Author Topic: More seatpost woes! Is there another sizes besides 7/8ths and 13/16th? (Read 2608 times)

oldschoolace · « **on:** April 28, 2015, 08:14 PM »

This fookin vitus has me stumped lads. After finding a glassfibre post lodged in the bottom of it the other day I gave the seat mast a good scrub and a going with a tube honer. Clean as a whistle now.

tried the cleaned up Gt post back in it today and it was still tighter than you would expect and wouldn't go much further past the keyhole slot.

I assumed as its French double butted tubing and that it has a glassfibre post lodged in it that it probably needs a 13/16th post but I reckon if I took the 1.6mm difference off the gt post it would rattle around in there like a Biro in a hooker $:-\$

Is there another size im unaware of or is it deffo 13/16 or 7/8th

Gnarlyscoots · « **Reply #1 on:** April 28, 2015, 08:30 PM »

Quote from: oldschoolace on April 28, 2015, 08:14 PM

13/16 or 7/8th

Is that 20.6 (21) and 22.2 mm yes

oldschoolace · « **Reply #2 on:** April 28, 2015, 08:34 PM »

Yep that's right for you younger kids

Gnarlyscoots · « **Reply #3 on:** April 28, 2015, 08:51 PM »

Quote from: oldschoolace on April 28, 2015, 08:34 PM

Yep that's right for you younger kids

I think I am right, I may be just b**********g but, didn't GT make their posts different sizes, chrome and painted? If you remove the paint from a GT post it is slightly smaller than a chrome post. I think it was GT anyhow $:-\$

glenboy · « **Reply #4 on:** April 28, 2015, 08:54 PM »

Yep there's 22.8 as well

Gnarlyscoots · « **Reply #5 on:** April 28, 2015, 08:56 PM »

Quote from: glenboy on April 28, 2015, 08:54 PM

Yep there's 22.8 as well

I think Clint means a post size in between 13/16 and 7/8 Glen

oldschoolace · « **Reply #6 on:** April 28, 2015, 08:58 PM »

I did wonder if the post was an oddball size Terry but I measured it with my digital calipers and was Bob on 22.2mm

glenboy · « **Reply #7 on:** April 28, 2015, 09:05 PM »

Ah got it terry and yes some gt posts are 22.6mm for some weird reason so maybe you have one of them Clint

glenboy · « **Reply #8 on:** April 28, 2015, 09:20 PM »

Easiest way if not is use a alloy or fluted alloy post and just sand it and polish it down a bit

Bigfrawg · « **Reply #9 on:** April 29, 2015, 06:38 AM »

Or smash the coont in with a hammer

snoopy72 · « **Reply #10 on:** April 29, 2015, 07:09 AM »

Shine a touch down the seat mast tube and make sure the weld from the top tube hasn't penetrated into the seat mast tube , I have had this before with a mongoose frame, once I carefully removed this tiny bump the seat post fitted perfectly all the way down the frame.

oldschoolace · « **Reply #11 on:** April 29, 2015, 12:58 PM »

Seat mast is clean as a whistle. Doubled checked my measurements and the mast is 25.4mm diameter with a 1.6mm wall which would mean it should take a 22.2mm post $:-\$

Gt post is deffo 22.2mm and its deffo round with no obvious dents, marks, anything that may make it a tight fit.
Really dont want to knock it in with a hammer $:-\$

Might just find a 20.6 post and shim it with a pop can if need be