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Slipper clutch - talk to me


CRM

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So you probably know more than me about slippers, so forgive my lame explanation.
The new clutch seems to work ok, but coming down the box from 3rd to 2nd it still locks the rear a little more than i would like, and i would prefer a smoother slip.
In the dry this can kind of work, but in the wet it would lock the rear for sure.
the clutch action seems ok, not too light or heavy, no clutch "slip" in the conventional sense under load, and you get that "snap" from the lever on the way up the box when "giving it the large"
Perhaps @toosmooth Paul can add some to my shite explanation. 
Anyway based on the diagram below which bits do i need to swap to get the rear not to lock so keenly when backing it in* 

Items in green and purple are the items fitted now
Dick spring main = 800n i have a spare 900n in the box
Torque limiter spring = 1100n and i have options of 1300n and 950n 

suterslipper.jpg

 

* utterly by accident in a controlled crash that never quite manged to come to fruition 

 

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It's a balance, basically you want a softer torque limiting spring. 

You will not stop the rear locking in the wet, you need to go so soft you would get clutch slip under power. 

Shift down later in the braking zone is the simple answer. 

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9 minutes ago, Superdunc said:

It's a balance, basically you want a softer torque limiting spring. 

You will not stop the rear locking in the wet, you need to go so soft you would get clutch slip under power. 

Shift down later in the braking zone is the simple answer. 

So the 950 is likely to do the trick? 
Chances of it being used on track in the wet are - pretty low even for me.
I would shift down later - but i am a complete fanny

3 minutes ago, Gobert said:

Apart from changing the various "springs", have you checked the pack height?

No and with no spares to shuffle it is what it is really. 
Oddly it was only the shift down by pit wall i felt it try and lock a bit, on the way up to Rocket sure it squirmed but i managed to back it in and square it off with the power*

 

 

 

 

*in my head, however in reality i ended up on a slightly different trajectory but not one with a grassy outcome 

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4 minutes ago, CRM said:

No and with no spares to shuffle it is what it is really. 
Oddly it was only the shift down by pit wall i felt it try and lock a bit, on the way up to Rocket sure it squirmed but i managed to back it in and square it off with the power.

 

That design looks very similar to the STM and when I had one on my 750, pack height was critical to getting it to work as it should. Even if you haven't the spares to alter it, checking it might give you an idea on where your "problem" lies.

 

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1 minute ago, sev said:

All the spares are still available from Suter.  the discs are standard suter 48T I think.

https://suterproducts.com to find a uk distributor.

 

I was just about to post the same - I used to adjust the pack height with different width steels which I would have thought that Suter would have available for their clutches.

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To be fair, Fabian came back to me suggesting the 950N spring will help a lot and if needed they can make and supply an even looser one. 
Good support from these guys.
I bought it via Colchester Kawasaki MSS originally 

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Pack height is very important, but as this was supplied new  it wont be too high, and it hasnt done lots of miles or race starts. As the plates wear the stack will get smaller and cause more slip, not less.

The Suter on my Sxv was really sensitive to stack height, untill I fitted a stiffer torque spring.

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cheers.

The one thing about this bike that i never get used to is the mechanical screeching sound as you pull away from the clutch.
It did it on the OE clutch too, that initial bite and pulling off sounds a bit "race bike" if you know what i mean.
The Ducati just sounds jangly and rough, this is jangly and screechy.
Only hear it to get the bike moving, as soon as its moving its silent. 

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32 minutes ago, Superdunc said:

Pack height is very important, but as this was supplied new  it wont be too high, and it hasnt done lots of miles or race starts. As the plates wear the stack will get smaller and cause more slip, not less.

The Suter on my Sxv was really sensitive to stack height, until I welded it then hit it with the hammer. 

EHui7ML.jpeg

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On 6/10/2022 at 4:35 PM, CRM said:

So you probably know more than me about slippers, so forgive my lame explanation.
The new clutch seems to work ok, but coming down the box from 3rd to 2nd it still locks the rear a little more than i would like, and i would prefer a smoother slip.
In the dry this can kind of work, but in the wet it would lock the rear for sure.
the clutch action seems ok, not too light or heavy, no clutch "slip" in the conventional sense under load, and you get that "snap" from the lever on the way up the box when "giving it the large"
Perhaps @toosmooth Paul can add some to my shite explanation. 
Anyway based on the diagram below which bits do i need to swap to get the rear not to lock so keenly when backing it in* 

Items in green and purple are the items fitted now
Dick spring main = 800n i have a spare 900n in the box
Torque limiter spring = 1100n and i have options of 1300n and 950n 

suterslipper.jpg

 

* utterly by accident in a controlled crash that never quite manged to come to fruition 

 

AFAIK The disk (not dick) main spring (green) is the 'pull' of the clutch

the 'slipper clutch' anti-hopping bit is the the 'torque limiter spring' (purple)

The Slippery Suter I have in RC8R one also has three spring options for the purple one. 

