Having just got back from Nicolai and with my friend having had all the bearings in his rear and some axles replaced, I had extensive discussions with the service/maintenance encyclopaedia known as Volker. It was enlightening and showed that I had not been maintaining my bike properly!
Firstly the caps are not preload. As previously mentioned the tolerances are very tight. Sometimes too tight. The caps are intended to keep the stays from developing any side to side play and causing wear, I guess that is a kind of preload but not in the normal bearing sense.
Most people when they maintain them (which should only be remove and clean and lightly grease, perhaps replace the synthetic washers if they show signs of wear) do up the caps too loose. They should be tight. When the shock is out and the linkage at the top of its travel it should take 6kg or more (6kg is ideal) of force to move it. This does not affect sensitivity, there is much more going through it when you just sit on it and exerted by the shock.
Due to the tolerances, if you do the back end too tight, it won’t be a problem, the worst that will happen is it will slowly wear to the right torque. If you do it too loose, it will knacker the bushings/axles. Simple as that. Too tight is fine, just a little too loose is not. If you can rotate the caps after locking them with the grub screw on Helius models, it may well be too loose.
If the light rider, riding lots, at any point set them up too loose, or even just on the loose side of just right he would get rapid wear. It is surprising how tight they should be.
I don’t think this is widely communicated and certainly was the case with my friend and why he needed so much changing.
Also some of the older bushings were hydroscptic and actually got bigger with age and caused increased wear. This is now not the case with any new bushing.
Just a regular check of tightness of the caps/system is good practice to ensure long life along with removal/clean of the axles/bearings after extensive use in crappy conditions. It’s not a long job.
The new Ion bearings have some additional sealing in them too which might be cause for consideration if you ride in bad conditions alot AND.are concerned by possible bearing life issues. (Which as mentioned with proper, sensible care you should not be).
I hope that helps.
And Rik, if my Ion 29 comes in at 29.5lbs with big wheels, big tyres, big forks and a big rear shock (I know I could lose 1.5lbs no sweat with very few changes) with bullet proof parts, a high end light side of the mark build should come in at 28lbs or less no problem. With pedals, especially if you use tyres at the lighter end of the spectrum like some of the new enduro Hutchinsons.
Posted 10 years ago
