Quick seat post shim question ( I'm being thick!)

[trxrincon]

Hey, I have a 30.0mm seat post I'd like to run in a 31.6 frame. Do I need a specific 30.0-31.6 because I can't seem to find any or would a 27.2-31.6 work as the look like the shim would open up a bit. Cheers Rob

 

[Timoth27]

Re:

Won’t work I’m afraid buddy even though the shim might open up to go over the seatpost it would then make it too big to go into the seat tube. 27.2 to 31.6 is 4.4 mm so if you squeeze the shim over the 30mm post you would be making the outside diameter 34.4 so too big for your seat tube. Hope that helps.

Thanks

Tim

 

[trxrincon]

Ahh got you, I'll keep looking. Thanks for the reply Tim.

 

[Timoth27]

Re:

No worries, I don’t really have any experience of shims but I would guess you might struggle to find what you want as the shim thickness will only be .8mm which is pretty thin.

 

[trxrincon]

Might it work ok with out a shim? I guess I could try?

 

[Timoth27]

Re:

If im honest I doubt it and I really would not want you to damage you frame. Also if you do get it to work you also run the risk of the correct size not fitting in the future if you close up the seat clamp area too much.

 

[trxrincon]

That's cool, thank you for the good advice!

 

[hamster]

0.8mm of shim isn't very thin at all. I run one of less thickness (25 into a 26.2) and there are plenty available...even down to 0.2mm thickness.

The ghetto solution is coke can material, but you could buy a 0.8mm shim - 27.2 to 28.8 - and widen it out. Probably you would have to remove most of the lip to get it to open far enough. It isn't ideal as the clamp area would be larger, so I would fit the shim the other way round (slot 180 degrees from the clamp).

 

[stew-b]

coke can.

 

[kyle888]

Re:

Try eBay pretty sure you can buy any size as people manufacture them in custom sizes. I’ve bought one before.

Edit: can only find 31.6-30.9 after a quick look.

Kyle