I thought that my rim was bent but it actually looks ok. I took the tire off and checked it with a zip tie and looked okay but when spinning the wheel fast the whole bike wobbles. What could it be? Can it be fixed or I need a new rim?
Rims looks fine but when going fast the whole bike wobbles
byu/muccapazza inbikewrench
by muccapazza
20 Comments
How do the bearings feel? When the wheel is out of the bike make sure you put some inward pressure on the axle caps, a spinning axle cap can give you a false positive.
Assuming you run tubless, has the tape ever been compromised? Is there a chance you have some dried sealant inside the rim channel?
The rim joint might have a heavy sleeve
It’s fine
One part of the wheel and or tire is heavier. If it bothers you you can find the heavier part of the tire and install it at the opposite side of the heaviest part of the wheel or come up with some sort of counter weight like a reflector or something. Ultimately when you are riding I doubt you’ll feel it.
Wheel is likely out of round and more oval, hence the wobble, only needs to be a tiny bit to cause that or it has a heavy spot on it somewhere likely where the two ends are welded together.
Thats called being out of balance, center of mass is not exactly on the axis of rotation of the wheel. Think of it as a rock tied to a string and you are swinging it on a circle, no matter how round the circle, it is not balanced thus causes wobble due to its mass.
Its fine, you have a mtb anyway, that shouldn’t be a problem :]
Forgot to add: it can bi fixed by adding a small counterweigts on the rim until you align the CoM with the AoR, you will have to repeat that every time you change an inner tube or your tyre
I had something like this and found changing the tire worked. I worried it was the rim, but something about the old tire was off balance enough to give me a steady bump.
So this is the same as the reason cars have little weights on their wheels. The material the makes up the wheel is not perfectly even and one side is slightly different weight than the opposite. I’ve never heard of someone putting a small weight like in a car, and special machines tell mechanics where and how much weight to add.
Frankly I would t worry about because you likely are going absurdly fast before you could even get significant vibration feel while riding.
Bike wheels/tires don’t really need to be balanced the way that car tires do. They just don’t spin fast enough for the force the effect the system when you are on the bike. As long as the wheel is not out of round, you don’t feel a thunk or something while riding, send it.
This is by design.
Opposite the valve stem, some rim manufacturers put a heavier spot on the rim (sometimes just a couple of heavy stickers) to compensate for the mass of the valve stem and cap.
With a tire and tube installed and inflated it should be better.
Couldn’t tell since you were spinning it to the moon – is a valve stem installed or not?
Is the valve stem in the rim? Unbalanced no matter what. Its not a car so it does not really matter
Check your hub that reminds me of the folks who go “it wobbles, tire need balanced” when it is bearings that are gone
Wheel is out of balance. Spoke mounted reflectors are terrible for this reason. Check the wheel for radial true. Remove any spoke mounted reflectors, replace with hi vis reflective tape on the rim, and use it to help balance the wheel. Usually, the rim has a heavy spot opposite the valve where the sleeve or pins in the joint are in non- welded rims.
Check the radial runout.
Wheel is out of balance. GCN have done a video on this:
https://youtube.com/shorts/XMfoaZ-NFLI
I would want to do the balancing with a tube and tyre installed as the imbalance on a bare rim could be intended to approximate the imbalance caused from the valve stem, which is the largest contributor.
Ehmm… because you tail is spring suppressed MAYBE
You need to balance the wheel, to stop wobbling. For example add some weights on the opposite side of the heavy side.
GUYS! I think that the MAIN issue was actually the tire! I swapped it with the front one and now I have noticed the wobbling in the front and the back is more stable !
My 80 dollar huffy bikes do the same… any bike with or without tire will do the same upside down