Navigation

You are here: Home / Messages / Heavy Twins / Stiff clutch

Stiff clutch

Up to Heavy Twins

Stiff clutch

Posted by robert_tuck at June 11. 2017

The kiddies,  (mere 40 year olds)  have been wimpishly complaining about the clutch on the 99  so I have replaced 50 year old cables and springs  with super nylon lined and graphite lubed  cables,found new easy run route etc,etc. The nett result being that I can barely operate them!, If it ain't  broke-----. I am suspicious that the springs supplied are  perhaps Atlas or just crap ,  Do our suppliers stock different springs for the dommies ? and is there any way of checking the rating of the springs other than the length?.

Re: Stiff clutch

Posted by Paul Knapp at June 11. 2017
Refer to next post. I can't delete this one.

Re: Stiff clutch

Posted by Paul Knapp at June 11. 2017

I had the same problem after fitting a new nylon lined clutch cable. The pull was notchy and stiff, worse than what I had removed. I was about to re-fit the old cable when I decided to try running some oil through it..... Instant improvement, clutch pull became very smooth and much lighter.

 

Re: Stiff clutch

Posted by robert_tuck at June 11. 2017

Hi Paul,I'm reading that oil rots the lining!, but you may be right.

Re: Stiff clutch

Posted by john_holmes at June 11. 2017

Oil expands the nylon and it ends up making it stiffer, flush it out with wd40 and then use silicone spray to lube.

Re: Stiff clutch

Posted by Dan Field at June 11. 2017

Measure the distance between the pivot on the lever to the cable nipple - centre to centre, most modern replica levers are 1.25" if you can find one that is 7/8ths youll find it makes an enormous difference. (It's what most nortons were fitted with i believe) I got a pair that were marketed as Amal replicas.

dan

Re: Stiff clutch

Posted by robert_tuck at June 11. 2017

Hi Dan, my bike had the orriginal 7/8 center clutch lever ,with a very worn pivot ,so i have  swapped that for a new 7/8 lever and a custom made perch /clamp. So thats not the problem.  No its likely to be the new springs  which to pinpoint I need some information  on. I'm also looking at the box internal lever which can be  set (like a brake hub lever ) at different angles to the cable depending how far in the screw in the clutch pressure plate is set. Not something you will find in any manual , they only refer to getting the assembly to line up with the cable entry.The ramp on the internal lever has been "releaved" a touch, a popular mod to make the bite less sudden I think.

Re: Stiff clutch

Posted by Dan Field at June 11. 2017

I noticed that on my clutch lever too, but haven't fiddled with it much as it works!

Re: Stiff clutch

Posted by anna jeannette Dixon at June 11. 2017
Previously robert_tuck wrote:

Hi Dan, my bike had the orriginal 7/8 center clutch lever ,with a very worn pivot ,so i have  swapped that for a new 7/8 lever and a custom made perch /clamp. So thats not the problem.  No its likely to be the new springs  which to pinpoint I need some information  on. I'm also looking at the box internal lever which can be  set (like a brake hub lever ) at different angles to the cable depending how far in the screw in the clutch pressure plate is set. Not something you will find in any manual , they only refer to getting the assembly to line up with the cable entry.The ramp on the internal lever has been "releaved" a touch, a popular mod to make the bite less sudden I think.

Hello if anyone wants to know Amal levers numbers and types I have a book full of them   hope this may just help someone in need   Yours Anna J  

Re: Stiff clutch

Posted by Paul Knapp at June 12. 2017

Previously robert_tuck wrote:

Hi Paul,I'm reading that oil rots the lining!, but you may be right.

..........................................

The oiled liner was fitted back in April 2013, and is still very smooth to use. I know that nylon absorbs oil, but there is enough internal room for this to happen. I have since installed a pair of Venhill throttle cables a year ago and they received the same oil treatment and are very light to pull. The stronger the clutch springs, the more the inner cable tends to bite into the relatively soft nylon making it difficult to use.

 

Re: Stiff clutch

Posted by robert_tuck at June 12. 2017

Hi Paul, I think I will try some thin silicon gun oil, Have to put something in there , as rust will surely get the bare dry cable. Also going to try an old cable just to confirm the issue. Checking thro the suppliers they all only do ! type of spring for amc  , don't think thats how it was, need old part no for Atlas springs to cross reference to my old 99 parts list.

Re: Stiff clutch

Posted by Bob Matthews at June 12. 2017

Hi Robert

I went through this exact problem a while back after buying some new clutch springs from fleebay.  Even with the spring screws loosened off, the lever was too heavy for my arthritic hands.

