I swapped an R1 shock I had revalved by GP Suspension for more rebound into my 2019 MT-10.
I was maxed out on rebound adjustment on my stock shock and was looking to respring due to having 0 free sag after putting in preload to get 35mm of rider sag. Whenever I would get on the brakes coming into a corner, it felt like I was being pitched forward and out of the seat. The leading edge of the tread was worn significantly lower than the rear trailing edge.
I bought a 18 R1 shock. It has length adjustment whereas the MT-10 damper does not. I checked the parts diagrams and saw that the majority of components are the same as the MT-10. I sent the shock in to GP suspension to have it rebuilt, revalved, and resprung for my weight of 235lbs (no gear). I let them know my primary usage is commuting, canyons, and hoping to add track days in the future. I told them the rear gets bouncy in the canyons and I believe that it doesn’t have enough rebound. They put a 500 lb/in (8.9kg/mm) spring in, machined two delrin collars (I believe it’s to accommodate the 2.25” ID spring, revalved, oil, nitrogen, and new reservoir cap.
The shock install was fairly simple. The hardest part was drifting out the relay arm to frame bushing. If I remember correctly, you have to drive it out from the right side of the bike to the left. Double check though, my memory can be poor.
I also threw in 1.0 kg/mm fork springs from Stoltec in. I did this with the forks on the bike. Take out all the preload, loosen the fork caps (36mm socket), put on a headlift stand, move the handlebar out of the way, set up a strap to compress the front end. I had to remove the fender and deflate the tire to compress the fork enough to get the spring compressor on the spring spacer (has holes in it) and to move the spring compressor low enough to put the holding tool in. Most annoying part was pulling up on the fork cap, down on the spring compressor, and sliding in the holding tool to loosen the damper rod nut to take the cap off. I only have two hands, an extra set of hands would have been handy. When putting the cap on, I ran down the damper rod nut all the way (gently or else it’ll get stuck on the damper rod shaft), threaded on the cap until it bottomed out, then ran the nut up.
Anyway, went out to the canyons, had a buddy help me refine the sag to 32/33mm front and rear, and dial in rebound (hot). The front and rear feel great. It looks like I might need more spring front and rear. The front is about 10mm away from bottom out, but I need to reset and check my zip tie more often. The rear doesn’t have any free sag. I emailed them to see if they have more spring rate suggestions.