Fitting a sigma Slipper Clutch

Done a good mod that people might want to copy? Post it here - full step-by-step instructions and pix.

FAQs can go in here too
User avatar
No. 47
Master of the twisties
 
Posts: 2824
Joined: Sat Jan 10, 2009 5:14 pm
Location: London and Kent

Re: Fitting a sigma Slipper Clutch

Postby No. 47 » Sun May 12, 2013 2:54 pm

Superdan - just trawled back through the thread and have a couple of questions:

- the last clutch plate is a friction plate, not a steel plate, in the OE set-up - did you replace that or the last OE steel plate with a steel GXSR plate?

- what do you mean by 'locking' the last plate?

-to check clutch centre/pressure plate tolerance, measure between the top of clutch centre and top of of pressure plate through one or more of the holes in the pressure plate with no plates fitted, then same again with plates fitted - difference should be 1.5mm - is that right?
'08 ex-Battle race KTM Superduke 990 R No.47
'08 OE KTM Superduke 990 R
'01 Ducati 996S

User avatar
Superdan
Thunder pumpkin rider
 
Posts: 6163
Joined: Wed Mar 28, 2007 1:58 pm
Location: North Lincs UK

Re: Fitting a sigma Slipper Clutch

Postby Superdan » Sun May 12, 2013 3:16 pm

I did swap my last plate for a gsxr one because that's what instructions said, however Tonys instructions made no mention of the 3 different gsxr plates you could use so we left it as stock.

Say you put all the plates in at 12 o'clock for example, the last plate goes in at 2 oclock, however again Tonys instructions made no mention of this and pics showed all plates in line so that's what we did.

As for last Q I never measured anything :D

User avatar
No. 47
Master of the twisties
 
Posts: 2824
Joined: Sat Jan 10, 2009 5:14 pm
Location: London and Kent

Re: Fitting a sigma Slipper Clutch

Postby No. 47 » Sun May 12, 2013 3:46 pm

These are the instructions I have (refers to Suzuki plates but not re replacing last friction plate with steel plate...................):

Sigma Performance Slipper Clutch for KTM990

Thank you for choosing a quality Sigma Performance Competition part. The Centre of the clutch now has a ball and ramp mechanism. When the rear wheel wants to turn faster than the engine this lifts the centre of the clutch until it pushes the pressure plate off the clutch friction plate pack and allows it to slip. The thickness and condition of the clutch pack is critical to the correct operation of the clutch and should be checked regularly. The clutch may be damaged if acceptable tolerances are not maintained. For more information on slipper clutches and their set ups see the slipper clutch section of sigmaperformance.com

** This clutch is designed to work with 6 x Suzuki GSXR1000K5/6/7 clutch springs part # 21413-41G00. Not supplied **
A KTM mechanic should assemble the clutch as follows.
Read the instructions and look at the photos before you start.
a) Access the Clutch in accordance with the KTM Workshop manual.
b) Using KTM Workshop tools remove old clutch centre.
c) Carefully record the order in which the clutch comes apart.
d) Clean all Loctite from the threads of the gearbox shaft. Clean the threads on shaft and inside the BIG Main standard nut with brake cleaner. (A)
e) Install preassembled slipper clutch drum. Ensure the clutch is home on the shaft..(B)
f) Place the supplied washer over the clutch centre (C ) IMPORTANT, the large washer acts as a travel limiter for the clutch lift mechanism. It must be on the shaft immediately next to the clutch centre. Do not use the standard washers.
g) Loctite (Loctite No. 620) the STD main nut (D) onto the top of the assembly at the standard torque settings (127 Nm) (E) while holding the unit with a standard KTM Clutch holding tool .
h) Install the standard clutch plates in the basket in a different order to standard. (F) first install a normal friction surface small I/D friction plate, (G) then a steel plate. Then fit (H) the chatter rings and (I) then the large I/D ‘narrow friction surface’ plate. The rest of the plates are fitted exactly as they came apart (J).
i) Install original clutch pushrod spacer to pressure plate and mount it to clutch drum (K) . Use 6 x Suzuki GSXR1000K5/6/7 springs (L) with the Kit buckets, tighten to 8-10 Nm (M,N)
j) Check correct clearance between the top of the clutch centre and the pressure plate using the hole in pressure plate. Correct clearance is around 1.5 mm. If you need to adjust the pack thickness the following standard steel plates are available from Suzuki. 21451-41G10-000 2.0mm thick, 21451-41G00-000 2.3mm thick, 21451-41G20-000 2.6mm thick.
k) For more information please see the separate instructions on the attached CD.
l) Remove the aluminium spacer from the inside of the clutch cover (O,P)
m) Using new gasket refit Clutch cover according to KTM workshop manual.
LIST OF PARTS
1 pc. Clutch drum preassembled
1 pc. Large washer
1 pc. Pressure plate
6 pcs. Spring buckets
6 pcs. Bolt M6

