Curious what Rivendell has told you, but I'm also wondering why you would go straight from 29.8 to 29.4, and not try 29.6. That would seem most straight forward and least likely to damage anything. They exist and, even if only in one-bolt designs, that's a small one-time, set-it-and-forget-it hassle compared to reaming a seat tube. Here's one.
https://www.thebikesmiths.com/products/kalloy-sp-359-7084?variant=41522031067296 On Thursday, March 13, 2025 at 11:19:11 AM UTC-6 lconley wrote: > Use an automotive brake cylinder hone to slightly enlarge the seat tube. > I always hone the seat tubes to remove brazing residue anyway. Brazing > residue is what scratches up your seat post. > Make sure that it is not just a crimped seat tube lug first. > > Laing > Delray Beach FL > > > On Thu, Mar 13, 2025 at 12:36 PM Gordon Stam <[email protected]> wrote: > >> Hey Gang. I have a 59cm Clem which takes a 29.8 seatpost. I got the >> tandem seat post from Rivendell in the proper size and it would not fit - >> too big around. Apparently my seat tube is a wee bit smaller than 29.8. I >> sanded down the Riv seatpost and made it fit but I would like to swap it >> out for something other than a single bolt design, which I finding is >> finicky with the seat tilt adjustment*. The only option I'm seeing is a >> Thompson Elite seatpost. Either that or use an adapter to fit a 27.2 >> seatpost, which I have and would prefer to avoid. BUT...if I get a Thompson >> in 29.8 I'm likely going to have to sand *it* down and since they only >> come in black that would look funky. Plus it's $100+. >> >> Alternately Thompson makes a 29.4 seatpost and I wonder if that would fit >> okay. If I order one and find it doesn't work I might have a hard time >> returning it because of the inevitable(?) scratches it will incur in the >> process. >> >> I've measured the seat tube ID at the clamp and get anywhere from 29.5 to >> 29.8. The 29.8 measurement is only along the front to back axis. Nowhere >> else do I get 29.8. >> >> So, Thompson and sand it down, 27.2 adapter, or live with the current >> post and deal with the adjustment? >> >> Any other ideas? >> >> *Trying to adjust the tilt yesterday the clamp seems to have sort of >> taken a "set". If I'm even close to where it has been it goes back to that >> position. Micro adjustment is just not happening. >> >> -- >> You received this message because you are subscribed to the Google Groups >> "RBW Owners Bunch" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To view this discussion visit >> https://groups.google.com/d/msgid/rbw-owners-bunch/fc4166d9-a491-4d6b-a001-b055f01831b5n%40googlegroups.com >> >> <https://groups.google.com/d/msgid/rbw-owners-bunch/fc4166d9-a491-4d6b-a001-b055f01831b5n%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> > -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/d/msgid/rbw-owners-bunch/4242530b-3645-484a-b909-4b97a407d46an%40googlegroups.com.
