Clutch adjusting

[JulianS]

The 6 spring plunger clutch is a completely different clutch to the 6 spring swinging arm and they cannot be compared. No parts interchangable.

If you go for the SRM pressure plate (it comes with fitting instructions) you need to reduce the push rod length due to the pusher so I would put a ball bearing between pusher and push rod, having hardened the end of push rod.

[a10 gf]

The 6 spring plunger clutch is a completely different clutch to the 6 spring swinging arm

Thanks (so not an imagination that the plunger 6 spring can behave differently (better, that is).

Cutting the clutch push rod and inserting a ball bearing reduces fiction and improves clutch operation.

The plunger uses a two part rod, the inner ends 'cupped' with a ball between them (= a 1 ball bearing :O) so should maybe have been used for the swing as well.

[RoyC]

The 6 spring plunger clutch is a completely different clutch to the 6 spring swinging arm and they cannot be compared. No parts interchangable.

If you go for the SRM pressure plate (it comes with fitting instructions) you need to reduce the push rod length due to the pusher so I would put a ball bearing between pusher and push rod, having hardened the end of push rod.

Thanks for explaining that Julian.
Is this the one I want on page 8 ?  -  £400-86  -  http://shop.srmclassicbikes.com/part-search?title=clutch&sku=

[JulianS]

Thats the one.

Photo shows the pressure plate fitted.

[RoyC]

Thats the one.

Thanks, I'll order it.

[ellis]

Beautiful clutch and a one finger operation. You won't be disappointed.

ELLIS

[RogerSB]

I fitted one to my 1960 Golden Flash last week - see pic. Also replaced the cush drive nut with SRMs upgrade version. For the clutch upgrade I also needed a 4 spring clutch centre puller, a 4 spring clutch locking tool, clutch spring adjusting tool and finally a sliding plate felt washer (which I changed at the same time). I had all this for my 6 spring clutch but no good for the 4 spring - so if you need any of that best order it at the same time to save postage.

Well worth doing - set it up first time - no slip or drag and can get neutral, with engine running, every time.

I also had to buy a split bearing separator & puller (from Screwfix) to get my 6 spring clutch centre off as it was on so tight. The 4 spring clutch centre puller I bought didn't stand a chance to get it off it was on the taper so tight. I tried using a 3 leg bearing puller on it and it broke a couple of the castillations off the centre so I then had to grind out a grove around it to fit the split puller from Screwfix on it. Then tightening it and a sharp tap on the end of the puller and it was off.

Then not forgetting the primary cover gasket.  I always make my own from gasket paper using a small ball peen hammer to tap and knock out the screw holes and then go around the cover to  accurately cut out the shape. Works a treat - a mechanic friend of mine showed me how to do it many years ago. That was the days when they made their own gaskets.

[RogerSB]

As an addition to my previous post the SRM clutch upgrade is very light at the lever compared to my previous 6 spring clutch and I've also found it needs very little lever movement to disengage and engage (only about 1/8") after taking up the 1/8" free play, so at first, compared to my 6 spring set up I feel it's almost on and off, so not very much slipping to take up the drive etc. Feels almost like racing changes, like we used to do years ago, without using the clutch.

[RoyC]

Thanks for that Roger.
I am looking forward to getting mine.
Your nuts don't seem to be tightened down very much, do they have locking nuts ?
Is that the pad behind the sliding plate that you changed ?

Anyone know what size ball bearing I need to get ?
Roy.

[duTch]

 

Anyone know what size ball bearing I need to get ?
Roy.

   I'm not sure of the exact bore of the pushrod tunnel, but the pushrod probably should be 1/4", so that will be the ball size. I doubt there'd be any easy to find balls that are slightly bigger than 1/4". When I did it- 'way back when'-, I used a 14" x 1/4" 'needle' roller.

[Butch (cb)]

I'm running a 6 spring on my S/A.

I keep meaning to change it out but it never gets bad enough. After the initial running in period I found it would just slip a bit. I adjusted it by road testing with the chain case off – just pulled down enough to remove the slipping and no more. It flips around like a witches hat in there but the action at the lever isn’t bad and it doesn’t drag either. Clutch on my Morini is considerably worse.

[JulianS]

As an addition to my previous post the SRM clutch upgrade is very light at the lever compared to my previous 6 spring clutch and I've also found it needs very little lever movement to disengage and engage (only about 1/8") after taking up the 1/8" free play, so at first, compared to my 6 spring set up I feel it's almost on and off, so not very much slipping to take up the drive etc. Feels almost like racing changes, like we used to do years ago, without using the clutch.

You get a more progressive action using a lever with 7/8 inch centres. The ones with 1 1/16 centres give more lift but a more sudden action.

[Billybream]

Hi Roy.
The clutch push rod is 1/4" dia and I used a ball from the steering head bearing arrangement.
When fitting the new SRM clutch you will need to shorten the existing push rod, might be best to get a new length of silver steel rod, easily obtained of EBay for a couple of pounds.
The ends of the rod need to be hardened, achievable with gas torch method.

[RoyC]

Anyone know what size ball bearing I need to get ?
Roy.

   I'm not sure of the exact bore of the pushrod tunnel, but the pushrod probably should be 1/4", so that will be the ball size. I doubt there'd be any easy to find balls that are slightly bigger than 1/4". When I did it- 'way back when'-, I used a 14" x 1/4" 'needle' roller.

Thanks Dutch, just ordered some.

[RoyC]

Hi Roy.
might be best to get a new length of silver steel rod, easily obtained of EBay for a couple of pounds.
The ends of the rod need to be hardened, achievable with gas torch method.

Ordered. £3-49 free P+P