USE Seat Post Shim 31.6 mm to 34.9 mm

Customer Reviews (3)
5 / 5| Write your review
£9.99 Please note this product has selling restrictions to your country. was
Manufacturer : 
SJS Cycles part number : 
Manufacturer part number : 
ID (inside diameter) = 31.6mm OD (outside diameter) = 34.9mm
Product Reviews (3)
Questions & Answers (12) Q & A
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Product Reviews (3)
Overall Product Rating 5 / 5
By Janet O'Callaghan
15 Dec 2020
5 / 5
I recommend this product
ProsVery cheap and looks good.
What can I say, it works, very well made.
Major upgrade for £9.99 !
By M J West
12 Mar 2019
5 / 5
I recommend this product
I am upgrading a cheap eBay folding bike that I bought some time ago. The frame is stiff and light, but many other components are poor. Quality tyres made a significant difference but replacing the plastic (!) shim, which came with the bike, with this precision machined one has transformed it. The saddle stays at the selected height - a fundamental requirement for comfortable cycling.
Use Seat Post Shim
By Kit Spackman
04 May 2012
5 / 5
Prosit works,light,looks good,good price
Great piece of kit! Trying to fit an old style Moulton APB alloy seat pillar into a newer style seat tube is an exercise in frustration as the diameter change so large. Until I found the USE item I was stumped, but that worked a treat. Not only is it a good price, it's well made, fits exactly and even looks good too.
Questions & Answers (12)
Is this the thermo plastic shim ?
30 May 2021
In the Q & A section it says that you think the shim is alu. Is this not the thermo plastic version ?
Thank you for your enquiry, yes it is alloy

WD 01/06/21
Is this aluminium or plastic please?
22 Apr 2021
Thank you for your enquiry, it is aluminium

WD 23/04/21
Can I use this shim with a carbon seatpost?
04 Sep 2019
Yes, no problem to use with carbon.

Thanks - 09/09/19
Specialized Kenevo
11 Jan 2019
Will this be ok for fitting a 31.9 diameter seat post into a Specialized Kenevo that has a seat tube diameter of 34.9?
Yes, this will work.

Thanks - 14/01/19
34mm seat post to 31.6mm
03 Dec 2018
Hello I am having trouble finding a shim to fit 34mm seat post for converting to 31.6mm suspension seatpost. I have severe spinal issues and can only tolerate electric bike with decent suspension seatpost. However the new bike I have just converted to electric has this odd sized post. I'm an engineer but wondered if gap in the 34.9 seatpost shim would accomadate the 0.9 mm difference fit into seatpost opening and fir 31.6mm seatpost???
Thanks in advance for any help its appreciated.
Unfortunately we could not recommend that would be suitable.

Thanks - 04/12/18
What material is this made from, is it plastic or aluminium etc?
29 Nov 2018
Hi there,

We believe that this is made from aluminium.

Can I use this with Pinarello FP2 Carbon 2012?
12 Feb 2018
Hi there,

As long as the sizes match up then this should work.

What size shim will I Need to use a 31.6 dropper post when the seat post on my gt is saying 34.9
10 Dec 2017
My seat post is 34.9 but my dropper post is 31.6. What size shim will I Need please.

This shim will work to convert your 31.6mm seatpost to fit the 34.9mm frame perfectly.

can i use the noted seat post shim with a scott scale 930
07 Dec 2017

If the internal and external diameter fit your specification then this will fit.

What is the lenght? Thanks
16 Nov 2017

This shim is 100mm in total length with 92mm fitting within the frame.

Hi, This Will Fit On Birdy Folding Bike Seatpost (34.9 Dia) Will Convert To 33.9Mm Seatpost Dia?
01 Nov 2016
Birdy folding bike seatpost dia is 34.9mm. I want to use litepro seatpost size is 33.9mm i need seatpost shim/ adapter to fit the 33.9mm seatpost on my birdy folding bike

We don't have any shims that are the correct size straight away for your needs I'm afraid. You could modify this shim by increasing the inner diameter to 33.9mm or you could use a "drinks can" shim as the alloy in these is usually around 0.5mm thick which would give a 1mm increase in diameter around the post.

Can You Please Confirm This Is The Correct Size Shim For A Moulton Tsr ?
19 Sep 2016
Can you please confirm this is the correct size shim for a Moulton TSR ?

We have never sold Moulton bikes so we have no way of knowing what size seat tube your bike has I'm afraid. If you bike has a 34.9mm seat tube then this would be the correct shim to take it down to 31.6mm.