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Old 11-15-10, 07:51 PM   #1
TugaDude
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Schwinn Seatpost Question

I recently bought a 1974 Schwinn Le tour road bike, have cleaned it up nicely and now am deciding whether to convert it to a singlespeed. I'm 90% sure I'm going forward with it.

I would like to know if anyone knows whether I can get a newer seatpost for it. I took the seatpost out and it has zero information on it regarding size. It is chromed steel and simply says Le tour.

I should also say that there is a metal shim in the seat tube that allows the seat binder to close tightly on the seat post. If I take the shim out, the binder doesn't close the seat tube enough to grip the post tightly. It just slips down.

Is there another way of approaching this? I think I read somewhere that you can grind a little of the metal away where the split in the seat tube is, allowing it to come closer together and hence making a tighter fit. That way I could at least dispense with the shim.

If nobody has another suggestion, I am going to take it to my LBS to have them size a new seat post or make recommendations.

Thanks!
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Old 11-15-10, 08:03 PM   #2
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Thats about it, if you don't shim out to the full ID of the frame's seattube,
[thats why the shim is there in the 1st place]
you have to buy the right size of seatpost,
and since you cannot declare what size the seat tube is in the frame by measuring yourself,
you have to take the bike to somewhere that can.
Kalloy is a budget brand of aluminum seatposts , and they are machined in many different diameters, if you want a seatpost that fits without a shim,
you have to buy one of the appropriate diameter ..

Cutting the slot in the frame wider to distort the seat tube down smaller ,
is a BAD idea.

Last edited by fietsbob; 11-15-10 at 08:10 PM.
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Old 11-15-10, 08:07 PM   #3
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Back during that era Schwinn used a 7/8" seatpost, the same as common on BMX bikes, on many of their adult offerings. If it looks to be about the same size as a handlebar, that's what it is.

Otherwise you can measure it fairly accurately, at least to get into the right ballpark, by wrapping an 11" strip tightly 3 times around on a slight spiral. Draw a line across all the layers, then unwind and measure. Divide the measurement by the number of turns, then by 3.14 to get the diameter. If you measured in inches multiply by 25.4 to get the mm size. If the answer is somewhere close to 27mm then it's probably 27.2 but you need to check before just buying a post.
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Old 11-15-10, 08:16 PM   #4
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Common saddle clips are 7/8'' they clamp onto the top of the seatpost, if there is no difference between the top and the bottom of the seatpost, it may be 7/8 '' - 22.2 mm ..
there are decent chrome plated chromoly seatposts in 7/8 and 1.0''
from SBS/redline, that are strong, work well when extended quite a ways out of a frame..
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Old 11-16-10, 11:03 AM   #5
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I had a couple of Le Tours ('77 & '78) and the posts were 1". I bought a couple of inexpensive 25.4mm x 350mm Kalloy seat posts from Niagara Cycle Works ($14 + S&H) and they worked great without the hassle of shims.
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Old 11-16-10, 07:36 PM   #6
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Originally Posted by CACycling View Post
I had a couple of Le Tours ('77 & '78) and the posts were 1". I bought a couple of inexpensive 25.4mm x 350mm Kalloy seat posts from Niagara Cycle Works ($14 + S&H) and they worked great without the hassle of shims.
Thanks for all the input!
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