Seat Post Heat Sink

Hey guys,

Planning on making a heatsink for a 31.6mm seatpost like the below photo

What outside diameter would you machine it to? The same size as the seatpost or a little smaller and rely on it expanding to a tight fit?

Thanks in advanced!
Steve

I think you’d definitely want it undersized. Inserting and removing it won’t be easy (if not impossible) if the fit is too tight. Consider inherent tube manufacturing variation in ID, roundness, straightness, etc. A well-designed internal collet can have quite an expansion range - these sleeves have a .125"/3mm allowance, for example.