Exploding balls

The other day while cycling home from work. I heard and felt the loud noise of what seemed to be a screwdriver being put to a bench grinder coming from my rear hub. After a big ‘WTF???’ I jumped off my bicycle and had a quick look-see and couldn’t find anything wrong. I then continued along and had some weird knocks and clicks coming from the rear wheel but only when freewheeling. After few miles I decided to stop and walk home via our LBS.

We then had a quick chat and figured out that somehow the rear cassette was loose. The single and thin bolt which holds it all together had come loose, and the sprockets where just moving about causing the noise. I then took it home and, yup, the whole cassette came off in many pieces, not as one big lump. So, after a good clean, I put it back together and made sure that the lock ring was nice and secure.

The test ride to see if everything was a ok, didn’t last long since the clicking and knocking had become worse. I then took my back wheel off again and had a play with the rear axle which I forgot to do when I cleaned the bicycle. It wouldn’t spin at all and I really had to grip it to get it to do so and it felt like there was gravel inside the bearings.

With the help of my LBS we took out the bearings, which are standard 6001 RS bearings. But the innermost of the four bearings in the HOPE XC (06-04-xc) hub had died. We took the rubber
seal off and found one of the bearings in bits.

So the question is now how come the bearings died only after 2500 miles ?

I have put in around 2100 miles and the previous owner around 2000-2500 miles. And I’m pretty sure that the previous owner had never taken the hub apart and wouldn’t be nasty to the hub either. Yes, I’m a big bloke and load the bicycle heavily but that is nothing compared to what the HOPE XC hub is built for.

Was the bearing a faulty one, the HOPE hub built wrong or had the whole thing been assembled wrongly?

I just got four new bearings from Ball Bearing Centre Ltd, 55-57, Park Royal Rd, Park Royal, London, NW10 7LP. So I do hope that they would last longer than the ones that have died. I will put the bearings in tomorrow and will keep you posted on how it goes.

If you are interested on ball bearing caring you wouldn’t go wrong with reading this Keep on rolling. Or how to keep your bearings (part 1) and Keep on rolling. Or how to keep your bearings (part 2). Part 2 is about cartridge bearings and both articles are written by Phil Osman. Too bad these links have now died and I can’t find these great posts elsewhere.

Note to one self : Do not use this route on your commute any more, first you drop your new front light and now this. And I have only been down this bit of road two times.