what bl**dy size is my seatpost
geordiefella
Posts: 302
i got an old marin bear valley se. got some new winter tyres etc but for the life of me i can't find the seatpost.
googled the seatpost size 27mm great. ebay>seatpost>doesn't fit.
well, ebay again 26.8mm, arrived, still too big. tenner each and i'm getting a collection of unsellable posts.
where do i get an internal tube measurer?
anyone know the actual post size i need?
does anyone know where my original one is? It's here somewhere.
Happy New Year.
Geordiefella
googled the seatpost size 27mm great. ebay>seatpost>doesn't fit.
well, ebay again 26.8mm, arrived, still too big. tenner each and i'm getting a collection of unsellable posts.
where do i get an internal tube measurer?
anyone know the actual post size i need?
does anyone know where my original one is? It's here somewhere.
Happy New Year.
Geordiefella
Cannondale BadBoy Rohloff
Cannondale SuperSix / 11sp Chorus
Ridley Excalibur / 10sp Centaur
Steel Marin Bear Valley SE
Twitter @roadbikedave
Cannondale SuperSix / 11sp Chorus
Ridley Excalibur / 10sp Centaur
Steel Marin Bear Valley SE
Twitter @roadbikedave
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Comments
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Measure the internal width of the post, but you'd need a vernier caliper to do it accurately, I think.
Can you get a shim from your LBS to fit the 26.8 post?FCN 2-4.
"What happens when the hammer goes down, kids?"
"It stays down, Daddy."
"Exactly."0 -
shim... no its still to big. i'll get a caliper... thanks.Cannondale BadBoy Rohloff
Cannondale SuperSix / 11sp Chorus
Ridley Excalibur / 10sp Centaur
Steel Marin Bear Valley SE
Twitter @roadbikedave0 -
You need vernier callipers to measure, very easy to use, I have a pair (they cost about 3 quid). Maybe someone on here that lives close by can loan you some?
Edit: Too slow0 -
thanks very much cjcp. venier caliper on its way. £9. digital, new. ideal.
much appreciated.
happy new year to you.Cannondale BadBoy Rohloff
Cannondale SuperSix / 11sp Chorus
Ridley Excalibur / 10sp Centaur
Steel Marin Bear Valley SE
Twitter @roadbikedave0 -
thanks dodgy.
been going backwards and forwards to the shed to measure, order, deliver, wrong, measure, order, deliver, wrong. caliper on it way.
thanksCannondale BadBoy Rohloff
Cannondale SuperSix / 11sp Chorus
Ridley Excalibur / 10sp Centaur
Steel Marin Bear Valley SE
Twitter @roadbikedave0 -
You'll find the callipers will come in handy for lots of things, good investment. I've got the digital ones too, but can't leave them in the garage as the cold gets to the batteries.0
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geordiefella wrote:thanks very much cjcp. venier caliper on its way. £9. digital, new. ideal.
much appreciated.
happy new year to you.
No probs. HNY to you, too.FCN 2-4.
"What happens when the hammer goes down, kids?"
"It stays down, Daddy."
"Exactly."0 -
The next seatpost sizedown is 26.4mm IIRC, go to LBS and see if they've got an old one you can try for size. Mine obliged with diameter but couldn't help me on the length when I needed one for my GT frame.I've added a signature to prove it is still possible.0
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You should try retrobike. I recently bought an old Marin Pine Mountain to do up as a commuter and the guys on the retrobike forums have lots of knowledge about old MTBs. (I didn't even know I'd bought a Pine Mountain until they helped out.)Never be tempted to race against a Barclays Cycle Hire bike. If you do, there are only two outcomes. Of these, by far the better is that you now have the scalp of a Boris Bike.0
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Late 80s and early 90s models had 26.2mm posts.0
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[pedant] It's not a vernier calliper if it doesn't have a vernier scale on it [/pedant]- - - - - - - - - -
On Strava.{/url}0 -
well. i got the gauge. thank you everyone.
measurements were about 26.38ish. not truely circular across the seat tube opening.
anyway, it was 26.4" fits perfect. £12 in the end. sent the other 3 i'd previously bought back to the ebay sellers. luckily they agreed to return them.
thanks all. winter bike up and running, studs an all! (just in time for the thaw, bo**ocks)
:-)Cannondale BadBoy Rohloff
Cannondale SuperSix / 11sp Chorus
Ridley Excalibur / 10sp Centaur
Steel Marin Bear Valley SE
Twitter @roadbikedave0 -
Out of curiosity, as I'm about to have to source a frame for a vintage frame I've just bought which doesn't have an 'existing' seatpost, I assume you measure from one side to opposite side of the tube interior?0
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Yes Sir.FCN 5 belt driven fixie for city bits
CAADX 105 beastie for bumpy bits
Litespeed L3 for Strava bits
Smoke me a kipper, I'll be back for breakfast.0 -
"Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
Parktools :?:SheldonBrown0 -
top tip to measure it super accurately on a budget - using a cigarette paper or something equally thin, wrap at around the sdeatpost and mark the exact circumference.
as the circumference is 2piR, reverse it back to find the radius and double this for a very accurate measurement of the diameter without and fancy tools.
think i might have read this on here (or lfgss) but am too lazy to search for the credit - sorry:)0 -
Alphabet
it is linked above."Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
Parktools :?:SheldonBrown0 -
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Alphabet wrote:top tip to measure it super accurately on a budget - using a cigarette paper or something equally thin, wrap at around the sdeatpost and mark the exact circumference.
as the circumference is 2piR, reverse it back to find the radius and double this for a very accurate measurement of the diameter without and fancy tools.
think i might have read this on here (or lfgss) but am too lazy to search for the credit - sorry:)
I think you might need those king size papers to get it round a seat post. How nice of Rizla to specially design bigger papers for cyclists...0