Arctic Cat just introduced their 2021 lineup today!

[Tcat100]

Somewhat true but not really. The secondary is also larger so the starting ratio is really the same.
The wider belt allows for a larger range of travel and more overdrive, not to mention increased strength. The Cat clutches are designed to run deeper into overdrive than the Yamaha clutches, that’s why the 24/50 gears can work.
The Cat clutch setup is really awsome, the more I look at it the more I like it!

https://ty4stroke.com/threads/team-primary-on-winder-secondary-mocked-up.155023/

Read Mikes 1st post

Is it? Anyone know the exact primary shaft diameter of the Yamaha clutch? From my quick calculations the difference in belt length really just makes up for the difference in shaft diameters, and the EFFECTIVE (ie where the belt rides, not the actual secondary diameter) secondary diameter is very close.

In any case, I can't speak to the stock Yamaha clutches, but I have run plenty of teams on 2 and 4 strokes. The primary is more durable than the old Cat clutches, BUT on the turbo 4 stroke mine were shot around 2500-3,000 miles. It's tough to get parts for them too. And the Team secondary's are notorious for not fully shifting out. Trail side, sample some sleds out there (2 or 4 stroke) and see where their belts ride on the high side of the primary, and often you'll see 1/2 - 3/4 clean. All I'm saying is, from a lot of experience, the Cat clutches are not a panacea...

 

[ClutchMaster]

Yea Tcat it’s probably moot because of the larger diameter of the cat primary clutch. The team secondary is 10.75” outside diameter. You can see in Mikes post that the belt sits really high in the Winder secondary, effectively negating the increased size of the primary shaft.
Technically the wider belt should give you more overdrive. This is evident in mikes post, he had to machine the secondary helix pockets to avoid binding issues.
The fact that people are not hitting full shift out with the Cat clutches is probably due to tuning. Many cat guys on this site have had great top end, so I’m assuming it’s the setup.

 

[Tcat100]

Yea Tcat it’s probably moot because of the larger diameter of the cat primary clutch. The team secondary is 10.75” outside diameter. You can see in Mikes post that the belt sits really high in the Winder secondary, effectively negating the increased size of the primary shaft.
Technically the wider belt should give you more overdrive. This is evident in mikes post, he had to machine the secondary helix pockets to avoid binding issues.
The fact that people are not hitting full shift out with the Cat clutches is probably due to tuning. Many cat guys on this site have had great top end, so I’m assuming it’s the setup.

It's interesting, I just measured my AC primary and it's only 8"! Also, took the liberty of doing the math and like I suspected the implied secondary diameter is almost identical given the difference in clutch shaft size Cat vs Yamaha (I didn't have a Yamaha clutch but I used my TAPP assuming it was close), center distance, and belt length difference. So my initial point is still valid, the CAT gearing is lower than the Yamaha to make up for the higher starting gear ratio due to the larger shaft/bearing. Also, looks like the CAT clutches will not achieve the same THEORETICAL overdrive ratio, if the Yamaha clutch is 8.25 or even 8.00 (not sure on that one).

 

[Turboflash]

This might explain why back in 2017 when the 998 was first introduced, it was widely stated out in snomo world that the Sidewinder had a little higher top end than the Cat (maybe 3-4 MPH). Not sure if it was deliberate on Yamaha's part, or that's just the way it worked out.

 

[ClutchMaster]

It's interesting, I just measured my AC primary and it's only 8"! Also, took the liberty of doing the math and like I suspected the implied secondary diameter is almost identical given the difference in clutch shaft size Cat vs Yamaha (I didn't have a Yamaha clutch but I used my TAPP assuming it was close), center distance, and belt length difference. So my initial point is still valid, the CAT gearing is lower than the Yamaha to make up for the higher starting gear ratio due to the larger shaft/bearing. Also, looks like the CAT clutches will not achieve the same THEORETICAL overdrive ratio, if the Yamaha clutch is 8.25 or even 8.00 (not sure on that one).
View attachment 150045

https://ty4stroke.com/threads/team-primary-on-winder-secondary-mocked-up.155023/

I don’t have a Team primary to measure but Mikes posted where the belts rides at full shift out in both the yamaha and cat primary’s. 7.95” on the Yami and 8.375” on the Cat.
This tells me the team clutches will have more overdrive if the secondary belt diameter is the same at the starting point. It looks to be slightly more because the belt sticks out of the sheave slightly more than the Yami belt.
What I’m getting at is 24/50 gearing on the cat vs. 24/50 gearing on a Winder Isn’t Apples to Apples.
I’m willing to bet 24/50 gearing on the Winder would be considerably slower top speed than 24/50 gearing in the Cat.

 

[Big_Phil]

Wish they would make the sidewinder with the yamaha side plates to keep the engine, jack shaft and drive shaft all in one box like they do on the Yamaha sleds. I bet it would cure the drivetrain issues with it and the track alignment problem.

Plates like this.

View attachment 150009

A Nytro chassis with the cat front end and cat skid would be the ultimate sled I think.