Misc: Everything Else Standard Comet Special

Bill Thomas

Well Known and Active Forum User
VOC Member
Can't tell you how many times I have refitted the Seat and Tank, They have both been fitted on a Vin',
But would not go on this right.
The Tank was with Norton Forks, And the Seat was on my L/ning rep'.
I have done a bad bodge, Even for me !, To get the Tank away from the forks.
I bought the Cases from a Friend about a mile from me, And the Gearbox and all the other fittings, From
another friend a mile the other way !, I swear they were together once ?.
There was a bad mark where the footrest took a lump out of the Chaincase, And the Vincent plate for clutch spring adjustment, Matched perfect, One from one friend and one from the other !.
But Ron says, That doesn't mean anything, because you would get the same mark from any Comet ?.
But I like to think I am putting them back together :) .
We say these bits are old, But they could have been sitting doing nothing for years ??.
All Good Fun, Cheers Bill.
 

Oldhaven

Well Known and Active Forum User
VOC Member
Time for something a bit more uplifting, I hope. I have been back at it recently after having to delay work on the project due to a move to a new house, then all the work involved in getting a shop mostly set up and finishing up what we could not afford to have the builders do In the rest of the place. I have had some health isssues that also made things difficult, but I am now well enough to continue spending time and money on this pile of bits. The pictures show the current state. The big change in plans has been to use a fairing I have had for decades that was originally intended for the Ducati 750GT I sold to finance this project. This required a fair bit of head scratching and fabrication since I did not want to do any more welding on the Dunfey UFM. It has a bracket for a fairing, but had to be adapted to the Ducati fairing/headlight support. It also required that I go back to my original plan of Laverda adjustable bars, though I really liked the European super bike bars I had on it in previous pictures. The stage I am in right now is creating a wiring loom from scratch, something I have not done before. It looks a right mess now as I am just getting it all roughed out before tidying it up. I am using a motogadget M-unit as a big departure from standard. I hope this experiment is worth it, but the concept is good as it combines lots of separate elements in one small box. It does mean that all the eggs are in one electronic basket. Once the harness is done it all comes apart for final finishing. Paint, polish, and completion of the final engine timing and tightening. I was going to do it in Flash grey, but my wife and a couple of friends say the Egli red on the tank is really nice, so that may be it, with some black and gold accents.

E7CB5553-2BF1-4C63-9CE9-6ACD68372348.jpeg
4F12CF15-9B1A-4AA4-9EC5-40E18538103F.jpeg
8C886D94-01FD-4101-A93A-657B7F38D601.jpeg
76BDB5AA-E40A-4014-94DD-494AB3A94B20.jpeg
BC664C80-BE10-4D26-9680-1939E96C625A.jpeg
 

Bradley Burt

Well Known and Active Forum User
Non-VOC Member
Hi Ron,
What is the offset of the Ceriani triple clamps or what's the front end trail?
What type of mono shock are you using and what is its length? It looks like the swing arm pivot point is higher than the rear axle like most modern motorcycles is this right?
Thank you.
 

Oldhaven

Well Known and Active Forum User
VOC Member
Hi Brad,

The Triple clamps were custom made a long time ago, probably from a casting since I can’t imagine that much carving being done on a couple of billets of aluminum. they are quite different looking than standard as you can see in some of the pictures I posted here earlier. I believe they are wider than usual so the Grimeca 4LS fits and I bought the forks and front wheel as a set. The guy I got them from had bought them from the original maker, though all he could remember was that he thought the guy was somehow associated with Team Hansen. I don’t really know the offset other than verifying by eye that they do have some. The mono shock is one of the Thornton/Works ones set up for the rear of a Comet That was availblue back when I was buying the parts for the bike. If you look back at the pictures you will see that the struts I use instead of an F106 frame tie are adjustable in length so the front end angle can be adjusted to vary the rake angle within limits. I don’t have the rear coil over preloaded much in the pictures and there is not a lot of weight on the machine right now, but yes the rear axle will be lower than the swing arm pivot. I had to make sure the seat was high enough to avoid the tire while remaining low enough to be comfortable. The 18” wheels help. I like it so far.

How are your two projects coming?
 

Oldhaven

Well Known and Active Forum User
VOC Member
Bruce,

I’d love to go to the rally but I have been slowed by health problems since I last posted pictures. I am feeling a bit better now and hope to get back to finishing the electrics and loom, then it’s apart for painting and final engine timing and button up. Probably not likely to be done until summers end now If I’m not being too optimistic. I really look forward to that though I am realizing that I designed a bike more suited to a younger rider than me.On the other hand, the low seat and the fact I can lean on the tank doesn’t seem too bad when I sit on it.

Ron
 

Bradley Burt

Well Known and Active Forum User
Non-VOC Member
Slow.
We currently have Kawasaki ER650 triples and GSXR forks. Unsure if we will use these in the end but time will tell. We measured the rake of a rapide to be 30 degrees (or pretty close to it) so these comets should be much the same. The triples have a 28mm offset so the trail will be large. Steepening the front end can be done, as long as we avoid the header pipe. I will get a couple of photos. The adjustable F106 is a great idea. What is the length of your monoshock between the mounting centres?
 

Bill Thomas

Well Known and Active Forum User
VOC Member
I don't think the Comet and Twin are the same ?,
The Comet steering feels quicker,
I don't think the distance between the rear pivot and cylinder head fitting are the same ?.
Cheers Bill.
 

davidd

Well Known and Active Forum User
VOC Member
Bradley,

I used a Terry Prince monoshock frame to build the jig, so it has all the same geometry. The RFM is an exact copy of Terry's, which is a copy of the stock Vincent RFM and it will fit in a stock Vincent frame. Terry used a long monoshock. I fit a Works Performance Vincent coil-over for the rear shock in place of the long shock.

The geometry of the Egli frame I made is essentially the same as stock Vincent except that I lowered the rake of the steering head, which Terry had also done on his frames. On my jig the rake is adjustable until I build it. The RFM geometry depends on how the gearbox plates are designed and how the coil-over is adjusted, like the stock Comet. Although the bike is styled like an Egli, it is more of an Egli style RFM with an Egli style 4" tube UFM. This was done so the frames would work on singles and twins.

DSCN1592.jpg


The rake is 26 degrees and the UFM was designed to work with the 600 GSXR fork.

David
 

Oldhaven

Well Known and Active Forum User
VOC Member
Brad,

The eye to eye length of the rear Works coil over on the special when unladen as it sits now is 10”. It compresses a lot now when I sit on it since I have not put in much preload while testing clearances. My feeling is that while I have a low seat height the way the frame works makes the swing arm pivot slightly higher than a classic Comet. The offset of the forks is about 2” from the steering axis. The distance between the fork legs is 7-3/4” And they are 29” long from top to axle. You can use the 26 degree figure David gives as the nominal rake, since I used his frame, and it was designed for that rear coil over, but I can adjust the rake/trail by varying the length of the frame tie struts. Since he designed for the GSXR fork my fork length will probably affect things too. I know it will be quicker steering than a classic Comet, but I will probably adjust to a medium trail. We’ll see eventually.
 
Last edited:
Top