what is a climbing wheel????and physics questions

[anerobic]

'm sick of ads proclaiming that wheels are for climbing. how did this come about?
there's nothing special about climbing as far as a wheel goes. yes weight matters a little as it does over all of the bicycle, but i don't see seat posts described as "climbing seatposts" because they weigh 50 grams less. i'd be very surprised if a 175 lb rider plus a 20 lb cycle could feel the climbing difference in a wheelset that was 100 grams lighter (88530 gms vs 88630 grams)
by the way, can any physicists out there tell me how much contribution 100 grams makes, say, in the rim of a wheel, when you are trying to sprint for the finish and you weigh 195 lbs with the rest of your bicycle? or how much energy goes into non aero spokes vs aero spokes in a sprint?

 

[Andre]

A climbing wheel's criteria:
1. good acceleration. This is accomplished by focusing the weight as close as possible to the hub.
This lowers the moment of inertia (less energy required to accelerate\decelerate the rim). Light
rims are critical, in concert with tubes \ tires. Also, some wheels have the nipples at the hub,
rather than at the rim.
2. low overall weight (less mass to haul vertically).

--
--------------------------
Andre Charlebois BPE, MCSE4.0, CNA, A+ webmaster for Triathlon New Brunswick www.TriNB.com
"anerobic" <[email protected]> wrote in message
news:[email protected]...
> 'm sick of ads proclaiming that wheels are for climbing. how did this come about? there's nothing
> special about climbing as far as a wheel goes. yes weight matters a little as it does over all of
> the bicycle, but i don't see seat posts described as "climbing seatposts" because they weigh 50
> grams less. i'd be very surprised if a 175 lb rider plus a 20 lb cycle could feel the climbing
> difference in a wheelset that was 100 grams lighter (88530 gms vs 88630 grams) by the way, can any
> physicists out there tell me how much contribution 100 grams makes, say, in the rim of a wheel,
> when you are trying to sprint for the finish and you weigh 195 lbs with the rest of your bicycle?
> or how much energy goes into non aero spokes vs aero spokes in a sprint?
>
>
>
> --
> >--------------------------<
> Posted via cyclingforums.com http://www.cyclingforums.com

 

[Nick Payne]

It climbs into your bank account and removes substantial funds...

"anerobic" <[email protected]> wrote in message
news:[email protected]...
> 'm sick of ads proclaiming that wheels are for climbing. how did this come about?

 

[S. Anderson]

"anerobic" <[email protected]> wrote in message
news:[email protected]...
> 'm sick of ads proclaiming that wheels are for climbing. how did this come about? there's nothing
> special about climbing as far as a wheel goes. yes weight matters a little as it does over all of
> the bicycle, but i don't see seat posts described as "climbing seatposts" because they weigh 50
> grams less. i'd be very surprised if a 175 lb rider plus a 20 lb cycle could feel the climbing
> difference in a wheelset that was 100 grams lighter (88530 gms vs 88630 grams) by the way, can any
> physicists out there tell me how much contribution 100 grams makes, say, in the rim of a wheel,
> when you are trying to sprint for the finish and you weigh 195 lbs with the rest of your bicycle?
> or how much energy goes into non aero spokes vs aero spokes in a sprint?

Well, it is a fact that the less weight you have to drag up the hill, the less work you do. How
important is that weight to you?? Only you can decide that. It's important to Lance and the
boys..very important. To you and me? Probably less so..definitely less so for me. Actually, I've
never seen an ad saying "climbing wheels" although it is a commonly used term in the bike shops.

Cheers,

Scott..

 

[Ted Bennett]

"Andre" <[email protected]> wrote:

> A climbing wheel's criteria:
> 1. good acceleration. This is accomplished by focusing the weight as close as possible to the hub.
> This lowers the moment of inertia (less energy required to accelerate\decelerate the rim).
> Light rims are critical, in concert with tubes \ tires. Also, some wheels have the nipples at
> the hub, rather than at the rim.
> 2. low overall weight (less mass to haul vertically).

