Slipper clutchs
 

Ok, i admit i don't know much about slipper clutchs. :puzzled:

I see there are 48 tooth slippers, 12 tooth etc...
So, what's are the advanteges/disadvantages of a 48 tooth vs one with less tooths?
Which is best?

The 48 tooth version will wear much less than a 12 tooth as regards the plate/basket interface.
Instead of the transmission forces being focussed at 12 points on each plate, there are 4 times that many contact areas giving less wear, longer life and smoother clutch action.
the 48 tooth basket seems to be a very worthwhile upgrade.
Don't reaaly know of any disadvantages.....

mt stm 48t has done getting on for 6k now without problems

Don't think technically there's much different between 12 and 48 teeth other than wear on the baskets. The only difference you'll have is spares possibly, 12 tooth plates are readily available, whereas 48 tooth you might have to order, and I'd expect to be slightly more expensive.

Thanks for the info guys :cool:

I just had a 2nd hand (1500 miles) STM 48 tooth slipper. It sounds much better but then a 1500 mile standard clutch would sound similar. I suspect it will wear better though.

My reason for wanting it was that I was locking the rear wheel on downshifts (on the track, not the road). As my braking got later and corner entry speed increased, I found I got worse at downshifting in time to be in the right gear for the exit! I was coing out in a high gear, having slipped the clutch in whilst in the turn (as KeefyB noticed in a recent photo!). Yesterday I tried it at Cadwell and whilst it takes a little "getting your head around" to learn to just drop into gear and not worry (too much) about feathering in the clutch, I noticed I was getting better at getting in the right gear for a fast exit.

That is until the bike packed up and becames a 375cc single. :mad:

[Edited on 20-9-2005 by HW]

Slipper clutch
 

Anyone bought or used a ATCORSE slipper clutch, came accross them but wasn't sure how good they are??/

I've just asked a friend who was sales manager at STM exactly that question last week. Slipper was for 999 and I also asked about different size slave cylinders for the 999 and MTS, this is for majority road use with occasional track days, heres his reply

On the tech side I recommend the 48 teeth basket and plate kit. Z 48 have three times more contact suface between basket and plates allowing a much more precise fit and MUCH longer life. Moreover the sintered material of the Z-48 plates is exactly the same used in competition and has a long life as well as great friction coefficient.

All STM clutches are available with 12 or 48 basket, I highly recommend the 48. The advantage of the 12 is that you can use your old plates but the function is not as good as with the special STM 48 plates. priod.

Regarding the clucth model I suggest the EVOLUZIONE (003MG048/45°+ D). It has a diaphragm spring (degressive action on the lever) and would fit weel with the bike and how you use it. Choose the 45° ramp angle that works fine on the road and for "occasional" track rides. The 35° ramp angle is more for racing with highly compressed engines. Basically with lower ramp angle (35°) you reduce engine brake a lot that maybe is too much for road use.
Slave cylinders should be 28 on the 999 and 30 on the Multistrada. The diameter depends on the master cyl as well, generally you can increse 2mm on the diameter compared to original. Increasing the diameter of the slave you reduce at the same time the travel of the pushrod, with all STM clutches with diaphragm spring releasing the plates is easier than standard coil spring clutches, so if you choose an STM Evoluzione you can increase the diameter of the slave without any problem of drag.

If you look for the ultimate racing product the clutch to buy is the Evoluzione Racing (003MG101/45+D), is the same clutch used by all top riders in the world, it is more expensive especially because it uses a bigger diameter diaphragm spring and some slighlty different features. Compared to the EVOLUZIONE the lever will be even smoother.

Do not forget to ask for the special push rod pin (044MG001). It is a simple part but VERY useful.

There is only 1 tool that you need to hold the pusher plate while tightning the main nut on the clutch: 002AMH001. A good mechanic can also do it without the tool.

Still think its horrible, for what my opinions worth!
If its that good, why do the racers all use the 12 tooth 6 or 4 posts?

have you used one?