Friday, 24 July 2015

FZR600 Head stock bearings changed

So the handling of the FZR is somewhat strange to say the least, a new tyre on the rear helped and now it has had all the wheel bearings changed (the guy that sold the bike included them in the package!), so I thought the last thing that would affect the fairly iffy front end would be the headstock bearings.

Got a set off Ebay - pyramid bearings that were cheap, and came with the bearing covers included, I couldn't better the price so went with them!

I stuck the races in the freezer, and the bearings on the window sill (it's currently about 36 degrees c over here), and went to strip the bike. Everything came off relatively easily, although I had to use a hydraulic jack under the exhaust system to hold the bike up, which was a bit dodgy, and as it is parked next to the Ducati, I didn't want it falling over and damaging anything. Anyway I shored it up with bits of wood to avoid disaster.

It took me the best part of the evening to get the lower bearing off the stem, very sweaty work, basically smashing away with a chisel and anything I could get my hands on, but it eventually gave way, the top race in the frame also came out pretty easily after tapping it out with a long drift stuck up from the bottom.

The lower race in the frame was a different matter! They give you 2 cutouts in the frame to allow you to see less than 1mm of race with a drift. Well nothing could get it to move, and despite inventing some ingenious tools with the grinder and pliers, nothing seemed to work for more than one good hit with the sledge hammer, they all just slipped. I saw some guys on youtube that used a dismantled bearing puller from the bottom to get a grip on the insed of the bearing, but that didn't work for me either.

So, after a couple of evenings abortive attempts, I got serious, and started using the dremel and a cutting wheel. I cut a couple of diagonale lines into the bearing and tried chiselling out the bits in the middle. Anyway this technique eventually worked (as it must), and the bearing came out, and it was pretty marked as well, so I think this was a good change.

Getting the new races into the frame went relatively easily with a long threaded bolt, and loads of old bearings and races to space things out and then do the bolt up, this pulls the race into place, despite some misalignment (fixed with a hammer!). The hardest part was fitting the bearing on the stem.

I had left the stem in the freezer for a couple of days, and the bearing in the sun, but it still only engaged a couple of mms onto the thicker part of the stem! I had found a furniture leg from the local DIY shop, which made a perfect drift over the stem, and with this and an old race I managed to get to within 2mms of the seat, before the "leg" started to buckle, in fact the old race I was using as a drift was actually butting up to the thickening stem, and I couldn't hit it any further, after I sussed this out I added a slightly larger diameter drift, and then we got to get it the last couple of mms, phew.... all done, just need to get it back together.

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