Comet Rear Suspension

[Big Sid]

Not all Armstrongs when held on an angle similar to the rear damper show Consistant damping but feel good when held vertical as in the front , these go up front . Those that feel Consistant held on an angle do fine on the rear , much better than original
Vincent dampers with dead float in their movement . They vary . Try it . Have done this several times with satisfaction restored .
A damper with float is worthless in the rear . Will explain if requested . Sid .

 

[timetraveller]

It is possible that I have missed something in all this but I have not seen any mention of the changes to the rear set up between the 'B's and 'C's. The distance from the pivot to the rear axel was lengthened and the support for the rear friction damper moved forwards. If the rear seat support allowed the friction damper to be in line with the pivot then any movement from a central position would cause the rear of the seat to move downwards which would probably cause the pillion passenger to feel that they were about to be catapulted backwards. Some slight upwards movement would counteract that at the cost of a less smooth ride. I am pretty sure that what Vincents were trying to do was to make the rear suspension less susceptible to different loading by making some of the load essentially unsprung and we have all used the system for years. I have a fully sprung set up on the ex-Cecil Mills bike with Petteford springs and although it is not as comfortable as a 'D' it is certainly more comfortable than the standard set up. I should also say that I too have noticed how much better the bike sits on the road and corners (normal road use not racing) when there is a pillion passenger. The bike feels like it is on rails when cornering but I have never been able to determine why. The rear Armstrong damper is still in good condition as are all pivots,clearances etc. The tyre pressures are correct for me solo so probably a little low for having a heavy rear passenger and yet the handling certainly feels better. Reducing the rear tyre pressure does not produce the same effect as if the rear pressure is low then enthusiastic cornering can make the bike feel like the rear tyre is squirming. Over to you chaps.

 

[Big Sid]

On poor rear stability , fearful handling on the curves , odd rear chain sounds pulling hard .
Check that the swing arm pivot isn't loose side to side . Kneel alongside and pull and push on rear frame looking for looseness .
The assembly needs to be shimmed between the two side plates , the big nuts to be a snug fit when slid into place , no end float .
Causes all manner of freaky sounds and unwelcome feelings . Not safe til shimmed . Sid .

 

[clevtrev]

On poor rear stability , fearful handling on the curves , odd rear chain sounds pulling hard .
Check that the swing arm pivot isn't loose side to side . Kneel alongside and pull and push on rear frame looking for looseness .
The assembly needs to be shimmed between the two side plates , the big nuts to be a snug fit when slid into place , no end float .
Causes all manner of freaky sounds and unwelcome feelings . Not safe til shimmed . Sid .

If you have a gap there, it is not possible for the pivot bolt to be tightened. The nuts would vibrate loose before you have gone very far. The Comet pivot plate on the timing side is flexible enough for this not to happen.

 

[Big Sid]

More on the rear pivot shimming . Where after the bearings are cleaned and shimmed to be just free to rotate nicely but no play proceed . Strip and grease the two roller bearings , build up , tighten nuts . Should be a very snug fit between the side plates , we used to say a firm boot kick to the tire going in . If any loosness is detected one needs to add a shim beneath the thin big nuts to widen the assembly , better one each side , til it's a snug fit , no loosness .
Be sure then to adj. the two thin nuts on the battery carrier to butt firmly against the backside of the G 50 plate . This to eliminate warping of this plate with a hot motor . Then tighten up the pivot shaft nuts . All should be solid yet free to pivot . This is all part of the machinery in a Vincent and should be treated as such .
If the wheel allignment is good and the dampers are functioning and the steering head adj. is sweet , THEN my son you will discover just how good a Vincent can be in the twisties . Enjoy ! Sid .

 

[b'knighted]

Hello Ian, Show us a photo, Maybe I was wrong, Cheers Bill.

We tried again today! the bike looks exceptionally scruffy in pictures and as you can see it was being worked on when the pictures were taken. Thinking about its appearance as the pictures were being taken I realised that the oddness is due to the absence of standard spring boxes. If you get close to the bike the seat obscures the spring over unit.

 

[b'knighted]

Close right view

 

[davidd]

It looks quite normal to me! I do like the look of the stock bike, but I am so use to seeing a single spring now it does not draw my attention. It certainly is a lot fewer parts.

David

 

[Bill Thomas]

Maybe if it was Black !! This is from a bloke who built a Blue Vin' !! Yes it's like a D, And I have and like them. Cheers Bill.

 

[hadronuk]

Help Needed with Girdraulic Research.

I would greatly appreciate a couple of measurements that would be very useful.
Details here:

http://www.vincentownersclub.co.uk/showthread.php?5975-Help-Needed-with-Girdraulic-Research&p=42852#post42852