Bicycle Mechanics - Seat Post Clamp Size

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tallstevens
09-14-10, 08:38 AM
Hello,

I am trying to find out the size of a seat post clamp for a Specialized Globe Sport. The tightening latch on mine broke so I need to replace the clamp. Do anyone know what size this particular bike uses?

fietsbob
09-14-10, 09:04 AM
Doesn't anyone have a tape measure?. or a yardstick?
tallstevens
09-14-10, 09:14 AM
Yeah that would be ideal, but I am about 200 miles away from the bike. :(
I was about to place an order for one online and figured I'd ask if anyone happened to know. Guess i can just wait until I get home to measure it.

fietsbob
09-14-10, 09:20 AM
What's the frame made of? steel likely 1 1/8th ..aluminum .. 1 1/4"
tallstevens
09-14-10, 10:06 AM
I am pretty sure it is an aluminum frame.
madpogue
09-14-10, 10:20 AM
I've had two aluminum road frames with two different sizes of seatpost and binder. My '03 Raleigh Capri had a 27.2mm seatpost and took a 31.8 binder. It's replacement, an '08 Raleigh Grand Prix, takes a 31.6 seatpost and a 34.9 binder. Do you know offhand the seatpost diameter?
Bezalel
09-14-10, 10:21 AM
Most modern seattubes are built to the following 3 sizes 28.6mm, 31.8mm, and 34.9mm. Take off your current clamp and see if there are any stampings inside.
fietsbob
09-14-10, 11:41 AM
Aka 1.125" 1.25" , 1.375".. inch and an eighth / quarter/ and three eighths.
tallstevens
09-14-10, 12:10 PM
Seatpost dia is 27.2
Bezalel
09-14-10, 12:27 PM
Seatpost dia is 27.2

In that case the seattube is most likely 31.8mm.
fietsbob
09-14-10, 12:29 PM
31.8 is probably OK, If no shims are inserted to use a larger ID tube.

roughly a 2.3mm wall thickness tube.


you can always return / exchange if the guess is off..