XR500 HPF mono rear suspension
Checking the swingarm with a magnifying glass, I found no less than 11 micro-fractures. These were beautifully weld-fixed by a specialist shop. The main pivot bushes were of course replaced.
When I got the bike, it looked quite tired at the back. It turned out that the custom made suspension mechanism was tired: all the bearings and pins were shot, and the funky suspension lever was stretched.
I decided to toss the needle bearings that I found in there and replace them with solid steel bush bearings. What is needed for these pivots is strength and endurance, not rotation speed.
New custom made lever arm and bearings and pins all around. But I chose solid steel instead of roller bearimngs, more durable.
The Fox TwinClicker was due for a service.
I got all the service parts for the Fox TwinClicker from Thor Lawson of course, and sent the little clicker wheels to be reanodized.
Servicing the shock was a pleasurable experience, but... back on the track, the rear of the bike was as stiff as a log, pretty much impossible to ride.
That spring is just humongous.
In a couple of hours at his shop, Phil Douglas put the shock on his dyno, connected to his computer, established that there was too much of this and not enough of that, replaced the spring with a lower rated one (8.5 kg/m vs. 10.4 kg/m), removed some of the valve shims inside, educated me thoroughly on the inner working of a shock absorber, et .... voilĂ , tuned for middle range on 14 out rebound and 4 compression.