Hi, Im curious of the actual cvtech numbers are on the primary springs in cf motos with cvtech trailblock clutch, especially the following model 400/450 500s/520 and 500ho/550.
Also interessed in What weights (how heavy they are) and if you can tell the what engaging rpms your machine have or stall speed if you prefer that term.

The reason for this is that I just bought a new primary cluch for my machine and it has a higher engagement rpms than my old primary cluch had and also a different shiftout.
My old primary had a 0951-1019 spring (wich is a 300/900 spring) in it with 16g weights. It had a engagement rpm of about 1800-1900rpms. But if I read online it seems like a spring with engagement value should have a shiftout at like 2200-2300 rpms.   


My new primary (wich i han't open up yet to see whats inside) has about 2200 rpm (start to engage at 2200 takes a bit more to actualy move). The shiftout actually suits me better but im not ure i like the engagaement to be that high.

I alo started to think if my old primary had this engagement rpm once in time. It had over 1100 hours and 31000km+ on it so is it possible that the spring lost some of it's strenght over time wich ended up lowering the engagement rpm?


On my new primary the shiftout is a bit higher 0-60km/h then it was on my old one. But 60km/h + it holds slightly lower rpms wich is good as i have cloked the secondary to A2 so before it was almsot reving "to much".


My machine is a 2017 c force 520s (500s in the US)   

I can add that my machine feel like it's got a good amount of power (for being a 495cc) with the current shiftout.

If I punch it it takes of good and better than my old primary. But I got this feeling that my old primary engaged a bit harder on like low and medium throttle but it might be imagination because it revs more with the new primary.

is it possible to get a harder engagement somehow ? don't want the engagement higher. Maybe slightly lower not 100% sure right now, have to do more testing

[2015 Z Force 800 53/Trail EPS]

As I read your post you like some aspects and not some others. And why you clocked the secondary to A2 needs more explaining. Here is the rate chart. Sounds like you need either some slightly heavier weights of a spring with a lower starting number. Either will give you a lower RPM engagement.

I have that chart aswell.

What im curis about is what the stock springs in the machines have for cvtech number as the parts diagram only show cf motos own parts number: And also what said spring gives for engagement rpms. Doing research and testing to see if im possibly going to change weights and spring.

But as a live in Sweden and cvtech parts don't grow on trees here and get parts is expensive as they usualy have to get imported from USA or Canada so if it's possible to find from other machines it could make it easier to get.

Why I clocked my secondary to A2, Simply because I wanted more low end power as I do technical and mudriding with 28" tires so it's nice to have some power and also good belt grip. it also mad it possible to crawl a bit slower without slipping belt. With my old primary it reved a bit on the high side at higher speeds but i think it was worth it for the low end power. Getting cluch kits here is not easy or cheap. So clocking the secondary was the "best" solution during the circumstances here.

With the new one the rpms is a bit lower at higher speeds and it dosn't rev quite as high when I "cruise" at higher speeds but rev up when I punch the throtle. So far i like that. It's the engagement im not sure how I feel about yet.

Do ypu know if there is a way to tell what the different starting number gives for engagement rpms? Sure weights have some impact on that but like a general number