measuring posts

ada73

ive just had a seat post come from ebay saying it was 27.2 now its come and it is way to small am i rite by doing it at the bottom of the post and going straight across with a tape

supersonic

It is the diameter of the shaft - tape measure not particularly accurate, but will give you a ballpark figure.

Is there a figure stamped into the tube?

stu8975

It should be stamped on the post what size it is...its measured by the external diameter...best to use a vernier caliper to get an accurate measurement...

ada73

thanks feelas your right it is on them and i need 30 . 4 :oops: :roll:

hucking_fell

You could still use that post with a shim

You'll need a 27.2 to 30.4 shim. They cost about £3 to £5 and you have the choice of plastic or alloy.

ada73

well i never new that would i get one from halfords do u think cheers mate

hucking_fell

Dunno about Halfords but CRC and Wiggle are out of stock just now.

I did find this:
http://www.ukbikestore.co.uk/Product/55 ... shims.html

£1.10 plus £1 postage.

I've never bought anything from them though.

If you move your seatpost up and down a lot a shim may be annoying as you need to keep it down in the frame by the QR collar. Still works fine.

ride_whenever

stu8975 wrote:

It should be stamped on the post what size it is...its measured by the external diameter...best to use a vernier caliper to get an accurate measurement...

Micrometer is much more accurate than calipers.

ratty2k

Yer, but you dont need to know to a 100th of a mm.... Its only in 10ths, so one of the cheap plastic verniers for around a tenner would be perfect.

Papa Smurf

Hucking Fell wrote:

I did find this:
http://www.ukbikestore.co.uk/Product/55 ... shims.html

£1.10 plus £1 postage.

I've never bought anything from them though.

I have, very good. A part of my item broke, got it replaced within days with some excellent service.