2016 RST F1rst Platinum Fork - Malfunctioning Lock-out Unit

[mtbvfr]

@SickBiker

Hello,

I hope all is well.

Technical support from RST in Taiwan has not been very helpful and I am hoping that maybe you can help me with a problem I have with my 2016 RST F1rst Platinum Fork which has been used for less than 500 kms and only on City roads.

After some delay I recently replaced the Rebound Assembly because the oil had leaked out of the bottom of Lower Leg. The bike had not been ridden whist in this state. I had previously installed the TRL (Tiny Remote Lever) for the Lock-out Unit and then the bike had been stored in a box. I discovered the leak, at some later time, when looking for something in the box.

After reinstalling the Lock-out Unit, I observed that I could compress the fork more than should be possible with the Lock-out Unit in the Fully Closed position even after following all recommendations and instructions from RST and from videos such as yours.

With the Lock-out Unit in the Fully Closed position, I have extracted it from the fork to check if the "Oil Flow Blocking Screw" at the bottom was fully retracted into the shaft. It appears to be and I could not turn it any more with a screwdriver neither.

For further analysis, I left the Lock-out Unit in the Fully Closed position to check if I could fully install it in this position which I could NOT. It can only be inserted about halfway. This would "seem" to indicate that the valve is blocking the flow of oil and that the O-ring, at the bottom of the Lock-out unit, is not damaged neither.

The unit does not appear to be physically damaged in any way that I can see but this is the first time I have ever serviced a telescopic suspension fork for a bicycle.

The response I received from RST was that they think the lockout unit has failed and needs to be replaced which is not cheap to do (about 38 € at Bike24). They have not indicated what are the possible causes of failure which would help me to determine if I actually do have a failure with the unit or if something else could be the cause of the problem.

Many thanks, MTB.