This is a competition accessory; for track or extreme use we recommend the clutch be stripped and the plate pack measured and inspected regularly.
Sigma Performance Limited Reg. No 3690135
Registered Office. Hanover House 18 Mount Ephraim Road Tunbridge Wells Kent TN1 1ED


and have just found this re checking clearance (refers to rotating metal plates but it's only the friction plates that have notched tabs):

Sigma Slipper Clutch, clearance checking and adjustment.

Clearance.

This procedure is recommended to ensure your clutch is set up correctly. If you use a new standard clutch pack on a clutch assembled correctly on to the bike then you should be able to use the clutch immediately with no additional work necessary to set it up for correct operation.

If you hold the pressure plate up to the light you will see that there are several holes through it that are not required either for the springs or the clutch centre. They are the furthest out from the centre. These holes are clearance checking holes. If you turn the pressure plate over and look at the pressure plate from the ‘back’ you will see they all come out in the groove that takes the clutch centre when the clutch is assembled. We use these holes, together with a depth gauge, to measure how far the centre has to rise when the slipper mechanism is activated.

All clutch metal plates have small notches cut in them. These deliberately destabilize the balance of the clutch plates and help the clutch pack ‘break’ when the lever is pulled in. On assembly make sure the notches are distributed randomly.

This procedure is normally done with the clutch on the bike but if you wish can be done off the bike (our pictures are of a clutch off the bike only for clarity).

1) Before you fit any plates to the clutch, place the pressure plate on to the top of the clutch centre.
2) If you look through the clearance check holes you will see the top edge of the clutch centre.
3) Simply measure the depth of the hole through the pressure plate to the clutch centre. The measurement differs depending on the design of the clutch. Pic a) and Pic b)
4) Assemble the clutch with all the correct plates (check your clutch instructions!) springs and spring collars.
5) Now, simply recheck the depth of the holes. The plate pack should have lifted the pressure plate slightly and the depth of the holes should be slightly greater than before. Pic c)
6) Subtract the first measurement (Para 3 above) from the second (Para 5 above) and you will get the clearance between the centre and the pressure plate A new unworn clutch pack should give a measurement of 1 to 1.2mm (1.5 for big twins) more than before..
7) For general track and other non-competition use the clearance should be between 1.0 and 1.2mm (1.5 for big twins). Check that the clutch and the clutch pack is assembled correctly if the clearance is over 2.0mm with a standard clutch pack. If the clearance is much below 1.0mm your clutch pack is worn and you should consider new friction plates.
8) Different clearances can give different effects. 1.0 to 1.2mm (1.5 for big twins) is ‘normal’. This measurement means the clutch will require little maintenance and will work well in most circumstances.
9) We include pictures of several different clutches to show the clearance check hole positions together with a clutch dismantled pic to save you from having to take it apart to see inside!

Changing the amount of engine braking felt through the clutch.

A second adjustment is to change the strength of the main clutch springs or their preload. The stronger the spring rate or the higher the preload the harder the clutch centre has to work to hold the clutch partially disengaged. The effect is to transmit more engine braking through, BUT it gives the plates a much harder time and they will wear out more quickly.

You do not have to change all the springs; you can say have 2 of the relevant manufacturers race kit springs and 3 (or 4 depending on the clutch) street ones, or three race kit springs, or four, the more stiff race kit springs means the more engine braking is transmitted through. Just make sure the race kit springs are distributed opposite each other to equalise their effect. Ensure you only use approved race kit springs from the relevant manufacturer or the correct additional preload collars provided by us. Before use ensure that any springs or preload collars fitted do not coil bind at full lift.

If you do deliberately increase the spring rate or preload for more engine braking feel you must monitor pack wear more closely as the higher loads inside the clutch will increase clutch pack temperatures and wear significantly.

