KTM Superduke 990R - New Tyres and Sprocket Carrier Bearings

Four years too late...

The old Superduke of Bridgey's has been somewhat neglected lately. And when I say lately, just the last four years or so. It's still pretty clean, don't get me wrong, but legend has it Boudicea was using the same tyres on her chariots. 

Now I wouldn't have bothered putting up this post for a pair of new Pirelli Rosso II's but, what was concerning, was the state of the sprocket carrier bearings. Well, one in particular.

The Superduke has some great engineering plusses, one of which is the two bearings fitted to the sprocket carrier. Four bearings in all to let the wheel spin in the manner to which it's become accustomed. Imagine the rigidity, the ability to keep that wheel inline no matter what angles it's trying to put down the power.

As much as I like to take the piss, it's a bloody good idea.

But during a routine tyre change, it became obvious that all was not well in the bearing department, and the sprocket carrier was extremely notchy. The two spacers that go in from both sides were rusty and I wondered if the water had been held in there and got past the seals.

The two spacers on the piece of wood need to be knocked out first. Then the bearings can be hit out, one from each side taking note of the small spacer in between.

A closer look at the bearings with seals removed showed the carnage. The cage had broken up and it came to a premature end. The cause? Possibly overtightened chain at some stage.

After a good clean-up, two new bearings were fitted and everything was good again. A good reminder to always turn the bearings by hand whenever you take the wheels out, any notchiness and it's time for replacement. 

If you're very careful when removing the seals with a pick, you may be able to clean them out and regrease them, as long as they are smooth and quiet, but for the cost of new bearings, it is advisable to replace them when in doubt.

Anyway, it's certainly nice to see the old girl back out and fighting fit.