Andre got the numbers wrong. Repalcing 1 with 2 puts those criteria in the order of importance.

Because of the low accelerations of a bike, rotational mass is by far the smaller effect.

--
Ted Bennett Portland OR

 

[Sheldon Brown]

There's a lot of nonsense talked about this. The total weight is not all that important, the key to
making a good climbing wheel is the weight _distribution_.

The typical wheel for flatland riding is completely symmetrical, with the weight distributed equally
around its perimiter. That's OK for the flats, but not any help for serious climbing.

I'm working on a radical improvement in wheel design, which will actually use a special _weighted_
rim, designed so that the extra weight is concentratd on the _front_ side of each wheel, so that as
you climb, the wheel's center of gravity will move downward, and the weight will actually _help_
you climb!

There are still a few bugs to be worked out of the design, but the engineers and alchemists at
ShelBroCo are confident the details can be worked out in time for the roll out of the Climb-O-Matic
wheelset in about 5 months.

We're hoping to incorporate the Power Wheel concept, and make it possible for overweight 60-year-old
bald guys to compete in the Tour de France, as long as the luddite mossbacks at the UCI don't outlaw
our new technology...

Carapace Completed Umber ShelBroCo Wheeling, West Virginia http://sheldonbrown.com/power_wheel.html

 

[Benjamin Weiner]

anerobic <[email protected]> wrote:
> I'm sick of ads proclaiming that wheels are for climbing. how did this come about? there's nothing
> special about climbing as far as a wheel goes. yes weight matters a little as it does over all of
> the bicycle, but i don't see seat posts described as "climbing seatposts" because they weigh 50
> grams less.

Climbing wheel = a wheel so light, underdesigned, or unreliable that you wouldn't really trust it at
high speed going downhill or over potholes.

when it's not an "aero wheel." BTW, Aero wheel = a wheel so (relatively) heavy that 200-lb riders
with money to burn feel it drags down their climbing performance.

 

[Onefred]

> 1. good acceleration. This is accomplished by focusing the weight as close as possible to the hub.
> This lowers the moment of inertia (less energy required to accelerate\decelerate the rim).
> Light rims are critical, in concert with tubes \ tires. Also, some wheels have the nipples at
> the hub, rather than at the rim.

That's debatable. Don't forget that the part of the wheel in contact with the pavement does not need
to move forward with the rest of the bike, but the top of the wheel must accelerate faster than
yourself. Have light weight wheels because they lower the overall weight. Ditto for handle bars,
forks, seatpost, etc.

For climbing and sprinting, I would want STIFF, lightweight wheels.

Dave

 

[Peter]

Sheldon Brown wrote:

> There's a lot of nonsense talked about this. The total weight is not all that important, the key
> to making a good climbing wheel is the weight _distribution_.
>
> The typical wheel for flatland riding is completely symmetrical, with the weight distributed
> equally around its perimiter. That's OK for the flats, but not any help for serious climbing.
>
> I'm working on a radical improvement in wheel design, which will actually use a special _weighted_
> rim, designed so that the extra weight is concentratd on the _front_ side of each wheel, so that
> as you climb, the wheel's center of gravity will move downward, and the weight will actually
> _help_ you climb!
>
> There are still a few bugs to be worked out of the design, but the engineers and alchemists at
> ShelBroCo are confident the details can be worked out in time for the roll out of the
> Climb-O-Matic wheelset in about 5 months.

Isn't that about one month too early for your usual product development cycle? Best of luck with the
product introduction in any event.

