APE clutch kit

[Anonymous]

Anyone ever installed one the APE heady duty clutch kit, with the extra friction plate and heavy duty springs? Any thoughts on it, ease of installation? does it eliminate drag and chatter as they claim? Going to install on 82 GS1100E, Thanks

[Mr. Jiggles]

Heavy duty springs are really hard on the left hand. If you have a stock or just slightly modded motor the stock springs should be fine unless your fiber disks are worn or you have gas in the oil. For drag you'd need to replace those metal disks that are warped.

I had HD springs on a bike years ago and would not use them again on a astreet bike unless absolutely necessary.

[Anonymous]

I had HD springs on a bike years ago and would not use them again on a astreet bike unless absolutely necessary.

The middle alternative it to replace half of the springs with the HD ones for more clutch bite, but not too much lever force required. A well set up stock clutch with fresh parts should be fine for most any reasonable street set up, though.

Mark

[Jethro]

I concurr, don't get HD springs unless you are dragging! They are pure misery for a ride of any length. I will never make that mistake again.

[Dink]

The clatter you mention will not be changed, unless you change the springs on the rear of the clutch basket.
Dink

[lecroy]

Let me start by saying that I have seen companies change there plate designs, so take this information for what its worth.

To answer your question. Yes, I have used APE's plates and others in my street and race bikes over the years with mixed results. If your clutch was slipping because it is worn out, sure the new plate kit will most likely fix the problem. If your plates are warped and the clutch sticks or grabs, theres a very good chance that a new set is going to fix the problem. Is the extra plate a good way to go? Well rather than give you some touchy feely information that this site is noted for, consider this...

All of these parts were used in my old GS1100 wanna race me bike. All of the plates are sold for the same MY/size bike. I'm sure this bike puts out more power than most street bikes, well maybe not, but for sure it puts out more power than my stock GS1100. On this bike I only use three springs and I really don't care about how stiff it is. I use the red colored APE springs.

This picture shows four plates. The upper left is an "extra" plate from a kit. The bottom left is a normal looking stock plate. The two on the right shows what happens when the plates can't hold the power. I have turned plates blue before. Any sign of of a slip condition like this and these go into the trash. I would also like to defend all of the different plates in that it would be VERY easy to point the blame to the plate when somthing like this happens. But it could very well be a poorly setup clutch or some people like myself, tend to run the clutch very soft. This can really takes it's toll on the plates.


This picture is a closeup of the of the four plates. Do you notice something different? That "extra" plate is nice and smooth. Is this good or bad? You figure it out. Myself, I would rather just add another stock plate. Both plates are the same thickness.


These are a few of the different fiber plates I have tried. I'm not going to name names, but because you are interested in APE, the plate in the upper left is one of theirs. Notice that they don't all look alike.


Notice how much less material is in the lower left's plate. If I measure the width of the the substrate, they are all about 0.550". This plate measures 0.470". Do you think this matters? Also notice how the substrate is made. The tab on the lower left is curled over. One other very important thing to notice is how the upper right plate differs from the other three. The fiber pads are all individual. I have had friends who have told me that they have torn these pads off before. I have never seen this problem firsthand.


The thickness of the substrate also changes a lot from company to company. Looking at the side profile, the far left is the APE plate. Notice how thick the two plates are to the right. Do you think it is better to have a thicker substrate? Notice the fiber thickness is about the same on all of the plates. The second from the left is our rolled over tab design. Measuring the thickness from left (APE) to right, 0.050, 0.035/0.075, 0.109 and 0.105 inches. The second from the left I measured both the plate thickness and the rolled over edge. Both left side plates are sold as high performance. Do you think that a thicker plate changes how fast the temperature rises in the stackup? Which plate would you choose for your bike.


The reason I am showing these is to give you some kind of feel for the different parts that can be sold to fit the GS. If the plates work in my race bike, I feel pretty good they will hold the power of my stock antique street bike.

[Anonymous]

That is a great post. It sure belongs in the garage section as an excellent learning/teaching tool. Thanks for the time you spent to do this for us.

[Paul]

When I started racing my GS, I was all for buying the "performance" clutch plates & springs. But I used to have a lot of bits off a tuning shop about 30 miles away from me. He used to make his money by importing & reselling American tuning parts. He was the European agent for Orient Express. But he told me to forget the extra plate kits & the "gorilla" springs & stick with stock Suzuki parts - which he couldn't sell me as he wasn't a Suzuki parts dealer!
Go figure!
When I started to make serious horsepower I could destroy a clutch in just one or two runs - then I installed a lock-up and never had another problem.
Another thing - an extra plate kit has thinner plates (got to be to get them in) so the tabs are thinner so dig into the clutch faster, which can then cause the clutch to drag.
Reading what I've just written I see that I'm just repeating what Leroy said above.

