FT: Frame (Twin) Help needed, Seat frame fixing points distance between eyes

[ray vinmad]

As your old Vincent is imperial, it`s 16 3/4".

And should the other dimension on the sketch be 8" (20.3cm) or 7 7/8"?
Ray

 

[Spqreddie]

My two frames are both 425 mm. Who made the frame in the photos? Cheers, Stu.

The old frame on the seat, i dont know. I got it with the pile of parts i bought as a "bike"...
The new one, i just ordered it from the spare company, but i dont know who is the manufacturer.

 

[Spqreddie]

Ah, sanity at last!

Thank you all!
After i posted my qyuery, i touht about it actually.. and sorry if I got "lost in traslation", but not easy to find am inches ruler in italy! and for not having translated the figure in english.

Thank you all for the replies, the spare company one is then ok, it was my old one wrong.

 

[ClassicBiker]

It's a bit like poetry it never translates properly from its native tongue the Vincent was built by imperial measuring with the normal dispensation to the French because they did play with engines around 1900 so we kept their bore and stroke apart from USA where cubic inches ruled.
So if it was built with inches it's only sensible to use inches thankfully with a digital guage and metric dials on the lathe I can use the devils stick but I certainly try and describe Vincent's in their proper tongue
As for cc, being a bit of a triumph fan I remember that 350cc. Is 21 cubic inches I wonder why?

The Triumph 21 a unit construction 350 was introduced in 1957. It was also the 21st year of the establishment of the Triumph Engineering Co. Ltd. In 1936 Jack Sangster bought the motorcycle side of the Triumph Motor Co.. So it was a double meaning 21 cubic inches introduced on the 21st anniversary.
Steven

 

[Bill Thomas]

I was very impressed with the Tiger 90, But I was very young !.
I later bought T/bird 1956 to ride while I rebuilt my first Vin' Twin, And thought that was a pile of junk !.
Cheers Bill.

 

[vibrac]

Did not have much to do with triumphs when I was younger except I did have a 1938-9 Bronze head Triumph twin that had been used for Moto ball it cost me £15 that was a handfull but it was transport while most of my money went on racing