When does a frame become a different bike?

[wild foamy]

Hey peeps,

There's been something brewing in the depths of my skull for a while now, and it came out in conversation with some lads at the pub last week.

basically, ive been planning a project for the past year or so, and now i've gotten rid of one of my old minis im more likely to be able to do it, i want to find a pre-1972 bike (probably a CZ or Honda CB as they are cheap and plentifull) and use its frame as a basis for a custom built tax-exempt toy with an inline twin engine of around 500cc, spoked wheels with retro cafe-racer styling.

So, say for example i got myself a 1971 CB250 and used its frame and V5 as my base, all the other parts will either be handmade, universal parts or from other bikes, but when would this bike no longer be considered as a '71 honda CB and thus have to be declared as something else on the V5C?.

thoughts appreciated peeps, much love <3

Foameh

[kenDAWG]

i do belive its once the original engine has been removed and replaced with non standard engine is it not?

i think then it would fall into the (modified - non standard - customized) bracket and not actually have a model name

[wild foamy]

The model name im not too fussed about, its more the year im wanting to keep as anything before 1972 is tax exempt

[kenDAWG]

ah yes i see what you are saying but you get the reg for the vehicle from the frame so im guessing you keep the age related plate along with the frame but the bike bracket it would fall into for insurance would change

[DirtyDT]

LINKY

[wild foamy]

blimey, looks like there's a lot more involved than i thought :S...

[kenDAWG]

im guessing yours would fit into the heavily modified section and you would have to have vosa inspect the bike - sounds like a right chore but if you wanna do something different you might aswell make enquirys to the cost and time for vosa to look at it

ken

[DirtyDT]

Just buy a pre January 1960 frame. No tax or MOT required anymore.

[wild foamy]

But then the same problem arises, at what point of its modification would that no longer be considered a pre-1960 bike?

[DirtyDT]

Don't know Foams. Pop up to you local SVA centre and have a word.

[Cynic]

Foamy go for the purists...The kind of thing me and my ol man do.

We took our stuff to a Brit bike meet as you do... The bikes in question being my dads 71 honda that i will have somehow. As well as my Dt.

You can imagine the looks we were getting. That honda of my dads in its day out classed every brit you could buy. The blade of its day. Both of our bikes being older than a lot of the exhibits didn't help.

So go get an old brit. An old bonnie one of the post units are cheap. Throw out the lead heart and graft in a rd400 motor. Then go see what happens at a triumph owners meet.........ooooh what about a dt400 in a bantam ha ha ha ha...