1959 Super Rocket with a Triumph clutch

[lawnmowerman]

Greetings all,

I have been involved in a few restorations over the past couple of years so my Super Rocket has been relegated to the back of the garage and only had the occasional outing.
I took it out last week and it suffered from a lot of clutch drag and difficulty engaging neutral - even on the move. I had a look at the cable adjustment which seemed ok so off came the primary cover - the first time since I bought the bike.

There was the correct amount of oil in the case but the chain seemed a bit tight. It looks like the PO fitted what I am reliably informed to be a brand new Triumph clutch - 5 friction plates and 4 springs. I removed the primary chain and noticed that the sides of the teeth on the engine sprocket were polished on the outside and a straight edge revealed that the sprocket needs to be moved inwards by about 1/8" to line up with the clutch sprocket.

Has anybody fitted a Triumph clutch and had the same issue? It looks like it may be possible to shave a bit off the inside face of the engine sprocket shock absorber centre to get things in alignment.

When I dismantled the clutch the plates were coated in a sticky residue which was probably causing the drag. I am assuming was the protective film on the new plain plates which the PO had not cleaned off before fitting so I have washed them clean ready to re-fit.

When it all goes back together I will get the chain adjustment right and use Castrol TQF - any views?

Many thanks

Jim

[chaterlea25]

Hi Jim,
It is a common enough problem 
Here is a link to a post I wrote on the problems that can arise

https://www.a7a10.net/forum/index.php?topic=9646.msg70166#msg70166

HTH
John

[lawnmowerman]

Thanks John. A great write-up and exactly the info I need. I can compare your measurements of the 1960 A10 sleeve with the one I have. I suspect mine has an overwidth shoulder at the back which needs about 1/8" shaved off. My shock absorber looks like it will not have much movement on the cam lobes before the spring becomes coil bound and the extra 1/8" will help.

Regards

Jim

[lawnmowerman]

Hi John

My sleeve was near enough the size of your A10 sleeve shown in your topic so I will go for 1/8" off the back of mine to get alignment. I would imagine my clutch adaptor is a little short and it looks easier to correct it on the engine sprocket sleeve.
One other question - the clutch cover I have is grey coated pressed steel with the four brass nuts. The clutch action seemed a bit heavy before I stripped it. The springs I have measure 50.4mm in length with a wire dia of 2.35mm. Does this sound about right or should I order some smaller ones - and from where?

Many thanks

Jim

[Triton Thrasher]

One other question - the clutch cover I have is grey coated pressed steel with the four brass nuts. The clutch action seemed a bit heavy before I stripped it. The springs I have measure 50.4mm in length with a wire dia of 2.35mm. Does this sound about right or should I order some smaller ones - and from where?

That sounds more like a pressure plate than a cover.

Does this help? http://www.britbike.com/forums/ubbthreads.php?ubb=showflat&Number=522943

The fitted length pressure in lb. ft. is per spring.
1.325" fitted length is with the nut tightened until spring bolt is flush with bottom of screwdriver slot. As coil bind can occur tightening more than the spring bolt flush with the face of the nut is not recommended.

definitions:
f.l. Free Length
ft.l. Fitted Length
w.d. Wire Diameter
c.b. Coil bind

57-1560 (650 4 spring clutch)
f.l. 1.975"
ft.l.= 1.325" @ 32 lb. ft.
w.d=.090"
c.b. = .790"

57-1830 (650 3 spring clutch)
f.l.= 1.815"
ft.l. = 1.325 @ 43 lb. ft.
w.d.= 0.104"
c.b.= 0.900"

57-4644 (750 twin 3 spring clutch)
f.l= 1.716
ft.l.= 1.325"@ 53 lb. ft.
w.d 0.115"
c.b. 1.025"

After Market
Emgo 88-57493 (replaces 57-1830)
f.l. = 1.755"
ft.l. = 1.325" @45 lb. ft.
w.d. = 0.104"
c.b. 0.865"
Barnett 501-86-03075 (old MT-75-3)
f.l. = 1.755"
ft.l. = 1.325"@ 45 lb. ft.
w.d. = 0.105"
c.b. = 0.865"
Precision Machine (not recommended for street use)
f.l. 1.886"
ft.l. = 1.325" = 72 lb. ft.
w.d. = 0.113"
c.b. = 0.965"

[lawnmowerman]

Thanks TT, useful information.
Yes I did mean the outer domed pressure plate but called it a cover plate in a grey moment 

I have been looking at Draganfly and Feked websites for springs. The cups I have are 35mm long so seem right but I think that the 50mm springs I have are for a 3 spring clutch. Feked are listing 45mm springs which have one coil less than mine so I have ordered some to try.
Having looked at some other posts regarding heavy clutch action, I checked my handlebar lever fulcrum distance and it is 1 1/8" instead of the original 7/8" so that may be a contributing factor to the heavy action.

Thanks

Jim

[JulianS]

Got my SRM 4 spring clutch out at moment;

Springs 50mm long, wire approx 2.25mm diameter.

Cups 35mm end to end.

Spring pins 48mm under head.

Handlebar lever pivot 7/8 inch.

Nice light progressive action clutch, no slip no drag.

[JulianS]

A65 springs are approx 45mm long and from 2.7mm diameter wire for the 3 spring setup.

[lawnmowerman]

Thanks Julian - exactly the info I was after. My springs and cups are the same as yours although I am not sure I understand how to make the spring pin measurement. My handlebar pivot is 1 1/8" instead of 7/8" so that would make the action heavier and not as progressive. I can live with it at the moment - it was just that a mate said he thought that it was heavier than it should be. I will try the shorter springs when they come and make sure they do not make the clutch slip before I refit the primary cover.

Thanks

Jim

[lawnmowerman]

A65 springs are approx 45mm long and from 2.7mm diameter wire for the 3 spring setup.

That's interesting - Feked are listing them for three and four spring clutches. They do not show the wire diameter - mine are 2.3mm so they may not make a lot of difference.

Jim

[chaterlea25]

Hi Jim,
Feked by name and fecked by nature 

The A65 springs will make the clutch action very very heavy

SRM have the correct springs for the 4 springer

John

[Triton Thrasher]

I find FEKED to be cheap and dependable, if not particularly knowledgeable.

I think Lawnmowerman already has the right springs.

[chaterlea25]

Hi TT,

I find FEKED to be cheap and dependable, if not particularly knowledgeable

Hmmm 

I have not dealt with them myself but GB's experience with the cam followers and the (lack of) quality and bad fit on a set of Guzzi silencers a friend bought, means I will not chance dealing with them

John

[Greybeard]

I've been pleased with their stuff in the past; particularly the exhaust system.

[lawnmowerman]

Hi Jim,
Feked by name and fecked by nature 

The A65 springs will make the clutch action very very heavy

SRM have the correct springs for the 4 springer

John

Thanks John.
I think changing the 1 1/8" handlebar levers to 7/8" will probably help a lot. The springs I already have are one coil longer than the SRMs. Unfortunately SRM do not give dimensions.
The Feked ones I have ordered look the same gauge as mine but are one coil shorter (9 rather than 10) making them 45mm long rather than 50mm. I will see what they look like when they arrive tomorrow.

Jim