I bought a set of the Gold Valves for the 1300 fork, which included the compression and rebound valves. No real issues installing them, the left leg went together easily and felt good on a bounce test, but the right leg had zero rebound damping!
So I disassembled the right leg and cartridge and expected that maybe I had made some stupid error and installed some part backwards, but nope, correct orientation, check valve operating as it should and shim stack all tight against the valve body. Just for S&G I reassembled the parts (double checking as I went) filled the fork and no change, still no rebound.
So it all came apart again and this time I took a close look at the machined valve body in case it had some obvious defect. It wasn't too hard to spot if you know the way the oil is meant to flow. Easily one way, bypassing the shim stack and pushing the check valve open, and hard in the other direction, when the check valve is closed and the oil is forced against and through the shim stack. I think there was a machining error on one side as there are three ports that are neither sealed on one side by the check valve nor the shim stack, so oil is freely passing when in rebound mode. One face of the valve body looks to be clocked 60 degrees out of alignment with the other side.
This is the rebound side where the shim stack sits. The shims seal across three ports, and the other six stay open..
This is the check valve side, and it seals across the three pairs of ports.
The pen mark shows one of the three ports which is unsealed on both sides. It should be open on the check valve side, but sealed by the shim stack on the other.
I have contacted Racetech today asking for a solution, and will update with their reply. In the meantime my ST now has a mongrel valve set-up with two RT compression valves, one RT rebound valve and one stock valve (but with the RT shim stack). Not sure whether that will be any good but that is what test rides are for.
So I disassembled the right leg and cartridge and expected that maybe I had made some stupid error and installed some part backwards, but nope, correct orientation, check valve operating as it should and shim stack all tight against the valve body. Just for S&G I reassembled the parts (double checking as I went) filled the fork and no change, still no rebound.
So it all came apart again and this time I took a close look at the machined valve body in case it had some obvious defect. It wasn't too hard to spot if you know the way the oil is meant to flow. Easily one way, bypassing the shim stack and pushing the check valve open, and hard in the other direction, when the check valve is closed and the oil is forced against and through the shim stack. I think there was a machining error on one side as there are three ports that are neither sealed on one side by the check valve nor the shim stack, so oil is freely passing when in rebound mode. One face of the valve body looks to be clocked 60 degrees out of alignment with the other side.
This is the rebound side where the shim stack sits. The shims seal across three ports, and the other six stay open..
This is the check valve side, and it seals across the three pairs of ports.
The pen mark shows one of the three ports which is unsealed on both sides. It should be open on the check valve side, but sealed by the shim stack on the other.
I have contacted Racetech today asking for a solution, and will update with their reply. In the meantime my ST now has a mongrel valve set-up with two RT compression valves, one RT rebound valve and one stock valve (but with the RT shim stack). Not sure whether that will be any good but that is what test rides are for.