beeballman

So kind of a silly question. i have a Garmin Speed sensor installed on my rear HUB. This causes the wheel to be kind of out of balance as it rotates, meaning the sensor does not go all the way around the HUB, it is banded to one side of the HUB so when the wheel spins it is heavier on that side of the HUB. Is there a way to balance that out, or is that just the way it is with a speed sensor installed on the rear HUB?

Psimet2001 

It depends on which speed sensor you're meaning but if it is one of the ones designed to go around the hub then it will always be like that. What's more the small weight of them and the fact that hub bodies aren't large means that any real imbalance you see is not from the speed sensor and is most likely from the tube valve or the rim joint. Unless that imbalance is huge you're never going to notice or feel it on the road.

eduskator

Do you actually feel something or are you just saying this because the weight of the sensor is not spreaded equally around the hub? You shouldn't feel anything unless you ride really fast or unless it's really heavy. If you do, it's most likely something else.

genejockey 

Find the heaviest point of the wheel - you can take it off and hold it so it can rotate freely until it stops. Now put the sensor on the other side of the hub from that point, and try again and see if it makes any difference at all. I got a dollar says no.

sw20

I have a speed sensor on my rear hub and can honestly say I haven't noticed any imbalance whatsoever.

Chuck M 

If you are actually feeling something, you need to check it out, but I think the chance of it being your speed sensor are going to be slim to none. If you are just worried this may be a potential problem, in the 80s we put Cat-Eye reflectors on our wheels that were big enough to be seen from low flying aircraft at night and there weren't any problems.

sdmc530

same here for years. I think if your feeling something you have a bigger wheel issue than the sensor.

Iride01 

I have the speed sensor that uses a wheel magnet on the spokes. I've always put it on the side of the wheel directly opposite of the valve stem just because that seems appropriate.

However the wheel doesn't really spin fast enough while riding for wheel balance to be any concern IMO. Especially for it's tiny weight.

Though in a bike stand or with the wheel off the ground, you could spin the tires much faster than you'd ever could in actual riding. So then you might see the effects of an out of balance wheel.

bbbean 

Add me to the list of people who have used a Garmin speed sensor for years without noticing any balance effect whatsoever. I also use the sensor when I'm training on the rollers with tires pumped up to maximum pressure, which should be a recipe for magnifying any balance issues, but they spin like a top.

If I was looking for something to produce a balance effect, I'd be looking closer to the rim where speed, wheel flex, and leverage could produce an effect. It's hard to imagine much of an effect from changes to weight at the hub. Consider how asymmetric a rear hub already is.