SRM clutch

[berger]

i spy with my little eye a locking ring inside the cush nut same as i have on mine

[BagONails]

i spy with my little eye a locking ring inside the cush nut same as i have on mine

That’s right Bergs, I had an excess of bare threads doing nothing, a spare nut and a lathe so what else was a bloke to do? Double nutted and Loctited FTW! 

[Tomcat]

I have the SRM clutch on my Super Rocket and it is very light to use but slips and needs adjusting. Does anyone know what heavier springs can be used in them?

[BagONails]

Happy to report the SRM clutch all went in with no problems, I ended up with a 1/4" steel ball inserted between my push rod and the SRM top hat roller bearing release purely because my shortening of the pushrod went awry somehow! I think the push rod was caught on something internally which resulted in it sticking out further and not being fully seated home when I took the measurement. With hindsight I should have compared my amount to come off the pushrod with the length of the SRM added part as they should have been the same anyway the steel ball has saved the day although you need to be careful installing it as a loose steel ball in your gearbox wouldn't be ideal...

My test run today revealed the clutch to be light and very grippy almost too fierce at this stage so we'll see how it goes once I get used to it. Neutral is now a breeze to find either from first or second gear. In fact there is so little drag that I even had some difficulty getting it into first to pull away and there's no crunch at all. I'm running with 220cc of a multigrade 10W40 oil suitable for motorcycles with combined engine/gearboxes and clutches running in oil. From a dry fill this amount just came up to my previously scribed line on the inside of the primary inner cover which corresponds with the chainwheel teeth and chain just dipping (being covered). This also resulted in signs of oil being flicked around past the filler hole when the engine was revved and when I stopped it a drip formed under one of the links in the top run of the chain so its definitely getting enough lube.  I will check this level after a couple more runs and see how it looks. no signs of leakage from the primary despite reusing the gasket which was pleasing too.

[BagONails]

Hi guys, I'm after advice from anyone who has fitted/is running one of these clutches (A10 SA. 4 spring). Everything is fine, the set up was easy and I followed the somewhat rambling SRM notes to the letter. The thing is whereas my old clutch was slipping this one is extremely fierce. It's like a light switch and hard to gauge with virtually no feel.

I tensioned the springs as instructed and have a full coil visible between the nuts and the pressure plate. I've ridden out 2 or 3 times since doing the job and there's been no change. It also feels a bit heavier than expected. I'm wondering whether I should back off the nuts by a turn and see how it goes. Luckily I have the later primary cover with the inspection plug so this is a quick job.

Is the clutch likely to improve with use (I would have thought not) if I leave alone or should I intervene? That's my question I guess. I figure it can't do any harm to try unless it starts slipping but that would be obvious immediately.

As ever grateful for any feedback. cheers BON

[berger]

BONails i'm not sure how to explain this and i haven't been to the pub!! some years ago my mates 4 spring on his triton was grabbing and we found he had the wrong parts or the right part that didn't go with the wrong part this was causing some lateral? movement making it grab as the clutch lever was released no matter how slow we tried to release the lever. if yours is ALL SRM then i haven't  got a clue and i will sod off to the pub *beer   thankyou for listening have a nice day

[BagONails]

That's a good point Mr berger. When I rebuilt the primary I fitted new chainwheel/basket, hub, adaptor etc amongst a lot of other stuff and put the old plates and springs etc back in. At the time I was unsure what other issues I would be finding with the bike and didn't want to spend too much on it. These new parts came from Feked.

Everything fitted well and worked fine with the old clutch parts except I couldn't get the thing to stop slipping. Now I've changed the driving and driven plates,  pressure plate, springs , nuts and cups. all parts from SRM. Everything fitted well and I could see no issues as it went together. These parts are all supposed to be compatible as SRM sells all of them separately.

When I built the clutch up I wiped all the plain plates with acetone in case they had anti corrosion product on them, then I rubbed them down gently on a sheet of fine wet & dry on a flat surface plate and found them very flat. Checked all around for burrs and sharp corners, all the usual things.

The clutch frees very readily, doesn't stick, doesn't drag at all. I can engage first gear from neutral with no crunch at all and similarly finding nuetral from first or second is a breeze, really impressive actually! Unfortunately though it is a bit grabby...

[ellis]

Hi BagONails,

That grabiness you speak of should smooth out once you get a few miles on it. I find it common when I have the clutch clutch down for inspection and wash the plates in carb cleaner it does tend to be a little harsh for a few miles. Glad to hear it does not slip and finds neutral ok, sounds like you have a very good clutch now. 

ELLIS

[berger]

BONails maybe a set of photos with pictures of clutch centre on mainshaft of inner and outer drum and which plate you start with would help, also which way your putting the recessed washer on. my mate also built his one with a plain plate grinding away on the chainwheel . i do remember now he managed to split the washer when tightening up the nut  because of the movement that was happening. he had got the recessed washer on the wrong way, i had to tell him the recess wasn't for the nut to sit in, it was to push everything into situ. as i say he had the wrong bits put together at one time but when everything was correct the washer on wrong was causing the snatch. at the time i knew nothing about 4 spring clutches but pointed out to him in engineering terms the washer recess wasn't for the nut to sit in. after much argument he turned the washer round and got a perfect clutch. he also made a brass thrust washer to try and get things right of course it didn't work

[JulianS]

My SRM clutch came with a thick plain washer to go under the nut, not a recessed one. Fits together fine works fine and chainwheel does not wobble because of the A65 type thrust washer. 

