What should I do if my back bike wheel wobbles?

As we shall see, there are in fact two phenomena that can generate constant jerks when you ride your bike. The first is what is commonly known as a wobble.

Wobble manifests itself as left-right shakes. If you feel that your back bike wheel wobbles (or even your front wheel), there's usually a problem with the wheel.

In this video, you can see exactly what it looks like:

The second type of phenomenon is a wheel hop sensation. In this case, you feel more of a vertical bump, as if the wheel were rising and falling with each rotation.

This event, which is rarer than the back bike wheel wobble, is just as unpleasant and is enough to spoil your enjoyment of the ride.

Whether it's a back bike wheel wobble or a hop, in the vast majority of cases the problem is caused by the wheel. In a very few cases, it may be the tire. The first step is therefore to establish whether the problem comes from one or the other.

To find out, check these points in the order given to eliminate the causes one by one:

1. Check If the Tire Is Properly Mounted

Some flaws such as those described above may simply be the result of incorrect mounting of the tire on the wheel seat. This can happen in particular with a tubeless-ready tire (sometimes also with a tubetype, but it depends on the wheel).

If the tire is not fully clipped in, the tire will not be evenly positioned around the wheel, resulting in a bike wheel wobble.

When fitting the tire, you need to have heard the snap sound when the tire clicks into place. If this has not happened, there is a good chance that the mounting has not been completed correctly.

To solve this problem, it's very simple: add pressure and the tire will settle itself. ATTENTION: It is mandatory not to exceed the maximum pressure recommended by the tire and rim manufacturers as it could lead to rapid air loss. Both are marked on the tires and rims.

We will explain below the reasons for this type of deformation in the various scenarios.

In the case of a back bike wheel wobble: 

There are two possible reasons why the wheel became deformed:

1 - Uneven left/right spoke tension

As a reminder, a back bike wheel wobble manifests itself as a left/right lateral movement. The spokes and their tension can be the cause if they are tighter on one side of the wheel than the other.

2 - The wheel may have taken an impact

If the wheel has taken a shock, it may have undergone a deformation that the spokes cannot compensate for.

In the case of a wheel hop: 

There are also two possible reasons for wheel deformation manifested by a vertical hop on each rotation: 

1 - Uneven top/bottom spoke tension  

When you look at the wheel in profile from one side, you see spokes that go all the way around the circumference. If the spokes running from the centre to one end are tighter than those running in the opposite direction, this creates what is known as a "false round", which causes the rim to hop on each rotation. This may be due to a welding defect. 

2 - The wheel may have taken an impact 

If you hit a stone or a root too hard while riding, this can create a flat spot on the rim. As it is no longer round, this generates a rim hop each time the wheel rotates. 

If the problem is spoke tension:

A professional or skilled cyclist can adjust the spoke tension to fix the issue.

If the rim is bent from impact:

There is no repair solution. The wheel must be replaced.

Pro tip: If you frequently ride on rough terrain, consider using wheels with stronger rims and reinforced spokes to minimize future damage