F: Frame Seat Dampers

timetraveller

Well Known and Active Forum User
VOC Member
A couple of things for completeness. Vic is probably correct that the loaded PTFE would be better then plain PTFE. Both IGUS in Europe and Pacific Bearings, in the States but with agents over here, are firms I have dealt with. The problem is that if one is trying to keep the original parts then some form of adhesion is probably required. The PTFE specially made for that is the only one I know of but there may be others. The other thing to note is that if one wants to keep almost the original appearance but still have a fully sprung seat then it is possible. The trick is to keep the original friction dampers but then support the base of them by two struts coming from two holes, one above the other, at the rear of the footrest plates. The magic can work because one is making a triangle, albeit a narrow angled one, by using two struts which start off about two inches apart where they fasten to the rear of the footrest plate. They can be through bolted to the central part of the friction damper. If the two supports are painted black then they hardly notice. All I can say is that by 1954 Vincents had fully sprung the seat and started to use a coil over damper. This was reportedly due to consultation with VOC members.
 
Last edited:

delboy

Well Known and Active Forum User
VOC Member
The original damper material was weatherstripping. It had no serious friction enhancers. It was easily available from automotive suppliers.

View attachment 39730

If you are looking for original replacements, I would start there.

I would think that Simmon's solution works very well. phosphor bronze is a relatively high friction material without being constantly flooded with oil. Fiction material may be too high in friction and too delicate to work as expected. As Simon says, it is more of a trial and error test to find what works well for the rider.

David
Hi David,
A useless snippet.
my old Ferodo agent told me years ago that it was known as "Bonrest" as it used to be used around engine compartments to seat the bonnet on car, to avoid metal to metal contact.
Regards, Delboy
 

Simon Dinsdale

VOC Machine Registrar
VOC Member
VOC Forum Moderator
Wouldn`t it be possible to use a closed ballbearing in this place?
Erik
I looked at that and there isn't really enough room due to the position of the two bolts that secure the damper drums to the RFM. Its the smaller bolt that stops the drums rotating that is the problem and you would have to either move that bolt and so then have to redrill the RFM bracket or you would have to make an alloy seat stay casting that is larger to allow a bearing to fit.
I looked at needle roller bearings and couldn't find anything off the shelf, that doesn't mean one doesn't exist though.
 

oexing

Well Known and Active Forum User
VOC Member
No need to struggle for zero friction in there I´d say. There is not a lot of motion in the strut bearing over full stroke of the wheel so some low friction material should be quite allright. Just get special plastic material for fabricating bushes and all is well. Below a link to IGUS for rounds for a simple lathe job - or find your local company which supplies anything like that.

Vic
IGUS rounds
 

Steve Morris

Well Known and Active Forum User
VOC Member
Thanks all for your help and advice. I have decided to use the bonnet rest webbing and keep it kind of standard. The bike is only ridden on high days and holidays so its a good job for now!

Another question, the round bushing inserts, Ive seen a few pictures where the outside of these looked like it was painted red? Mine were painted roughly in silver hammerite but today when i cleaned the struts and bearings up i noticed some red paint on them? Should they be red??
 

vibrac

Well Known and Active Forum User
VOC Member
I dont think anything on a Black Vincent was ever red which is why I always add a few touches of that coulor on the engine perhaps the horn and at the moment red handlebar grips
NB is this what happens to rebellion after half a century?
 
Top