Thanks Ron....Ian

email (option): ian@wright52.plus.com

Hi Chaps,
I have made a frame gauge to Ron's dimensions and measured my rear frame, only 3mm off, not bad considering the state of it! However there is more to this than meets the eye, the diameter of the down tube is 38.11mm and the seat down tube is 34.81mm a difference of 3.3mm. As all the measurements are being taken from the tube centres the straight edge is not running parallel to the centres, I would suggest using a 1.6mm spacer on the rear tube in order to achieve parallelism.
Hope this all makes sense and helps.
Cheers
Jim

email (option): johnboywalton13@msn.com

Well spotted Jim...It all makes sense...The discrepancy in tube diameters could be easily missed..Ian

email (option): ian@wright52.plus.com