[upper]

Hey guys, long time lurker, first time poster,

I've had my cbr tri colour for a month now and when I first got it I took to the back streets for a strap. I noticed the clutch was slipping in high revs but blamed it on tapping it into neutral or slow clutch release since i didn't know better. I changed the oil and replaced it with Motul 5100 10W50 oil and oem filter (the old oil was still in good nick). It kept slipping and found out why from a few pm's to studricho. So it's led me here with this topic. The fibre plates look fine, the grooves are still clean but the steel plates have me wondering. I haven't replaced a clutch in a cbr before and couldn't find any used steel plates on google that look the same as the ones below.

Steel plates (notice the small random silver scuff marks)

Friction plate (they all look like this and look fine)

Friction plates and steel plates.
Notice the difference in colour of the steel plates.


At first i thought the steel plates were heat treated which left them discoloured, but discounted this after seeing brand new plates. They look like theyve been through some really high temps to come out with those colours. My guess is they're warped and thats why there are random scuff marks from the friction plates because theyre inconsistent around the plate? But they look straight laid flat on glass.

I would of asked the previous owner, but they only had it for a short period and basically sold it for a friend. I've never had any other problems apart from this. I can still ride around in low revs with no problems but when i open up the throttle in lower gears, there's a 40% chance that it will slip.

I'd appreciate any advice or opinions on this or even if you've had the same experience. It'd help heaps.


p.s. the new site looks awesome [hr]

And the first friction plate (since i'm only allowed 10 images in one post)

 

[Guest]

What did the old friction plates measure up to?

 

[upper]

all of them were 3mm, but the first friction plate was 3.5mm
what's your thoughts on the steel plates?

 

[phreak911]

With Motul 5100 I think it is common to have a small amount of slipping when changing gears at high revs. I'm pretty sure I have read somewhere on here that this is quite a common occurance. I know mine does it when I'm really using the rev range... Not a huge amount though, but noticable.

Maybe someone can shed more light on this for both of us...?

 

[Humbug]

if you are worried about slippage, use stronger springs.

 

[Stavros]

If the steels are flat, they're fine. Discolouration is probably just a result of the slippage. You could give them a bit of a rough up if you're paranoid, but it's probably not necessary.

Roughing can be as simple as just swirling them around on a concrete floor. Or use 200 grit sandpaper, dry.

Not sure what the wear limits are on the frictions, but it'll be in the manual.

A previous owner may have used synthetic car oil with friction modifiers in it, which is death to a motorcycle wet clutch. If that is the case, you'll need new friction plates 'coz the old ones will be contaminated with slippery shit from the oil and won't work properly ever again.

Springs... yeah, you could change 'em, but if it's slipping with stock springs, something else is wrong and you're better off fixing that than just masking the problem.

 

[upper]

Update: Had the plates checked out by a Honda guy and got told that motul 5100 is causing the clutch slip since it's semi synthetic. They reckon I should be using motul 3000 instead since its mineral based. It's got me confused since I keep hearing 5100 is what you should be using for a cbr250rr:s

What do you think?

 

[Chrissybenn]

he could be looking for a quick sale of some oil instead of quoting you a few hundred to fix and possibly making no money?

 

[richo]

Call martin at Aussieparts.com !!

He'll sort you out with EBC fibres and 110% springs. A few people have ridden my bike with them. Heaps better.

 

[Drew]

If the steels are flat, they're fine. Discolouration is probably just a result of the slippage. You could give them a bit of a rough up if you're paranoid, but it's probably not necessary.

Roughing can be as simple as just swirling them around on a concrete floor. Or use 200 grit sandpaper, dry.

Not sure what the wear limits are on the frictions, but it'll be in the manual.

A previous owner may have used synthetic car oil with friction modifiers in it, which is death to a motorcycle wet clutch. If that is the case, you'll need new friction plates 'coz the old ones will be contaminated with slippery shit from the oil and won't work properly ever again.

Springs... yeah, you could change 'em, but if it's slipping with stock springs, something else is wrong and you're better off fixing that than just masking the problem.

+1 to car oil, sounds like BS that the motul would be causing the problem because the friction faces should be in hard contact after the clutch is fully engaged. Also, if theres a residue there its pretty likely that thats the cause of the problem.

 

[Guest]

Update: Had the plates checked out by a Honda guy and got told that motul 5100 is causing the clutch slip since it's semi synthetic. They reckon I should be using motul 3000 instead since its mineral based. It's got me confused since I keep hearing 5100 is what you should be using for a cbr250rr:s

What do you think?

Fucking BULLSHIT. Dont go back to that guy. The misinformation you will hear about oil is astronomical. That Honda dealer you are going to is not to be trusted at all.

Look closely at the slots in the outer clutch hub and tell me if you can see wear from the tangs of the fibre plates where they sit/engage. I bet that is your problem.

Actually take photo's of your outer clutch hub from side on for me please. I reckon these slots are no longer smooth and the plates are not sliding smoothly. Repeated impact from clutch abuse causes the fibre plate tangs to actually cut into the outer clutch hub. This causes your problem.

Post some more photo's. I cant tell from what you have posted, the colour is inconsequential. I need to see your outer clutch hub from a few angles.

Using stronger springs or spacers is what a dodgy mechanic will do to conceal a problem to pass a roadworthy and sell a bike. Dont listen to Humbug. He's leading you up the garden path.