What gives ??

[Tomahawk kid]

!!!???? I needed to replace my seat post on my new build Klein Adroit, which is coming along at a fantastically slow pace Having removed the scratched & tatty old seatpost , a Lappierre , I got the size 31.6 & decided to order a brand spanking new Thompson Elite 31.6 , which came this morning all resplendent in it's cloth bag only to find it doesn't fit ! It goes in about an inch then sticks tight.Whats happened ??

 

[kingbling]

First of all double check your measurements seat post seat tube
then check the seat tube for excess build up of gunk inside

 

[Tomahawk kid]

First of all double check your measurements seat post seat tube
then check the seat tube for excess build up of gunk inside

Thanks for the reply. I cleaned the gunk out, grease & alu dust. The diameter on the post are the same, the Lappiere says on it Ø 31.6 & the Thompson one the same .The lapierre is a snug fit but can be raised & lowered but the Thompson gets stuck. tried spraying the Thompson with GT but it makes no difference.

 

[Tomahawk kid]

Re:

I just had a look at the dealer manual from '96 & that year the seatpost had Ø 31.6 I'm at a loss ??

 

[kingbling]

Do you have a set of callipers to measure it thats the only way your find out whats going on. I've had similar issues in the past and not all seat posts are what they say.

I take it there's nothing wrong with the seat tube itself

 

[Tomahawk kid]

Re:

I've got some from Aldi, digital ones but I don't thing they're much cop. I might just have to take the posts & frame to a local engineers to get the Ø measured, have a feeling the Thompson one is a tad too big though both post Ø measured 31.6 with my micro. The seat tube looks like there's something in it the data tag perhaps but it doesn't interfere with the post lowering . ???

 

[My_Teenage_Self]

It'll be alu oxidation and grease in the tube, I've had that exact problem on a number of frames.

Get a broom hadle or similar, and either wet and dry, scouning pad or something, and really get stuck in. You'll be amazed how much muck comes out.

 

[gashmar]

Re:

You could still use the Aldi calipers just to check that both the seat posts are the same diameter regardless of the actual dim.
Whatever the reading they should both be the same then at 31.6 and if there is a difference at least you will know which one is thicker.

 

[02gf74]

Manual callipers will measuere down tk 0.05mm that is more than enough.

31.6 mm is correct size.

 

[Tomahawk kid]

It'll be alu oxidation and grease in the tube, I've had that exact problem on a number of frames.

Get a broom hadle or similar, and either wet and dry, scouning pad or something, and really get stuck in. You'll be amazed how much muck comes out.

Spot on Problem solved, I had a 25mm wire end brush tacked onto a bit of threaded rod which I put on the end of a drill & off I went After further fettling with some oxide paper stapled to a broom handle the new post slid n but only so far looking in I saw another problem,remnants of the old Thompson post ram Jammed firmly in the seat tube :roll: Some WD40 & long handled pliers & a bit of cursing & it came out !