APE clutch kit

[lecroy]

?Give a man a fish; you have fed him for today. Teach a man to fish; and you have fed him for a lifetime? You have access to a dyno and I would only by guessing at your problem.



We have Massive Massakins at 225HP, followed by Bad Billy Bob at 200 and King KZ in third with a wopping 170. All impressive numbers.

[kz]

OK, lecroy

I just wanted a hint from you, if you think investing in a new set of fibers and a new set of stock springs was a good idea in your opinion.....

EDIT:

I'm living in Sweden so according to our laws you could advise me to run my bike without oil and then run over my grandmamma, it will still will be MY responsibility to check your statement, not yours.

So, you don't have to be afraid of the responsibility of having to support me for a lifetime, anyhow I like your posts, very informative.

[Paul]

Karl
If your clutch is slipping the plates are probably worn, and/or are not flat any more due to excessive heat build up.
Heavy duty springs may solve the problem, but won't rectify the cause.

[kz]

Karl
If your clutch is slipping the plates are probably worn, and/or are not flat any more due to excessive heat build up.
Heavy duty springs may solve the problem, but won't rectify the cause.

Hi Paul,

If I understand you correct, in your opinion a perfect stock clutch/springs should not slip with my engine configuration?

[Paul]

No, what I'm saying is that if your stock clutch/springs is not perfect you will get slippage at your sort of power level.
What are you using the bike for?
Is it a street bike or a race only bike?

[Dink]

Karl
If your clutch is slipping the plates are probably worn, and/or are not flat any more due to excessive heat build up.
Heavy duty springs may solve the problem, but won't rectify the cause.

Hi Paul,

If I understand you correct, in your opinion a perfect stock clutch/springs should not slip with my engine configuration?

Karl I would replace all your plates and springs with brand new stock. at worst I would change to a half and half mix of stock and "H-D" springs,but only after making certain you are getting slip with stock.
Dink
Or you can return your 1150 to stock and send the 1327 to me and II will sort it out for you

[lecroy]

Springs can take a set. I have seen the steal plates glaze and the friction plates wear. I have friends who have bead blasted the steal plates to remove the glaze. I have friends who have used washers to shim the stock springs, preloading them. I have also seen people cut the spings to unload them. I have also seen people try to adjust the tension on the clutch with the cable. :roll: These are the real bikers.

What would I do?

Staying in shape is important at any age. Lifting weights is not all that bad for you.

First, I would never shift a bike using a clutch lever. (Ok let the touchey feeley letters come) I also would not try and use old plates if I had the bike apart. If I am building a 175HP "performace" engine, why am I going to try and use old plates and springs? Next, I would not use a stock clutch in a 175HP "performance" engine. Why put something in that was a known problem with a stock engine? I would just put in a billeted basket and be done with it, or as a minimum have the stock basket modified.


What would I recommend you do?

I would just bite the bullet and buy all new springs and plates. All stock parts. I would then return to the dyno for more testing. I would be VERY anal about the whole thing, making sure it's really the clutch slipping and not the tire. I would instrument both the crank and output shaft to make sure I knew what I was looking at. I would turn off the filters in the software to make sure that it was not masking the problem. If this fixes the problem, your done. If the clutch really does slip then you need to start adding force. I would not do anything else until you have all new parts. Not old parts. New parts and it slips.

If it slips with the ALL NEW parts (springs and plates) and you are sure its really the clutch and not the tire slipping on the drum, you have a few choices. Shim the stock springs, go with every other APE spring (cant do this with the Kaw), go all APE springs, try the APE plates, get a lockup or some compination of these. Use the data from the dyno to make an informed decision. If the clutch slips at 100HP and you have 75 more in the bank, I don't think that adding a few shims will help.

If you really just can't handle the spring force to keep the clutch lever pulled in, the lockup is going to help. I know I said I would not put one in the way I use it on a street bike. And again I will state that the way I use it is a BAD thing if you want any life out of your plates. For the street, you can leave the 6 stock springs in and just use the arm weights to start getting the added force. DONT try and run 3 springs. If the arms alone are not enough, add the stock nut and bolt that came with the kit to every other arm. If this is not enough, go to all six stock weights. If this is not enough, start adding weight. Once you get the clutch to be stable, I would add a little more just to play it safe. Maybe 10% on top of what you ended up with. That, or just leave the weights that came with the clutch on and try it. If you can break the clutch loose with the ALL new springs, plates and stock springs on the lockup I think your putting out a LOT more power than you think.

Last, I would post your results so others can learn from it.

Hope this helps. Good luck.

