Combi Clutch Mag lever 7/8" Pivot

Bikes or not. Whatever
Les H
Posts: 86
Joined: Fri May 27, 2022 9:54 am
Contact:

Re: Combi Clutch Mag lever 7/8" Pivot

Post by Les H »

Thanks Will and Paul for the information and views. I agree it would be nice to know the original size used. I have to say I think it was 7/8" because all my old levers and mostly original '55 VH are that type. Perhaps someone who knows could let us know...I wonder what the National Motorcycle has fitted on their bikes? I have to disagree with you though Paul about the lever pivot having no effect on effort required. It's all about lever ratios, the smaller pivot distance pulls the cable a smaller amount for any given angular movement of the lever so the "mechanical advantage" is increased. The trade off is that there is less movement on the cable but this in practice does not matter as the clutch is disengaged fairly early on the pull-in. I have spent some time trying to lighten the pressure with the current 1 1/16" lever. I have fully lubed the cable and with the tank off, moved the cable run all over the place, even to positions that would not be practicable with the tank fitted but it is still way harder than my VB clutch which is delightfully light. Maybe the clutch springs are far too strong?. I do not unfortunately have another good VH to compare it with. It could be that if lighter springs were fitted the 1 1/16" size would be reasonably light... by the way the springs are adjusted right out to flush with the studs so cannot adjust them out any more...Perhaps info on springs would be useful to me...Many thanks...
will_curry
Holder of a Silver Anorak
Holder of a Silver Anorak
Posts: 959
Joined: Thu Oct 08, 2015 12:56 am
Contact:

Re: Combi Clutch Mag lever 7/8" Pivot

Post by will_curry »

To get a good light clutch action the clutch cable has to run down the front downtube and along the
top of the primary chaincase. If it comes down the saddle tube the bend to enter the gearbox is
too tight for modern cables.

I measured 3 sets of clutch springs. All were more-or-less 42mm long and all wound with 7 turns.
One set had a wire of just over 2mm thickness and the other two had a wire thickness of around 1.6mm.

The thicker ones are from the fabric clutch and the thinner from the cork clutch.

Springs from Draganfly are to suit their bonded plates and are more-or-less as strong as the fabric springs.

Is your clutch just heavy or does it feel as though the pressure plate keeps binding and then freeing?

For what it's worth I've just done over 100 miles of country lanes on the 500 with the 3-plate fabric clutch
and it's been 3-finger operation all day and at least 70mpg with E10.
Les H
Posts: 86
Joined: Fri May 27, 2022 9:54 am
Contact:

Re: Combi Clutch Mag lever 7/8" Pivot

Post by Les H »

Hi Will. Thanks for the extra info particularly the clutch cable run. . I have to say that is one route I didn't try. Hopefully the cable is long enough. I suppose it passes by the left side of the cylinder on route. I don't know what spring gauge I have or what friction material but will investigate once the more immediate things have been put back on as I hope to ride this bike soon and continue the "rolling" improvements. It is one bike I bought that has the possibility to ride it without a complete total restoration first. Will continue with feedback when I have details on any findings. Thanks again Will. I appreciate your help with all my problems...with the bike that is...ha ha :)
User avatar
paul.jameson
Holder of a Golden Anorak
Holder of a Golden Anorak
Posts: 2933
Joined: Wed Oct 12, 2011 3:04 pm
Location: Herefordshire
Contact:

Re: Combi Clutch Mag lever 7/8" Pivot

Post by paul.jameson »

Your argument on mechanical advantage is absolutely sound but the point I was trying to make is that you can have a beautifully light clutch whether you have a 7/8" lever or a 1 1/8" one. I think you will find that correct cable routing, use of cork plates and the springs to match and little wear on clutch basket and centre will give you the light clutch you are looking for.

Don't be afraid of making your own cables. If you do, it is easy to make them an inch or two longer for a better line. If you are a commercial cable manufacturer, making the cable an inch shorter will save you lots of material in the long run so commercially made cables tend to be as short as they possibly can be. An extra inch can make all the difference!
Paul Jameson
35 LG (project), 37 RH500, 52 ex ISDT KHA, 54 KH(A), 75 Healey 1000/4.
Former Machine Registrar & Archivist, General Secretary and Single Spares Organiser (over a 25 year period).
Now Archivist (but not Machine Registrar), Gauges and Clocks Spares Organiser.
nevhunter
Holder of a Platinum Anorak
Holder of a Platinum Anorak
Posts: 5026
Joined: Tue May 10, 2011 9:42 am
Location: Victoria.. Australia.
Contact:

Re: Combi Clutch Mag lever 7/8" Pivot

Post by nevhunter »

Being able to reach the lever at full leverage position helps too. I put a chain joining link in the opening so the lever stays closer to the bars on the front brake IF the clutch is adjusted appropriately you could do it there, also. Nev
Les H
Posts: 86
Joined: Fri May 27, 2022 9:54 am
Contact:

Re: Combi Clutch Mag lever 7/8" Pivot

Post by Les H »

Hi Nev. Your chain link idea takes my memory back to about 1965 before I even had a motorcycle. I used to read the monthly Motorcycle Mechanics magazine and even to this day I remember the regular feature of "Readers Tips" and the little drawn illustration of that idea submitted by one of its readers, I think he might have won a pound for his idea. I bet he would never have imagined that someone remembers this nearly 60 years later :)
nevhunter
Holder of a Platinum Anorak
Holder of a Platinum Anorak
Posts: 5026
Joined: Tue May 10, 2011 9:42 am
Location: Victoria.. Australia.
Contact:

Re: Combi Clutch Mag lever 7/8" Pivot

Post by nevhunter »

Thanks Les but it's an idea from long before I used it (and still do) My first bike was about 1950 . Todays good bikes have adjustable lever fulcrums etc. I also don't wind the tire nipple nut right down so any tyre slip is picked up before the valve is torn out. Happy riding.. Nev
Les H
Posts: 86
Joined: Fri May 27, 2022 9:54 am
Contact:

Re: Combi Clutch Mag lever 7/8" Pivot

Post by Les H »

Hi Nev. The tyre valve nut is one I hadn't heard of, but its a good one...
Les H
Posts: 86
Joined: Fri May 27, 2022 9:54 am
Contact:

Re: Combi Clutch Mag lever 7/8" Pivot

Post by Les H »

Oh dear. After sorting out new levers and fiddling around, I realise the late Ariels used adjusters that fit into the levers...There's no real way to avoid this especially with the front brake cable with its big ball nipple end. So, I am now thinking of just buying a pair of new levers complete with adjusters, or ones that can be fitted with adjusters and suffer the 1 1/16" pivot ratio. I'll get used to it I guess.
Post Reply

Who is online

Users browsing this forum: Bing [Bot] and 3 guests