Seat Post SIzes ?

[brass monkey!]

Forgive me,.......but

Is a 7/8th inch size seatpost the same as a 22.2mm seatpost, they look the same? Why is one imperial and the other metric ?

or are they slightly different 

[gt0733]

i don't know the answer but i will say i bought 2 cro-mo 22.2 seatposts for my redlines. one slid straight in with no problems on the proline frame (1983) but the mid school frame(1990) was tight enough that we had to do a bit of massaging of the seat tube.

[Trev]

i've got some primo seatposts for sale and they are labelled at 22.2mm (7/8"), so i guess they're the same.

[Stodgy]

Yep, 22.2mm = 7/8"

[brass monkey!]

I though so , but I bought a 22.2mm labelled seatpost, which was a real tight fit into an old school frame, I was worried I had got the wrong size....?

 

[jimwise68]

What are all the seat post sizes?

There is the 22.2 the 25.4 but my mate has an early DB Pro Star and can't get a seat post to fit as it is slightly larger than a 22.2.

Will it need a shim or is there a mid size seat post that fits between normal size and the Burner size?

[electobooty]

Am curious about this myself.
I know there is the normal os size, then the burner size also the ultra slim uni turbo.

So why does my renthal and redline slip into my Diamond Back nice and snug, but it needs a shim for my aero reflex,

[dj_benice]

type seatpost in us gay  bay last time I checked they had about half a dozen diff 20-26 n summat mm ones for bmx n then you got all the mtb n road bike sizes 

[jimwise68]

Am curious about this myself.
I know there is the normal os size, then the burner size also the ultra slim uni turbo.

So why does my renthal and redline slip into my Diamond Back nice and snug, but it needs a shim for my aero reflex,

What size is the Aero seat tube?

[electobooty]

Seems to be 22mm, though I can't be too accurate with a tape measure

[jimwise68]

Strange cos my Redline and Kuwahara both take a 22.2 mm seat post.

Well I think anyway! 

So I thought the Aero would have been slightly bigger.

[selfpreservation]

I BOUGHT A NOS mongoose Proclass POST FORM THE STATES IT WAS 22.6 MM WTF  was tight as a gnats chuff ended up getting minced n a vice 

[thebigdog]

my cw z1500 has a 22.6mm  seat post in it which is quite scratched...trying to find one is hard..as 22.2 seems to be the most common 'old school' size,which crops up for sale.