Not so much today, but a few days' worth of fettling. Way back in the mists of time I built a bike for Cubester's 13th birthday and I got a Magura Thor 140AM fork for it. The fork has been used on and off for four years, but now he's riding my old canyon-framed bike which has a 150mm RS Revelation on it, so the Thor was shelved. I decided to sell the Thor and set about servicing it. A lower leg service is simple, you simply remove the lowers, clean them up, put new wiper seals and foam glide-ring in the leg and squirt in a few cc's of fork oil. Except when I tried to remove the the bottom leg adjuster to get at the hex slot I found it had corroded into place. A trip to a mate who is braver than I am and the adjuster (essentially a hex key with a retaining system of captive ballbearings in the inside of the lower damping leg) was removed. When I split the lowers the inside was bone dry, and there were signs of corrosion around the wiper seal seats. Those have been cleaned out with wet and dry, and I've got a set of Fox 32mm wiper seals and glide-rings in the spares box. They look the same, so I'll try them today. If not, Magura ones are £15.
Next, there was a weep of oil from the compression damper so I googled "Thor fork service" to discover that none of their tech docs tell you how to do it. I rang round to discover that Magura insist you take them to a specialist to service them. A quick check found only two places that will do that, and they charge £100 for a complete service. Not one to spend £100 unless I have to I set about dismantling the compression leg. The gold platform compression adjuster knob pulls out and exposes the tiny torx screws holding the lockout dial onto the top of the damper. those removed and the dial slides off. The top of the damper assembly has shallow 28mm spanner flats, and so I treated myself to a big adustable spanner ( a socket has a chamfer that won't reach the flats as I discovered that day) and that simply unscrews. The offending oil seal is an O ring on the threaded section of the assembly which was twisted and ungreased, so it was carefully picked out and inspected, regreased and replaced.
Curious to see how the damper worked I then made a couple of basic errors. It has a platform damper and blow-off system working on plungers and springs. It has an adjuster that is seated via some captive bearings to give a clicky effect, and a central tube that holds the plunger. I had a couple of "pingfukkit" moments with a wayward captive ballbearing and bolloxed the reassembly so it wouldn't go back together properly. Sweating now because of the potential £100 bill I spent about three hours desperately trying to reassemble it. I got it looking right a couple of times but it wouldn't seat back in the leg properly until I eventually realised I had got a small component in the wrong order on the upper assembly. During that sweating period I discovered that a new damper assembly was another £100 if I absolutely had to replace it, all the more incentive to get it right.
However, the might of logic and a calm period in the kitchen under some halogens eventually found me putting it all back together again and eventually ready to screw it back in. I had to ask around to discover that it probably takes about 60ml of 5 weight suspension fluid in the damper leg, so that has now been added and the damper replaced. Phew.
Only thing now is that I have a fork that I won't sell because I can't be 100% certain it'll work properly, so I'm going to put it on the Soul to test it out. If it works I may treat myself to a new frame to put it on........