SCHNITZ CLUTCH MOD REPORT

[OB_Dirty Pete]

I installed the Schnitz clutch mod today on Speed's recommendation, and I couldn't be more pleased.

Now it's a NORMAL motorcycle when it comes to getting off the line, and now I alone make the decisions about slipping or engaging the clutch.

It works smoothly no matter how hard or light you launch.

Unlike Speed, I have found no change in transmission or gear changer operation (he said it was notchy after the install).

With the supplied 3/8" clutch spring spacers, the clutch lever is now more than twice as hard to pull...not that it was hard before, but you really know you're pulling a lever.

With the springs that tight, I don't think there's any way the clutch is going to slip. Was it slipping before? Not.

I did 3 very hard launches in quick succession with a lot of clutch use and got no clutch slip at all and, of course, none of that infuriating clutch grabbing.

I also purposely induced rear wheel skid by downshifting without matching RPM to clutch speed. Now it's a NORMAL bike and downshifting will skid the rear. Big deal. Tragedies like that will not happen at all if you perform proper downshifts by matching RPMs.

Yngve was right about how Schnitz accomplished this, but there's no way you can do it on your own without a skilled machinist.

The two stock interlocking core pieces have to be welded together, but you or your mechanic could not do it in the perfect alignment that is required without a custom made jig and a pressure fit for welding. That's what Schnitz is charging you for. The only guy on this board who might be able to handle it on his own is Maui, but as we all know he's not mentally stable around dangerous machinery.

I'm seriously pissed about paying all that money to put the Busa back to where it should have been in the first place, but I strongly recommend it to every Busa owner who is not a downshift spastic.

You can install it yourself in under an hour, and Schnitz only takes a couple of days to get it to you.

$219 plus the usual extra rips.

 

[OB_Animal]

Ordered one earlier today and really happy to see your review. It's the only thing on the stock Busa that I absolutely hated!
After all those years of riding on lots of different bikes I sometimes felt like a beginner when trying to make a quick getaway on the Busa.

 

[OB_ducmanic]

Pete,
I am curious about the rear wheel lockup as my bus has a tendency to lock up anyway. This is a great mod if it works as well as you say. As a precision machinist and really good welder i can make anything i want, just too lazy and not enough time in the night-

ducmanic
Los Angeles

 

[Frank Adams]

hey pops...i hope you make VERY sure
you put your clutch plates all
back in the same way you took
them out.

i have heard of a few people that
mixed the direction of them up
and eventually ended up smoking
the clutch.

just try to make sure you put
the metal & fiber's back facing
the same way....

also i just wanted to let you
know you missed the year of my
birth. thanks though, that would
make me younger than i really am.

another thing. brock davidson needs
to recieve the credit on those
clutch mod's. not schnitz.

they sell them for him. his outfit
makes them.

[This message has been edited by frank adams (edited 29 September 1999).]

 

[OB_Dirty Pete]

Yes Junior I laid them all out in a row in sequence of re-assembly on a clean white cloth, just as I always do with disassembled parts.

Thank for thinking of me though.

 

[OB_Dirty Pete]

Ducmanic, what do you want to know about the rear wheel lock up thing?

I'm surprised you were getting it. I haven't got it even on the track when I've made a downshifting error. For that purpose, the clutch worked well.

Anyway, I suggest you just go for it.

Freedom from the Hayabusa Clutch Gremlins!!!!!

PS: Forgot you're a machinist and didn't know you could do advanced welding. You can save yourself some good $ by doing this yourself. If you want a detailed description of the finished assembly vs the orginal parts, let me know and I'll describe it as accurately as I can. You'll know what to do from there.

[This message has been edited by Dirty Pete (edited 29 September 1999).]

 

[OB_speed]

we had a bag of washers with our clutch mod. but instead of puting two on every spring I stager them and put them on every other. I still have added spring pressure but its not as hard as with all of them on. I will sacrifice a bit then again my left forearm will not be bigger than my right one either


I dont know what the springs look like on the TLR but the ones on the hayabusa are wirey little fuckers. They look thin and the coils are very wide, but I guess they are working for most of us. And I dont remember seeing any pink strip either. I will check them when I open it up to check my clutch mod this weekend.



[This message has been edited by speed (edited 30 September 1999).]

 

[OB_Dirty Pete]

Speed, are you saying Schnitz sent you a bag of washers instead of the 6 nice billet spacers I got from them?

 

[OB_speed]

hmmm .. Yep I think so.. It would have been one of there very first sets.. maybe they didnt have the billet spacers ready yet. Oh wait I think I did get spacers with that, know that i recall.. brain fart I think

You could always try 3 instead of 6 they will still give you even clutch pressure and reduce the pull on the lever. Just stagger them every other one. getit ? or use all six but It makes it really rough if you have to ride in traffic much.



[This message has been edited by speed (edited 30 September 1999).]

 

[Guest]

Thanks Pete, (and Speed) but from what I have heard one of the guys tested the new pink stripe springs and they were the same length and tension as the original TLR springs. Possibly a better metal compound??