Some times major increases in engine power mean stiffer springs are needed to stop clutch slippage going forward. Things will work far better if the increase in spring rate is just sufficient to handle the extra power. For some bikes we have built clutches with different angle ramps to ensure that stiffer springs do not affect the gentle slip action most top racers prefer.

Remember, all or clutches are designed to function just fine with a new original clutch pack, and new original clutch springs. If you insist on experimentation these numbers are intended to provide a little guidance to competent mechanics. Before you start playing remember that we believe the standard numbers, a 1 to 1.2 mm clearance (1.5mm on Ducati’s and other big twins) and the standard plates and will do just fine for most riders in most situations. All these comments should be read in conjunction with the fitting instructions included with your clutch.

If you want more information on setup, including the latest information we have on racing settings check out the race setup page in the slipper clutch section of our website http://www.sigmaperformance.com
'08 ex-Battle race KTM Superduke 990 R No.47
'08 OE KTM Superduke 990 R
'01 Ducati 996S

User avatar
No. 47
Master of the twisties
 
Posts: 2824
Joined: Sat Jan 10, 2009 5:14 pm
Location: London and Kent

Re: Fitting a sigma Slipper Clutch

Postby No. 47 » Mon May 13, 2013 12:11 pm

No. 47 wrote:Just stripped out the clutch - 10 steel plates (no. 7 on the parts fiche), 11 friction plates but all the same id (no. 8 on the parts fiche?) but some with slightly different friction pad pattern, no Belleville spring (no. 11 on the parts fiche) and no thrust washer (no. 12 on the parts fiche)..........................no idea why it's not been fitted as per Sigma instructions.

Can see from the parts fiche that friction plate no. 10 is a larger id than the no.8's but what's different about no.9?


Neil Spalding tells me that this "set up is pretty standard for racing and if its working fine wouldn’t recommend changing it. Indeed we ask that the std ‘chatter rings’ and their large id plate be removed from quite a lot of clutches.............."
'08 ex-Battle race KTM Superduke 990 R No.47
'08 OE KTM Superduke 990 R
'01 Ducati 996S

User avatar
No. 47
Master of the twisties
 
Posts: 2824
Joined: Sat Jan 10, 2009 5:14 pm
Location: London and Kent

Re: Fitting a sigma Slipper Clutch

Postby No. 47 » Mon May 13, 2013 12:28 pm

Mustn't forget to soak the new friction plates in oil for 24 hours as reminded by Spalders - had forgotten that tip learned from many years on old BSAs, Triumphs, Nortons and, very briefly, a Vincent (should've kept that one) - too many years on Ducati dry clutches, I guess.
'08 ex-Battle race KTM Superduke 990 R No.47
'08 OE KTM Superduke 990 R
'01 Ducati 996S

User avatar
No. 47
Master of the twisties
 
Posts: 2824
Joined: Sat Jan 10, 2009 5:14 pm
Location: London and Kent

Re: Fitting a sigma Slipper Clutch

Postby No. 47 » Wed May 15, 2013 12:30 pm

Received clutch kit and now clear that thrust plate and Belleville spring sit inside larger id friction plate so o/a clutch pack depth unchanged with/without them - one question, Belleville spring is installed with concave surface outermost?
'08 ex-Battle race KTM Superduke 990 R No.47
'08 OE KTM Superduke 990 R
'01 Ducati 996S

User avatar
Superdan
Thunder pumpkin rider
 
Posts: 6163
Joined: Wed Mar 28, 2007 1:58 pm
Location: North Lincs UK

Re: Fitting a sigma Slipper Clutch

Postby Superdan » Wed May 15, 2013 12:41 pm

yes like this not sure if thrust washer/beville spring are the same but I know the part you mean:

Image

After fitting Tony's he rang Spalders and said the clutch pack should not be aligned as per OEM and the SIGMA photos, but in a random order.

