Q. My bike has a funny click! Every so often there is a sort of click when I am pedalling. After a few minutes it stops and may come back after half an hour or more. Is it serious?
A. A funny click? Well, I suppose we’ve all had that and it is always difficult to track down without more details.
However I’ve had something similar and it could be wear on your ‘bottom bracket’.
First, what is a bottom bracket? It’s the thing that goes between your pedal cranks and allows them to turn round and get the power from your legs to the chain and turn the back wheel.
This diagram shows all the bits. You don’t need to understand it in detail but it’s enough to say that after a few years bits start to wear out.
The little ball bearings wear a little bit , become smaller, and don’t quite fill all the space allowed for them and instead staying exactly the right space apart, they can be free to catch up with the one in front and leave a tiny gap behind the and the spindle, or axle drops into the gap. It’s only a tiny amount and at first it only happens when you are pressing hard on the pedals like when you’re going uphill. As the wear gets worse over time it starts to happen when you are riding normally, and on the flat.
So, why does it go away after a few minutes? Simply the balls catch up and shuffle themselves back into the right order.
But, as it’s wear it won’t get better, and may get worse, turning from a slight click, into a knocking sound, and may soon cause the bike to break down.
It’s a fairly easy thing for a bike shop to fix. Older bikes have loose ball bearings that have to be packed in grease and screwed together. The right sized balls will be correctly spaced if the right number are used. Too many balls or too few and the spacing won’t be right, so manufacturers developed sealed bearings that are ready assembled in a factory to precise dimensions.
These are sold as fixed units but different bikes need different sized units, so unless you know exactly which size you need it is better to leave it to the shop to fit.
Having said that it’s a fairly simple job so shouldn’t be very expensive to get done.
I hope that I have diagnosed the right ‘click’ for you.