So it seems like even the guys on the Grizzly Central are fighting about the best
sheave.
It's a big stink about Coop vs JBS. I can't 100% compare apples to apples, but I had a Coop
sheave on my Grizzly 550, and my buddy had a Coop
sheave on his 700 (this was pre-JBS days), and it was nowhere near the difference in low end power as the JBS
sheave on my Rhino. The Coop
sheave with the cut and welded cam plate was good for top end in low range, but overall low end gain wasn't the "OMG" night and day difference you get from a JBS
sheave on a Rhino. In fact, I even put a 1mm shim in after the Coop
sheave, and still wanted more bottom end power.
I don't know all the magic or the physics behind the different schools of thought concerning sheaves, but I can say that the JBS
sheave is where it's at. Count belt ratios all you want, I'm past bench racing those numbers. You'd think a 27% or greater reduction in the starting ratio of the Coop
sheave would be in your face and awesome and low. It was not. I no longer recommend Coop's machined sheaves to my Grizzly buddies, and have not recommended his work for a long time. When we get to talking about clutches, I say that I have three words:
Hot Rod Style