To surface the rebound valve do it yourself with a piece of glass plate or granite and 400 grit wet dry sandpaper. Scribe a figure 8 pattern on the wet dry on the surface plate. I used 200 to get the notch out of the rebound side as it cuts faster then worked my way to 600 to get a smooth finish. Also I see GP has upgraded the rebound setup by supplying a bellville washer to replace the spring and cup washer, I like that setup better will need to update the race bike. The check plate is crucial to the rebound operation as there is no rebound valve control until the check plate closes.OldTLSDoug said:Thanks Doug. I made a holder and it works good, I have the rebound pistons out and also he recommended drillling the cup for the bottoming piston to regain the travel and still have bottom out protection if you are going to wheelie. I will take pictures of all this.
I have 3 sets of cartridges to practice with and I have the rebound pistons out. I had to smooth the shaft to get the piston off, the edge just below the threads was sharp and held it up. I use the torch and it works great. I have to surface the rebound pistons so the new valving will work right. I just need to figure out where to get it done.
More to come, I am on nights so progress is slow.:banghead