Suspension - please explain.

Marcus Bowden

VOC Hon. Overseas Representative
VOC Member
This is what I did in order to get a little more hight above the battery tray to hold a bigger battery, it also saves a third of the weight of the suspension units and they can easily be adjusted (preloading up or down) by grabbing hold of the springs and turning them, also helps when fitting. Next mod will be to cut up some 1/4" aluminium plate making a large diameter hole to fit around the spring claws, leaving a handle 2 to 3" long that can be drilled its whole length into the hole that receives the spring claw. The spring claw is then machined with multi castellations around its periphery. A shaft and ratchet paw slid up the hole with spring. The shaft and ratchet paw have a small lever that can twist shaft/paw 180 degrees to work on the castellations turning the spring units C.W. or A.C.W. to raise or lower suspension, have also been made for racing Vincents with success..
bananaman.

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THE 3/4" UPPER SECTION HAS BEEN INSERTED WITH SINTERED BRONZE BUSH as FIRST SET WORN OUT IN LESS THAN 10k miles. So bored out and bushes fitted. Also, ensure that a vent hole is there.

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SIDECAR PETIFORD SPRINGS & KONI DAMPER AND AS COMFORTABLE AS SONS SERIES "D"
WITH BAGS OF TRAVEL.

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timetraveller

Well Known and Active Forum User
VOC Member
What is the Greg Brillus mod to the oilite bushes>?
The mod consists of removing the Oilite bushes totally and boring both rear eyes of the lower link by a few thou to take a 32 mm O.D. ball race, two ball races each side so four in total. Some other people have replaced the Oilite bushes with needle roller bearings. If I supply the whole kit which I think gives the best ride, performance etc. then stainless steel concentrics are supplied to replace the original eccentrics which went through the Oilite bushes. Occasionally there has been some misunderstanding in that there are those who think that these concentrics are fundamental to the modification. Not so. The fact that they are concentric is not important. There is one size of concentric if the Oilite bushes are to be used and another if the ball race mod is to be used. It is not the fact that this is a concentric which is important but the geometry of the centre of rotation for the rear of the lower link which changes the geometry. It is the geometry of the lower motion block of the new steering head which effects the change.
The reason that I recommend the Greg type conversion to anyone who can afford to spend the extra money is that when Chris Launders was doing the original test riding we had a perfectly good system consisting of the normal AVO damper and 36 lbs/inch springs with three inches of pre-load. When Chris removed the Oilites and, in his case, replaced them with needle rollers the front of the bike 'pogo sticked ' so badly that we thought that the damper had failed. The reduction in friction led us eventually to going to 45 lbs/inch springs with just over two and a half inches of pre-load and a stiffer damper. Chris weighs about 20 stones/127 kg and it was this that lead me slowly to the understanding that the total mass that one is springing and damping has to be taken into account.
 

greg brillus

Well Known and Active Forum User
VOC Member
Don't bother machining the eyes, this would be very expensive, just get them honed at an engine reconditioning shop using their hone they use to resize connecting rods. That way the eyes are kept perfectly in line and the amount removed is a maximum of less than 8 thou on an as new link. Using four of (x 4) 32 x 20 x 7 mm sealed bearings you want not more than 7 tenths of a thou interference, any more and this will distort the bearings and crush them too much. Lightly grease all the parts on assembly to the stem, you will need one or two of the supplied shims on the inside between the large inner washer and the stem lower block to space everything correctly. Use a washer under the heads of the main bolts, this will help align the upper spring cases with the lower halves better........Use a steering damper of your own choice making sure you get full lock to lock travel.............Good luck with it all.
 

Howard

Well Known and Active Forum User
VOC Member
Thanks Marcus, always good to see a Vin built to be used. Looks like we've been thinking along similar lines, more travel and height/preload adjustable. I wonder if Pettifords are a bit too strong for a Comet ridden mainly solo. What do the friction dampers do? I can't see how they work with a fully sprung seat.
 

Marcus Bowden

VOC Hon. Overseas Representative
VOC Member
Pettiford's did sidecar and solo springs and I think are carried by the VOCSC, mine are sidecar strength, I was thankful I'd left the friction dampers still connected by a link arm to the back of the seat as my hydraulic damper collapsed at the 95 international after leaving the first stage as we did quite a number of miles on rough roads but screwed up the friction that gave a reasonable amount of damping, somehow managed to get a new Koni in Christchurch fitting it in the cattle yard prior to the John Britton interesting talk.
bananaman.
 

Howard

Well Known and Active Forum User
VOC Member
Pettiford's did sidecar and solo springs and I think are carried by the VOCSC, mine are sidecar strength, I was thankful I'd left the friction dampers still connected by a link arm to the back of the seat as my hydraulic damper collapsed at the 95 international after leaving the first stage as we did quite a number of miles on rough roads but screwed up the friction that gave a reasonable amount of damping, somehow managed to get a new Koni in Christchurch fitting it in the cattle yard prior to the John Britton interesting talk.
bananaman.
I'm sure I'm being lured into something, but what's the Banana for?
 
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