taguy4

I have read on this forum that the seatpost size on Tenax framed Super Sports is 26.6mm, and that's what the one is in my bikes frame and it matches the appearance of Sekai posts I've seen in Schwinn literature so I'm thinking it could be original to the bike. Problem is it fits very loosely in the seat tube: you can literally wiggle the post back and forth in the tube when it's installed, and when you barely loosen the clamp it just drops all the way down. When the post is clamped down the slit on the back of the seat lug comes together almost all the way, too. This makes me think a 26.8mm post would be a better choice for this bike. My Panasonic DR-5000 has the same wall thickness tubing as this bike's frame and it takes a 26.8mm seatpost. I know it's standard practice for seat tubes to be reamed a bit after brazing to restore their roundness and bring them to the finished dimension the framebuilder wants so I'm thinking this seat tube must have gotten reamed a bit more than what Schwinn was aiming for if they were going for the 26.6mm inside diameter. I'm under the impression that it should take a little effort to insert a seatpost in a frame and not just drop down into it on it own weight and then be totally loose before tightening the clamp down.

Any thoughts?

murady009

26,8 suitable

taguy4

I tried the 26.8mm post out of my Panasonic and it fits a lot better than the 26.6.

1962Ford

According to the catalogs online, it should be a 26.6mm which matches what I have had on 2 Schwinn Travelers from 1988 and 1989.

taguy4

The 1986 catalog scans I found online have the seatpost line in the spec sheet blacked out for some reason for the Super Sport, but the rest of the Tenax frame bikes take a 26.6mm seatpost which to me seems too small for my bike as mentioned above. That's why I posted this because there seems to be a contradiction here. The seatpost was up pretty high in the frame when I got the bike - and the bike seemed well used - so it looks like the previous owner of the bike must have been able to make the 26.6mm seatpost work, even though I'm having serious thoughts as to whether it's right for this particular bike.

taguy4

Seems to me it's most important to go by what best fits the frame than by a set of specifications in a Schwinn catalog. It's hard for me to believe that every Tenax Super Sport (and other model) frameset that Schwinn made measured exactly 26.6 on the inside of the seat tube cluster - there had to be a little (or a lot of) variation. I'm thinking having a seatpost as loose in the frame as mine was is going to cause all sorts of problems down the road. There might be a reason why the seat was jacked up so high on this bike when i got it: it might have been that high because it had trouble creeping down, so the previous owner just kept resetting it extra high to compensate for it wanting to creep down little by little over time rather than get the right size seatpost.