Hello ST,

I've been experimenting with a way to mount a draft box to my TT bike which does not have any mounting bolts.For my first attempt I bought the draft box and hanger designed for the Ribble TT bike (currently ridden by Joe Skipper). The bracket clamps around the seat post and hangs behind. With some bodging I made it work but in all honestly it looked a bit sh*t.

I have since used some free online software to design a hanger which mount's to the rear facing bolts of my seat clamp and then hangs down the seat tube with mounting bolts for the draft box. The design has a recess for the trailing edge of the tube and seat clamp and a small recess for a cable tie in order to prevent any potential bouncing of the box over our rough UK roads.

I had a prototype printed in ABS plastic as proof of fit etc. however this structure clearly is not strong enough to withstand the seat clamping loads needed given the design (the prototype only cost £15 to be printed and delivered to me).

My question is simply what material would be suitable without spending mega bucks? This is not a commercial venture, just an experiment. I know very little about materials and 3D printing. Without having this printed in Aluminium would a resin-based plastic be string enough?

I think this design would work for other frames with rear-facing seat clamp bolts (thinking older Cervelo p3 etc). Happy to share the design file with anyone who wants it.

Please ignore the massive seat clamp bolt, I was messing around with washers to spread the clamping load).