chalo

Guest
[email protected] (Gary Young) wrote:
>
> Are there any cartridge bearing hubs currently in production that
> don't cost an arm and a leg? I know you recommend the JuJu hub, but it
> seems to be available only in a 32-hole version, not 36.


SunRace make sealed bearing hubs besides the JuJu in other drillings.
I use their high flange 36 hole and mid flange 48 hole BMX hubsets on
other bikes.

Formula, Quando, DiaTech, Bulletproof, and World Class are other
brands that produce budget-priced sealed bearing hubs. Of these I
know for sure that Formula and DiaTech offer cartridge bearing
cassette hubs, even in 48 hole drilling. Specialized sealed bearing
hubs tend to be inexpensive and nicely made. Like all OEM-market
parts, all those I have named will be available only intermittently in
the retail market.

Chalo Colina
 
On Tue, 3 Aug 2004 23:29:41 +0100, "Trevor Jeffrey"
<[email protected]> wrote:

> The small group decent was required as crank revs of est. 180rpm where
>attained. I think this may have been using 52x12 on 27" wheel. The bicycle
>descent speed recordings where done using cycle computers, and as we could
>overhaul cars I do not disbelieve the max speed recordings. Personally I
>was able to attain pedal revs in excess of 200rpm on the road for short
>periods. This was acheived by daily training for five weeks of round pedal
>action using light gears with acceleration bursts upwards of 10 seconds.
>All training was kept easy. The use of a cadence meter useful as I would
>push a bit harder at each burst through a ride.
>TJ
>


Dear Trevor,

Yes, 180-200 rpm on 27 inch tires with a 52x12 produces
62-70 mph for tires of 2136 to 2155 mm.

But here's a typical comment on how useful pedalling is at
60 mph and 180-200 rpm:

http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&[email protected]

or

http://tinyurl.com/5znt5

That is, can you pedal a freely suspended rear wheel up to
that speed and cadence?Jobst Brandt suggested this as a test
years ago, but I haven't found anyone addressing it.

Maybe you're the one to break new ground here?

Carl Fogel
 
G

Gary Young

Guest
[email protected] (Chalo) wrote in message news:<[email protected]>...
> [email protected] (Gary Young) wrote:
> >
> > Are there any cartridge bearing hubs currently in production that
> > don't cost an arm and a leg? I know you recommend the JuJu hub, but it
> > seems to be available only in a 32-hole version, not 36.

>
> SunRace make sealed bearing hubs besides the JuJu in other drillings.
> I use their high flange 36 hole and mid flange 48 hole BMX hubsets on
> other bikes.
>
> Formula, Quando, DiaTech, Bulletproof, and World Class are other
> brands that produce budget-priced sealed bearing hubs. Of these I
> know for sure that Formula and DiaTech offer cartridge bearing
> cassette hubs, even in 48 hole drilling. Specialized sealed bearing
> hubs tend to be inexpensive and nicely made. Like all OEM-market
> parts, all those I have named will be available only intermittently in
> the retail market.
>
> Chalo Colina



One thing that's made me stick with Shimano hubs is the worry that the
cassette freehub body might go bad. Do these cartridge hubs use the
same type of body as Shimano hubs. If not, are replacements readily
available?
 
C

Chalo

Guest
[email protected] (Gary Young) wrote:

> One thing that's made me stick with Shimano hubs is the worry that the
> cassette freehub body might go bad. Do these cartridge hubs use the
> same type of body as Shimano hubs. If not, are replacements readily
> available?


I don't know, and I don't know. I have only one cassette hub among
approximately 20 bikes, and as it's relatively new, I haven't opened
it up to see whether it uses a cartridge bearing cassette.

Many sealed bearing cassette hubs I have seen and serviced use a
regular Brand S clone cup & cone freehub body. This is questionable
practice, since any axial preload necessary for proper functioning of
the freehub also gets transferred to the cartridge bearings, which
don't need or like it. It does resolve your issue, though.

