Cutting head tube on steel frame

Simmo72

Hi
I have an old steel frame, which has a 2 inch extension on the headtube..think van hooydonk style 1990.

I want to convert to a 1 inch threadless carbon fork but this means I also need to reduce my headtube height as it will just be too high so the extension must go

Firstly If I cut the head tube so it ends up looking like a normal frame will this work, can I then just stick on a Chris king nothreadset or equivalent?

Secondly, how do I cut it? I was thinking along the lines of a plumber style pipe cutter rather than a hacksaw, not that I have anything to work on a 1 inch head tube. too risky with my skills. Any ideas, my best thought at the moment is to call around local engineer companies. My lbs won't touch it as they don't want the risk if making a mistake.

Cheers

iga

I can't visualise the extension but I've tried cutting an aluminium fork steerer with a pipe cutter without any joy. It makes a decent guide line for a hacksaw mind. Even the professionals use a hacksaw (http://www.youtube.com/watch?v=Ff-mdVTBt7E) but with a guide, something like this would do the job: http://www.parktool.com/product/oversiz ... ide-sg-7-2 Good Luck!

Matthewfalle

Measure twice, cut once very slowly and carefully. Or phone a frame builder and see if they will do it.

mikenetic

Do you have a picture?

Head tubes are normally a plain gauge material, but before you cut best to check with a feeler gauge to verify that.

There are a few options to cut it.

You can use a very oversize version of a plumber's pipe cutter, but you need to wind the tension up very gently. Too much force and you can crimp the end of the tube in. It's perfectly possible to get the end square using a hacksaw, engineer's square and a flat file.

However, you'll also need to ream & face the newly cut end to get it perfectly circular for the headset cup, and to ensure the top surface is flat and on a parallel plane to the lower surface. Cutting it will remove any prior frame prep.

A frame builder is your best bet. For someone with the correct tools it's not too bad a job, provided the head tube is of standard construction. A less radical version of what you're doing is pretty much standard practice when you build a frame with a lugged HT.

Monty Dog

Your extended headtube is also known as Freuler type after Swiss rider Urs Freuler who was a bit lanky. Cutting it down depends on the headtube construction, particularly if it is lugged or re-inforced. If the headtube is constant thickness you'll be OK but as said, better take it to a framebuilder as it's not really just a hacksaw job as it needs to be finished correctly to allow the headset to function.