 

[Velocat]

Peter wrote:

> Sheldon Brown wrote:
>
>> There's a lot of nonsense talked about this. The total weight is not all that important, the key
>> to making a good climbing wheel is the weight _distribution_.
>>
>> The typical wheel for flatland riding is completely symmetrical, with the weight distributed
>> equally around its perimiter. That's OK for the flats, but not any help for serious climbing.
>>
>> I'm working on a radical improvement in wheel design, which will actually use a special
>> _weighted_ rim, designed so that the extra weight is concentratd on the _front_ side of each
>> wheel, so that as you climb, the wheel's center of gravity will move downward, and the weight
>> will actually _help_ you climb!
>>
>> There are still a few bugs to be worked out of the design, but the engineers and alchemists at
>> ShelBroCo are confident the details can be worked out in time for the roll out of the
>> Climb-O-Matic wheelset in about 5 months.
>
>
> Isn't that about one month too early for your usual product development cycle? Best of luck with
> the product introduction in any event.
>

I'm sure Sheldon allows for the usual last minute slippage...

 

[anerobic]

i agree that making a wheel's rim light is good for acceleration, but that's more important in sprinting/jumps than in climbing, since most ridiers i know don't accelerate while going uphill, they just ride a constant pace. they should be called sprinting wheels rather than climbing wheels

 

[S. Anderson]

"Benjamin Weiner" <[email protected]> wrote in message news:3f7a161f$1@darkstar...
> anerobic <[email protected]> wrote: Climbing wheel = a wheel so light, underdesigned,
> or unreliable that you wouldn't really trust it at high speed going downhill or over potholes.
>

> when it's not an "aero wheel." BTW, Aero wheel = a wheel so (relatively) heavy that 200-lb riders
> with money to burn feel it drags down their climbing performance.
>

I saw an interesting wheelset once..whole bike actually..a person who shall remain nameless, drilled
holes around the entire circumference of both rims between the spoke holes, about the diameter of a
schrader hole. All the way through both walls..drilled out a Dura Ace crank, both sides...Vitus
979..Kinesis fork..I think the bike weiged about 12 or 14lbs. In any event, the bike and rider won
the Bavarian Hill Climb Profi Championship in Berchtesgaden. Now, me looking at that bike, I
think "What a loon!" However, he DID win...what can I say to that?!? More power to him.

Cheers,

Scott..

 

[Werehatrack]

On Tue, 30 Sep 2003 22:18:15 -0400, "S. Anderson" <[email protected]> may have said:

>I saw an interesting wheelset once..whole bike actually..a person who shall remain nameless,
>drilled holes around the entire circumference of both rims between the spoke holes, about the
>diameter of a schrader hole. All the way through both walls..drilled out a Dura Ace crank, both
>sides...Vitus
>979..Kinesis fork..I think the bike weiged about 12 or 14lbs. In any event, the bike and rider won
> the Bavarian Hill Climb Profi Championship in Berchtesgaden. Now, me looking at that bike, I
> think "What a loon!" However, he DID win...what can I say to that?!? More power to him.

Given that back in my motorcycle days, we called this "cheesing", I have to wonder; was he Swiss?

--
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.

 

[S. Anderson]

"Werehatrack" <[email protected]> wrote in message
news:[email protected]...
> On Tue, 30 Sep 2003 22:18:15 -0400, "S. Anderson" <[email protected]> may have said:
>
>
> Given that back in my motorcycle days, we called this "cheesing", I have to wonder; was he Swiss?
>

Nah..he's a Canadian living in Germany..his home course basically..but still, I wanted to chew him
out about all his namby-pamby light stuff, then he goes and wins..what could I say?!!? "Nice
race!" heehee..

Cheers,

Scott..

 

[anerobic]

i'm looking at new wheels-it would sure help to be able to compare them , not just by weight, but by "moment of inertia" or some measure of how hard it is to turn the wheelset. has anyone tested a number of wheels this way? i think all it takes is a ramp-tighten the cones and let the wheel spin on it's axle down the ramp. compare different wheels for accelerability...

 

[Mark Hickey]

anerobic <[email protected]> wrote:

>'m sick of ads proclaiming that wheels are for climbing. how did this come about? there's nothing
>special about climbing as far as a wheel goes. yes weight matters a little as it does over all of
>the bicycle, but i don't see seat posts described as "climbing seatposts" because they weigh 50
>grams less. i'd be very surprised if a 175 lb rider plus a 20 lb cycle could feel the climbing
>difference in a wheelset that was 100 grams lighter (88530 gms vs 88630 grams) by the way, can any
>physicists out there tell me how much contribution 100 grams makes, say, in the rim of a wheel,
>when you are trying to sprint for the finish and you weigh 195 lbs with the rest of your bicycle?
>or how much energy goes into non aero spokes vs aero spokes in a sprint?