As to whether there is good parts support for a given cartridge
cassette hub, the answer is maybe, probably, perhaps. I imagine that
it varies a lot from maker to maker, with maufacturers that have an
established or growing reputation to uphold (e.g Specialized and
DiaTech respectively) doing a better job of it than no-name or
OEM-only manufacturers. Anyplace you can buy a budget cartridge
bearing hubset would be a good place to ask whether _that seller_ can
get you spare parts.

Chalo Colina
 
T

Trevor Jeffrey

Guest
carlfog[email protected] wrote in message ...
>Yes, 180-200 rpm on 27 inch tires with a 52x12 produces
>62-70 mph for tires of 2136 to 2155 mm.
>
>But here's a typical comment on how useful pedalling is at
>60 mph and 180-200 rpm:
>
>http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&[email protected]

tx.hpl.hp.com
>
>or
>
>http://tinyurl.com/5znt5
>
>That is, can you pedal a freely suspended rear wheel up to
>that speed and cadence?Jobst Brandt suggested this as a test
>years ago, but I haven't found anyone addressing it.
>
>Maybe you're the one to break new ground here?


??

TJ
 
T

Trevor Jeffrey

Guest
[email protected] wrote in message ...
>Yes, 180-200 rpm on 27 inch tires with a 52x12 produces
>62-70 mph for tires of 2136 to 2155 mm.
>
>But here's a typical comment on how useful pedalling is at
>60 mph and 180-200 rpm:
>
>http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&[email protected]

tx.hpl.hp.com
>
>or
>
>http://tinyurl.com/5znt5
>
>That is, can you pedal a freely suspended rear wheel up to
>that speed and cadence?Jobst Brandt suggested this as a test
>years ago, but I haven't found anyone addressing it.
>
>Maybe you're the one to break new ground here?


??

TJ
 
D

David Damerell

Guest
Chalo <[email protected]> wrote:
>The combination of no axial adjustment, no periodic maintenance,
>complete replaceability, and the lowest amount of bearing drag is an
>unbeatable advantage for sealed cartridge hub bearings IMO.


The point was driven home to me when replacing the original '89 Suzue
cartridge rear hub on the tandem with a cup-and-cone (why? 'cos the old
one is freewheel, and I don't fancy carrying the tools to pull one on the
road, and 40-spoke to boot); the cartridge hub is really enormously easier
to work with. The front hub stays; and if I have time to shop around next
time I need a hub, it sure as hell won't be cup and cone.
--
David Damerell <[email protected]> flcl?
 
On Mon, 2 Aug 2004 20:56:56 +0100, "Trevor Jeffrey"
<[email protected]> wrote:

>
>[email protected] wrote in message ...
>>What hill do you descend in excess of 60 mph?

>
>That was not a cue to go totally off topic. The hill/mountain? is Moel
>Eithinen sometimes called the Bwlch as opposed to the Old Bwlch or Bwlch
>Penbarra which contains a 1in3 hairpin. It's in N. Wales.
>TJ
>


Dear Trevor,

Would this be the area?

http://www.streetmap.co.uk/newmap.s...&mapp=newmap.srf&searchp=newsearch.srf&dn=651

or

http://tinyurl.com/65jax

That is, I see a Blwch Penbarras in the upper middle
1000-meter square, a Moel Ethinen in the center square, and
a Blwch-y-parc in the lower two right squares, with 10-meter
contour lines.

Carl Fogel
 
On Thu, 05 Aug 2004 15:52:45 -0600, [email protected]
wrote:

>On Mon, 2 Aug 2004 20:56:56 +0100, "Trevor Jeffrey"
><[email protected]> wrote:
>
>>
>>[email protected] wrote in message ...
>>>What hill do you descend in excess of 60 mph?

