Re: [CR] Seatpost size

Dear Todd:

There's no guarantee with any bike, but there's a few probablilies.  If t he frame has a butted seat tube, a french frame of that vintage will 80% of the time take a 26.4mm seat post, with 26.6 being the next most common.  My mid 70's Follis takes a 26.6.   If the frame has a straight guage s eat tube, who knows?  Somewhere in the late 70's/early 80's, the french b ikes went to english tubing sizes and the ubiquitous 27.2 became more commo n. 

Don't buy an expensive post until you've had a chance to try several posts in the frame first.  There is a frame sizing gadget that has multiple dia meters one after the other on a single rod.  Most good shops have them, a nd will usually check post size when you bring the bike in.  Of course th ey're hoping to sell you a post.  I think over time I've gotten a sample of most of the common sizes, and keep them in the seat post box for detecti ve work.

Tom Adams
Manhattan, KS