500 cc Norvin pictures wanted

Black Flash

Well Known and Active Forum User
VOC Member
Hello fellow Vincenteers,

I am desperately looking for as many 500 cc Norvin pictures I can get, close ups, all you have got. I am planning to build a Norvin with my brother from a left over rolling chassis of a Triton and an engine of my brother.
we are a bit unsure how to do it, as many Norvins we saw had the engine very high in the frame to avoid cutting frametubes, or have the engine canted backwards slightly, so that the Vincent writing on the timing cover is pointing uphill.
So I wonder if somebody tried splaying the front downtubes to slide the engine between them, or cut the downtubes off, or any other clever idea we have not thought of yet. As far as I know the centreline of the crank should never be higher than a line drawn through the front and rear wheelspindles for a good c of g

If you have picture please mail to: comet636(at)gmx.de

thank you very much for your help.

If you have no picture but useful comments, please write in this forum, we are waiting

cheers
Bernd

Forgot to say, we will use a Commando type gearbox
 

Black Flash

Well Known and Active Forum User
VOC Member
hello Phil, hello Dave,
thank you very much for your pictures. regarding your pictures Dave we thought about cutting the tubes just underneath the gusset plate under the headstock and hang the enginefrom there. cutting the lower rails roughly in the middle so the engine is held by the rearmost lower bolt that originaly goes through the primary chaincase, the engine, the gearbox bracket(FT 104?) and then the big plate surrounding the gearbox. like that we could easily mount the engine with the crankshaft being 2 " lower than the ""usual fittment.
Also the engine can be mounted further forward to help the weight distribution being closer to a standard 99 or Atlas Norton
we just wonder about the looks of it. it should be similar to the MHR norvin, but this bike looks really odd, we are simply not sure if that is because of the crazy exhaust of the MHR or the missing downtubes.
lets say it like this, will it still look like a Norvin without the downtubes? Will it look nice after all?
 

Bill Thomas

Well Known and Active Forum User
VOC Member
Hello Bernd, I have 2 good photos of a twin with no down tubes, If you want them, Is your e/mail (at) or @ ? Cheers Bill.
 

Black Flash

Well Known and Active Forum User
VOC Member
hello Bill
I would appreciate your pictures alot.
my email is @
I just wrote it different to stop spam flooding my mailbox.

cheers
Bernd
 

Little Honda

Well Known and Active Forum User
Non-VOC Member
Hello, Bernd,
there was a title story about that Norvin w/out underslung tubing in CB magazine in app 1985, or so. This bike was
subject of mech. eng. degree of Birmingham University, if I am right. I saw it at the first Dolomite rally. It is now in
the hands of an italian member. Perhaps Giovanni can help? Or you ask the CB archive.
Good luck with yr build.
Mike
 

Diogenes

Well Known and Active Forum User
Non-VOC Member
Sorry to say that your post reminds me of one of Bruce Main-Smith's classic replies to a similar request.
On the lines of "If you need to ask that question you probably do not have the knowledge and experience needed to carry out that work safely and successfully."

"As far as I know the centreline of the crank should never be higher than a line drawn through the front and rear wheelspindles for a good c of g"
That is just a rule of thumb of doubtful validity, as you can see from handling tests done in Japan.

The thought of chopping bits out of the frame makes me wonder why you want to use a Norton frame anyway, if you are going to butcher it.
The Egli approach is sounder.

If you want to see a Norvin [ 500cc and 1000cc ] built by someone with lots of knowhow and racing experience [Peter Darvill] see 'Motor Cycling' 05 June 1958.
 

Black Flash

Well Known and Active Forum User
VOC Member
hello Diogenes,

The reason to use the Norton rolling chassis, is that I still have one together with the very necessary documents needed in Germany. I would like an Egli frame even more, but I have not seen an original one for sale. With a new replica frame I have to fulfill the 2011 exhaust emissions with that Comet engine together with a lot of other paperwork, which makes it impossible.
Also I do not have another UFM, RFM nor Gridraulics or Bramptons. If you know somebody who wants to swap those parts or an original Egli frame, for the Norton chassis, please put me in contact, I will happily swap.
 

vince998

Well Known and Active Forum User
VOC Member
hello Phil, hello Dave,
thank you very much for your pictures. regarding your pictures Dave we thought about cutting the tubes just underneath the gusset plate under the headstock and hang the enginefrom there. cutting the lower rails roughly in the middle so the engine is held by the rearmost lower bolt that originaly goes through the primary chaincase, the engine, the gearbox bracket(FT 104?) and then the big plate surrounding the gearbox. like that we could easily mount the engine with the crankshaft being 2 " lower than the ""usual fittment.
Also the engine can be mounted further forward to help the weight distribution being closer to a standard 99 or Atlas Norton
we just wonder about the looks of it. it should be similar to the MHR norvin, but this bike looks really odd, we are simply not sure if that is because of the crazy exhaust of the MHR or the missing downtubes.
lets say it like this, will it still look like a Norvin without the downtubes? Will it look nice after all?

Hi Bernd,
I´ve been thinking of doing the same for a while now (splaying the downtubes and maybe welding a cross tube between)(as soon as i get a rolling chassis together :))
The MHR Norvin looks all wrong and way to long, probably because of the lack of down tubes (gap between front of engine and front mudguard is way to big and looks very ducati-ish)
Would love to talk (i´m currently in westerwald). Send a PM with tel Nr if you wish.
 
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