Hi I'm going to look at the clutch ('71 commando) this weekend as it's very heavy. I've read there is a plate from RGM that will help but which one am I actually going for? There's loads of them on the site. Thanks.
Maybe there's a rule to…
Maybe there's a rule to follow but I'm not aware of one.
At the risk of being condescending, do you understand how the diapragm clutch on a Commando works? The clutch will be 'heavy' initially and then go light as the spring "snaps over" and the clutch releases. You will definitely feel this and it should happen at 2/3 to 3/4 of the lever travel (according to taste). If the overall plate thickness does not allow this to happen it will remain 'heavy' throughout. The angle of the actuating arm in the gearbox is also a factor, you would like it to be an acute angle to the cable when the clutch is engaged and an obtuse angle when full disengaged, i.e. it crosses over 90 degrees for maximum leverage at about mid travel.
If, after adjusting the clutch by the manual, i.e. with the cable slack and using the adjuster bolt in the centre of the clutch plate, you still don't get the snap-over effect, you can try winding the adjuster in until you do. It's difficult to judge the cable angle thru the inspection hole but it's something you can observe while you look for the best feel. Then, when you're happy, measure the distance between this and where the adjuster should be for the correct clearance - hint: the adjuster bolt is 20TPI. Add a plate to pack out by this amount. You might find that simply adding an extra steel plate gives the desired result. Don't be tempted to run the bike with incorrect clearance on the adjuster.
A free running cable always helps but be wary of oiling the teflon lined ones. Also check the cable run (no nasty kinks) and how it enters the box. If it's still too heavy, you could try a longer lever :)
RGM 3mm Plate
Replacing one of the 2mm thick metal plates with a 3mm one from RGM (0607463) should lighten the clutch. I have fitted one to three Commandos now and it improved things in every case.
But it is not the only factor. Clutch cable needs to be free running and correctly routed. Lever in gearbox must be properly inline with cable entry hole. There is a wealth of info on this site and the access Norton site about this.
Yeah I've tried to get some…
Yeah I've tried to get some spray down it but I'm convinced there's something else wrong.
Thanks Stan I don't actually…
Thanks Stan I don't actually know how it works I was hoping to not have to take apart a restored bike. I've got plenty that need work already. The clutch is a four finger wrestle across the whole travel. The cable looks to be travelling though pre determined holes but I can't say what it looks like at the actuating arm end. I guess it's coming apart no matter what.
Thanks, I'll dig around some…
Thanks, I'll dig around some more.
What Commandos and Velocette…
What Commandos and Velocette singles have in common — an idiosyncratic clutch that will fox those who are unaware of its special features …
(It is fair to say that the Velo clutch contains considerably more gotchas than the Commando one; quite possibly the most discussed topic on Velo forums.)
Yes, but once my 1961 Velo…
Yes, but once my 1961 Velo MSS clutch was set up correctly it became superb, smooth and light.
A way forward
Until you know what you have, difficult to plan, there are 2 thickness of pressure plate and three thicknesses of friction plate used over the years.
Assuming you have the spring compressor, if not beg, steal or borrow one!
Now footrest off, undo cover and catch oil. Remove adjusting screw and apply compressor, don't screw in futher than adjuster was and slacken cable at bars, tighten nut till diaphragm is dished outwards. Now use feeler gauges to measure gap between circlip and front face of diaphragm, that is max you need to gain and write it down!
Now remove circlip and dismantle clutch and see which you have. Could be four or five friction plates and a variety of solutions:
If five bronze plates, then you can swap one or two for fibre ones or the old postage stamp style which are thicker or fit a thicker plain plate
If four fibre ones then it's fit thicker plain plate or buy some new fibre ones, or thinner pressure plate and extra plate.
Seem to recall the Americans had a good site dealing with this issue, where you measure the stack height of plates and aim for paticular dimension, maybe someone will add a link.
As Martin suggests - the. Stack Height is critical.