Unless the hill is really, REALLY steep, aero will still trump weight. So if you want to go up a
hill faster, get a set of wheels that weighs 100g more, but doesn't have (say...) fat aluminum
spokes. ;-)

Mark Hickey Habanero Cycles http://www.habcycles.com Home of the $695 ti frame

 

[Qui Si Parla Ca]

anerobic-<< 'm sick of ads proclaiming that wheels are for climbing. how did this come about?
there's nothing special about climbing as far as a wheel goes. yes weight matters a little as it
does over all of the bicycle, but i don't see seat posts described as "climbing seatposts"
>><BR><BR>

C.mon,. you are using way too much sense here. Congratulations on not being swayed by the
marketeers..

AND, even before I delve into the other 10 posts, where the weight is, the rim or the hub, the
difference is almost not measureable as well.

This 'a pound on the wheel equals 3 on the bike' kind of nonsense.

Peter Chisholm Vecchio's Bicicletteria 1833 Pearl St. Boulder, CO, 80302
(303)440-3535 http://www.vecchios.com "Ruote convenzionali costruite eccezionalmente bene"

 

[Qui Si Parla Ca]

andre-<< A climbing wheel's criteria:
1. good acceleration. This is accomplished by focusing the weight as close as possible to the hub.
This lowers the moment of inertia (less energy required to accelerate\decelerate the rim).
>><BR><BR>

Like I said..this is almost not measureable, it is so small..NO rider can tell the difference. A
study I read said something along the lines that doubling the rim weight increases energy to spin
the wheel by .1%..that's one tenth of 1 percent.

Peter Chisholm Vecchio's Bicicletteria 1833 Pearl St. Boulder, CO, 80302
(2)440-3535 http://www.vecchios.com "Ruote convenzionali costruite eccezionalmente bene"

 

[Jobst Brandt]

Andre Charlebois writes:

> A climbing wheel's criteria:

> 1. Good acceleration. This is accomplished by focusing the weight as close as possible to the hub.
> This lowers the moment of inertia (less energy required to accelerate\decelerate the rim).
> Light rims are critical, in concert with tubes \ tires. Also, some wheels have the nipples at
> the hub, rather than at the rim.

Could you expand on about what acceleration you are concerned. Is it the start of the hillclimb at
the starting line, something all riders overcome whether on a flat time trial or starting from a
stop elsewhere?

I think if you consider what the hill climber wants is constant speed, something a flywheel would
enhance, however flywheels must be heavy to do any good (or damage) so it must be the work of
carrying the wheel up the hill that is essential. Where do you believe acceleration enters in
climbing? Have you considered what levels of acceleration a rider produces in a hill climb. Is it
not the same as riding in the flat except with added drag from the slope?

Myth and lore about rotating weight has been part of the pseudo science of bicycling far to long to
be repeated here in the "tech" group.

> 2. low overall weight (less mass to haul vertically).

And even that is not as important as it is made out to be considering the size of water bottles most
riders carry. Remember, they are not setting records in the TdF... but they believe all this
rotating mass jive.

Jobst Brandt [email protected]

 

[Rick Onanian]

On Wed, 01 Oct 2003 04:32:38 GMT, Mark Hickey <[email protected]> wrote:
>Unless the hill is really, REALLY steep, aero will still trump weight. So if you want to go up a
>hill faster, get a set of wheels that weighs 100g more, but doesn't have (say...) fat aluminum
>spokes. ;-)

When a hill is shallow enough that I have to worry about aero on it, I don't call it a hill at all.
On something I call a hill, I generally end up going pretty slow.

>Mark Hickey Habanero Cycles http://www.habcycles.com Home of the $695 ti frame
--
Rick "Never seen flat land" Onanian