Wheel balancing?

[OperaLover]

Anyone done this? Met a very cool old school mechanic who swears this helps with high speed stability. I had my bike in the stand and spun the rear wheel and sure enough it does start to oscillate the faster it goes. We balance wheels on cars, should we do it on bikes? Or, is my weight over the wheel enough to keep it in check?

Any thoughts on this?

Thanks!

[avalonracing]

I'm sure that it wouldn't hurt when you are going over 80mph. On a glass smooth road. Otherwise if your tires are good and your rims are true I would think that any road that we ride would negate any effort put into "balancing" a bike wheel.

[TimmyB]

Isn't that the thinking behind the counterbalance on the ambrosio nemesis rims?
http://cdn3.media.cyclingnews.futurecdn.net/2010/04/12/2/quick_step_boonen_rim_600.jpg

[Mark McM]

While balancing your wheels clearly can't hurt, it isn't really necessary. You can't really compare the need to balance wheels on a bike with motor vehicles. Not just because bicycles rarely get to the speeds where balance matters on a motor vehicle, but more importantly the "suspension" on a road bike is much, much stiffer than on a spring suspension motor vehicle. So yes, your weight on the wheel is enough to keep it good and planted to the road.

[OperaLover]

I'm sure that it wouldn't hurt when you are going over 80mph. On a glass smooth road. Otherwise if your tires are good and your rims are true I would think that any road that we ride would negate any effort put into "balancing" a bike wheel.

Wheels are true (campy neutrons with GP 4000 Stires).

Is there significance to 80 mph? I don't drive my car over 80 (office, I do not speed), but we still balance car wheels.

I agree that a bad road surface would work against the benefit of wheel balancing, but I wouldn't take a bad road at high speed either.

I do like to take a nice road at 40 plus. And my bike "feels" less stable the faster I go. Or, it may be all in my head. Maybe "balancing " the wheels will help my mind get past the instability I "think" I feel.

It appears the balancing is done counter to the seam, so near the valve stem. Maybe that's why the Salon V folks swear by the Nemesis rim.

I will try it and report back.

[David Kirk]

An oldie that might help -

http://www.kirkframeworks.com/blog/2009/04/03/riding-tip/


dave

[forrestw]

My regular wheelset has a small vertical out-of-true at the joint (Velocity Escape, that's how it came from the factory) which I can feel if I'm riding on rollers and can just barely feel at say 20-30 mph speeds on super-flat / smooth pavement (if I'm not pedalling). I have done plenty hard cornering on it and never had a problem, have hit 60+ on descents and at those speeds there's enough other sensory input I can't feel anything coming that rear wheel.

If that has no effect on my bike's handling (I didn't want to go through the hassle of returning / rebuilding for a non-issue) then the couple of grams out of balance is something you'll never feel.

Sure, when you spin it up held in a stand it will vibrate some, 20# bike not rigidly held down it becomes noticeable. Add your weight to the equation and it has no effect.

The main reason you have to high-speed balance auto wheels is that they are materially thick and can be in static balance but not in dynamic balance so left-right balance needs to be addressed. (This is only in after-market tires, the auto makers require tire companies to provide them with in-balance wheels so that they don't have to balance on the production line. We chumps buying replacement car tires get the ones Detroit won't use.) Anyhow, a bike wheel is effectively a 2-d structure and so dynamic balance is truly a non-issue.

[flydhest]

I heart Dave Kirk

[Louis]

An oldie that might help -

http://www.kirkframeworks.com/blog/2009/04/03/riding-tip/


dave

Once located, could you put the washers under the rim tape? (assuming you're using clinchers)

[David Kirk]

Once located, could you put the washers under the rim tape? (assuming you're using clinchers)

I never thought of that but I suppose you could. it could make getting the tire on/off a challenge depending on the size and thickness of the weight being used.

I've also see it done with very small weights on the spokes but I like the idea of getting the weight as close as possible to the thing that is actually causing the balance issue - the rim/tube/tire.

One could conversely drill holes in the rim on the heavy spot. Don't sue me if you go down this road.

dave

[bart998]

When I worked in a shop one of the other mechanics had balanced his wheels. He did this by crimping small fishing "shot" weights around the spokes by the nipples and soldering them. He swore by it. I never bought into it because of the comparatively low weight of the wheel compared to the rider. The oscillating force of the wheel can't overcome your weight. Your speed would have to be extreme, or the weight imbalance extreme to cause a problem. Fast descents have never caused me a concern due to "balance" issues. Fork alignment yes, not wheel balance.

