slipper clutches...

[Pierre - Team PMR]

can someone please explain how these work.  I understand the basics behind them, but I would like to know how racers like them - how well they work, if its worth the $800 investment.  How much maintenance is required to keep them working well.

Also, how do these operate?  Can you downshift without blipping?  can you just downshft a few gears without releasing the clutch between shifts?

[Gixxerblade]

I thought about buying one but with all the new bikes coming out with them and racers getting new bikes every 2 or 3 years I figured I would wait and suck it up this year.

[Jeff]

Funny.  I was just having this discussion with a colleague of mine who races as well.

Here's some info I wrote earlier:

http://www.cbr600rr.com/pages/reviews/yoyoclutch.htm

Now, to go a bit beyond that info.

The slipper clutch works by doing just that.  Slipping.  It would be the equivalent of pulling in the clutch slightly while downshifting.  It allows the plates to slip and not lock up the rear tire.

How do I like mine?  I'd trade my quickshifter, power commander and exhaust for it any day of the week.  After suspension, it would be the next upgrade I'd put on the list.

They operate by having basically a "ramp" on which the clutch basket sits.  There are ball bearings on the ramp and springs to hold the basket down on the ramp.  When the back-torque on the clutch exceeds a certain point, the clutch rotates forward, riding up the ramp on the ball bearings and causing the clutch to slip.

It does NOT eliminate engine braking.  On my 600rr, mine will engine brake up to about 10.5k RPM on the slipper clutch.

Can you downshift without blipping?  Well, yes.  But I wouldn't recommend it.  Can you downshift a few gears without releasing the clutch?  Everyone who has a slipper clutch tries this and about craps themselves when the back end slides like mad.  

Basically, you downshift EXACTLY as you do without a slipper clutch (blip, one gear at a time), but once you understand how it works and the feeling of it, you can rip-off downshifts as fast as your hands & feet will allow them to be done.

You can go from 6th to 2nd in just a couple of seconds (like 2) without a hop or slide.  Whereas without the slipper clutch, you'd take 2-3x that amount of time AND the rear would be hopping around.

I personally figured that a quickshifter would be money better spent.  While the quickshifter is great, I couldn't have been more wrong.  The slipper clutch is, in my opinion, one of the best things you can put in a bike.

My personal experience is with the Yoyodyne clutch.  Talk to Fred at www.yoyodyneti.com and tell him I sent you over, he might be able to hook you up with a discount.  I'm not sure.  Otherwise, Rob from lithium sells yoyodyne and STM.

The yoyodyne has some quirks which I've worked out with Fred and he has solid install information on them to prevent my problems.

[Super Dave]

Pierre, e-mail me or PM me...

[Pierre - Team PMR]

Pierre, e-mail me or PM me...

Email sent - thanks!

[extrakt0r]

Oh, Oh... CC Me Please  ;D

[Super Dave]

Pierre...email my reply back to me and I'll forward it to Mike above...

[clarkie]

It does NOT eliminate engine braking.  On my 600rr, mine will engine brake up to about 10.5k RPM on the slipper clutch.

Can you downshift without blipping?  Well, yes.  But I wouldn't recommend it.  Can you downshift a few gears without releasing the clutch?  

Everyone who has a slipper clutch tries this and about craps themselves when the back end slides like mad.  

Can it eliminate engine braking?  Yes - the STM clutches have different springs so you can adjust the engine braking down to nothing (although that will wear you clutch faster)

Can you downshift without blipping? hell yeah, i have never done it on any of my bikes without slipper clutches so why not do it with one

Can you downshift a few gears without releasing the clutch? see above - i guess you need to ask a few more people Jeff

[clutch]

pull in the clutch, bang the down shifts and dump it.  No rear wheel lock.  Great for certain turns and going into turns like a turn off a straight.  Pull it in, click 3 down and dump it.

[Jeff]

Okay, you'll get many opinions on the topic.  I gave mine.  

Buy one and see what you can get away with.  I posted what I can get away with and what I can't, and what is smoothest for me.

Yes, it depends on the type of slipper clutch as well as the spring rate you choose (if you change it).

One other downside (gee, I hope this doesn't conflict with the great wisdom of world champion Aaron Clarke) is that you can lose track of gears if you're not counting since the revs don't necessarily match the wheel speed.

[clarkie]

stop your bloody crying Jeff  ::)

when you make comments like this

 Everyone who has a slipper clutch tries this and about craps themselves when the back end slides like mad.  

you should try talking to 'everyone' or maybe just say 'i tried it and crapped myself' instead of proclaiming yourself to be a hell of a lot more experienced than we all know :)

One other downside (gee, I hope this doesn't conflict with the great wisdom of world champion Aaron Clarke) is that you can lose track of gears if you're not counting since the revs don't necessarily match the wheel speed.

firstly it's spelt 'Clark' and secondly, you have to count...............

[DanO966]

save your money on a slipper clutch and spend it on tires!!.  Talk to Super Dave and work on your technique.  ya they are cool.  Ya you can back your bike in without really trying....but you don't really need one to go fast.  I can back my bike in and I don't have a slipper clutch, I just feather the clutch on decel.  You can either control wheel hop with good rev matching, slipping the clutch (much like a slipper clutch does) or you can just blip the throttle when the rear wheel starts to hop.  

If you want to go faster, just give it more GAS!!! :)