The best cure at the moment for us is to use shims, but 3/8 is bigger than any I have heard of so far. I will strip my clutch soon, I have considered going the "Suzuki warranty" way of getting a new back torque limiter and springs, but know from other people that it will only last another 10,000kms or so and I will be back to square one. I would prefer to work on my baby myself, and just shim it.

Will let you know how it goes.

By the way, about 1000 miles before your clutch craps it you will notice a distinct "clunk" sound on hard downshifting, this is the back torque limiter starting to go. After that, the next thing is a 1/2 second slip when changing down a gear and full throttling. At least that's how it goes with the TLR!

And for Speed, are you sure it a good idea to run shims in every second spring? Won't this put uneven pressure on the plates, and possibly cause the plates to warp??

 

[OB_Animal]

DP and Speed, thanks for the info on no need for oil drain.
As for the spring pressure (stock or with Schnitz' spacers), hasn't Barnett come out with some Heavy Duty replacement yet and possibly even plates that can take more mis-use to compensate for the lack of additional pressure after the Schnitz mod (as I seem to remember from some of the first tech-talk about the Busa about a year ago, our bike has that strange inner/outer clutch cam thing working in 2 ways, preventing lock-up when downshifting/engine-braking and being sort of a power-assisted clutch putting more pressure on the plates when the immense torque of that engine worked it the other way)?

 

[OB_Animal]

DP, do I understand correctly BTW that with the Busa you can take the clutch-cover off without draining the oil first. Maybe use of sidestand required? (I have centerstand also)

 

[OB_Dirty Pete]

Animal: I figured the Schnitz spring spacers DO put more pressure on the plates by pre-loading the springs in exactly the same way that the pre-load adjustment works on the suspension. That's why the clutch lever is so much harder to pull. Am I missing something here?

Also, I haven't heard about the interlocking cams doing any "power clutch" thing. The concept is that the stock cams lock up in one direction but not in the other. When you weld them up it does not affect the way the stock assembly behaves in the post lock-up acceleration mode.

ONE NOTE: After some more miles on the Schnitz modified clutch today, I have to agree with Speed that the transmission clunks into gear harder than before. But shifting effort and accuracy are not affected. You are no more likely to miss a shift than before, and finding neutral is no more difficult.

And God it's great to apply any amount of power and clutch modulation you want off the line without risking cranking the bike up into an embarrassing vertical sprocket wheely.

Going to go through even more tires though...

 

[OB_EXCLR8]

Dirty Pete would you be interest in selling the stock clutch parts?

 

[OB_Animal]

DP, will see if I can dig-up where I read about that sort of "power-clutch".

Must say that I can't see from the pic of those clutch inner/outer cams in the shop manual how it works, but I remember that Suzuki told something about this in their detailed tech press info almost a year ago and that it was this extra mechanism working during acceleration (and independent from the anti-lock/hop feature on deceleration) that allowed them to use such darn small clutch plates and light springs in the first place.

Only point I'm worried about is that the stock springs indeed seem relatively feeble and although the added pre-load of the Schnitz spacers will surely improve things no end, it would be better still to have a set of heavier/thicker springs IMHO.

 

[OB_Animal]

Oops, forgot 1 more thing there.

It also feels and sounds like there's some power-clutch lock-up mechanism at work on fierce acceleration when you're trying to modulate power and clutch against eachother with the stock Busa clutch.

Or is this a known side-effect of the anti-lock mechanism during downshifting or engine-braking and does e.g. the TL or GSXR750 also display this same behaviour?

 

[OB_Dirty Pete]

EXCLR8: Thanks but no thanks. Being able to return the bike to stock in case I decide to sell makes me keep all my stock bits around.

The cams are cheap anyway...Schnitz only gives you a $79 break if you ship them the parts as exchange. What am I saying? Ripzuki probably wants $700, right?

ANIMAL: I certainly agree that stronger springs are better than pre-loading weak ones any day.

 

[OB_maui]

Dirty Pete

You hit on something in the first part of the post re using a jig. Doing anything like this requires your work not to move around. Sudden extreme heat on small parts will make them walk. A proper jig can take hours or even days too make. The cost can easily exceed the service. As far as welding goes, I wouldn't consider anything short of TIG. After all is said and done, this is still a modification. Welding can change the properties of the materials used. This could cause flexing or premature wear. Does any one have a straight out replacement part? Could this be made lighter and still maintain integrity?

Gotta go turbo Grammy's wheel chair now, Grampa just went to NOS and it really pissed her off.

 

[OB_speed]

99TLR, I am not real worried about warping because it is symetrical. The clutch plate is round and I have one stronger spring every 1/3rd way around the circle. and a lighter one in between. I dont believe that those parts are that delicate.. I have increased plate pressure .. more than stock but less than all spacers in.

As long as they are equally spaced It should be okay, I think.

Strong 1 3 5
Weak 2 4 6

 

[OB_Yngve]

Morethatusual Dirty Pete: I am very dissapointed in the fact that U dont think I am able to do such an easy thing.....but then again U dont know me. I am the inventor of handythings in Norway and can do anything!!!! ( at least in my dreams. )