[Mr. Jiggles]

Excellent post, Lecroy.

For future reference would you care to mention who makes the last three fiber plates?

[Anonymous]

what causes the plates to break

Does anyone know what causes the friction plates to break? What color should the steel plates be before replacing? I didnt find any bluing but I did notice some glazing that should be easy to remove. Thanks for all of the info.

[Mark Harrop]

Damn good post.

When I changed the clutch in my 750, I was told by someone on this board to go with the stock components.

Like a dummy, I installed HD springs. After 10 minutes of stop and go traffic...I swore I was getting carpal tunnel syndrome. Put the stockers back in...didn't notice any difference except in lever-pull.

I would like to try a lockup clutch. I hear you can run half the number of springs and really lighten up the pull. How do they hold up on the street. Are they harder on the basket?

[BadBillyB]

Like Paul said above, the factory Suzuki clutch plates are the best. The thinner plates are steel and the thicker (stock) plates are aluminum. They dont dig ditches in the basket nearly as bad as the steel ones. The factory plates with stock or slightly stiffer than stock springs would be the best set-up in a mildly modified 1100.......I have a forged MTC 1100 basket in my GS1000 (which allowed me to run 1 more friction plate) with the red race springs and factory friction plates and it works flawless....Good for up to 200 HP.......Billy

[massakins]

I've used both OEM and APE fiber plates in my dragbike (slick, wheelie bar, lockup, 225hp w turbo, 740lb). A lot of trial and error has resulted in several clutch issues, but I am very impressed with the APE unit. Your application may indeed vary, but I found the APE plates to be approximately 1/3 the price of OEM and more readily available. This was the reason for my purchase of the first set. The OEM plates are very good as well, but can get pricey and aren't always readily available.

Today I have an APE set installed, plus one spare APE set and three spare OEM sets. One very bad day at the track in 2002 I consumed four sets of plates. That's behind me now, but its good to have the spares.

I'd be very reluctant to deviate from these two sources for the rigors of drag racing.

[lecroy]

Yes, both the APE and the lower left plates substrates are steel. The two I show on the right are aluminum. As far has how the steel versus the aluminum substrates causing damage to the basket, to be quite honest, I have not seen a problem with the stock basket or the billet baskets I use.

But, consider this:

Measuring the weight of a single plate using a Sartorius scale, the APE plate came in at 76.04g. The lower left 54.70. Upper right, 41.55 and bottom right 40.76. I am guessing that the reason the lower left's plate is so narrow was to offset some of the weight by giving up surface area.

So, 9 plates X 76.04 = 684.36g (not including the extra steel plate needed)
8 plates X 40.76 = 326.08g
or a difference of 358g or 0.8 lbs.

Do you want this extra spinning mass in your bike?

So, what about the surface area? The APE pad has a surface area of 8.9sqin per side. The lower left is 6.0, the upper right is 6.0 and the lower right is 7.1. Interesting the lower left, even with all that subtrate removed, is very close in weight and surface area to the two plates on the right, plus its made of steel.

Is more surface area better? There are just too many things to consider to make a call.

As for the cost, I really can't comment on the price difference. It's not something I would even consider. This is a performance forum.

No, I would not recommend putting a lockup on a street bike with the setup I am using. Way too little weight and too light of spring tension. If I put my current setup on my stock GS, I would be replacing plates more often than I would care to. Sure you could put a lockup on a streetbike and run all 6 stock springs, but why? For looks? Maybe to brag? I don't see what it's getting you.

This idea of clutch tuning is way to complex for this thred. There are just way too many things going on. Someone need to write a book on this and make lots of money from those of us who have no idea what we are doing. I have my wallet open.

I have never broke a steel or aluminum substrate. I remember one of my old bikes in the 70's having fiber substrates. Now those I broke. Does anyone use these still?

Well, hope this helps clear up some of your questions.

[kz]

Interessting info lecroy

I tuned my engine without replacing the clutch, stock clutch, used approx. 20.000 km on stock engine.

As I tested the bike on a dyno the clutch started to slip at heavy load.

I put in HD springs and the slipping problem went away.

So far so good.....

BUT, after a day in mixed traffic with stop and go, my left hand wasen't in the shape it used to be.....

The last part of the trip I actually only used the clutch for starting and shifted without pulling the clutch.

If I understand the posts here correctely I have two choices to reduce the needed power for pulling the clutchlever:

Replace half of the springs to stock or bye a complete new stock OEM fibers and/or plate and mount stock plates.

Do you think this engine (1327 see link below) will work without slipping, if I mount brand new stock OEM fibers?

http://www.karl.zellner.com/Dynojet1327-RS40.jpg