‘The owner couldn’t believe how much better the bike handled’
Top mechanic Paul Knight found a host of horrors when a BMW R90S was brought in
Paul Knight set up shop on his own two years ago, but has been working on motorcycles for nearly 40 years; when this spotless BMW R90S would have been in its prime. When this classic came into his A55 Motorcycles workshop in Penmaenmawr, near Conwy, the owner had reported a puddle of ‘brake fluid’ after storing it over the winter. So he didn’t expect to find a leaking fork seal, especially when the owner told him another dealer ‘only did them about 1800 miles ago’. Paul said: “The previous dealer had ignored the pits in the chrome on both fork legs, maybe because they were hidden below the fork seal dust caps. So both legs needed repairing.”
The forks are disassembled in a fairly conventional fashion, however when the damper rod was withdrawn a load of debris fell out of the bottom of the leg.
Paul added: “A call to my friendly BMW specialist revealed this is a common problem with forks that haven’t been fully stripped for ages.
The urethane shock absorber degrades and breaks apart.
“I was beginning to suspect that the other dealer didn’t bother to strip and clean the suspension unit, but just changed the seals with the least possible effort. The specialist also suggested I take a look at the larger bump stops in the lower fork leg. The bump stop holder was absolutely filthy, full of degraded bits of the other damper and general slime.” Paul fitted reconditioned tubes from Philpots in Luton. He explained: “The hard chrome on the re-con units are better than the OEM tubes.” The whole job cost £480, and that included cleaning up the pads which had already been contaminated by the fork oil as dribbled down the leg and into the brake caliper. The bike then passed an MoT and the owner couldn’t believe how much better the bike handled.
‘The seals had been changed with little effort’