User avatar
No. 47
Master of the twisties
 
Posts: 2824
Joined: Sat Jan 10, 2009 5:14 pm
Location: London and Kent

Re: Fitting a sigma Slipper Clutch

Postby No. 47 » Wed May 15, 2013 12:52 pm

Ta - thrust washer/plate is flat in section profile and the Belleville spring curved in section profile (not curved overall across diameter) - I assume that your diagram is outside to lhs and engine/gearbox to rhs.
'08 ex-Battle race KTM Superduke 990 R No.47
'08 OE KTM Superduke 990 R
'01 Ducati 996S

User avatar
The Gin Reaper
moderator
 
Posts: 1052
Joined: Mon Mar 22, 2010 10:18 pm
Location: inspecting the tarmac at most racetrack hairpins.....Naarfolk ingerland

Re: Fitting a sigma Slipper Clutch

Postby The Gin Reaper » Wed May 15, 2013 1:37 pm

.... I see that our very own No47 made it on to Neil Spaldings of Eurosport and sigma slipper clutch fames twitter feed! ..... Good pic to but I can't find the link to it at the moment.... It looked like a very out of shape approach downhill into possibly Mansfield at cadwell?

https://mobile.twitter.com/Spalders/sta ... 5422088192
Favourite quote - "after watching him take everything so in his bloody stride, it made Jim Lovell look like a panicky little bitch!"

never argue with an idiot..... they will drag you down to their level and beat you with experience....

User avatar
The Gin Reaper
moderator
 
Posts: 1052
Joined: Mon Mar 22, 2010 10:18 pm
Location: inspecting the tarmac at most racetrack hairpins.....Naarfolk ingerland

Re: Fitting a sigma Slipper Clutch

Postby The Gin Reaper » Wed May 15, 2013 1:42 pm

Edit last... Not cadwell but found pic

https://mobile.twitter.com/Spalders/sta ... 0336197633

Image
Favourite quote - "after watching him take everything so in his bloody stride, it made Jim Lovell look like a panicky little bitch!"

never argue with an idiot..... they will drag you down to their level and beat you with experience....

User avatar
No. 47
Master of the twisties
 
Posts: 2824
Joined: Sat Jan 10, 2009 5:14 pm
Location: London and Kent

Re: Fitting a sigma Slipper Clutch

Postby No. 47 » Wed May 15, 2013 3:33 pm

What is this thing called Twitter?

Image

Image
'08 ex-Battle race KTM Superduke 990 R No.47
'08 OE KTM Superduke 990 R
'01 Ducati 996S

User avatar
Tony the Tiger
Two wheeled terror
 
Posts: 140
Joined: Sat Feb 23, 2013 3:44 pm
Location: North Lincs UK

Re: Fitting a sigma Slipper Clutch

Postby Tony the Tiger » Wed May 15, 2013 3:46 pm

The Gin Reaper wrote:Edit last... Not cadwell but found pic

https://mobile.twitter.com/Spalders/sta ... 0336197633

Image


Looks like Donington, braking for the Melbourne loop

User avatar
No. 47
Master of the twisties
 
Posts: 2824
Joined: Sat Jan 10, 2009 5:14 pm
Location: London and Kent

Re: Fitting a sigma Slipper Clutch

Postby No. 47 » Thu May 16, 2013 9:57 am

All done, all good - thanks for the input - will be replacing the GXSR springs and the OE with the race clutch plate set-up, though, and refitting the OE damper to see whether perceived additional slight vibration when clutch is disengaged is real or imagined.
'08 ex-Battle race KTM Superduke 990 R No.47
'08 OE KTM Superduke 990 R
'01 Ducati 996S

User avatar
No. 47
Master of the twisties
 
Posts: 2824
Joined: Sat Jan 10, 2009 5:14 pm
Location: London and Kent

Re: Fitting a sigma Slipper Clutch

Postby No. 47 » Thu May 16, 2013 10:30 pm

No. 47 wrote:..........but the basket can be rocked laterally slightly ..................anyone have their Sigma visible/accessible at the moment and let me know if theirs is similar or not?


