Cycling UK Forum

Hello techies,
I am paying the price of not doing my homework at college.
At the front end of the bike, I need to join a hardended fork stem onto a fork crown or onto a pair of fork legs. All these parts are made of steel.
What would be the best joining process to keep the hardening of the fork stem and to minimise the residual strain on the joint(s) to the fork system please?
A relatively robust joint would be appreciated.

Thank you in anticpation of your help. Kind regards, Peter

Least likely of all to do any damage at all to steerer and blades would be to clamp and/or glue them into a substantial machined-out-of-solid alloy fork crown - like some suspension forks are made. Modern engineering adhesives can be extremely strong.

The old-school method of minimising interference with a previous heat-treatment hardening process, is silver brazing.

Isn't it unusual to have the fork steerer hardened?
Dreadfully nosey of me, but why?

Several methods.

Shrink fit gives a massively strong joint.
Mechanical clamping with a slit in the outer and clamping screws.
Knurl the cylinders then machine back to give a 4 thou clearance and glue with epox resin

You need a specialist engineering shop who really know what they are doing to do any of these properly.

Shrink fitting would be my favourite
Al

531colin wrote:Isn't it unusual to have the fork steerer hardened?
Dreadfully nosey of me, but why?

Sounds odd. Hardened tends to also mean brittle. Although maybe not so much for case hardened parts.

I'm not a metallurgist nor do I play one on TV but maybe 'tempered' would be a better description than 'hardened'. If you were to weld the bits together then tubes would loose their tempering (or specific degree of hardening)?