The ZRX1100 is really showing its age as a classic bike now… time has flown by. Front maintenance with fork OH and stem lubrication requested. Starting with stem lubrication. Previously we’ve done stem OH & and fork oil changes. Newtech NC100 grease really holds up well – I find myself thinking about that The lower side is in good shape too. The bearings still have plenty of grease on them, which is great. Wiped off the grease. The upper side is fine. The lower side has a bit of wear marks. This is where judgment comes in. If it rubs off with Scotch tape or similar, it’s just surface shine and not a problem. Apply Newtech NC100 grease generously to both upper and lower bearings and reassemble. The ZRX has a really effective upper seal, so assembly requires careful attention. Disassembling the fork. Right-side-up forks are really nice – so much easier! The fork oil is fairly dirty. The fork oil has been changed before, but it’s never had an OH in 60,000 kilometers. That’s amazing – it doesn’t leak! I was genuinely impressed. The stroke area develops vertical lines and shine. I think it’s always worth smoothing this out. When the seal passes over this shiny part, it makes a “pep-pep-pep-pep” sound? Sorry for the unclear description. Not a smooth “swoosh” but more “pep-pep-pep-pep”…
It’s like the friction is poor and it catches. I hope you can picture that. Areas that don’t stroke aren’t mirror-polished but have a slight dimple texture, like this. From experience, if you smooth it out, the fork is less likely to leak oil. Check the inner tube for runout and bending. No issues found. The fork seal passes through and we reassemble with SKF Green. This is the original width. This is the SKF, with a difference of 0.55 mm, so we don’t use the included plastic backup ring. ★This is just my opinion, but I don’t apply grease to the oil seal groove. Dirt tends to get inside surprisingly often.
If you seal grease into the oil seal groove, ● dirt may accumulate inside but won’t come back out. ● Some greases harden or become crumbly over time. For these reasons, I assemble with fork oil pooled in the seal area. (Not absolute – just for reference.) After stroking, we vacuum bleed and adjust the oil level to finish.
