Measuring frame angles

What do I need and how do I measure frame angles?

An inclinometer. Builders merchants for a couple of quid maybe?

http://www.mptools.co.uk/products.asp?partno=250471

Summat like that?

It looks like you just stand this on the tube to measure the angle which may work. Does anyone know if the angle is in relation to the other tubes or if it is with the top tube horizontal to the ground? Logic tells me that it is with the top tube horizontal...

works on gravity, will tell you what the angle is relative to the ground plane

bevel protractor -- an engineers tool very accurate.
Look on eb-----

The inclinometer shown here is pretty inaccurate, say +/- 0.5 degrees.
But still workable for rough values.

Bevel protractors are used by frame builders, but not always that good if you use tapered tubes.

Usually frame angles are not measured on a frame or bike that is ready. It's just used for making drawings.
After building it, you mainly measure other dimensions. This will give the angles after some drawing or calculating.
E.g. seat tube length (frame size); top tube length, centre BB - centre front hub.
Pro mechanics have very nice jigs (home made) to measure a frame or bike and set up the bike currectly.

What are you trying to do or is this just for info?

Thanks for the replies people. The main reason I wanted to measure frame angles is to help me identify an old claud Butler bike I have picked up but yes I'd think it would be really interesting to know how the angles effect the ride of a bike.

Oh and I feel such a fool because in hind sight it is obvious that the seat and headtube angles are in relation to the top tube....

Hi Tel,

Sorry to be subverting the forums rules a bit here, but I've just signed up and wanted to tell you that I want the beater you have advertised. I know I need to wait 24 hours before I can respond to the thread, but you mention that if you have no takers, you'd dump the bike and I'd not want that.

You mean this one? http://www.lfgss.com/thread41505.html Post a reply on there mate and I'm sure we can do a deal and don't worry I can't bring myself to dump anything! You should see my garage!!!