Britbike forum Forums British Motorcycle specific Brands Bsa bulletin board '71 front forks on a dry frame A65?

A couple of points as I see them.
1) this bike is not for racing and even if it was it is going to be a pretty good rider to tell the difference between 28 and 27 degrees.
2) this bike is not for "show"
3) unless the actual headstock is radically different in angle between the two frames then there is naff all difference in the yokes offset.
4) the actual angle of the forks FROM VERTICLE, which is the angle that actually matters, not from the frame, is dramatically affected by the rear suspension. put a 1/2" longer shock on and all bets are off, the angle will come down by several degrees. Same thing with tyres. I had to play around with the afore mentioned to get a better fork angle once I had fitted a '71 set of forks and a 21" wheel to my '67 B44. All good in the end.

Reading off the drawings in the books.


1970 the engine centre line as the datum

The dry frame is 16 7/8" from the datum to the centre off the lower steering head bearing plane


1971 OIF

The swing arm centre is the datum line , this is approx 1.2 inches above the motor centre line, .
The 71 drawing shows datum to lower steering head plane centre is 13.643, adding 1.2 , gives 14.84, about 2 " lower than the dry frame? relative to the motor that is

never mind all that, I am sure it will all be fine, its been a popular upgrade for decades.