The Guzzi 750T front end - a couple of learning points……
I have been enjoying life in the ‘relaxed’ lane with my 750T. It’s been good fun round the lanes down here in West Somerset, and also when out exploring the moors with their blanket 40-mph limits. There have been a few issues - to be expected with any 32-year old bike, but generally things have been getting better.
In the past few weeks I have been working towards the upcoming MOT. I knew that I had to replace the fork stanchions, as there was at least one area of rust on each leg, within the area of travel of the fork seals, and so the fork seals were shot. Luckily there wasn’t much oil in the legs, but what remained was getting out.
So I stripped the front of the bike down, and fortunately Gutsibits were able to help with the replacement parts. Replacement fork stanchions are apparently approaching rocking horse poo status, so I was happy to get a pair, although they are not cheap! I may get the original stanchions replated and re-ground to act as spares in the future.
Learning point #1: do not trust the fork ‘dust covers’ to keep the rain out of the top of the fork slider. They don’t (or didn’t) fit the fork legs particularly well and water gathered under them after a ride in the rain. At some point one of the previous owners had stored the bike away wet, and a small puddle of water had eaten into the fork stanchion’s chrome finish, subsequently followed afterwards by damaging the fork seals. I have now fitted some black Ariete 07901 fork gaiters instead of the ‘dust covers’ to the forks, and they do seem to keep the rain and muck out.
Anyway, after fitting new fork legs, fork seals, gaiters, and the correct amount of ATF as fork lubricant, and checking that the dampers were still OK (they were…), I refitted the forks, wheel, mudguard, calipers and associated plumbing back onto the bike. A test ride showed that the front end was a bit more controlled and that the brakes (I’d cleaned out the calipers) were working fine.
A few days after my test ride, I started to check all the stuff that comes up during the MOT. All seemed to be in order, but there was a small click/knock from the front end of the bike as it was pushed back and forth with the front brake on (RH disk). I presumed that this would be the steering head bearings, as these had come up in a previous MOT test some years back - the DVSA ‘Check MOT History’ website is actually pretty handy….
So I adjusted the steering head bearings and took the bike for another test ride. Great, a further improvement in handling, but still there was that click/knock at the front - reduced in severity, but still there. Grrrr. I thought that it could only be the wheel bearings now.
Today I dropped the front wheel out again, and ordered some new wheel bearings - 6004-2RS. Once I removed the old bearings, I could see that one bearing was fine and smooth running, but the other was slightly rough and showing a few signs of water ingress. Good time to change them then.
Learning point #2: After wiping the accumulated gunge out of the bearing housings in the loose front wheel, I thought I’d just clean up the edges of the disks with a bit of Scotchbright. As I gripped the edge of the disk, it moved slightly in my hand, compared with the rest of the wheel. Really only a tiny amount of rotary movement (<1mm), along with a tiny sideways flutter. And then the light bulb came on - floating disks! D’oh!!! So, apart from the previous possibility of loose head bearings, there was also this very small amount of rotary movement in the disks, probably the origin of the knock at the front in the first place…….
The floating disks are there because the previous owner of the bike had got hold of an alternative front wheel for the bike with floating disks, from another later small block Guzzi as an improvement in braking. I have the original wheel too, but that needs a new tyre etc.
When the new bearings turn up, I’ll fit them, and this may also give a small improvement in handling, but they should at least last now. I also have an explanation if the MOT man mentions the slight knock at the front - the floating disks have all round clearances to allow for expansion or misalignment when they get hot.
Cheers, Bob
