Mk111 Heavy + Dragging Clutch Advice Please

GRM 450 · Mar 15, 2020

Thank you all again,
The central nut is tight
I will order a new venhill cable, I can’t remember what brand the existing one is,
New friction and steel plates,
It has always had engine oil in the primary,
Has over time become harder to pull the clutch,
Only noticed the drag recently, I did put a seal to the gearbox but don’t recall which. Will look .

The distance from the pressure plate to the spring retainer is a very tight 1mm (40 thou) using feeler gauge
So I assume the plates have worn down

Graeme

L.A.B. · Mar 15, 2020

GRM 450 said:
The distance from the pressure plate to the spring retainer is a very tight 1mm (40 thou) using feeler gauge

Could you explain that in a bit more detail as I don't understand where you are measuring the 1mm?

Edit: Unless you mean between the diaphragm spring and the spring retaining circlip (or circlip groove) as below?

Edit2: A measurement of 1mm from the pressure plate without the diaphragm spring would make the stack height 'high'. High enough that the (approx. 2.0mm thick) spring would be inverted (beyond 'flat') when installed.

https://www.oldbritts.com/ob_clutch_info.html

Mk111 Heavy + Dragging Clutch Advice Please

Staytite · Mar 15, 2020

Hi
If I remember correctly there are two different thickness standard pressure plates?
I think the thicker pressure plate is needed for the fibre/steel plate stack?
And the thinner pressure plate for the bronze/steel plate stack?
Are you using the correct pressure plate for your fibre/steel stack?

GRM 450 · Mar 15, 2020

L.A.B.

When the complete clutch assembly is reinstalled, with the clutch removal tool holding tension off the spring diaphragm disc and the spring “circlip “ installed.
There is 1mm tight clearance between the spring diaphragm disc and the spring retaining “circlip”

Hope that makes sense

Graeme

L.A.B. · Mar 15, 2020

GRM 450 said:
When the complete clutch assembly is reinstalled, with the clutch removal tool holding tension off the spring diaphragm disc and the spring “circlip “ installed.
There is 1mm tight clearance between the spring diaphragm disc and the spring retaining “circlip”

Hope that makes sense

Yes, so the stack height sounds about normal.

GRM 450 · Mar 15, 2020

L.A.B.,

You are saying the stack height, therefore the clutch plates, are as they should be ?

Then I’ll have to wait until the new cable arrives and see what difference that makes.

worntorn · Mar 16, 2020

Does the pushrod move back and forth freely when the clutch assembly is out?
You could try with one hand operating the handlebar lever and the index finger of the other hand pressing on the end of the pushrod .

Glen

L.A.B. · Mar 16, 2020

GRM 450 said:
You are saying the stack height, therefore the clutch plates, are as they should be ?

Yes, so I wouldn't expect the stack height to be the cause of the heavy clutch action although increasing the stack height slightly should help to lighten the clutch action.
http://atlanticgreen.com/ndnsclutch.htm

GRM 450 · Mar 20, 2020

Hello all,

To finish this thread,,,,
The through shaft, ball and arm are how they should be. The arm is as close to 90 degrees as it can be to the cable entry.
I installed a new Venhill Featherlight cable.
No or very little difference.
I have set all up as per the great advice and all measures correctly.
I'll get oil in the primary and engine, button it all up, get it off the bench and road test it soon.
I really appreciate all you chaps time answering my questions and offering advice.
Perhaps it's just another '77 build from suspect parts thing?

Regards
Graeme

Bernhard · Mar 20, 2020

GRM 450 said:
Hello all,

To finish this thread,,,,
The through shaft, ball and arm are how they should be. The arm is as close to 90 degrees as it can be to the cable entry.

Regards
Graeme

Is this with the clutch pulled in that it's at 90 degrees, or as normal before clutch is pulled?

GRM 450 · Mar 20, 2020

Before

L.A.B. · Mar 20, 2020

GRM 450 said:
Hello all,

To finish this thread,,,,
The through shaft, ball and arm are how they should be. The arm is as close to 90 degrees as it can be to the cable entry.
I installed a new Venhill Featherlight cable.
No or very little difference.
I have set all up as per the great advice and all measures correctly.
I'll get oil in the primary and engine, button it all up, get it off the bench and road test it soon.
I really appreciate all you chaps time answering my questions and offering advice.
Perhaps it's just another '77 build from suspect parts thing?