[RogerSB]

Ian, I remember after I replaced my 6 spring with SRM's 4 spring it felt very different and seemed to take up immediately and I felt it was a little too fierce at first, but in no time I got used to it and became unaware of it (like a headache you know when you have one but you can't remember when it disappears).

I've just checked my notes and I fitted my 4 spring on 25 Nov 2017 and I've not had to touch it since - and a sidecar has been fitted to my GF since 2019, so it's had to work hard.

Here's a pic of my clutch anti stick tool - in use and out of use  psst, You can buy them at Halfords  .

Rog.

[Jules]

Doesn't leaving the clutch cable under tension like that, over time, tend to stretch the cable Roger???

[Triton Thrasher]

Doesn't leaving the clutch cable under tension like that, over time, tend to stretch the cable Roger???

Clutch cables stretch.  There’s an adjuster.

[RogerSB]

Hi Jules, It's adjusted only just enough to separate the plates, so it's not pulled right in, that's the advantage of a cable tie, as it's the same adjustment every time. When you think of it all the cables come under a lot of strain every time they're used and as Triton Thrasher pointed out cables can be adjusted.

However, I only slip the cable tie over the lever when I know I won't be using my bike for a while. That usually means a week or two because I've always made a point of using my bike a least once every couple of weeks - if possible, including the winter. That's as long as it's not wet, as trying to be a good custodian of it I try to avoid getting it wet and dirty.

Rog.

[BagONails]

Thanks for all the info and somewhat reassuring experiences from some.

BONails maybe a set of photos with pictures of clutch centre on mainshaft of inner and outer drum and which plate you start with would help, also which way your putting the recessed washer on. my mate also built his one with a plain plate grinding away on the chainwheel . i do remember now he managed to split the washer when tightening up the nut  because of the movement that was happening. he had got the recessed washer on the wrong way, i had to tell him the recess wasn't for the nut to sit in, it was to push everything into situ. as i say he had the wrong bits put together at one time but when everything was correct the washer on wrong was causing the snatch. at the time i knew nothing about 4 spring clutches but pointed out to him in engineering terms the washer recess wasn't for the nut to sit in. after much argument he turned the washer round and got a perfect clutch. he also made a brass thrust washer to try and get things right of course it didn't work

Berger, I'm hoping to avoid taking it all down again but we will see how it goes. I am pretty sure it is all assembled as it should be and I know for sure the dished washer is the correct way around! I actually bought the SRM thrust washer but found the Feked supplied chain-wheel and adapter did not allow me enough material to machine a register for it to run on so I didn't use it in the end.  I doubt that being missing would affect the action too much. I think the thrust washer helps to keep the chain wheel running in line and would improve the clutch if you were suffering from drag, a problem I definitely don't have.  This is also heartening for me in as much as my original problem was the clutch being out of alignment. The new adapter did not correct it sufficiently and I had to re-machine the taper to get the alignment I needed. The fact I have no drag at all suggests that everything is now very much in line and stays in line when the clutch is pulled in.

My SRM clutch came with a thick plain washer to go under the nut, not a recessed one. Fits together fine works fine and chainwheel does not wobble because of the A65 type thrust washer. 

Julian, that is interesting, I didn't notice they supplied a different design of washer and they didn't mention it when I spoke to them. I explained I would have a mix of parts and they didn't expect any problems.  So I put the dished washer back on...something to bear in mind if the issue doesn't improve with use. Thanks.

Ian, I remember after I replaced my 6 spring with SRM's 4 spring it felt very different and seemed to take up immediately and I felt it was a little too fierce at first, but in no time I got used to it and became unaware of it (like a headache you know when you have one but you can't remember when it disappears).

I've just checked my notes and I fitted my 4 spring on 25 Nov 2017 and I've not had to touch it since - and a sidecar has been fitted to my GF since 2019, so it's had to work hard.

Here's a pic of my clutch anti stick tool - in use and out of use  psst, You can buy them at Halfords  .

Rog.

I know what you mean Rog and I think this may be behind the "improves with use" sentiment, does it really or do we just get used to it?
Good to hear you found it to be a bit fierce from new and even better to hear you have tested it well and had no problems 

Thanks too for your notes, earlier in this thread, I found them very handy in trying to interpret SRM's slightly arcane fitting instructions! Cheers

I'm going to keep riding it for now as there is nothing obviously wrong and see how it goes. I'm also using standard 10W40 engine oil for motorcycles with wet clutches in the primary just in case the ATF type F was to blame and paying close attention to oil levels etc. The old plates were not fouled with oil but they were very shiny and worn.