I only have the one it came with, which I assume is the standard (middle stiffness) one, so I've not experimented*

From what I've read of the RC8 powerparts instructions, it mentions how to swap the (purple) springs and says

'the softer spring results in a more gentle response of the anti-hopping effect' 

so on yours, yes by the sounds of it, maybe you need to try the 950N

 

*tbh, I've not felt the need to, it seems to work just fine as it is - albeit that's on the road only so far

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On 6/10/2022 at 6:43 PM, CRM said:

So the 950 is likely to do the trick? 
Chances of it being used on track in the wet are - pretty low even for me.
I would shift down later - but i am a complete fanny

No and with no spares to shuffle it is what it is really. 
Oddly it was only the shift down by pit wall i felt it try and lock a bit, on the way up to Rocket sure it squirmed but i managed to back it in and square it off with the power*

 

 

 

 

*in my head, however in reality i ended up on a slightly different trajectory but not one with a grassy outcome 

On what bike is this? On the GSXR I had, I set up the secondary throttle plates to open the throttle ever so slightly when the main throttle was fully closed. That, together with the slipper, gave that two stroke feel

 

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10 hours ago, RonniB said:

On what bike is this? On the GSXR I had, I set up the secondary throttle plates to open the throttle ever so slightly when the main throttle was fully closed. That, together with the slipper, gave that two stroke feel

 

That'd terrifying, no closed throttle on fully closed throttle. 

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33 minutes ago, theo said:

That'd terrifying, no closed throttle on fully closed throttle. 

I concur; I run the BMW at maximum engine braking - I find it far too scary having little or none...

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10 hours ago, theo said:

That'd terrifying, no closed throttle on fully closed throttle. 

I think it was Chili who ran his Idle speed at 5000rpm on his WSBK SRAD, to reduce engine braking.

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Both my H2 SX SE and and the Gen-3 Busa had adjustable engine braking in the menu done by the ECU.

 

“Engine braking control system cancels out the effect of engine braking to suppress rear tyre sliding or skipping and provide even smoother, more controllable behaviour than ever before. A choice of three modes plus an OFF setting allows the rider to control the effective strength of engine braking to match riding conditions or user preference” 

 

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12 hours ago, theo said:

That'd terrifying, no closed throttle on fully closed throttle. 

Actually not, it felt very good.

I copied the maps from the full power map, to the two others, so the only difference was the amount of engine braking. That meant I could adjust it on the fly. And I only enabled it in 2, 3 and 4 gear. 

The woolich stuff for the K9 was quite open to play with this

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1 hour ago, Superdunc said:

I think it was Chili who ran his Idle speed at 5000rpm on his WSBK SRAD, to reduce engine braking.

This was a common thing a few year’s ago. 
The Drayton Croft Mallory Park race school NC30’s had a 4000rpm idle.

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I think the natural learning progression with the smaller two strokes back then and the nature of the tires, made the wheels-in-line the preferred style. In which less engine braking helps. I remember racing on michelin pilot race, their operating window being super narrow, if they had a slide, I had a shit and an off..

 

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14 hours ago, theo said:

That'd terrifying, no closed throttle on fully closed throttle.

When I bought that PoS minitiwn I really struggled to get used to the relatively high engine braking it had compared to the ZX6r. On one of the coaching sessions that Bemsee provided on the practice day, the instructor (can't remember who) suggested I try and increase the revs to about 2.5k at tickover once the bike had warmed up. It helped massively with entry to the slower corners like Druids, Montreal or the crappy Melbourne loop.

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  • 1 month later...
On 6/15/2022 at 8:45 PM, Superdunc said:

I think it was Chili who ran his Idle speed at 5000rpm on his WSBK SRAD, to reduce engine braking.

My local dealer ran a tuned SRAD that was set at 3,5K. Made a funny noise, when he selected 1st from a standstill 

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Small update, i removed the clutch the other day and fitted the 950N spring, and even banging it down into first at around 50+ it doesnt really lock the rear anywhere near as much as it did so i am happy with that.
HOWEVER - the judder is now unreal, almost makes the clutch unusable and a real on / off affair even with the graunching sound on the initial pull away.
I wonder if the lighter spring has had an impact on that or perhaps the rear springs need some looking at

 

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Also parts #25.1 and #25 in the diagram show the order they need to be in to allow #6 to locate and be secure with the circlip #9
However 25.1 and 25 need to be reversed to fit as this back to front order is the only way #6 can sit right and locate and be secured.

i wonder if this would be having the judder and grabby issue i am getting. 

thoughts ? 

suterslipper.jpg

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Yes, I would say fitting the parts in the incorrect order is almost certainly causing the judder.

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well managed to get it in the correct way as shown in the diagram - but not without incident!!.
test ride will have to wait a while - unless i ride it to A&E, to be fair my flesh and blood may act as a cush drive

It took around 20 mins to actually stop bleeding and is a nice deep stab wound lol. end of finger 2h later is still tingling.

4a1984c5-6f49-4d1f-ac3a-2e084abc0901.jpg

 

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