R6 clutch spring mods..

ya I meant those springs too. the physics still applies; they get stiffer when they are cut shorter. I can't see the pics there, but it sounds like I thought right.

I wonder if the spring-design change for later years was related to them breaking.

 

I've been told the older ones were more prone to braking when they were cut. Also to keep an eye on the springs after some are cut or moved. I keep a couple extras in my spares box.

 

Just measured my stack, it's 2.75mm
So I guess it's time for a new clutch kit

 

What did you measure that's 2.75mm?

 

There's supposed to be a 4 there..
42.75 mm haha

 

Just checking .

 

You agree start with a new kit at the height Rick recommended?

 

Rick is a lot of things, but he isn't wrong.

And, like a lot of things, make checking your clutch part of your race weekend prep.

 

Can someone at lease explain the logic for having your clutch stack .5 taller than the manual reads?


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at 42.75mm, the friction plates are likely well within range. they prob are borderline new. if u want it thicker, id find the thin steel and replace it with a regular or thick one.

the crew chief I worked with at MA last year and two good engine builders all recommended starting shorter than 42.75mm. I wouldn't touch it. but hey, there is more than one way to skin a cat.

 

I think it is to get more slip. More stack height was going to be the next thing we tried.

 

Isn't more stack height less slip?
I thought that's why graves bikes run low stack numbers for more slip, and have to replace clutches a lot.
Maybe I'm confused, my head hurts from this stuff haha

 

I just remember, I was going to try Rick Matheny's recommendations next time out on stack height.

We tried moving the one spring with fingers to the outside and he wouldn't get consistent slip. Sometimes it felt great and other times not. That may have been because he learned to use his clutch lever as a slipper coming into corners on his SV and Moriwaki. He would often be trail braking into the corners while also slipping his clutch lever out at the same time.

We had plans of trying to move the spring outside, change the stack height to Ricks recommendation, and see what that did.

If that didnt work, then he was going to see if he could start quickly releasing the lever without slipping it himself. Not sure if that would have helped, but it wasn't doing what he wanted.

 

going from 3 intact "Y" springs, down to only 1 being intact (fingers cut off other 2).. will DRAMATICALLY reduce engine braking. As Rick M stated.. best to try a gradual reduction.

When i bought Josh Day's bike (that Rick built), and Rob Jensen's bike (both 08's) i literally couldn't ride them with that much eb reduction. I felt i was going to ride off the track. I eventually settled on the fingers half cut on only 1 spring (other 2 were intact). these are the older thinner "Y' springs. They did get wider/stronger in 2010 as RM mentioned. Then over past few years, i've gotten pretty good at managing the ECU engine braking (how quickly butterflys close on throttle bodies).

As i've gotten faster, and better with the front end of the bike (Josh and Rob were wicked fast), i've recently gone to fingers cut off 2 "Y" springs, and my engine braking maps have more reduction at high rpm, then ramp it down to almost full eb reduction at mid rpm, where you are mid corner

 

Melkman, I'm on my phone, you may have answered this earlier, on the one spring left with fingers, where do you have it, inside, middle or outside position?

I think since Tyler came off a RS125 initially, he was always looking for less engine braking.

I also think the newer Flashtune software gives a lot more adjustability for engine braking versus what we had.

 

When I came from an SV and transitioned to a slipper, I had to unlearn a smooth clutch release, to fully utilize it.

Also as mentioned - the settings are personal preference. I like engine braking. At the time last year, the latest revisions to the R1 kit box had improved significantly in the engine braking maps. I could get into a corner hot, and the slipper/engine brake was smooth as butter. I absolutely loved it. It was unlike anything I had before.

 

That was something we suspected, could be a change he needed to make. After his accident, we had a bunch of time to talk about what to try next.

 

depends on how much additional slip you want. You can put the washers in first, then the final spring in last, less tension/preload on that "Y" spring. Lots of slip...
I put the full "Y" spring in first, with washers on top now, but remember, i had up until not that long ago, been running TWO full "Y " springs

 

you know you can utilize the optional thicker metal plate from the standard 2.0mm metal. this increases your stack height back to spec. This assumes your individual fibers are above 2.8mm (min spec)
not reading the manual can get rather expensive

 

True,it's not a new clutch though, it's what was in the bike when I bought it.