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B40 Frame Help

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Hi I am looking for some information on a B40 i have just purchased and about to restore to useable condition.

The bike has Bultaco front and rear wheels and forks. It has later GB engine fitted and engine number ties up with what may have been a WD bike.

The main question is the top frame rail modification, i guess it was done to allow the barrel and head to be taken off without engine removal but when was it done, picture attached any info appreciated. thanks derek

b40rt should be able to help with this.

Such an optimist. Can't really see anything, frame top tube may have been extended to sharpen up the steering ?

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Such an optimist. Can't really see anything, frame top tube may have been extended to sharpen up the steering ?

I took the section out last night and is basically a solid piece, the 4 screws holding in place are metric thread m6.

It was tight in place and when i went to replace i had to push the front end down slightly to get it back in position, which as you said may have been added to sharpen the steering, May be just a mod by somebody to allow the head or barrel to be taken out whilst in situ.

Hi,

recon your right about cylinder head removal. I used to have a BSA A65 classic race outfit which had the same thing done to 1 of the frame rails to be able to get the motor out. With the bultaco bits and metric allen bolts I would say the mod was done some time in the '70s or later. would guess it's a one off special built by someone who knew what they were doing....should make you a nice bike, keep us up to date with the refurb.

Maybe it's my eyes but I really struggle to read Bashplate's italics..

Thanks Bashplate ! I have just had my first pair of reading glasses though so it might be me? :)

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