M695 clutch questions

[cencalal]

Is the amount of slip in the slipper clutch adjustable at all?  I know I'm in learning mode with the new 695, but at this point I wouldn't mind if it slipped a bit less.  This M695 has 9000 miles on it and the clutch doesn't slip on acceleration. All my other bikes have had standard wet clutches, and downshifting presents no problems...

Why was the clutch lever adjuster screw glued in place on these bikes.  I'v got small hands (in fact everything about me is small, which is why I bought the little Monster - well, maybe not everything... ), so I removed the glue and turned the screw out a turn to get the engagement a bit closer to the bar.  I've read that this is an issue for others too.

I'll be changing all the fluids, including the clutch...

Thanks

[BK_856er]

The adjuster screw on the clutch lever is to set the free play at the master cylinder.  It's epoxied in place so it's not messed with.  Inadequate free play can lead to clutch drag and overheating/slippage/accelerated wear.  The correct way to adjust the lever position is with aftermarket adjustable levers.  But there too, you need to get the correct free play after fitting the new lever.  Yeah, the stock setup has the takeup pretty far out from the bar.  Turning the screw out increased your free play, so you shouldn't have a (new) problem with drag, but now you have some extra slop before disengagement.

To your question, no the wet "slipper" or APTC clutch is not adjustable.  I suppose you could get in there and tweak spring preload, but not worth the effort.  Doesn't sound like your issue, but make sure to run a proper moto oil.  The APTC can be sensitive to oil brand/type/viscosity.

BK

[cencalal]

The free play is fine and lever reach is good enough to not change levers.  I was just wondering why they would defeat the adjuster - not what the purpose of the glue was. 

I just changed the oil today - don't know what was in there, but it was dirty and seemed thicker than the Castrol RS 10/40 I put in.  But the clutch wasn't slipping under power.  I just wouldn't mind a bit of engine braking.  Maybe I should just stay on the gas and not slow down very often! 

[BK_856er]

Presumably they locked in the correct plunger free play adjustment to discourage customers from messing with it, thinking it was a lever height adjuster for example, and causing warranty claims.  The brake side is the same way - big safety issue there.

Some folks have swapped out the APTC for a standard wet clutch.  That would gain you some engine braking.

Otherwise, the APTC has three small springs under the pressure plate that, together with the stack height, control the slipping behavior.  Maybe fresh springs or shimmed springs or a new clutch pack would help.

BK

[clubhousemotorsports]

As others have said do not play with lever bleed down. Buy a reach adjustable lever and make that one fit you better (don't forget to set bleed down on that one).

Yes the APTC clutch can be tweaked you can but a kit from parts unlimited to do so. There are four or five different kits so the size is probably different between them I would check with Adige on which one you may need. I happen to be installing a couple of these in Aprilia sxv550's right now, one has been used for a few years of track duty so it has been used and used hard for a while. And just an FYI these same clutches sell for about $900 so do not think Ducati put in a cheap clutch.

All the tuning kits are is shims of varying thickness to preload the pressure plate, more preload = less slip on deceleration try a 13x18x1.5mm shim
the kit comes with 4 size shims but you could easily make them.

[cencalal]

Thanks for the responses.  As i see it, a bit of lever reach adjustment is possible as long as you don't turn the screw in far enough to take out all the lever free play, causing clutch slip, or turn it out so far that the master cylinder piston isn't fully depressed, causing clutch drag.

I'm not sure what is meant by "bleed down", but I'll be changing the clutch fluid and making sure it's properly bled.

Took a look at the Adige site, where they say that the APTC clutch also functions on acceleration as a bit of traction control - can someone explain this?  And shimming the springs for a bit more engine braking seems simple enough, if later on I feel I need it, but is there a downside to that mod?
I always enjoy getting to know a new bike - haven't had one yet that factory did "right".  But then I haven't had a Desmoseidici yet...   

[Speeddog]

~~~SNIP~~~
... where they say that the APTC clutch also functions on acceleration as a bit of traction control - can someone explain this? 
~~~SNIP~~~

Got a link to what you were reading?

[BK_856er]

I've been out of the loop for a couple of years and it's nice to learn that Adige offers shims to tweak the APTC - cool! 

