Let's talk clutches...

[kliff]

This is a subject that will probably get beaten to death, once we get things rolling.

Aftermarket, stock, modified, hybrids.....it's eventually all going to be addressed.

Well today, I was screwing around with the clutch for the 72cc power unit I'm putting together. I ran into so REAL interesting problems.....

Check out some of these specs and pics.
Stock springs in a PEACE 50cc clutch, use .066" wire

Generic Taiwanese 1500 rpm(yellow) springs, under the powder coat, measure .058", and have 2 extra coils. Those extra coils, on the long end, are a bit of a problem. Negating the user the ability to install the springs, unless you want to resort to dremel or milling machine clearancing. NOT exactly, "plug and play."



Here's a pic, comparing the OEM 50cc spring(center) the 50cc A/M (right), and the 150 A/M (left)



Those 2 extra coils, completely blew that installation, the 150 springs are just too long.

Well I didn't open this joker up, NOT to do something. Think I'll lighten, and balance the shoes. Though they are all marked "4," does this mean they were quality checked, and matched.?



Out come the scales.....



Only to find weights of:
131.8gr
132.2gr
135.7gr

Those first 2 didn't look too bad.....but that third, would have meant on quick shoe, followed by the other 2 in a progressive hook up, and possibly on helluva vibration...

I took the lightest shoe, and trimm it down even more, to 129.6gr, then brought the other 2 down to that same weight.
When this thing hooks, it's gonna hook, all at once....just like I like 'em!

Here's a couple of shots on how I removed weight from the heavy shoes to match the lightest....TIME CONSUMING! Don't just drill a hole and think its done....we're talking .010-.015" at a time, once you're within 1 gram... 2 hours guys, 2 hours, just balancing.





Then put it all back togeher with an NC 1000 torquer, and we'll have to wait a while to see what happens...like anything else, you modify, this is just the start, I'm sure I'll need to take one or 2 stepps back, to make a leap forward.... but at least I've taken that first baby step....LOL

[kliff]

While we're talking about clutches.....or at least I'm rambling to myself.... one other little trick you can try...bt it takes us back to the variator...

And it is kinda a variable that needs to be worked over slowly for best results, though even the first "trim" can show results with the right clutch mods, and Var weights....

yeah, yeah, I know...WTF!

Trim the length of the Variator sliding face shaft. You know that big shiny silver thing, the sliding face slides on..... yeah thats the one. It does slide smoother than greased goose crap on glass right? If it doesn't start polishing....it should. But the mod is to shorten this shaft. NOT much. a reduction of .25mm(.011") is a start, .50mm(.0215") works pretty good......be sure you mark the face of the variator with a sharpie, just to see how high the belt is rising... best to do a before and after. Don't wanna run it slap out of the pulley, but -.50mm is looking good to me rat now...

Just a thought.... besides, it too DAMN QUIET over here!

[Rebel]

Kliff we are trying to sleep now. But thanks for the info.

[Enviromoto]

I went down 1mm once and it made the belt ride up into the starter bendix.

[Rebel]

OK, now the way I see it, making the shoes a little lighter will let them start grabbing a bit earlier and since they are all the same weight now, they all should go at the same time. Seems to me that putting bigger springs on will hold them in a lot longer. Having springs hold them back longer will or should bring the RMPS up before the shoes grab hold and make things go. Now isn't this basically the same thing as using a higher RMP spring in your variator?

[kliff]

Nov 12, 2009 19:20:18 GMT -5 Enviromoto said:

I went down 1mm once and it made the belt ride up into the starter bendix.

So far, I'm thinking -.50mm > -.25mm is gonna be in the ball park.

1mm & more, I reserve for 150cc clutch tuning...