Originally Posted by
Duragrouch
Yes, but 33.9mm diameter seatposts, are designed to fit into a slotted aluminum bushing (Dahon calls it a shim) that is only 75-100mm long, that fits into the frame tube. I forget what the outside diameter of the bushing is supposed to be, it's really thin wall, but just enough; There is clearance fit between the seatpost and seat tube, below the bushing. Without the bushing, and with the hugely long seatpost, the inside diameter of the seat tube had better be perfectly round, and dead straight for the whole length, otherwise the seatpost will not go down to fold. I think that is the reason for the bushing, because there are multiple welds to the seat tube on most folders, that can cause the tube to not be perfectly straight or round for its whole length. I had problems with a long seatpost that was still WAY shorter, going into a mountain bike whose seat tube was not kept straight enough from the factory. Most bikes, the seatpost only goes in, what, 6"/150mm?
Take heed, and abandon the siren song luring you to the rocky shore of bike-build heartache. Make a clean break to a reasonably priced but virginal frame that will place you in good stead with the bicycle-building gods. Or, rather than creating your own religion as it were, go for the package deal with a folder that is turn-key fully equipped to go. As it is said.
That is really helpful. (not to discourage me
) No seriously, that makes sense out of this whole seat tube affair...already found a shim which I will braze into the neck of the seat tube. that should give both stability and seamless "slideability" to the seat post. (I realized that I mis-measured the seat tube. it's actually 34.9 not 33.9mm. I have a reamer and will go through the entire seat tube to smoothen it out a bit and then insert the shim which is 34.9-33.9mm.
The voice of reason and sanity...always unheeded as my ever distraught teachers and parents can attest to.
Originally Posted by
Schwinnsta
Undoubtably the safest advice, but as someone who is unable to keep from altering bikes to better suit me, and has experienced successes as well as failures, I would listen to the sirens so long as you see no you think it would work.
Ah, a fellow traveler on the rocky roads towards
Ithaka, i.e. in this case towards the final folding frame folly fantasy frontier...but with the financial stakes so low (outside of the rear hub which is about 80USD) the whole shebang will cost me no more than max 70-80USD in parts I shall set sails for the unknown! Wont be able to say that I haven't been duly warned by Duragrouch if my ship hits Scylla or is swallowed by Charybdis!