New and Improved Steerer Tube

[zigzag]

a while ago i acquired a folding bike, which, like most folding bikes was designed for upright riding position. the handlepost had a thermoplastic shim to accommodate T-shaped steerer/handlebars:






upright position combined with straight handlebars is sub-optimal for riding longer distances, so couple of years ago i've changed the original handlebars to "ergobars" and a standard a-head stem. as the inside diameter of the handlepost is 29.0 mm, the only bodge i could think of back then was to use quill to a-head stem adapter (which came with two shims itself - for 1" -> 1 1/8" stem and 22.0 -> 25.4 steerer) combined with a 25.4 -> 29.0 thermoplastic seatpost shim.








this solution worked quite well, but was not ideal - handlebars could not be quick-released and the whole assembly was unnecessarily complex. so recently i came up with a better idea

all i needed was a 29.0mm donor seatpost and a pair of capable hands and machinery - which loadsabikes kindly offered, top man!

after a quick sketch and posting the seatpost i had it back in less than 48hrs - fantastic!










the section of the seatpost was machined precisely to a 1 1/8" blueprint - that's what i call attention to detail!!




now having a steerer of the required spec it was a two minute job to install it. the new assembly feels stiffer, looks tidy and has a benefit of height adjustment and quick-release - what's not to like?!

[Kim]

Top botching 

[Bodgeit]

Proper job!

[loadsabikes]

Top botching 

Botching How very dare you

[Wobbly John]

Excellent work. 

I'm suprised you didn't change that nasty quick release clamp while you were at it. 

[zigzag]

Excellent work. 

I'm suprised you didn't change that nasty quick release clamp while you were at it. 

cheers, i see what you mean. the qr clamp does have a function and it's rear facing part is welded to the handlepost (which is not a problem with a dremel tool). handlepost's outer diameter near the clamp is 32.1 and the closest diameter seatpost clamps come at 31.8 (usually for 27.2 seatposts). so it would have to be reamed/sanded out by 0.3mm.
the replacement clamp must be wide enough (current one is 24mm) to distribute the force over wider area. if you have a suitable good looking qr clamp ("new and improved" ) in mind - i'm interested to hear and consider!

[Canardly]

This 'ere forum never ceases to amaze me with the range of skills that members have.

[Sergeant Pluck]

Top work, all!

[Russell]

Well thought out mod, ZigZag!

This was what I did to improve the riding position on a Dahon.  Always did intend to do the job properly with a bit of cutting and welding but hey ho!

[loadsabikes]

That must be some sort of record ;Dbut I've no idea what for

[Kim]

It's the bicycle equivalent of when you route an audio signal from output A to input B via every adaptor in the box because someone's run off with your A to B cable.

[zigzag]

some impressive clampwork there, Russell. not sure how to simplify the setup if you want to keep the shifter and lights where they are now.