Bending a seatpost (intentionally)!

[simon.r]

A bit of an odd one this, so any help appreciated.

I'd like a 25.8mm swan neck seatpost with a 'traditional' top (like this): http://www.ebay.co.uk/itm/SNAKE-BIK...N-/201500511185?&_trksid=p2056016.m2518.l4276 but they only seem to be available in 22.2mm or 25.4mm.

I can't find a shim from 25.8mm to 25.4mm or 22.2mm, so I'm wondering if it's feasible to bend a steel 25.8mm seatpost? (Something like this http://www.ebay.co.uk/ulk/itm/252257037092 ) A coiled spring insert, heat and brute force? Whaddya reckon?

 

[Pumpkin the robot]

Get a 25.4mm one and I will send you some 0.2mm thick shim to use with it. We have lots of different thickness shim at work. You will be able to cut it with scissors.

 

[simon.r]

Get a 25.4mm one and I will send you some 0.2mm thick shim to use with it. We have lots of different thickness shim at work. You will be able to cut it with scissors.

Great, thanks. Will message you.

 

[tyred]

Cut a shim from a Coke tin.

If you are bending one, I'd use a steel one rather than alloy as it;s less likely to crack and find someone with a pipebender.

 

[simon.r]

Cut a shim from a Coke tin.

If you are bending one, I'd use a steel one rather than alloy as it;s less likely to crack and find someone with a pipebender.

I did think about the Coke can shim (I've done it in the past), but this is on a new frame and I'm reluctant to risk damaging it (even though I reckon the risk is low).

Agree about steel rather than aluminium.

 

[screenman]

I have to ask, why set back?

 

[Profpointy]

I'd very much doubt the wisdom of bending it.

However shiming to the correct size, made from coke can or otherwise, is a perfectly pukka engineering solution. Seriously yes it is.

 

[steveindenmark]

It sounds like a blacksmiths job.

 

[simon.r]

I have to ask, why set back?

Just to get my position on the bike more comfortable. I have a left knee that doesn't bend beyond about 90 degrees and normally use a pendulum crank ( http://www.getcycling.org.uk/details.php?id=460 ). This is for a sit up and beg bike, which I reckon fitting a setback post to, along with a shorter left crank (already fitted) will sort me out.

 

[screenman]

I have seen a seat post welded to another one to create set back, I would be going the shimmed method myself.

 

[2clepto]

if you do bend the seatpost fill it with sand first and tape up both ends after the sand has been compacted down. itll avoid the seatpost kinking.

 

[RichardB]

Drinks cans make ideal shims - right thickness, soft and malleable metal, easy to cut. From an engineering point of view, nothing wrong with it. I've used them on handlebars and seat posts, never a problem. Just make sure it's nicely trimmed so that it doesn't show, and especially doesn't show words like 'Special Brew'.

Personally, I wouldn't dream of bending a seatpost, even a steel one. The thought of what could end up happening if it snapped makes my eyes water.

 

[FrankCrank]

....well, I never knew you could get pre-bent seat posts till I read this - learn something new every day...