Looks like the pressure is on Keith!
Was! Is!
Keith just finished my primary drive, thanks Keith and Kenny at CycleX. Hint on surprise bike...its not in the picture, the lay down bike should be ready next April!
Kenny's dampers arrived this morning. Best dampers I've seen. Finished Billy's assembly just before supper. Will 2nd day ship in the morning so I know what Bill will be doing this weekend.
Short, long story. Some time back, (before Kenny had his made), I had some 90 durometer Viton dampers made. Bill's primary was the first one that was going get them for testing. During assembly, I discovered that they were just TOO HARD. They would take a set if you mashed on them and not spring back - NO GOOD. I have rebuilt several primaries with the competitors damper kits and they are pretty fair, ranging 80-85 duro, and I firmly believe the bolts should be 1/4-28 instead of the 6mm. The holes in the hub are perfect for the 1/4-28 bolts. Not as much thread engagement with the 6mm bolts. They get hammered for sure in a performance drag bike.
Voila! Cycle-X to the rescue with 2nd day delivery! Kenny's dampers appear to me to be the PERFECT solution! After letting them warm to room temperature this morning, they measured consistently at 85 duro. They performed extremely well to my "mash" test, springing back to shape with no indentions remaining from the "mash" tool. In fact, I could compress them to 50% of their original size and they sprang back with no residual indents. Pretty sure Kenny's rebuild kit includes the 1/4" bolts as well as a pair of new roller bearings for the hub. This is a pain in the a$$ job getting the countersinks to the proper depth and located at exactly 60 degrees even with a Bridgeport and an indexer. Forget getting it perfect on a drill press unless you really a pro.
Disclaimer: I own 0% of Cycle-X and receive 0% commissions from their primary kit or rebuild sales.
Bottom line: Cycle-X offers the primary rebuilds as a turnkey service with the correct parts and machining procedures. He can even balance the darn thing for a little extra $.
My advice - call Kenny. No better bang for the buck IMHO.