Interesting to see the rear of the dual seat's motion on the video. Now we know why the pillion passengers complain. Nevertheless a very instructive video.
FF: Forks Modified Steering Stem
- Thread starter greg brillus
- Start date
In the interests of originality (I presume that anyway) Paul Packman retained the original seat supports and friction dampers, but moved those friction damper drums right up tight to the top of the rear frame tubes where they enter the casting, he has said that in that position the seat hardly moves at all when the rear frame member moves through its entire arc, I have never seen Paul carry a pillion passenger though, I do wonder if the more acute angle of support might cause strength problems if you were two up.
UPDATE. Ok chaps. I was at the factory earlier today and all the parts are more or less finished. Also a box containing forty 45 lbs/inch springs and some more 36 lbs/inch springs was delivered a few minutes ago. I will be collecting the machined parts tomorrow and the only unfinished parts are the six lower links which have to be line bored to take the 32 mm diameter ball races. I will start and press the tubes into the motion blocks in the next few days. The only remaining problem is the AVO dampers. Chris, who has been testing out his bike with one on the front, has found that it now has little or no compression damping and only slightly more extension damping. You will recall that when new this damper was barely moveable by hand and I am expecting a phone call this afternoon from AVOs as to what has happened to the damper. In the mean time Chris' test show that, at least as a temporary measure, one can use any other damper one has available, Vincent, Armstrong, Koni or Thornton, with safety and the advantages of the new geometry if not the ultimate in comfort. Thank you to all those who have waited patiently and more updates should follow over the next few days.
If the thornton video is for real(as in believable) it's no surprise that George Brown went for the 7R front end and brake and so many of us built norvins. The scenario depicted can only be described as "F" rubbish!
I'd like to see your Norvin out handle the racer I built ...............
I don't think George had a 7R front end the day he came a close second to the works AJS porcupine at Dunholm and the rode home to Stevenage Gunga Dinn was pretty standard and when he did build that special it was very soon a straight line sprinter not a lot of road holding extremes there
If you examine the racing photos of George Brown on the Grey Flashes and Gunga Din, he is clearly using shorter springs. That would make the handling very good. However, the Girdraulic was never received as a serious advancement in fork design. For those of us who have raced Girdraulics this is a bit of a surprise. The advantage of racing a Vincent in a Pre-50 type of class gives the Vincent a serious advantage over other production bikes based primarily on it's suspension.
Even so, I can see why George Brown was eager to move on to something more modern. You really had to know a lot to get the Girdraulic to work well and it could still spit you off in a blink of an eye in an unexpected situation. This quiet undercurrent of questions about the Girdraulic lead many folks, like Peter Gerrish, to applaud the arrival of the Egli. It was lovely to mount a Vincent with more precise and reliable handling.
I look at much of this recent work to tune the Girdraulic as a great result. I think you could put Alan Cathcart or Beau Beeton on Greg's bike and they would be over the moon. Except for the lower power, they would love the little single racer I built. These bikes are not quirky at all. If you are slow through the corners it is the rider's fault, not the bike's. It is nice to get the bikes to perform at this level with only a few mods.
David
Even so, I can see why George Brown was eager to move on to something more modern. You really had to know a lot to get the Girdraulic to work well and it could still spit you off in a blink of an eye in an unexpected situation. This quiet undercurrent of questions about the Girdraulic lead many folks, like Peter Gerrish, to applaud the arrival of the Egli. It was lovely to mount a Vincent with more precise and reliable handling.
I look at much of this recent work to tune the Girdraulic as a great result. I think you could put Alan Cathcart or Beau Beeton on Greg's bike and they would be over the moon. Except for the lower power, they would love the little single racer I built. These bikes are not quirky at all. If you are slow through the corners it is the rider's fault, not the bike's. It is nice to get the bikes to perform at this level with only a few mods.
David
Well really the only actual fault with the Girdraulics was the amount of extra travel they tried to use. In principle they function pretty much the same as the Brampton's, with longer links. I had the pleasure of riding three different twins today, a good well used B Rapide with Brampton's, a newly restored B Rapide again with Brampton's and a C Shadow that I had just completely gone through following it's restoration from the UK. The Shadow I had also upgraded the front end with the new stem kit, Kwaka steering damper, and a Thornton shocker up front and same coilover on the rear. I rode all bikes at least twice each, and in fairly close time frame from one to another. It is without any doubt that the Shadow's front end felt way smoother and a lot more comfortable than the bikes with Brampton's, the front forks/links moving in a much more fluid manner and far more travel over the same bumps in the road surface. The owner of the Shadow took the bike for a quick spin, and could instantly notice the difference. I await further testing and feedback from him, as he does some quite serious ridding. I also have a Comet belonging to this same gentleman, to carry out the stem mod to very soon, and I told him the Comet will feel better again......... This is a guy who has much experience in riding bikes with Girder forks of many different makes. It is unbelievably good to be able to make this kind of comparison whilst riding these bikes literally back to back just to see how they behave from one another. It is an excellent result. I didn't get much work done today really, but I had a very successful one none the same. Cheers.............Greg.
Never mind outhandling , We have won four major concours de elegance awards , how many races did you win outright. That was my object., to win with a vincent hot rod!So when I tire of the show circuit I can terrorise the populace with the noise and poise of a fast vincent.I'd like to see your Norvin out handle the racer I built ...............
For anyone who has not seen it, in the March issue of CBG there is a 10 page Alan Cathcart article on the "unrestored" ex-Jack Ehret Lightning. On the Girdraulics he says "..the handling becomes more assured as you up the pace, with greater precision in steering than the relatively primitive telescopic forks of the day. No wonder John Britten and Claude Fior ..... developed alternative versions of the Vincent blade forks three decades later...."
Perhaps he should be invited to test ride the new Girdraulic geometry?!!
Perhaps he should be invited to test ride the new Girdraulic geometry?!!