>>
>>That was not a cue to go totally off topic. The hill/mountain? is Moel
>>Eithinen sometimes called the Bwlch as opposed to the Old Bwlch or Bwlch
>>Penbarra which contains a 1in3 hairpin. It's in N. Wales.
>>TJ
>>

>
>Dear Trevor,
>
>Would this be the area?
>
>http://www.streetmap.co.uk/newmap.s...&mapp=newmap.srf&searchp=newsearch.srf&dn=651
>
>or
>
>http://tinyurl.com/65jax
>
>That is, I see a Blwch Penbarras in the upper middle
>1000-meter square, a Moel Ethinen in the center square, and
>a Blwch-y-parc in the lower two right squares, with 10-meter
>contour lines.
>
>Carl Fogel


While it's not the Bwlch near Moel Eithinen, there is a
short Welsh grade called Bwlch-y-Groes that descends to
Dinas-Mawddwy with an impressively steep upper 1,000 meters:

http://www.salite.ch/groes1.htm

The link above shows a drop from 546 meters to 464 meters
(16.4%) in 500 meters of road, followed by a drop from 464
to 384 meters (16.0%) in the next 500 meters of road, an
average of 16.2% for a kilometer.

This is followed by another kilometer at 14.2% grade from
384 meters down to 242 meters.

(The site's list of 54 Welsh climbs lists this one at an
average of 12.5%, with no others averaging even 9% and no
obvious stretches exceeding 12%.)

Here's a map:


http://www.streetmap.co.uk/newmap.s...&mapp=newmap.srf&searchp=newsearch.srf&dn=654

or

http://tinyurl.com/4qhg9

And here's a commentary page:

http://www.iseran.com/Atlas/bwlch_y_groes.html

Plugging 0 watts power (no pedalling) and -0.164 slope into:

http://www.analyticcycling.com/ForcesSpeed_Page.html

calculates a speed of 27.54 mps (61-62 mph) for a 75kg bike
and rider.

For a -0.142 slope and 0 watts power, the same defaults
yield 25.74 mps (or 57-58 mph).

Of course, this assumes that the approach, distance, and
curves allow the bike and rider to reach terminal velocity
within a kilometer.

If there's an unlisted stretch of paved road in Wales whose
grade exceeds 10%, the folks at http://www.salite.ch would
love to hear about it. (Click on English and a display
appears by country, including Wales.)

Carl Fogel
 
B

Bill Lloyd

Guest
Well I guess in the UK they don't have the altitude, but I've hit 63.5
mph in the Sierras in eastern California, descending from north lake
Tahoe to Truckee.

The grade isn't all that steep, either -- maybe 10%? But it's at 8500'
give or take.


On 2004-08-02 20:29:38 -0700, [email protected] said:

> On Tue, 3 Aug 2004 02:54:19 +0100, "Trevor Jeffrey"
> <[email protected]> wrote:
>
>>
>> [email protected] wrote in message ...
>>> I'm not quite clear whether you mean that your hill includes
>>> the 1 in 3 hairpin, or 33% grade, or if you mean that the
>>> hairpin is in the other hill, but either way it seems
>>> unlikely that anyone does 60 mph through a hairpin.
>>>

>> The old road contains the hairpin. The new road is declared a trunk road.
>>> What would you say the grade is on the section where you
>>> exceed 60 mph?

>> 10% maybe less, have to check by map.
>>>
>>> Is this the mountain bike trail that I see on the internet
>>> when I google for bwlch, or is it a road? That is, are we
>>> talking about a ski-resort dirt-descent specialty-downhill
>>> or a paved road?

>> Single carriageway trunk road. Scares the **** outa some.
>> Motorcyclists coming towards you at 100mph+ dont always return to their
>> nearside, I guess so they can see around the bend which of course I want to
>> cut. The lead rider must keep their head up for this reason.
>> It takes three or four riders riding close to get past 100kmh
>> TJ Now stop it!
>>

