This thread has become a prime example of over engineering.
Here's a great example of "What the Customer Wanted"...
http://www.uoregon.edu/
Here's another link that you folks in the UK will appreciate:
http://www.businessballs.com/
You can probably find a plastic dial protractor with a magnetic base in the UK for £4 to £10 which will more than suffice for casual use.
Chas. Colerich Oakland, CA USA
Neil Foddering wrote:
> I have tried, without success, to measure the frame angles on my 1930s and 40's bikes; does anyone know whether a purpose-made tool is available to do this (preferably idiot-proof)?
>
> Neil Foddering
> Weymouth, Dorset, England