Can someone explain the slipper cluch?

[Beau]

I know it uses vacuum, but can someone tell me exactly how and when it works, and why it's beneficial?

[go cytocis]

It limits back-torque when down-shifting to prevent momentary wheel lock-up. It's for people who don't know how to rev match. :D

[Big twin]

Very useful on a race track ....

[go cytocis]

Very useful on a race trackYup, true! I was wondering if my original response would invite rebuttal!

Certainly under race circumstances, where fractions of a second count, a slipper clutch makes it easier for the rider to shift fast (or even slam-shift) without upsetting the bike's balance, and it also allows the rider's focus to stay on important things, like the approaching corner for example, rather than perfectly rev-matching every downshift (a near impossible feat).

Personally, on the street and at track days, I've never relied on a slipper clutch, even on bikes I've owned with slipper clutches. Partly due to my muscle memory which was trained long ago to rev match, and partly because the sound of an unblipped downshift hurts my ears. I guess I'm also old school; I feel like a slipper clutch is just one step away from having an automatic transmission! :p

[Beau]

I've always rev mattched on the street and would on a track too. So I guess that's why I've never felt like I've "felt" it working. I tried shifting without the clutch while riding aggressively yesterday. I found the sweet spot for it for most gears, but I didn't know if the slipper came in to play in those clutchless shifts.

[anrkizm95]

It's for people who don't know how to rev match. [up] [cool]

[poinographer]

Slipper clutches are for people who know how to rev match, too. All of the top racers use them. Apparently some of us think we know better (or at least rev match better) than the champions? :)

[RT Performance]

the 1125 vacuum slipper was a complete failure it really doesn't work
the thought process behind it is simple genius...if it actually worked.
when you shut the throttle plates especially at high revs the engine creates huge amount of vacuum.
so they ran a vacuum diaphragm that actually loosens the clutch plate just like if you where pulling the clutch lever slightly. allowing the clutch to slip and not drag the rear wheel under harsh braking rear wheel is lightened dew to front brake application.

The 1125 all it really does is make you bike sound like a loose bucket of bolts on decal.

one that do work are fantastic. you can drop three gears while braking tip in and twist up the throttle in the p[roper gear already

[Bullettooth023]

very helpful in an off road setting. Getting stuck going up a hill sucks but having a slipper gives you one less thing to worry about when trying to get going again.

[Beau]

RT, does it help with clutchless shifts? I understand, now, the purpose of unloading some of the engine braking from the rear tire. I've locked it up many times when using both brakes and the rear is light under heavy front brake pressure. Sometimes though, I feel like the slipper is functioning when I'm accelerating. Just sometimes, and maybe it's the engine not being fully warm, when I roll the gas on with some attitude behind it, it feels like the engine goes and then the bike follows. It's not drastic clutch slippage, but it bums me out and I feel like I'm losing performance. But again, it only happens sometimes and maybe there are other factors that just make me think it's the slipper.

[Beau]

very helpful in an off road setting. Getting stuck going up a hill sucks but having a slipper gives you one less thing to worry about when trying to get going again.

I don't have any off road experience, but maybe try using the rear brake to hold you in place as you let off the clutch. Once it gets in the friction zone you can get off the brake and it'll just ride away.

[Disturbed1]

Quote:
very helpful in an off road setting. Getting stuck going up a hill sucks but having a slipper gives you one less thing to worry about when trying to get going again.

Beau,

I think he is talking about a Rekluse clutch. These types of clutches are used on dirt bikes. They allow you to make clutchless up-shifts. Also, you can let out the clutch and not move until you apply throttle, causing the clutch to engage gradually as you build momentum. I have one in my Honda CRF450.

A slipper clutch uses a ball and ramp assembly in the clutch. When the rear tire applies force to the engine and drivetrain, as you down shift into a corner, it causes the clutch to disengage. Which is very useful, as you will not get rear wheel hop, which could unload the suspension with catastrophic handling affects.

http://www.yoyodyneti.com/Product/Hub_and_base.jpg

Go to the yoyodyne website here for a better explanation.

Yoyodyne Slipper Clutch Info (http://www.yoyodyneti.com/motorcycle_slipper_clutch_operat.htm)

[go cytocis]

Slipper clutches are for people who know how to rev match, too. All of the top racers use themNo doubt, racers do in fact use slippers by default that most race bikes have been equipped with them for years, but because they are vacuum operated, the very act of rev-matching effectively disables the slipper action. Or said another way, if you rev-match on a bike with a slipper clutch, the slipper is inactive, therefore, slipper clutches, aren’t really for people who know how to rev-match :D .

very helpful in an off road setting. Getting stuck going up a hill sucks but having a slipper gives you one less thing to worry about when trying to get going againHmmm, perhaps we’re talking about 2 different things (?) I ride off-road but I’m not aware of a situation like you describe where a slipper clutch, which limits back-torque, would be helpful getting un-stuck going up a hill [confused].

[nitto12ss]

No doubt, racers do in fact use slippers by default that most race bikes have been equipped with them for years, but because they are vacuum operated, the very act of rev-matching effectively disables the slipper action. Or said another way, if you rev-match on a bike with a slipper clutch, the slipper is inactive, therefore, slipper clutches, aren’t really for people who know how to rev-match .

Lets see you grab 3 gears coming off a fast straight into a low speed corner at a competitive pace relying only on rev-mating and tell me how that works for ya. A slipper gives you a advantage in a race environment, period.

[go cytocis]

A slipper gives you a advantage in a race environment, period.Â*Yup, agreed, I think we're saying the same thing. :)

[Beau]

So the slipper is there so you can downshift without using the clutch lever, while the throtle is closed, and has no effect on up shifting. Is that correct?

[nitto12ss]

So the slipper is there so you can downshift without using the clutch lever, while the throtle is closed, and has no effect on up shifting. Is that correct?

No you still use the clutch for downshifting. You just don't have to rev-match and modulate the clutch to keep the back end from unsettling. Just grab your gears and dump it. If you want full throttle up shifting with no clutch, you need a quick shifter.

I have both on my race bike. You can hear the slipper working quick shifter in action in the video. GoPro has been messing up on me lately, so this is probably one of the better videos I have that will give you a example of each component.

6WfDXUmEj2U

[Beau]

Great video! Is the squealing sound the slipper having a hard tome keeping up with engine braking?