GPR Camp: Replica Racers

I’m setting up a GPR 50 and would like to know if some of you forum members have any solutions to changing the Derbi from conventional to reverse (GP) shift pattern. I race several bikes, all of which are GP shift pattern and I would love to set up my GPR with GP shift to avoid confusion.

Has anyone devised an elegant solution to this?

Roll Out the Barrel
There are multiple ways to achieve this with the GPR. A novel approach is to employ the shifter barrel from a Senda engine. Since the shift lever on the Senda is placed like a conventional dirt bike shifter it uses a stander shifter barrel.

The GPR however due to its rear sets, has a revers barrel to provide for setting the shifter pedal to behind the engine. The problem with this approach is that you have to remove the engine, split the cases, and then replace the barrel.

Rear Sets and Linkage
Another option is to employ a linkage solution—similar to what many other bikes employ. If you have an older GPR (1998-2004) it shares the same rear sets as a Cagiva Mito. I Mito shift lever would work on the GPR, but the hole to attach the shifter isn't tapped, but that's easy enough to achieve. If you have a newer GPR (2005-2009) you can replace the pegs in the rear sets to accommodate one that has a shifter lever. If you have the latest GPR (2010-2014) you can get replacement rear sets that feature a linkage.

I love the Senda shifter barrel approach. I'm gonna try that.

Thanks so much!