slipper clutch...??

[Tigger]

Sorry to be such a newbie. Whats the slipper clutch all about? Did some browsing and found out that there is a "poo poo" load of physics and dynamics to a slipper clutch but still confused http://www.sigmaperformance.com/slipperclutch.html. I always read reviews about motorcyclists wanting a "slipper clutch" on a bike test for instance the cbr600rr. So why doesn't every manufacturer create one on every current model if there are so many pros about them. Any tips would be helpful. Thanks.[/url]

[Mintbread]

$$$.

[Logitech105]

Well said.

[ninja79]

$$$.

That just shows how much Hondas are overpriced. Suzuki and Kawasaki RR's have slipper clutch for uhhh... "free". But anyway, as a newbie, this is NOT something you should be worried about.

[Patient]

My GSX-R has a slipper clutch and i had the same questions.
I'm no pro, but heres how it was explained to me.

- Slipper Clutch:

Allows the clutch to "slip" before fully engaging. In circumstances where your clutch engaging quickly can be dangerous (Downshifting in a turn) your clutch will allow for some give.

Basically what this means is that if you need to downshift in a turn, your clutch wont fully engage when you ease off the handle. Your clutch will slide in a "rotational" pattern until you find your gear/rpm. Makes for smoother shifting, and less "Catch n Pop"

Thats how i understood it,
I'm sure theres holes in my explanation, please correct me if im wrong.

[sv-wolf]

OK Tigger, I'll have a go at this for you.

Imagine you are a MotoGP rider. You have screamed down the striaight and are hitting the corner. You need to slow but you need to do it quickly. You brake, change down and come off the throttle, fast.

Problem.

Slowing down agressively like that means that your bike's back wheel is now driving the engine, not the other way round. The result is something called 'back torque' or more commonly 'engine braking'. Basically when the wheel turns the engine, the engine resists on the compression stroke. There won't be a lot of air in the cylinder if you have come off the throttle, but the piston still has to compress it. This is a particular problem for your Moto GP bike which has a high compression engine and therefore produces an exceptional amount of 'back torque'. So what does all this mean? Well, it means that you are going into the corner with your rear suspension now seriously destablished. Whoops!

To make matters worse still you are braking hard, throwing all the weight of the bike onto the front wheel, which gives you even less traction at the back. You could brake earlier, more gently, and save a spill, but you would lose the race.

So it's the techies and design gurus to the rescue. To deal with this problem your bike has been fitted with a slipper clutch. A slipper clutch is basically very simple. It is designed to automatically disengage the engine from the drive train when the wheel starts turning the engine. You barrel into the corner, get on the brakes and off the throttle, you change down, and as a result you start to engine brake. The slipper clutch detects the back torque and disengages. Result: no pressure on the engine, no engine braking, more stability. (Well, we are assuming that, in other respects, you know how to handle the thing!)

Back torque is a particular problem on high tech Moto GP bikes. These beauties have a highly sophisticated design which configures the chaindrive and swingarm systems so that, under normal riding circumstances, the swingarm pushes the back wheel into the ground to get more traction. Unfortunately when the bike begins to overrun, ie when the wheel starts turning the engine, this same, normally very useful configuration, causes the chain to start yanking the back wheel off the ground. Again, the need to prevent engine braking. So even more need for the slipper clutch.

On the road engine braking can be very useful. On my big V Twin SV1000 I hardly use the brakes at all. Closing the throttle and changing down will usually bring me quickly to a halt. And it will do it safely in most road conditions. It is a debateable point whether a slipper clutch is useful on a road bike. On a big, highly bred four-cylinder sportsbike, you can discuss the matter. It depends what you want to use it for.

As for how a slipper clutch works. Well, there are various designs. Many use a ball and ramp mechanism, but it is very difficult to describe without a diagram. You've got access to the web so I suggest you look it up there. There are plenty of sites that will explain it to you.

Make sense? Done my best.

[Kal]

Personally I'd rather not have a slipper clutch. I like the clutch I have just fine although I might feel differently if I were riding a 100bhp+ superbike. I like Wolf use engine braking heavily on the road and a slipper clutch would limit that.

If I am overbraking on the eninge and locking the rear wheel up I feather the clutch which works just fine.

[intotherain]

OK Tigger, I'll have a go at this for you.

Imagine you are a MotoGP rider. You have screamed down the striaight and are hitting the corner. You need to slow but you need to do it quickly. You brake, change down and come off the throttle, fast.

Problem.

Slowing down agressively like that means that your bike's back wheel is now driving the engine, not the other way round. The result is something called 'back torque' or more commonly 'engine braking'. Basically when the wheel turns the engine, the engine resists on the compression stroke. There won't be a lot of air in the cylinder if you have come off the throttle, but the piston still has to compress it. This is a particular problem for your Moto GP bike which has a high compression engine and therefore produces an exceptional amount of 'back torque'. So what does all this mean? Well, it means that you are going into the corner with your rear suspension now seriously destablished. Whoops!

To make matters worse still you are braking hard, throwing all the weight of the bike onto the front wheel, which gives you even less traction at the back. You could brake earlier, more gently, and save a spill, but you would lose the race....


...
Make sense? Done my best.

+!

Nicely worded. never fully knew why engine braking existed.

Thanks

[safety-boy]

My ZX-6R had a slipper clutch (still does I imagine ). The dealer said it would take some getting used to, but it didn't really. Going back to a regular clutch took the getting used to. Once you start downshifting without the bike lurching, you'll fall in love.

--Dave

[oldschoolorange]

Ok so oversimplify the explination A slippper clutch is just an overrunning clutch?