[chupapuma]

Hey R6-Forum readers. I am having a heck of a time figuring out a bit of a problem I am having.

At the last track day of last year, I noticed that my clutch might be slipping. I was able to continue the day alright, but figured I would take a look at it later. Well, the following weekend when I took it out, sure enough, I noticed (what I assumed) was slipping. I went ahead and replaced the clutch.

Now, when I inspected the old clutch, nothing looked too beat up. The stack height was in spec and I didn't notice any warpage or discoloration. I decided to replace it anyway since I had the parts and I had the case off. I opted for the two thicker plates and it measured on the high end (maybe just over) of spec with my caliper. The ones I was replacing were closer to the bottom end of spec.

Well, today I got out and for the first 30-45 minutes of a ride I noticed nothing, but then I had (what I assume) is slipping. The first time it happened I let off pretty quick. The second time I was staying on a bit more to see what happened.

The Video is on YouTube. Both runs should be 4th gear.
https://www.youtube.com/watch?v=v3C8aZAfuI4

Also, I took some photos of the clutch adjustment as it is. I have heard that the R6 clutch likes to be loose. Maybe I just don't know what that means? I rode the bike for 2k miles with it adjusted like it is here (or darn close) and only starting at the end of last year did I ever notice this slipping. That being said, my skills have also improved so that could have something to do with it.

Photos are here: http://imgur.com/a/WJEHZ
These were taken about 20-30 minutes after finishing the ride. Maybe as the engine gets hot I am falling out of adjustment?

So R6ers, what say you? Is my clutch set too tight or is something else wrong? Could I just be spinning the rear (seems unlikely)? I am pretty much out of thoughts and am hoping others can help weigh in.

 

[MELK-MAN]

what was your exact measurement on the stack height ? yes. your clutch is slippin badly. i would try a little more clutch lever free play, but need to know the exact stack height. i have never needed both optional thick metals to make up the correct in spec stack height. What were the free length of the clutch springs? shouldn't need to replace em, but wondering.
I have posted lots of times about it this .. so if i don't reply (away from my computer) can search.

 

[chupapuma]

I will take it out for a spin later with the clutch cable loosened a turn and see how it goes. The stack height specified in the manual is 42.4-43.0mm. My calipers were measuring it at 43.1mm or something. I know it was just over the top of the spec range.

Unfortunately I installed the clutch back in February and it seemed fine but I only used it for commuting (kept the revs down). Also, I think my calipers aren't to be trusted entirely. The thicker plate is only .3mm thicker, but I remember seeing 42.5 with the one and then just over 43mm with the other.

Everything (Springs/Fibers/Steels) was replaced with an OEM Clutch Kit. I measured everything (individual and as a group while installing) and it all was in spec.

Would too thick of a stack cause slipping? I would think if anything it would make it hard to get it to disengage.

 

[MELK-MAN]

how did the pressure plate look ? if it was massively worn, it is the same as having less stack height. how was the basket and center hub ?
yes, there is only .3mm difference in the optional metals. Having a stack too high will affect the slipper clutch action but only being .1 over the limit should have it hook up fine. Measuring accurately is needed though. i usually set my stack on the edge of the bench with enough hanging over to measure. try to get all the metals and fibers lined up well too. then check in a few spots.
Your individual fibers really should be 2.9mm or better (new is 3mm, min spec/worn is 2.8mm).

make sure your cable at the bottom has the two 12mm bolts tight so the cable is secure, and double check your free play ( you said you took another turn out).

 

[chupapuma]

@Melk-Man

I wanted to thank your for your help. I kind of put this thread out before trying out some of the more obvious stuff as this thread kept rearing its ugly head.

Turns out, I loosened the cable as much as I could where shifts weren't (too) clunky and it didn't creep when in gear. I also took the time to lube the clutch cable extra good.

I pulled on it hard in 1-4 gear and all seems amazing now and the clutch is grabbing super. I guess that as the RPMs increased the slack just wasn't enough. I feel like something must have changed since I have put thousands of miles on the bike and never had a problem. Though, after building the clutch again I did set it to the higher end of the spec for stack height. perhaps that had an effect.

Again, thanks for your help. Lesson thoroughly learned: Set the clutch cable as loose as possible before chasing gremlins...