• Welcome to the forum website of the Vincent H.R.D. Owners Club.

    Should you have any questions relating to the Vincent H.R.D. Owners Club, or Vincent H.R.D. motorcycles in general, please contact Graham Smith, Online Forum Webmaster by calling 07977 001 025 or please CLICK HERE.

    You are unrecognised, and therefore, only have VERY restricted access to the many features of this forum website.

    If you have previously registered to use this forum website, you should log in now. CLICK HERE.

    If you have never registered to use this forum website before, please CLICK HERE.

Comet clutch

Tug Wilson

Well Known and Active Forum Website User
Non-VOC Member
Still digging in my baskets I have identified the clutch from the limited illustrations available, however the hub will only carry 5 plates in total 6 at a push but the parts book lists 5 friction and 6 steel. Is this a later clutch or not for my 1950 Comet? The hub fits the mainshaft and the outer housing spring plate etc is identical to illustrations. Can anybody help?
 

Hugo Myatt

Well Known and Active Forum Website User
VOC Member
Hi Tug,

This is not an unknown problem. There are actually two different thicknessess of plain plates that have been used. It sounds as if yours are all the thicker ones. A lot of us Comet owners use a mix of thick and thin plates to get them all to fit. The only other solution is to reduce the thickness of the friction plates by rubbing them down on a smooth surface covered with sandpaper until all the plates fit. A tedious business. You say all six will fit but at a push. This usually results in the outer most plate popping out of the clutch drum and turning so that all drive is lost.

Hugo
 

Tug Wilson

Well Known and Active Forum Website User
Non-VOC Member
Thanks for suggestion but that was a total of both types of plates I could fit!
However turns out it was a rogue Ariel clutch in box with gearbox. This is turning into some rebuild! Gentlemen please ignore this post I'm going for a lie down.
 

redbloke1956

Well Known and Active Forum Website User
Non-VOC Member
Hi Tug, I had the same problem when fitting new plates to my AJS, and believe that if your springs are strong enough, your plates are all in good condition, and as Hugo mentioned...you don't end up with the final plain plate extending past the basket when clutch is operated (as mine did with too many plates) then the quantity of plates shouldn't make a difference.
Have just fitted new plates to my almost finished comet so should know soon if this concept also works on the Vin (greater horsepower of the Vin might make a difference though)
Good luck with it mate.
Kevin
p.s. The Comet clutch is so similar to my AJS clutch that they are interchangeable, being part of a Burman setup (which are used in many british bikes) I "think" the clutch/parts could be off any one of a long list of British bikes.
 

Hugo Myatt

Well Known and Active Forum Website User
VOC Member
Hi Kevin,

Been there, done that, i.e. fewer plates. Result, I'm afraid, clutch slip. Most new or re-lined friction plates have too much meat on the inserts.

Hugo
 
C

charlottevictoria

Guest
The plate are the same as many many other Burman cluches. I have had an ARDIE from 1929 with Burman-gearbox where the plates where absolutely identical to the Comet's parts!
 

timetraveller

Well Known and Active Forum Website User
VOC Member
Hi Gentlemen, perrhaps I can tag along here on the back of this thread. A year or so ago, when I was supplying the needle roller thrust race mod for the twin clutch push rods, five of you asked if I could do the same for the Comets. There was also an enquiry to see if I could do the same for the Honda clutch which some people are using. It is not possible for the Honda clutch as its design means that there is not enough free space inside the clutch to let the new parts fit. As I have no expertise with Comet clutch I was kindly lent five Burman outer aluminium pressure plates in order to help me to design the bits. The first was from Ian Savage at the Spares Company who lent me one with a 5/8" UNF thread in the centre to take an adjuster. The other four all had a steel top hat bush pressed into the centre of the aluminium plate with no provision for adjustment at that end. Incidenmtally all five of the ali plates were also different but not with regards to hole centres etc. These top hat bushes had holes worn into their centres with depths varying from almost nothing to all the way through! I have now worked out how to make a needle roller adaption for these Burman plates but it is going to mean boring out the centre of the plates and putting a 20 mm diameter adaptor in there. Even the 5/8" thread is not large enough to allow me to make a part robust enough for me to be happy to sell these. So the question to the Comet owners who are potentially interested in this mod is as follows. If you want to go ahead with this are you prepared to let me modifiy your own plates? Would you like me to buy new plates and modify those so that your original stays as it is? I know that at least one of you is prepared to have me modify his old plate and there are only five of you anyway. Feedback to me at enw07@btinternet.com Thank you chaps.
 

Tug Wilson

Well Known and Active Forum Website User
Non-VOC Member
Hi, as this thread is still running please note my input 31/01/11 where "eureka" moment is noted. I have to say I could have rebuilt two T-----h basket cases to one Vincent however I love a challenge and the old girl should be worth it eventually but my bank manager and more importantly the wife have doubts!
 

Tom Gaynor

Well Known and Active Forum Website User
VOC Member
I've just been reading KTB, looking for pitfalls since I'm building a big-bore Comet: new plates are thicker than old plates, with results noted here, but it suggests that four modern plates work as well as five old ones, particularly if used with the thinnest (0.031") steel plates where possible. The stack height should be made up by steel plates under the pressure plate, taking care that the top one doesn't escape the splines on full lift. The implication is that the first plate into the basket should be a thick steel one. (VOC spares sell them.) I haven't tried this yet, but expect I'll have to when the 572cc Comet makes the jump from "basket of bits" to "motorcycle that may one day run". Lots of potentially useful dope on Burman clutches in KTB, recommended.
Hi Tug, I had the same problem when fitting new plates to my AJS, and believe that if your springs are strong enough, your plates are all in good condition, and as Hugo mentioned...you don't end up with the final plain plate extending past the basket when clutch is operated (as mine did with too many plates) then the quantity of plates shouldn't make a difference.
Have just fitted new plates to my almost finished comet so should know soon if this concept also works on the Vin (greater horsepower of the Vin might make a difference though)
Good luck with it mate.
Kevin
p.s. The Comet clutch is so similar to my AJS clutch that they are interchangeable, being part of a Burman setup (which are used in many british bikes) I "think" the clutch/parts could be off any one of a long list of British bikes.
 

nkt267

Well Known and Active Forum Website User
VOC Member
The implication is that the first plate into the basket should be a thick steel one. (VOC spares sell them.)
Yes correct.An interesting point here is that in my collection of Burman clutch plates I have a thick plain plate that has the splined section thinner than the plate section to allow the stack to be position slightly nearer to the chain wheel, maybe to stop the top plate coming out. Also the shoulder at the rear of the clutch centre can be too thick and I have had to slim this down in the lathe to make a stack fit. Finally if you buy clutch springs at a show there are at least 2 or 3 different lengths available, if I remember correctly the difference is whether the inserts are cork or Ferodo, I use the longer prewar type and I can now squeeze blood from a stone.:D .John
 
Top