Recommendations for performance shock

[grunbay]

I am building a 2000 Derbi GPR 80 (EBE075 motor) into a road racer. I need a rear shock absorber. The 2000 GPR 80 has a 10mm bolt fixing at the top, but a 12mm bolt fixing at the bottom which leaves me a little bit stranded in that I can't find a performance-oriented shock with the requisite 12mm bottom. I suppose I can Press in a different grommet at the bottom, but that is somewhat problematic.

Where do you recommend I look to find a performance shock that will fit the early GPR?

[toratora]

There's currently not a lot available. The Risse Racing is probably the best thing you can order at the moment. The biggest issue isn't the mounting holes, rather the distances from the mounting points to the shock towers. The Derbi requires a rather long neck on both ends of the shock. Thus most shocks available wouldn't work even if you were able to adapt the mounting bolts.

[Rj_666]

I used a 'custom' shock from http://www.dnmshock.com/products-single ... M shocks.
I've also been looking at Racing Bros

I've been SUPER happy with my DNM unit

[Dangerous Dave]

I had one custom built for my 2000 GPR by worxshocks.com. The first iteration wouldn't bolt up (due to the long neck previously mentioned here), but they were able to correct that. They also give a 30-day ride comfort guarantee, so you can send it back in the first month for revalve and/or respring as necessary. I've been very happy with it.