kosmo886

I just noticed that both my front and rear wheel...if spun when holding the bike or having it on a stand will sort of wobble/pulse in a front to back kind of motion. They don't move side to side or rub on anything...they just make the bike want to move back and forth if suspended in the air. I have no idea if they have always done this or not, but it doesn't seem like a great thing. When I compare to my gravel bike...if you spin the wheels on that, it's very smooth and doesn't cause the bike to want to move. Any thoughts?

PeteHski

Are you using tyre sealant? It pools at the bottom of the wheel and throws the wheel off balance when you spin it up on a stand. Out on the road it all evens out.

terrymorse 

Bike wheels aren't balanced, which you can feel if you hold the axle and spin the wheel.

But since wheels are very light, it doesn't matter. Just ride.

alxsmlv

It's either tyres/tubes haven't been fitted properly or the wheel itself needs to be trued

datlas 

This is a very controversial issue.

I honestly think it's ok to ride bike wheels that are not balanced. I have a Reynolds rear wheel that is clearly unbalanced and it's ok. But some cyclists think it's very important and will even put a counterweight on their wheel to get it balanced.

It's possible you may feel pulsations when riding at a resonant frequency (I do), but most likely you will not notice anything.

My advice? Ride more and worry less.

georges1

Tries to have the hubs or the hubs axles adjusted , if it is not those then it is probably the tires

tempocyclist

It's the valve. The wheel is ever so slightly heavier on one side which causes this "wobble" when spun freely off the ground.

You can fix this by "balancing" your wheel with a little bit of golfer's lead tape weight, but whether this is an "issue" when riding is debateable.


That's my take on this also.

Possibly if you're racing a TT and at the pointy end of the results board it matters. I've never bothered before, but I am going to try this on my deep section wheels which feel fairly "unbalanced" in this respect.

tempocyclist

Found the video regarding this:

MikeWMass

The question, however, is whether it makes any real difference on the road.
The amount of hop you get when sitting your weight plus the weight of the bike on the wheels is certainly less than when holding the wheel in your hands.
I have never noticed hop on wheels that were not out of round and had good tires, the fastest I have ridden was just over 51 mph.
I am also in equipoise about the claim to save energy.
I would be interested to see speed vs power with the same bike and wheels, balanced and unbalanced.

PeteHski

The clue is that he can hold the frame with one finger even when the wheels are out of balance. Increased energy claims are a load of BS. The only reason you need to balance car wheels is because of resonant frequency vibration - which is usually around motorway cruising speed and therefore a genuine problem. I've never experienced this kind of resonant vibration on a bicycle, so I don't worry about it.

I think because people can easily "feel" the out-of-balance when spinning wheels on a work stand, some believe it must be important. But those forces are tiny and insignificant unless they cause a resonant vibration, which would be obvious to the rider.

tomato coupe

It's the valve on carbon wheels, but usually the welded joint on aluminum wheels.