BK

[cencalal]

There wasn't much to read at Adige - I knew about the function on downshifting and the lighter lever pull, but hadn't heard the claim about "traction control".  They're presenting the APTC clutch as a racing tool - my impression (limited) before this was that it was more of a novice rider aid...?  To me it sort of feels like riding a two stroke - like you need to add some rear brake.  If there's no disadvantage in shimming the springs I may eventually give that a try. 

http://www.adige.eu/public/ENG/products/aptc.asp

[Howie]

Clutch free play should be 1-1.5mm, less and you will have problems with slip.  If the compensating port in the master becomes blocked or partially blocked pressure will build and the clutch will slip. The free play is there to compensate for expansion from temperature.  Whenever you see a screw epoxied over the manufacturer did it for a reason.

The stock clutch in your 695 is a far cry from a true racing slipper.  You got it right that the purpose is lighter pull and prevent lock up on a ham-fisted downshift.  It should not slip on acceleration and should not slip on decel under normal shifting.  If it slips on acceleration you have a problem that needs attention.  Could be lack of free play or wrong oil.  Check cheap first.  If you are rev matching on down shifts shim the clutch.  If not, alter your riding technique

[cencalal]

Is Adige referring to a different version of this clutch? 

[clubhousemotorsports]

The stock clutch is a APTC slipper clutch it is the same slipper that is sold for many racing motards as well as Ducati. Ducati put it in to be an easier clutch pull (which it has) but it does not change the fact it is still a slipper clutch and is the same as any other RACING slipper clutch. The only differences are how they are tuned and the system used.

Are there better wet slipper clutches.. sure. But I have a few racers who swear by the one you have now in your bike. A slipper clutch has benefits racing but lets not get ahead of ourselves with the "racing" label. It is there as an insurance policy in case you take too many downshifts or go the wrong way, also give stop and go traffic an easier pull.
All good things right?

Slipping on acceleration is likely a wear problem or a setup problem (clutch lever), sort it out and all will be good. A non slipper will have the same problems if it is also not set up properly so stem one is to get the hydraulics right. The screw in your lever is bleed down NOT reach adjust ability. You can play with it and bring the lever closer to the bar with it but you are giving up clutch travel in doing so. As long as you do not find you have clutch drag it should be fine. If you cannot get neutral then you went too far.

Plus remember you are wearing out your clutch every time you slip the clutch,  on acceleration from a non-engaging clutch or too much slipper function in deceleration. The Aprilia I was working on gets 1-2 years out of a clutch pack because he uses the slipper function often on the track.

[cencalal]

Thanks clubhouse.  I guess I somehow gave the impression that I was having clutch trouble, but all I meant to say was that I noticed reduced engine braking on deceleration, which I assumed was normal, with this clutch.  All seems fine otherwise - no slip on accel, no drag, smooth shifting, etc.  I've adjusted the lever so that I have a bit (10mm) of free play, and the engagement point is still well away from the bar, with no change in performance. 

So maybe I should ask - is it normal for this clutch to feel like there's less engine braking on decel than my SV650 has? 

As for the "racing" thing, the Adige website, which has only one small page about the APTC clutch, says this:

  The APTCâ,,¢ works: while downshifting, exiting a turn, during acceleration. This form of traction control allows for a far more rapid ascent to top speed.

Here's that link again:     http://www.adige.eu/public/ENG/products/aptc.asp

Thanks again
Alan

[Speeddog]

The way the APTC clutch works, it pinches the clutch plates tighter when you're on the throttle.

I can't see how it would perform any sort of 'traction control'.

[clubhousemotorsports]

Traction control from the aspect that when you down shift too much and the rear wheel is hopping a foot in the air because it is trying to lock the rear/spin the motor too slow.  The slipper should disengage the clutch on deceleration allowing the rear tire to keep traction = traction control.

the SV does not normally have a slipper clutch so yes this is a function of the slipper doing its job. You can tune some of this out by increasing the force needed to get it slipping. pre-load on the large clutch springs between 1-1.5mm will make it a higher force to break the pack open on decel. The preload is clamping the pack together but when it is separating the spring rate is the same so once it is moving it is as original.

Do you want more engine braking?
If so then try tuning the preload and see if there is a point where you are happiest. If not , you simply may not want a slipper clutch. I would bet that there is someone who would take yours off your hands.