Regards
Graeme

You said previously:

GRM 450 said:
But it still seems hard to pull the lever. We measured it at 10kg and over at the lever.

My Commando's clutch pull with a thicker 3.0mm RGM plain plate is 9kg (at the lever end) and definitely feels lighter so 10kg doesn't sound all that bad.

Bernhard · Mar 20, 2020

GRM 450 said:
Before

Max amount of leverage is when the clutch angle is at 90 degrees pulled in, ( give or take) once it goes over that you are loosing leverage, unless someone knows different?

think of this as your drum brake lever!!!!

dynodave · Mar 20, 2020

32 posts, well now 33 while I'm typing, and I don't perceive any positive results.
New cable, but what kind of cable? normal steel bowden, has it been "properly" lubed or a teflon lined cable?
IMO length matters... big time ..affecting tightness of bends? And What is the routing... good or bad ?

This discounts the baffling advice given on stack height analysis.

L.A.B. said:
http://atlanticgreen.com/ndnsclutch.htm

My article is a bare bones info without the detail for lesser analytical ability to apply the tidbits.
sorry to be so short, but BDM's approach does not seem to satisfy either...LOL http://a20b767e.magix.net/#xl_xr_page_1

historical tid bit of entertainment:
http://atlanticgreen.com/JML-BDM.htm

L.A.B. · Mar 20, 2020

dynodave said:
New cable, but what kind of cable? normal steel bowden, has it been "properly" lubed or a teflon lined cable?

"I installed a new Venhill Featherlight cable."

dynodave · Mar 20, 2020

L.A.B. said:
"I installed a new Venhill Featherlight cable."

So I have to research what the hell this marketing term means?
Are these also the crappy ones with short end connection cylinders that don't fill the bore in the 9/16/ .570" wide lever?
Makes the cables break early due to high rotation friction?

L.A.B. · Mar 20, 2020

dynodave said:
So I have to research what the hell this marketing term means?

Yes, so? Venhill Featherlight cables have been mentioned no end of times on this forum so shouldn't need any detailed explanation.

dynodave · Mar 20, 2020

Well I did do a fair amount of looking and finally covered their norton offerings and discovered, unfortunately, I would NOT use their clutch cable product on my bikes.
I'm still on my maintained 1988 cable. I have had to make cables, like when I got the AN throttle cables that were to short and made my bike idle at 3-4000 rpm.

Flanders in California has/had the components I have used in my cable making. If they don't work , I know who to blame...look in mirror!

http://www.flandersco.com/index.html

L.A.B. · Mar 20, 2020

dynodave said:
Well I did do a fair amount of looking and finally covered their norton offerings and discovered, unfortunately, I would NOT use their clutch cable product on my bikes.

I've used Venhill cables for many years with no problems.

The Venhill cables for use with alloy levers normally have a 6mm nipple in a nylon sleeve so should be less friction as there's no metal to metal contact and no need for lubrication as the nipple pivots within the nylon sleeve.
https://www.venhill.co.uk/cables-amp-components/n10-nylon-nipple-sleeve-38in-od-n10.html

Problems occur when this type of nylon sleeved nipple is used with sheet metal levers for which they are not intended and Venhill cables for sheet metal levers should have full size/length metal nipples.

worntorn · Mar 20, 2020

Slippery Stainless on slippery Teflon, no messy annual lubing required, what's not to like?
I've had them for several years now as well.
On the bike that gets a lot of use, the cables still look as new at the ends, which is where cables generally fray and let go.
I doubt I'll ever wear them out.

These cables are available at fairly low cost for a Norton as they are stock items.
They are quite expensive for some other bikes, where a custom order is required.

Glen

Mk111 Heavy + Dragging Clutch Advice Please

GRM 450

L.A.B.

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Staytite

GRM 450

L.A.B.

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GRM 450

worntorn

L.A.B.

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GRM 450

Bernhard

GRM 450

L.A.B.

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Bernhard

dynodave

L.A.B.

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dynodave

L.A.B.

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dynodave

L.A.B.

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worntorn

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