How are the boss secondaries performing compared to years prior


New member
Jan 3, 2013
Just wondering how the mountain guys feel these perform compared to the 12-15 cat or even a tied? It seems people like the boss but dont get the top speed or track speed of previous clutchs. Ive been seeing the delrins help and also running lower angles.

Any thoughts or comments appreciated!
Last edited:


Well-known member
Oct 30, 2008
Billings MT
I put a 2018 primary with MDS weights and a Tied secondary setup from Racin' Station on my prolite 900 at the end of last year. These replaced my 2014 clutches running Bikeman Goldstar weights and BDX helix with shift assist bearing under the spring. I thought my old clutch setup worked pretty well. The reasons I changed it is at 1800 miles the secondary seemed to be binding and not backshifting consistently, the primary was starting to get worn, and I wanted to try the new style 2018 primary.

The new setup definitely engages smooth. Backshift is spot on and shifting in general seems to follow what my thumb is doing on the throttle. My disappointment is that on upshift in the flats it seems to hit a wall at about 60mph and just stops. It will eventually slowly overcome it and speed up some more, but I didn't have nearly this issue with my old setup. It would pause briefly at 60-65mph then take off like it grabbed another gear and run out to 85mph. I'm geared 2.52 on my belt drive for reference. I know mountain riding doesn't really happen above 60mph unless you're running boost, but it's still a little annoying. I haven't had enough rides to tell if it's the way the weights are setup or what. Might have to shuffle them around a bit and see if I can make it run the same. I'm hitting and holding my target RPM. Old setup was good on belt life as long as I was running factory cat belts. Not enough miles on the new stuff to tell.

Both the 2018 primary and the tied secondary are heavier than the clutches they replaced. Between the clutches and belt I gained 1.6lb.


Premium Member
Premium Member
Feb 2, 2014
Rocky Mtn House AB
I feel something is holding the secondaries back from more track speed. I’ve tried several spring and angles- 42-45-46-48. With the 18 roller primary it seems to work best with the secondary stock 48 angle.

When I was playing around last March, I found my stock 48, was binding with the rollers. I had to open them up with my die grinder so from bottom to the top the rollers didn’t hang up. Seemed better, spot on actually but I also added more weight to primary, so I don’t know. But I can say my clutches are both running maxed out, there’s nothing left to give. The belt will take sharpie mark off the entire primary, and I have burnt rubber on the center shaft of the secondary.