>
> Dear Trevor,
>
> If you reveal marvels like this, you can hardly expect
> people to stop asking for explanations. (I will, however,
> skip the raised eyebrows about motorcycles routinely
> climbing such grades at over 100 mph.)
>
> For a typical bicycle rider's weight and profile, a long
> stretch of extremelly rare 15.4% grade is required to reach
> 60 mph.
> Heavier riders with improved tucks can do better. Chalo
> Colina, for example, may be able to reach 60 mph on a mere
> 6.6% slope, since he enjoys considerably increased force
> (over 400 pounds with bicycle) without a corresponding
> increase in wind drag.
>
> Pedalling, of course, is unlikely to be of any value. Over
> 157 rpm is required to pedal 60 mph on a 700c 53x11 and
> would involve losing more to increased wind drag than could
> be made up.
>
> Perhaps you could check the details again with the other two
> or three riders involved and persuade them to favor us with
> a post or two about the maximum recorded on their
> speedometers?
>
> Meanwhile, you might enjoy plugging a few figures into this
> speed calculator:
>
> http://www.analyticcycling.com/ForcesSpeed_Page.html
>
> Set the power to 0 watts and the slope to -0.154 and you'll
> produce a speed of about 60 mph for a 75kg rider and
> bicycle. Plug in Chalo's 182kg and the result converts to
> 93.5 mph.
>
> I never trust my conversions, so I like to check them here:
>
> http://members.aol.com/javawizard/speed.html
>
> You can reduce various factors to increase speed, but you'll
> have to keep them believable. A 10% slope with the defaults
> produces only 48 mph. Increasing this 25% would be
> impressive.
>
> You may also have some explaining to do in order to convince
> people that a peloton coasts downhill faster than a single
> coasting rider. As I understand it, the lead rider works
> like a dog and those who follow enjoy the reduced wind drag
> available just behind him.
> There are regular discussions here about whether the leader
> benefits slightly from someone filling in his slipstream,
> but I can't recall anyone claiming an improvement of more
> than a mile per hour.
>
> People do maintain sites reporting impressive climbs and
> descents for bicyles, so you might want to look into getting
> your local route listed if it turns out to have a
> significant stretch of 10% grade.
> Here are two links to places that list notable climbs:
>
> http://www.ulb.ac.be/di/ssd/ldoyen/e/v.html
>
> http://www.cyclos-cyclotes.org/altigraph.html
>
> Cheers,
>
> Carl Fogel
 
On Mon, 9 Aug 2004 14:43:12 -0700, Bill Lloyd
<[email protected]> wrote:

>Well I guess in the UK they don't have the altitude, but I've hit 63.5
>mph in the Sierras in eastern California, descending from north lake
>Tahoe to Truckee.
>
>The grade isn't all that steep, either -- maybe 10%? But it's at 8500'
>give or take.
>


Dear Bill,

Here are the sites again if you'd like to play with the
numbers.

http://www.analyticcycling.com/ForcesSpeed_Page.html

http://members.aol.com/javawizard/speed.html

Plugging in -0.10 for the grade, 0 watts for no pedalling,
and 0.950 for air density around 2600 meters produces a
terminal speed for the other defaults such as 165 lbs of
riders and bike of 24.4 meters per second, or 54.5 mph

To reach 63.5 mph, you need extra power or reduced drag,
either from a tighter tuck, a steeper grade, a tailwind,
another vehicle to draft, or a heavier rider.

Pedalling is generally held to be counter-productive at such
speeds with ordinary bicycle frames and gearing. At 63.5 mph
with a 2124mm 700c tire and 53x11 gearing, you must spin up
to 162 rpm before the chain engages the rear wheel--such
furious pedalling is likely to add more drag than any useful
propulsion.

For example, a 102 kg bike and rider (214 pounds), will
coast up to 63.5 mph on the hypothetical 10% grade with the
0.950 air density.

Or the default 165 lb rider could simply tilt the road to a
grade of 13.4% at that altitude.

As an overweight Shetland pony, if not a modest Clydesdale,
even I could presumably roll my 110 kg carcass and bicycle
down your 10% grade at 66 mph (assuming that it's nice and
straight and uncrowded and long enough), so your
high-altitude claim of 63.5 mph seems quite plausible.

Drop it down to sea level air density and my 66 mph drops to
58 mph.

It should be remembered that many high speed claims may be
made quite honestly by riders unaware of handsome tail winds
or the advantage of 40 pounds of baggage. My best speed
coasting down my daily hill is 15 mph higher than usual, a
tribute to a fine west wind, while my regular victories over
a friend in coasting contests down the same hill rely on my
extra fifteen pounds of ballast, much like any underhanded
soapbox derby triumph.

Carl Fogel