[BadBillyB]

I have run almost every clutch combo there is, at one time or another. My spare parts box has 4 different color clutch springs in it. The GREEN ones are softer than stock and came with a Karata Ent. lock-up clutch that I bought many, many years ago. I affectionately call it "the trash compactor" as you didn't necessarily need good clutch parts in it for it to not slip. I dont recommend a lock-up type clutch unless your making more that 250 HP and have a forged basket. The SILVER (or unpainted) ones are stock of course. The BLUE ones are stiffer than stock but not as strong as the RED ones, which are perfect for a motor putting out more than stock HP levels. Theres more than 2 choices when deciding on clutch springs.....I cant for the life of me remember who markets the BLUE springs, but they are a good compromise.......Also the friction plates that you guys are calling APE plates look strikingly familiar to the ones I liked so many years ago and were marketed by "Cir Cycle"......maybe thats where I got the BLUE springs.........Steel plates should not be judged by the color marks on them but rather by their "flatness".....just clean them, stack them together, and hold them up to a light, take the one on the bottom, move it to the top. Do this repeatedly and you will see the ones that are warped.......Works for me.........Billy

[lecroy]

Hey Billey Bob, I wondered if you were going to hang around or not. Glad you decided to stay.

I agree that flatness is important and for sure needs to be checked. Even if the plates remain flat, but have been heated to where it has shown a color change that the material has changed its properties. When the clutch slips like this we have a nice super heater and a good oil bath but its hard to control the tempering process in these conditions.

I don't agree with HP being the only factor on when to use a lockup, slider or any other kind of clutch. I also don't agree that the billeted basket is required. If you look for a post about 2 strokes and RD, you will see a picture of a little 350cc RD I put a lockup on. I am sure that it does not put out even close to 250 HP. To me its all about clutch management. Controlling the slippage. That RD ripped into the low 11s last summer by the way with no spray. 8O

I think I am the only one saying that the upper left plate I have shown is from APE. I am so anal about things that you know I am going to have a picture of these in their orignal packing.



Bench racing is such fun, where is the warm weather????

[kz]

A new day, a lot of new inputs, and major decisions that have to be made...

Well,

The advise to stay in shape and lift weights with my left arm has already been given by amused friends, I'm afraid it only solves the problem to certain limit. :roll:

Why use old clutch plates in a tuned engine?

This demands a short resum?, it all started two years ago as a drove on the connecting bridge between Stockholm and Liding? in second gear and 8500 rpm. Suddenly the gear popped out, and I experienced that a GS can rev far behind the scale of the tacho. 8O

That was the day a learned "never shift a bike using a clutch lever".

Anyhow, i decided to save the GS and not just repair the engine, which now had a new strange noise, back to stock shape.

A lot of decisions had to made, and for the clutch I focused on the clutch basket and modifyed it.

For the plates/fibers/springs the question at that time was if I needed HD springs or not.

The fibers had been replaced earlier and worked fine, so I mounted them back and thought that the day they are worn out I change them.

As I wrote earlier the clutch started to slip, and my thoughts went direct to the HD springs, mounted the HD-springs, the slipping problem was solved and I just didn't think of the fibers any more, until I read this thread. My next step would otherwise have been, to replace half of the springs with stock springs.

I now learned that the OEM-fibers and other aftermarket fibers can differ a lot, I have non-OEM fibers mounted now.

I also learned the importance of the plates being in good shape.

So, I thank you for your input, I will order new OEM-fibers/plates/springs and see what happends.

I will post the result here.

EDIT:
Typing errors.

[kz]

Or you can return your 1150 to stock and send the 1327 to me and II will sort it out for you

If I get your wheather in return, I might concider it, as lecroy wrote "Bench racing is so fun".

I just came home from the Ski slope, but now it's only a month or two left, then it's time to move from the dyno to the street.

If biker66 happends to read this:

YES, we have a ski slope in Liding? with snow!

[kz]

No, what I'm saying is that if your stock clutch/springs is not perfect you will get slippage at your sort of power level.
What are you using the bike for?
Is it a street bike or a race only bike?

It is a street bike, but I plan to test it on the track as well.

[BadBillyB]

I don't agree with HP being the only factor on when to use a lockup, slider or any other kind of clutch. I also don't agree that the billeted basket is required. If you look for a post about 2 strokes and RD, you will see a picture of a little 350cc RD I put a lockup on. I am sure that it does not put out even close to 250 HP. To me its all about clutch management. Controlling the slippage.

My statement was about GS motors 750/1000/1100....not all engines. The clutch basket in the late 70's GS 1000's is a piece of junk and will not handle much more than stock power. If you put a lock-up on one of these, you can easily explode the whole clutch out the bottom of the cases. Been there, done that. I expect, but dont know for sure, that the 750 basket is probably the same design. The 1100 basket on the other hand is a much nicer piece and can be easily fit into a 1000 motor, allowing you to run an extra plate, which is desirable......The more plates you can fit in there, the less clamping force (spring pressure) is needed to prevent slipping........Billy

[kz]

Old fibers now dismounted....

That?s how the fibers and plates looks, works fine with HD-springs, slips with stock springs.

I still don't know why two of the fibers differs from the other, #2 and #4 in the upper row, but that?s how the came as a set from the supplier.

[Paul]

Have you checked the steels for flatness?