Bump

Sigma, OE or any other.
'08 ex-Battle race KTM Superduke 990 R No.47
'08 OE KTM Superduke 990 R
'01 Ducati 996S

User avatar
No. 47
Master of the twisties
 
Posts: 2824
Joined: Sat Jan 10, 2009 5:14 pm
Location: London and Kent

Re: Fitting a sigma Slipper Clutch

Postby No. 47 » Fri May 24, 2013 7:39 pm

Anyone?
'08 ex-Battle race KTM Superduke 990 R No.47
'08 OE KTM Superduke 990 R
'01 Ducati 996S

User avatar
No. 47
Master of the twisties
 
Posts: 2824
Joined: Sat Jan 10, 2009 5:14 pm
Location: London and Kent

Re: Fitting a sigma Slipper Clutch

Postby No. 47 » Sat Apr 26, 2014 10:28 am

Just about to replace friction plates again as clutch started slipping shortly after swopping over to new engine - turns out my Sigma had been fitted with two flat washers under the main shaft hub nut and not the dished compressible washer supplied by Sigma - emailed Neil Spalding and he personally delivered a new one to my door foc (unlike Dan, have always found him really willing and able to help) - also tells me that the dished washer should be installed with concave face outwards/convex face inwards, ie "pointy side pointing inwards".

Still unclear why the first set of plates lasted the race miles plus circa 50k road miles and the last two sets only 10k road miles each though....................
'08 ex-Battle race KTM Superduke 990 R No.47
'08 OE KTM Superduke 990 R
'01 Ducati 996S

User avatar
No. 47
Master of the twisties
 
Posts: 2824
Joined: Sat Jan 10, 2009 5:14 pm
Location: London and Kent

Re: Fitting a sigma Slipper Clutch

Postby No. 47 » Wed Sep 10, 2014 9:38 am

No. 47 wrote:Still unclear why the first set of plates lasted the race miles plus circa 50k road miles and the last two sets only 10k road miles each though....................


This is likely reason:

Image

Image

Image

Inner bearing surface of pressure plate has worn to friction plate pad profile after circa 85k miles - new set of friction plates still give required 1.5mm depth though - new pressure plate on it's way.
'08 ex-Battle race KTM Superduke 990 R No.47
'08 OE KTM Superduke 990 R
'01 Ducati 996S

User avatar
No. 47
Master of the twisties
 
Posts: 2824
Joined: Sat Jan 10, 2009 5:14 pm
Location: London and Kent

Re: Fitting a Sigma Slipper Clutch

Postby No. 47 » Mon Aug 22, 2016 10:29 am

Another cheer for Neil Spalding at Sigma - replaced clutch friction plates over the weekend, due to clutch both dragging and slipping, and found new pressure plate had worn again exactly same as previous - texted Neil for advice and he came back immediately by texts and mobile phone calls despite the fact that he was in Brno covering the MotoGP (congrats to McPhie, Lowes and Crutchlow) - don't know many suppliers who would do that.......................looks like hub ball bearings/ramps have finally worn out at approaching 100k road miles plus race miles, ie not lifting pressure plate as far as it should be, so time for a complete new kit.
'08 ex-Battle race KTM Superduke 990 R No.47
'08 OE KTM Superduke 990 R
'01 Ducati 996S

SuperDoopa
Two wheeled terror
 
Posts: 324
Joined: Mon Jul 15, 2013 1:06 pm

Re: Fitting a Sigma Slipper Clutch

Postby SuperDoopa » Mon Aug 22, 2016 6:45 pm

No. 47 wrote:Another cheer for Neil Spalding at Sigma - replaced clutch friction plates over the weekend, due to clutch both dragging and slipping, and found new pressure plate had worn again exactly same as previous - texted Neil for advice and he came back immediately by texts and mobile phone calls despite the fact that he was in Brno covering the MotoGP (congrats to McPhie, Lowes and Crutchlow) - don't know many suppliers who would do that.......................looks like hub ball bearings/ramps have finally worn out at approaching 100k road miles plus race miles, ie not lifting pressure plate as far as it should be, so time for a complete new kit.


I follow Spalders on Twitter and he is one of the most interesting and informative blokes to follow. He has replied to some of my tweets personally, which were appreciated :)

User avatar
No. 47
Master of the twisties
 
Posts: 2824
Joined: Sat Jan 10, 2009 5:14 pm
Location: London and Kent

Re: Fitting a sigma Slipper Clutch

Postby No. 47 » Mon Aug 22, 2016 7:52 pm

Aye, not on Twitter myself but saw he tweeted (twittered?) photo of pressure plate and apologised for reference to customer complaint - Cal Crutchlow's dad offered a Morris Minor clutch.
'08 ex-Battle race KTM Superduke 990 R No.47
'08 OE KTM Superduke 990 R
'01 Ducati 996S

Previous

Return to How to do it!

Who is online

Users browsing this forum: No registered users and 1 guest