Bicycle Mechanics - Do wheels have to be perfectly weighted around the diameter?

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phillycommuter
10-27-10, 10:24 PM
Apologies in advance if this is a silly question.
I'm just starting out doing DIY adjustments and I'm in the middle of replacing and tuning my brakes (just regular v-brakes). Anyhow, in the process, I was checking the wheels with my bike upside down and noticed that the front wheel tends to develop some momentum on its own after I stop it. I tried to find where the weight was coming from by balancing right where the wheel does not roll forward or backward on its own) and revealed the balance point was close to the center (drawing an imaginary line down) of the reflector on the spokes. This seems logical since this is added weight on the wheel.

On the rear wheel, the heaviest point seems to be the area of the valve stem , which is opposite the rear reflector. I don't know if this affects anything at all but I'm wondering if its important to have "balanced wheels" i.e. evenly distributed weight throughout the wheel or if this is insignificant considering the amount of weight added by the rider. Thanks for any input.

FBinNY
10-27-10, 10:29 PM
A rule of reason applies here. The impact of imbalance depends on the amount of imbalance and the rotating speed of the wheel. Given the working speeds of bicycle wheels, I doubt you'll ever notice a functional consequence of the amount of imbalance introduced by the reflectors, and wouldn't worry about it.
clarknick67
10-27-10, 11:58 PM
Yup, it is not necessary to worry about it much.

operator
10-27-10, 11:59 PM
You'll worry about it when you start descending at 70-100kph constantly. Balanced wheels are necessary.

Ask fulcrum why they have 2 round spokes out of the rest bladed.
phillycommuter
10-28-10, 12:03 AM
You'll worry about it when you start descending at 70-100kph constantly. Balanced wheels are necessary.

Ask fulcrum why they have 2 round spokes out of the rest bladed.

interesting, i guess the effect would likely be multiplied in force once your wheels are spinning fast enough.
Still, just a small curiosity and I thank everyone for answering.
Sixty Fiver
10-28-10, 12:17 AM
Spoke mounted reflectors are a bad idea... anyone who has serviced higher mileage wheels can tell you that this is where spoke tensions will be negatively affected.

Better to use something like 3M reflective tape as it does not affect your wheels and provides a much better reflective surface than wheel mounted units.
kingsting
10-28-10, 05:22 AM
You'll worry about it when you start descending at 70-100kph constantly. Balanced wheels are necessary.



I have a feeling that if the OP has spoke mounted reflectors, they have no plans on ever attaining those kind of speeds... :rolleyes:
badamsjr
10-28-10, 06:01 AM
Spoke mounted reflectors are a bad idea... anyone who has serviced higher mileage wheels can tell you that this is where spoke tensions will be negatively affected.

Better to use something like 3M reflective tape as it does not affect your wheels and provides a much better reflective surface than wheel mounted units.

+1 You could also consider reflective sidewall tires.:thumb: