Fixed Gear measuring

Am currently building up my own fixie from pretty much scracth. And as a novice builder was looking for some guidance on measurements and buying;

A) How should i go about measuring the shaft of the bottom bracket so that i can buy and fit one the corrrect size

B)How should i go about measuring and fitting etc. the aparts for a headset?

Thanks

W.

Sorry for posting in wrong forum. Any advice would be much appreciated however.

W.

Firstly, whichever BB you use will need to match the threading of the frame. It then depends on the cranks you are using - the tapers need to match and the axle length needs to be correct to give the right chainline. If you're buying new, you can find out which BB matches which crank. Also check the transmission database for combos that people here use

OK thanks, however basically where do i start! Sorry novice questions indeed.

This information is given as it seems from the photo that you have threaded forks and that they hopefully have british threads.

To find the right sized headset you will need to know three measurements:

a, what is the diameter of the steerer at the top.

b, the diameter of the collar at the base of the steerer above the fork crown (this will tell you what size crown race your headset will need)

c, you will need to find out the stack height, measure the length of the steerer from the top of the fork crown to the top of the steerer, then measure the height of the headtube and subtract this from the length of the steerer. This is your stack height. (Do not get a head set with a larger stack height than that of your bike, if it is smaller you can cut the fork down or simpley use spacers to fill the gap)

OK thanks, however basically where do i start! Sorry novice questions indeed.

Find some cranks, then work from there

It's probably worth taking your bike in your lbs to get the headset and BB fitted, headsets can be tricky even for experienced mechanics, ask them if they can measure your seat tube diameter and advise you on cranks / chainline. If your intent on doing it yourself you will need a ruler and a set of verniers for a start http://www.tooled-up.com/Product.asp?PID=142730&Referrer=froogle

To work out what BB length you need, you need to know which crankset and rear hub you will be using.
Read this.
http://sheldonbrown.com/chainline.html

For headset sizing read this:
http://www.sheldonbrown.com/handsup.html#sizes

Basically read the whole site. You may find that you still need help afterwards. But then you will be better equiped to ask more precise questions in the Mechnics and fixin forum. Where I'm sure you will recieve the help you need.

Best of luck with it.

Cheers guys!