Just bought myself a 350mm Thomson Masterpiece (longest they do) for my Specialized Epic and reading the fitting instructions it says to make sure the post is inserted past the top tube. The Epic has a lot of seat tube before the top tube begins and is reinforced with a brace. I know that I'm going to have to run the post pretty close to its minimum insert so will I be okay with the post even if it doesn't extend past the top tube because of the bracing or am I going to need to get a refund and something longer?
All aluminium Epics (which I guess yours is, as you say about the bracing bit) have a small hole on the RH side of the seat tube. This needs to be covered by the seatpost or you'll void your frame warranty.
See I rang up Specialized UK to check and the guy on the phone said about this hole but when he went to check on an Epic they just had lying around, it didn't have one, nor does mine unless its the smallest hole known to man or I'm just being blind. He did say that if the Thomson was at least at its minimum insertion point it should be fine.
Nick, any idea how far down the seat tube it is on a large?
Strange! It is pretty small, I'd say 2mm across. I've no idea how far down it is to be honest, I'll try and measure one at work tomorrow, we've gotta have a large Epic kicking about! If it's not got that hole they'll be obliged to warranty the frame if it snaps anyway, can't tell you you should've covered a hole that doesn't exist, if you're below minimum insertion you'll be fine.