Ensure that the diaphragm plate is truly flat using the compression tool.
The stack of clutch plates along with the flattened diaphragm plate should be level with the retaining groove in the clutch housing, the groove that holds the retaining circlip (06.0751).
The clutch cable should not be housed through the wiring harness grommet in the frame, it should be lined up in a smooth curved layout. Not zip tied tightly to the frame.
The clutch operating lever (06.0715) should be rotated so it is in line with cable inlet in the gearbox outer cover.
If all the above setups are correct, you should have a smooth easy action clutch. If not, you have other issues with the clutch.
Righto thanks, this will…
Righto thanks, this will give me something to go at. The joys of buying a restored bike eh?
Heavy commando clutch
I replaced one of my 2mm metal clutch plates on my 1972 750 with a 4mm plate from RGM. I could just get the large circlip in that holds the diaphram spring in place. I took it for a spin and had no clutch slip at all but the clutch was so much easier to pull in. I had bought a 3mm plate as well so I could add either 1, 2 or 3mm to the stack height but an extra 2mm did the job. Plates cost about £8 each plus VAT and postage to UK. Its miles better now. If you can't get the large circlip in the groove you've added to much to the stack height. Clutch cable also needs lubricating usually and a nice smooth run to the lever without tight bends.
So it's apart and this is…
So it's apart and this is what I have. 2 friction plates are slightly under size approx 3.54 which I guess are meant to be 3.6mm although all seem to be visually in reasonable condition. RGM don't have them in stock and Andover was £85+ vat for a full set! The cable is attached to the box as in the picture and seems about right to the untrained eye however is the routing correct going through that bracket and grommet? please see pics. Oh and the oil is a bit manky what's the most common used? [img]https://i.imgur.com/yTvejtb.jpg[/img] [img]https://i.imgur.com/JSVajpv.jpg[/img] [img]https://i.imgur.com/td0g0vO.jpg[/img] [img]https://i.imgur.com/eXCET1h.jpg[/img]
Are my pictures showing?
Are my pictures showing?
Try again ......
Try again ......
My Commando clutch used to…
My Commando clutch used to be so heavy that I always carried a spare cable due to the handlebar cable-end being pulled off on a regular basis. I eventually changed the pushrod and the difference was like night and day.
The original pushrod must have had a slight bend in it.
Checked that out but it's…
Checked that out but it's fine.
Commando clutch actuator.
Not telling anyone how to suck eggs, but the cable to push-rod actuating lever may also be a snag.
The Commando lever is not the same as an Atlas or Dommie, just in case whoever rebuilt the bike made an error.
Good luck, I concur the stack height is critical!
Feels like success! I bought…
Feels like success! I bought a 3mm and 4mm plate from RGM. Tried the 3mm and it did feel better but was still stiff so out with that and in with the 4mm. Still plenty of room for the circlip and still heavy for what I'm used to but more than usable. Haven't ridden it yet so hoping for no slip but I can't see a reason why it would as there's still slack in the cable after adjusting it up. Just got to give it a go, thanks for the advice. Next 2 posts will be how do I set up the isolastics as the vibes are painful and how to get the brakes better than dragging my feet along the ground.
Hidden things alright. The…
Hidden things alright. The front wheel was loose so I tightened it up only to find it would lock up. Took it all apart to find the wrong bearings and other pieces of the assembly missing. Bodging is one thing but that was stupidly dangerous.
I have just fitted a 3mm…
I have just fitted a 3mm plate place of the 2mm. It significantly reduces the weight of the clutch. The only thing I have found is the the manual says to back off the clutch pushrod adjuster by one full turn. I have I need to back it off air less to stop it dragging slightly and making it hard to select neutral when stopped
Every Haynes manual I have ever read has a picture of how to lubricate a cable making a little funnel out of plasticene and pouring oil into the cable until all the oil has run out the other end.
I use a plastic bag secured with a cable tie or duct tape to make the funnel.
I would seriously try this dodge first.