Forking About

 February 2024

Time to take the front end down and replace the split gaiter.  Not surprised it failed as they were something of a stretch fit.

Some problems getting the stanchions free of the yokes.  Assumed it was down to the interface with the alloy yolks, plenty of advice from the good folks in the Tonti FB group.

Turns out that taking the centre nut off the steering column and lifting the top yoke freed it all up.  When this is tightened down it actually compresses the rubber grommets on two fork shrouds which carry the headlamp.  Creating a vice like grip on the stanchions. Once it was lifted a few millimetres the stanchions pulled out freely.  

Earlier on releasing the pinch bolt on the RH slider it sprung outwards about 4mm, implying something up with alignment.  The bike has suffered excessive stiction  in the front suspension forever and I've never cured it.

So took some time to check alignment.  Removing the dampers and draining the oil freed up the sliders allowing a check on fork seperation across full travel.  160mm all the way as per specification, no sign of any deformation in either stanchion.

Reassembled with new gaiters, once again had to undo steering head cap nut (the one with the eagle logo) - has to be slackened to decompress the rubber inserts and allow the stanchions to push through.

Checked steering head bearing play before tightening up.  None felt.

Releasing the pinch bolt  springs the fork away from the spacer.

Reassemby detail;

Reassembled the forks with new ATF and gaiters and put in the yokes. Positioned the front wheel minus calipers and mudguard, lowered the jack down to line up the spindle and pushed it easily through by hand and loaded the RH spacer in the gap. Gentle tapping with a rubber mallet seated the LH end of the spindle against the bearing. At this point the spacer looked right, just able to rotate it by hand. So then I tightened up the LH pinch and did the fork pumping thing (took out sump jack and off the centre stand obvs) and pulled it back on the c/stand. The spacer rotated by hand with a very very slight bit of lateral play. A gentle tap on the LH spindle end resulted in zero play but still free to rotate. Tightened spindle nut up - this locked in the spacer and no rotation possible. So tightened up pinch bolts bottom up. Measured disk to slider gap, same both sides about 3mm. So now just need finally tighten spindle nut, fit calipers mudguard headlamp and instruments and ride it! I think the stiction is what it is, and maybe because of the double seals in the sliders. Quite why the RH fork seemed to spring away when I undid it I don't know. It all seems in spec to me!