SS Clutch - how heavy?

conti-mental · Post by **conti-mental** » Thu Oct 30, 2008 12:08 pm

Hi Guys,

Just took the rebuilt SS out for a spin, and it's 'traditional' clutch action is causing me to question the setup.

It's fitted with Surflex plates, and I've used these on Triumphs in the past with very unsatisfactory results - needed huge spring preload and was virtually impossible to get a slip-free clutch without it dragging.

I remember having to use 450 springs on the SS to stop it slipping, and the net result is one seriously heavy clutch!

I recently got an upgraded clutch for the Triumph which is perfect - light and slip free with no dragging.

The question is...is the same stuff available for the SS?

Or can anyone recommend some tendon strengthening exercises?

Cheers!

Andy

Post by **BevHevSteve** » Thu Oct 30, 2008 12:21 pm

http://www.bevelheaven.com/~BB/phpBB2/v ... c.php?t=92

read the above post. You need to do some simple maintenance on the clutch rods and/or cable that is all.

My clutch pull is not so bad with the heavy springs etc.......

conti-mental · Post by **conti-mental** » Thu Oct 30, 2008 3:42 pm

Hi Steve,

The clutch action is actually nice'n'smooth...it's just heavy!
I just rebuilt it, so I'm fairly confident there's little or no stiction in the pushrod assembly, which conforms to the parts book.

Where I'm driving from is that the clutch is inherently heavy to prevent slip. I seem to remember the 450 springs were an essential mod for racing.

the Surflex plates I've had experience of need heavy springs to work, but when I got some replacement plates for the Bonnie (regrettably un-branded, but are a lighter coloured compound and I think they're on an alloy base-plate - reminiscent of J*p plates) it made me realise that the Surflex plates were the problem, and they look to be the same material as on the SS - I was just wondering if there was anything out there in the aftermarket for Dukes?

Cheers,

Andy

nottonight68 · Post by **nottonight68** » Sun Nov 02, 2008 2:04 am

heavy clutch?
i've had my ss for 31 years and clutch slip was always a problem
i put in new plates and used h/duty 450 springs-made clutch a gorilla job and it still slipped
i now think its the plates/design
solution please

abmartin · Post by **abmartin** » Sun Nov 02, 2008 6:14 am

I just did a back-to-back clutch test comparison on the bikes in my shed. Bearing in mind that the temperature is at the freezing point, these are my results:

1937 Ariel Red Hunter - light action
1970 Bonneville - light action
1977 Yamaha XT500 - medium action
1979 900SS - the heaviest but not a whole lot more than the XT.

I believe my Duke was fitted with Surflex plates from new. Unlike the experience of others, I have never noticed a slipping problem. In any case my experience with Italian bikes is that they generally have heavy controls.

nottonight68 · Post by **nottonight68** » Mon Nov 03, 2008 12:08 am

being that you live in canada
may'be its an oil heat/viscosity problem
perhaps other owners can comment
hot/cold climate-slip/no slip

abmartin · Post by **abmartin** » Mon Nov 03, 2008 1:47 pm

It actually does get hot here in Canada. It just doesn't last as long as it does in Australia. Come over and check it out sometime - lots of other Aussies do!

conti-mental · Post by **conti-mental** » Sat Nov 15, 2008 2:08 am

abmartin wrote:I just did a back-to-back clutch test comparison on the bikes in my shed. Bearing in mind that the temperature is at the freezing point, these are my results:

1937 Ariel Red Hunter - light action
1970 Bonneville - light action
1977 Yamaha XT500 - medium action
1979 900SS - the heaviest but not a whole lot more than the XT.

I believe my Duke was fitted with Surflex plates from new. Unlike the experience of others, I have never noticed a slipping problem. In any case my experience with Italian bikes is that they generally have heavy controls.

This is my experience: My clutch works fine, it's just that after a long lay-off (i.e. not riding the SS), and riding a lot of other stuff, it's made me realise that it's unacceptable by modern standards. Come to think of it, the standard brake setup needs a reasonable amount of force to work well...

I was figuring that if the aftermarket can do something for lowlife Triumph owners, then surely there's hope for upstanding citizens like us

That said, maybe I'm missing the point - if originality is everything I'd be leaving well alone, but unfortunately I'd rather ride it, and the roads around here require a lot of gearchanging!

Cheers,

Andy

Pescara · Post by **Pescara** » Wed Nov 19, 2008 9:54 am

I don't believe all SS clutches were created equal... nor were all Surflex plates created equal, or all SS clutch springs.

As I understand it, the OEM plates were Surflex but the design changed sometime in the early 80s. The change was to delete lining material at the inner edge of the plates, making the average radius of the remaining material larger. This increased the torque capacity of the clutch. I believe the plates sold as "competition" or "Surflex" are the later type.

I found in researching my own bikes that the springs changed somewhere along the line too. Later springs are longer and are not interchangeable. The heavy 450 springs are often installed as replacements for the early type of spring.

On both my black/gold '80 900SS and blue (very late) '82 Darmah I used the late type Surflex plates with stock springs to resolve slipping. 450 springs did not fit either of those bikes. The resulting action was and still is a bit heavy, but not nearly so heavy as it is on bikes with 450 springs... and the clutch neither slips or sticks engaged when the bike stands for a while.

Hope that is helpful. My notes above are based on experience probably a decade ago, and my memory. Somebody more recently involved may wish to comment. That said, the results of that decade old work are still working fine on my SS!

SS brakes can be made more sensitive with EBC HH pads, and contrary to popular opinion I have not found that they wear cast iron disks rapidly.

conti-mental · Post by **conti-mental** » Wed Nov 19, 2008 11:19 am

Pescara,

Thanks for the VERY useful information - the EBC pads will be ordered, and soon! I may have to skim them down for the early calipers, but not a big deal; a price worth paying, I think

Can you remember what the difference was between the early and late springs?
It just so happens that the engine I'm currently working on is missing the springs & buckets.

Cheers,

Andy

Pescara · Post by **Pescara** » Wed Nov 19, 2008 2:16 pm

conti-mental wrote:Pescara,

Thanks for the VERY useful information - the EBC pads will be ordered, and soon! I may have to skim them down for the early calipers, but not a big deal; a price worth paying, I think
Can you remember what the difference was between the early and late springs?
It just so happens that the engine I'm currently working on is missing the springs & buckets.

Cheers,

Andy

As I remember my '80 SS and '82 Darmah springs and buckets were longer than required to use the 450 springs that people installed on 70s V-twins to increase clutch torque capacity. This would make sense if Ducati was trying to lighten the clutch in the late 70s: longer, lower rate springs could be preloaded more to achieve the same clamping force but less increase in force as the lever is pulled towards the grip.

Memory is fallible so make sure and verify this stuff as you go forward... I offer no guarantee other than saying I went through this once successfully! I will say that the "competition" Surflex plates were a *lot* better than those originally installed: easier to select neutral, no slipping under load, no extra shimming of springs required. I bought the "competition" clutch pack years ago from Gowanloch.

All the best.