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- Posts: 90
- Joined: Sun Feb 19, 2012 8:08 am
I was thinking of buying a Suntour GPX seat post for my 1989 Elan. The Suntour post is 27.2mm - the standard size.
Before purchasing though, I thought I'd measure my existing post. My calipers measure it's diameter at 26.4mm.
Now I don't know if its just a measurement discrepancy, or if my frame can accommodate a 27.2 post.
Seat tube outer diameter measures 28.9mm and is made from Tange 5 tubing.
Any wisdom you could share would be appreciated.
- Derny Driver
- Posts: 2400
- Joined: Wed Nov 21, 2012 12:18 pm
- Location: Wollongong
But the only real way to tell is to try a few different size seatposts in there. Some tubes may have been reamed - there is no way to tell. Even measuring the top opening may not be accurate.
I keep old seatposts of different sizes to test the frames I buy. I have posts in 26.4, 26.8, 27.0, 27.2. My latest aquisition is a 26.2 but I managed to find a seatpost to fit it on Ebay. I make things hard for myself by always trying to match the seatpost to the groupset.
Save your Suntour post for another frame. If you have Japanese components then maybe you can find a SR post in 26.6
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Derny Driver wrote:But the only real way to tell is to try a few different size seatposts in there. Some tubes may have been reamed - there is no way to tell. Even measuring the top opening may not be accurate.
I keep old seatposts of different sizes to test the frames I buy. I have posts in 26.4, 26.8, 27.0, 27.2.
All true, but you could go to Bunnings and buy a set of internal calipers, take a few readings below the seat clamp slot and take the average. Should be pretty close that far down the tube.
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- Joined: Tue Feb 20, 2007 9:29 am
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uart wrote:8Track wrote:Before purchasing though, I thought I'd measure my existing post. My calipers measure it's diameter at 26.4mm.
See 10speed's post above. It's 26.6
A 27.2 post definitely will not fit.
Sure it can.
Just need a bigger hammer. And a file. And another bike and seatpost.
Hope that was useful
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