I've been given a very nice FSA carbon seat post with a 32mm setback. Unfortunately the seat tube diameter is 32.4mm. Having done extensive googling I can't find a seat post shim that does 32.4mm inner diameter to 34.9 outer diameter. I'm currently using double shims (very successfully) to allow the use of a 27.2mm seat post in my 34.9 mm downtube. I can obtain a seat post shim that is 33.9mm inner diameter to 34.9 outer diameter which leaves me needing a shim which is 0.75mm thick. What would be the best material to use to bodge a DIY shim to fill that gap. For example, I can ebay an aluminium sheet that is 0.7mm thick (100mm x 300mm) but is that sufficiently bendy that I might have a chance? I appreciate that this might also need an additional beer can shim or two.
Alternatively, does anyone have the technical ability ( or know of someone who does) to produce a 32.4 inner to 34.9 outer shim.