So I bit the bullet and ordered another set of springs from RGM for £3.90 + vat https://www.rgmnorton.co.uk/buy/clutch-springs-set-of-3_879.htm?bskt=04085ff4-06ce-4dc2-8a69-0aee07c525fa the part number matches my parts book (040385) and I found the difference in lever action to be astonishing.

It seems there has been two different wire sizes used in the springs although the spring lengths have largely remained the same.  The RGM ones have a 0.102" diameter wire size (which is the smaller of the two) and my clutch is now as light as a feather.

Also, have a look here........ http://www.nortonownersclub.org/noc-chat/technical2-heavy-twins-forum/226010758

 

Hope that helps, Bob

Re: Stiff clutch

Posted by robert_tuck at June 12. 2017

Thanks Bob,thats exactly the info I needed and shows that I have the wrong springs fitted,Don't remember where they came from and it illustrates how important it is for suppliers to give detailed information with the product and that we sorely need a good database to work from. Interestingly our suppliers only supply one spec spring for all models now.

Re: Stiff clutch

Posted by robert_tuck at June 12. 2017

Well done RGM for  giving a detailed spec  on the springs , no one else seems to bother.

Re: Stiff clutch

Posted by david_evans at June 12. 2017

John, You say that oil expands the nylon, yet the Commando rocker feed pipe is nylon. In another post you recommend the use of silicon grease on electrical connections. I used to use Vaseline but have been thinking of using silicon grease. Any thoughts on the pros and cons of either. I'm not being critical, just wondering if there's a good reason for either.

Re: Stiff clutch

Posted by john_holmes at June 12. 2017

I have roller garage doors with nylon edge guides, all have warning labels saying to not lubricate with oil or they will jam, have not tried using oil to see if its true but the silicone sunroof guide spray I use does work well and I have seen another door jammed after it was greased. As there are several grades of nylon it may be the particular grade they use on the door guides but Venhill also warn to use light oils only after a wd40 flush but they have gone to teflon lined, its not clear if that advice applies to their old nylon lined or just the current teflon. Vaseline can be used instead of silicone grease as I have used it when I ran out but silicone grease is also called dielectric grease as it has dielectric properties so surplus grease will not allow your Lucas smoke to escape, not sure if vaseline is as dielectric but its a bit thinner and messier so I now keep a stock of silicone. Silicone grease is a lot easier to get hold of nowadays.

Re: Stiff clutch

Posted by Paul Knapp at June 13. 2017

I bought my clutch springs for my ES2 from the NOC shop. No problem, light pull on the lever to release. I see they are listed for the heavy weights.

Re: Stiff clutch

Posted by robert_tuck at June 13. 2017

Previously Paul Knapp wrote:

I bought my clutch springs for my ES2 from the NOC shop. No problem, light pull on the lever to release. I see they are listed for the heavy weights.

The springs may be perfect for your bike with 28bhp? ,but does that make them right for a 50bhp SS or Atlas?.

Re: Stiff clutch

Posted by Paul Knapp at June 13. 2017

Same part number for either single or h/weight according to the Club spares list. More than adequate for my 28HP ? dragging a chair, so much so, I have backed off the adjustment to reduce the hard take up.

Re: Stiff clutch

Posted by robert_tuck at June 13. 2017

Acording to the data supplied by Phil Hannam there are 4 different specs for springs and the SS/Atlas ones are shorter and heavier gauge than the 88/99 ones .  I certainly can't work with the ones supplied , however this issue in now superceeded by a bigger one, My plain plates are cutting grooves in the new rgm hub and inside the drum. It looks like the drum is too loose on the bearing and rocking around  , possibly bearing wear ,wont know untill I've got it to bits, Do we have any go/no go specs for drum bearing surface? may have to try some oversize rollers. RGM say their spiders have a proper register inside  to locate on the shaft,,the orriginal one certainly does not .

Re: Stiff clutch

Posted by stephen_fox at June 15. 2017

Hello all, my first post here, and I'm a bit late. Sorry!

I'm in Normandy, and have just rebuilt my 650ss engine. I fitted a handlebar end mirror on the offside for France, and was forced to move the clutch lever inward so it could pull in without fouling. I have found this to provide more leverage, and effectively makes the clutch lighter. Most of the strength in the hand is in the first two fingers, so having them in the best position is important. Maybe worth a try if your hand is grumbling!

My clutch pull is also notchy though, so perhaps I need a new cable too.

 

Powered by Ploneboard
This is Brio Diazo Plone Theme