Balancing wheels on the bike
 

Is it possible? ie: with the bike lifted off the ground and the wheels fitted to the bike (chain removed from the sprocket at the rear) will the wheels turn freely enough on the wheel bearings for gravity to expose a heavy spot in a tyre?

I know it would depend on how heavy the heavy spot is, but lets say 10 grams or more, significant enough to cause a vibration.

Assume free running and properly greased wheel bearings.

I'll try it at the weekend by sticking a 10 gram weight on a balanced wheel and see if it turns, until then, any thoughts?

Thanks

Re: Balancing wheels on the bike
 

I couldn't, was ages ago, so cant remember which bike i tried it on. If you have success, ill be trying again.

Re: Balancing wheels on the bike
 

No its not.

Re: Balancing wheels on the bike
 

No, too much drag from dust seals and stuff.

Re: Balancing wheels on the bike
 

With completely worn out seals, very loose bearings, pads levered away from the discs and the chain removed etc. it might sort of work on the rear. On the front you have the additional drag of the speedo sensor.

Re: Balancing wheels on the bike
 

id be interested if someone can come up with a diy version of a wheel balancer. has anyone got a bought balancer that can give us insight into how it does the job? could we use the wheel axle rod as part of a diy version?

Re: Balancing wheels on the bike
 

ABBA do one, but you'd need to be doing a lot to justify the cost.

However it doesn't look too difficult to make something similar

http://www.abbastands.co.uk/product_details.asp?id=14

Re: Balancing wheels on the bike
 

wheel balancer is basically 2 cones a rod and some tiny low friction bearings. i have one and don't use it as i have found something else which works.

Re: Balancing wheels on the bike
 

Set of axle stands and a socket extension through the bearings, works fine.

Re: Balancing wheels on the bike
 

So have I, it's called an electronic static and dynamic wheel balancing machine. Never could get it right the old way.

Re: Balancing wheels on the bike
 

I checked one on machine after doing it on axle stands and it was fine, you can get within couple of grams easily.

No difference between static and dynamic balance on those machines, just easier, they're not like a multi-plane balancer that you'd use on a crank or something.

Re: Balancing wheels on the bike
 

Not for bike tyres anyway, but wide car alloys with low profile tyres can be a nightmare to balance. This was the only machine I could find that would balance the wheels on my Vectra SRI properly.

http://www.gsp9700.com/how/index.htm

Re: Balancing wheels on the bike
 

i just remove valve core pour in required amount of ceramic tungsten beads (dynabeads) replace core fill with air and away i go.

Re: Balancing wheels on the bike
 

Interesting...never seen Dynabeads before.

Re: Balancing wheels on the bike
 

+1

Re: Balancing wheels on the bike
 

i was sceptical about them but i have been using them since April and they work. no more ugly weights to get in the way of cleaning my wheels :-)

i calculate the weight required by multiplying .25g by the width of the tyre e.g. .25x160 = 40g

they are suposed to be re-usable if your a tight wad but for the price of them i just use fresh ones as i got a big bag of them, enough to do 2 fronts and 4 backs for about the same price as i was going to pay for the sticky lead weights.

Re: Balancing wheels on the bike
 

Explanation on their website doesn't help much :confused:

Re: Balancing wheels on the bike
 

i'll sum it up.. as your tyre rotates the beads collect inside your tyre at the point your normal weights would be at. but as your tyre wears this point changes so external weights would be inaccurate where the beads will move to where they are required to balance the tyre. this makes the beads a constant dynamic balance. one thing to note is that they don't work at low speeds e.g. below 25mph but if your tyres need balancing at these speeds then there is something wrong elsewhere.

Re: Balancing wheels on the bike
 

What's to make them collect at the light spot? I can't think of any physical reason.

Re: Balancing wheels on the bike
 

That's a car wheel though, dynamic balancing (2 plane or more) lets you balance any "rocking" imbalance which static balance doesn't show.

Re: Balancing wheels on the bike
 

i can't tell you any scientific explanation as i'm not a guru. but they do work. i have resisted telling people as i knew i would get 'its a load of bull' yada yada.

ok so its not the cheapest way of doing it as it works out to about £2 a wheel but the convenience outweighs. i suppose if i was a tight wad i could re-use them.

i found this on youtube which sorta explains the effect.

http://www.youtube.com/watch?v=eq263...eature=related

Re: Balancing wheels on the bike
 

That's what I said!

I know!

;)

Narrow bike wheels are not as likely to suffer from that type of imbalance, at least not to the extent it causes the rider a problem.

Re: Balancing wheels on the bike
 

I'm not going to hurt my brain trying to figure out the physics of it. But if you spun a shaft with two rotor blades on it, and there is enough friction between the blade and the shaft for them to start spinning too, but they are still free to rotate on the shaft.

Then and put an equal weight on one end of each rotor blade, and spun the shaft, would the blades not start to spin on the shaft in equilibrium with the two weights staying opposite each other? It's the least resistance way for them to spin.

Are these balancing weights not just doing the same? They are free to move so they naturally find the place in the wheel and come to rest where they need to move the least?