Suspension - please explain.

Albervin

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I assume you now have spacers between the springs and damper on the lower mount. When you rebuilt the damper what oil did you use? This can be critical to a good set-up. Most suspension tuners say " soft springs and firm dampers" and that has worked for me for forty years. The friction seat stays are a hangover from Series A and B bikes. Light machine oil on the damping fabric stops squeak, judders and still gives a smooth damping for the passenger. You say you have 1/2" each end of bump stop. That doesn't sound right. There should be a bump stop at the top of the piston but not 1/2". With modern oils I use a 3/8" Nylothane bump stop. IF the damper is compressing to full travel then you have to do a few things; but one at a time. First I would put heavier oil in the damper. Then I would think about changing one spring to a heavier one. Before doing anything you need to measure suspension sag; both static and with you sitting on the bike. This is critical for a comfortable ride. Cable ties are your friend here. Happy days.
 

Simon Dinsdale

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Howard, I have done the nylon inserts on my C Shadow seat stays and it improved the rear suspension feel a lot. Think of it this way:
Series B usually had no rear damper (I think the last of the B's may have though) so the only rear damping is the friction damping in the rear seat stays. Series C's had a hydraulic damper but kept the seat friction dampers as well which defeats the point of the hydrauic one and they end up fighting against each other. When you fully spring a rear of a Vincent most owners first comments are the rear suspension suddently came alive and worked a lot better, my C Rapide did.
On my C Shadow I fitted bearing grade nylon ring instead of the friction material and so the seat stays move easily but most important don't flop around sideways as that will allow the seat to move sideways and put strain on the seats front mounting brackets. Result is the rear suspension is now controlled by the hydraulic damper.

Simon
 

Vincent Brake

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IMG_20200522_105249.jpg
IMG_20200522_105142.jpg
 

Bill Thomas

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This was from Vincent brake/speet.
He turned a bit out of the inside of the alloy bit , To make room.
 

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Vincent Brake

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Don't know where i got them from anymore. Howard.

Later i went to works performance.
Coil over.
Better and way lighter.
But no, not looking standard...
 

Ken Tidswell

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Pettiford springs allow more travel but you might have to compress them in order to fit them even with the damper fully extended. Are you sure that there is a hydraulic bump stop in the damper? I am not saying that there isn't but I have never noticed it and how would a hydraulic bump stop work? Is that part of the Paul Ennis modification? Fully sprung is a major improvement, hence the Series 'D's. AVO coil overs are a good way to go. At the front then the John Emmanuel mod with my mod for the springs and the Greg Brillus mod to the Oilite bushes makes a dramatic difference to front end comfort and I am currently out of stock so I am not trying to sell you anything.
Many decades ago a young J Surtees suggested that that the handling of a Vincent would be improved by lenthening the rear spings by 11/2 inches . Since PCV was not good at receiving suggestios about his product it never happened. However the heretics among you did just this i am one. Fitted longer rear springs and aKoni and went fully sprung fot touring and the ability to carry luggage. The longer springs sharpen the steering and fitting a19 inch rim makes it better. Where's the bonfire.
 

Howard

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Longer spring box inners help alot to prevent thespring boxes fouling on extension
Ken, I'm not a purist. The Comet I raced had coil over damper front and fully sprung rear, I 'd love to build one like it, but it's not what I need, and it's not what my current Comet deserves, I'm trying to keep it standard/useable (if that makes sense). I love the work that's gone into some of the unnecessary art, like chain adjusters and friction dampers, and removing things like that take me further from the essence of Vincent. If it has to stay bumpy, so be it, but if I can make it a bit more comfortable and look the same, all the better. I had heard PCV didn't take criticism well. :)
comet.jpg
:)
 

vibrac

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At least if you have the Paul Ennis mods you are well on the way to getting the best out of a standard damper I know a standard set up can be made to work well (heck I raced on one long enough even if I had a broom with a short handle) however nowadays with todays roads I am glad I have coil over AVO and coil over Bramptons. When we were finally were allowed out last week and I tested out my brood after the winter, I found bumps on my test loop road on the 35 KSS Velo and 52 Trophy that I had not felt on the Comet something must be working right.
 
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