[OperaLover]

Thanks for everyone's input. The mechanic in question is not charging too much for this service so it's worth a try.

[false_Aest]

If a mech is gonna do it . . . do it.

Otherwise, there are better things to do. Like cuddle your wife/kids for 15 minutes.

[fogrider]

so, on my climbing wheels I'm going to add weight? there are very few spots that I can get up to 50 mph and its only for a few seconds...I sit for many minutes at a time trying to keep my spin up to maintain 9 to 12 mph. there is no way I'm going add weight my rims!

[rice rocket]

so, on my climbing wheels I'm going to add weight? there are very few spots that I can get up to 50 mph and its only for a few seconds...I sit for many minutes at a time trying to keep my spin up to maintain 9 to 12 mph. there is no way I'm going add weight my rims!
OTOH if you crash and break your face on a descent and you're off the bike for 6 months, think about how much time you gained on your next climb due to lack of fitness. ;) The extra grams is the wiser choice ATMO.

[soulspinner]

Arent Campy/ Fulcrum wheels balanced?

[RPS]

Wouldn’t it help to quantify these out-of-balance forces rather than guessing? I think it is absolutely necessary if one is to analyze the problem in a more comprehensive manner (i.e. – beyond stating they are small relative to rider weight and therefore don’t or shouldn’t matter).

Mark made an excellent point that bicycles are not like automobiles because they lack suspension and therefore can’t be compared directly. I’ll add for those that don’t know that out-of-balance auto tires don’t normally create enough force (compared to the weight of the vehicle resting on that tire) to lift the tire off the pavement either. Yet we’ve all seen auto tires bounce or skip off the pavement at high speed for lack of proper balance. And it’s not because out-of-balance forces become so large at 80 MPH to overcome the car’s weight. Not without help anyway.

It's not as simple as saying one force is greater than another and that makes everything work out OK.

[David Kirk]

Wouldn’t it help to quantify these out-of-balance forces rather than guessing? I think it is absolutely necessary if one is to analyze the problem in a more comprehensive manner (i.e. – beyond stating they are small relative to rider weight and therefore don’t or shouldn’t matter).

Mark made an excellent point that bicycles are not like automobiles because they lack suspension and therefore can’t be compared directly. I’ll add for those that don’t know that out-of-balance auto tires don’t normally create enough force (compared to the weight of the vehicle resting on that tire) to lift the tire off the pavement either. Yet we’ve all seen auto tires bounce or skip off the pavement at high speed for lack of proper balance. And it’s not because out-of-balance forces become so large at 80 MPH to overcome the car’s weight. Not without help anyway.

It's not as simple as saying one force is greater than another and that makes everything work out OK.

I agree.

I will also add that it would be very rare that balancing the wheels would make or break a ride. That said it can't hurt and takes very little time (5 minutes a wheel at best) and in many cases the bike will feel better. I see no compelling reason not to do it other than you just don't want to. If you don't want to you'll be just fine. But if you are a detail type person and like to make everything just so then invest the very small amount of time and enjoy the process.

dave

[RPS]

For what I’d expect as typical out-of-balance mass (say, in the range of 2 or 3 magnets, a few heavy washers, or a valve stem or two), I estimate the forces at 80 feet per second (about 55 MPH) for a 700C wheel (yes, I think size matters) are in the range of 4 pounds or so (based on my scale and samples I weighed). That’s not very high by comparison to 60 to 100 pounds resting on a typical bike wheel.

Having said that, the question then becomes how and when does 4 or 5 pounds of imbalance become that significant. It’s the same theory as a car tire, just different numbers for the most part. ;)

[jimcav]

on my carbon edge tubulars. I never had to on my eurus clinchers, but i went tubular and am not going back. my bike went into high speed death wobble on fast descents and what made it rideable was putting 1-2 sensor magnet(s) [depending on which wheel, i had edge 38 and 68) across from the valve. what made it perfect was when i found out the bike was designed for a 45 rake fork and i had a 43 on it.

so, it can matter. I was about to give up on that bike until i saw Dave Kirk's article

[palincss]

so, on my climbing wheels I'm going to add weight? there are very few spots that I can get up to 50 mph and its only for a few seconds...I sit for many minutes at a time trying to keep my spin up to maintain 9 to 12 mph. there is no way I'm going add weight my rims!

Do you really believe the amount of weight you would use to balance a wheel would make it more difficult for you to maintain your speed climbing a hill? Or that you could even detect that amount of weight added to the bike?