Seat Post/QR Size

Mojo_666

I am trying to establish what size/diameter seat post and what size QR seat post clamp I would need for the below bike?


http://www.wiggle.co.uk/gt-avalanche-expert-2007/

Cheers
Mike

1mancity2

http://www.singletrackworld.com/forum/t ... -avalanche

Mojo_666

Cheers, that limits my buying options on seat clamps it seems.

1mancity2

Thats seatpost size so I think your seatclamp would be around 31mm but not sure on that.

cooldad

Measure it.

Mojo_666

The 20 miles between myself and the bike do not make that a viable option right now...............further searching suggests it is quite probably a 31.8 clamp size though.

junglist_matty

I doubt the frame tubes are 2.3mm thick (that's if your seat tube is 27.2mm and your thinking of buying a 31.8 clamp)...

The common clamp sizes being:
28.6, 30.0, 31.8, 34.9, 36.4, 38.5

Mojo_666

junglist_matty wrote:

I doubt the frame tubes are 2.3mm thick (that's if your seat tube is 27.2mm and your thinking of buying a 31.8 clamp)...

The common clamp sizes being:
28.6, 30.0, 31.8, 34.9, 36.4, 38.5

I get what you are saying and am inclined to agree but I am just only going on what I have read. I am not actually planning on buying anything, just trying to find out if/when a time comes where I might need a part or feel the need to spend some cash on something I don't need.

I will measure and make a note sometime..unless someone comes up with a definitive answer that is.

Thanks for the comments so far.

1mancity2

My frame has a 30.9mm seatpost and a 34.9mm seatclamp.

1mancity2

Pretty sure now,

http://www.bikeradar.com/forum/viewtopic.php?p=15726066

concorde

At the risk of sounding stupid! Just measured my diameter and it was about 33/34ish. Hard to tell exactly with a measuring tape. So could I get this QR clamp http://www.chainreactioncycles.com/Models.aspx?ModelID=44200 in the 31.8 size?

Cheers

cooldad

Measure the circumference- much easier to be accurate, and use maths - see FAQ's
viewtopic.php?f=40043&t=12726337

concorde

Cheers, the actual seat tube is 11cm approx, seat post is more 10cm.

concorde

Concorde wrote:

Cheers, the tube the seat goes into is 11cm approx, seat post itself is more 10cm.

Can anyone confirm which of these measurements I use?! The tube the seat post goes into, or the seat post tube itself?

Cheers

cooldad

The seat tube for the clamp and seatpost for the seatpost.

concorde

cooldad wrote:

The seat tube for the clamp and seatpost for the seatpost.

Cheers Cooldad. 11.5cms it is then so that works out at 36.6mm :-)

Struggling to find one that big!

nicklouse

Concorde wrote:

cooldad wrote:

The seat tube for the clamp and seatpost for the seatpost.

Cheers Cooldad. 11.5cms it is then so that works out at 36.6mm :-)

Struggling to find one that big!

There are a few out there.

concorde

Went with a 34.9. Seems to work!