Clutch slipping

[2fast]

Took my last ride of the year a couple of weeks ago. While passing a cage using just about full performance, I noticed that my clutch was slipping starting at about 7500 rpm. I shifted immediately and it quit slipping. I did this once more to see if it repeated. It did. The clutch is adjusted properly for clearance so does this mean I need to do a new clutch? If so, is doing plates generally enough? Got about 30K on this bike. Any recommended sources for parts? Thanks!

[MartyA]

This site has LOTS on clutches and slipping.

Quick question, are you using 'regular' oil or the slippery synthetic / synthetic blend stuff?

[2fast]

Just regular prehistoric stuff. I'll do a search for slipping. Thanks.

[mitch]

clutch

When u say adj are u talking about up at the bars, or did u pull the side cover and check it there? If u did then sometimes dirty oil will make them slip under hard running . hope this helps ..............MITCH

[Geezer]

A weak clutch will slip more in the lower gears.

On the onther hand a draging clutch cable can keep the clutch from fully engaging. Disconect the cable on both ends and make sure it slides smothly both directions. If not, lube it and try again. I've seen a lot of clutch problems traced to a dry or dirty cable.

Geezer

[TopCatGr58]

Originally posted by Geezer
A weak clutch will slip more in the lower gears.

snip
Geezer

This is totally contrary to what I've read and experienced!?!? In the lower gears it's easier to turn the wheels, the engine has better leverage and there's less resistance in the drivetrain to the wheels, so the clutch usually will hold at least moderately in the lower gears. But in the higher gears, there's more resistance/less leverage to being turned, and so when you try to apply the engines torque thru the drivetrain, the clutches can't hold and start to slip !

Can you explain the how for them to slip "more" in the lower gears?!

puzzled T.C.

[MartyA]

It's all about friction. I think you are right, TC, sorta.

Picture your XS with a clutch that is close to the edge, ready to slip. Put the XS at 5,000 RPM in first gear. The clutch is ready to slip. You give it a little gas, and the clutch starts to slip, but you might still be able to accelerate. Now put the same bike at 5,000 RPM in 5th gear. The clutch might be slipping now, but give it some gas and it will likely slip.

Your leverage analogy is somewhat correct. In the first gear example, it takes only a few horsepower to keep the bike going, and you have the 'leverage' - lower gear - to make it go faster with less horsepower requirement.

In the 5th gear example, you have raised the wind resistance exponentially, and raised the gearing - the "lever," and, it takes much more horsepower to keep the bike going. So the extra horsepower overcomes the clutch friction, and slipping occurs - maybe sooner than the 5,000RPM in the first gear example.

The difference is when the clutch slips at 5,000RPM in 5th gear, you REALLY feel it.

Of course other things can come into play, sticky cable, throwout bearing, oil, etc.

Does that make sense?

[Mike Hart]

fwiw, my own experience is that clutch slip first becomes noticeable in 5th gear, then when it is worse, 4th gear. It has to get really bad to slip in the lower gears.

[kkrazyt85]

Clutch slippage

I have found that clutch slippage is first noticed in the highest gears....of course if you use synthetic oil you can get slippage in all gears....that stuff is to slick for our old designed friction clutches....the rings love it but the clutch can't get a decent purchase between the plates.... I remember many years ago when I lived in the Florida keys I had a 750 triple Kawasaki and it slipped bad in top gear...since the speed limit was 55 I really didn't need any gear higher than 3rd....it would foul the plugs within 5 miles at 55 in any higher gear...3 cyclinder 2 stroke...as I remember that bike smoked as bad as my 135 evinrude outboard... It was fast in a straight line but didn't want to turn at any speed over 100 and it picked up a horrible front end shudder at 105 on thru 113...once past that it would smooth out...I know I know why go that fast...lets see..fast bike, 18 years old and because I could still like the speed not the vibration though

[Huron52]

Two things that I can think of are.... the type of oil and age of clutch.

Mine did slip and I replaced for my own peace of mind. Then I would know that everything was new. That work about a year and a half. then it started to slip again. But it only slips when it is cold engine and oil. No slipage once it warms up to operating temperature.

[mainlylinux]

I remember last year or so I had a slipping clutch...I also had some extra heavy duty clutch springs laying around. I put in the heavier clutch springs, changed the oil to golden spectral synthetic, and the slipping went away.

Of course, my left are got 3 inches bigger than my right because of it. I eventually went to a bike junkyard and bought a clutch lever off of a 2000 ninja; it was one with the adjustments on it, and after some adjusting it made the pull a little easier.

Dan