Seat Post Shims

[Mart]

I need some help

Looking for a special Ti seatpost (layback) in 31.6mm diameter, with a good seatclamp (something like a Thomson) but drawing a blank everywhere I look ...... However I could get a shim and use a smaller diameter one

Ive never used one and know nothing about them so looking for advice on what they are like
- Do they hold solid? or do you get slippage in use?
- I see USE do shims 100mm long - is that enough?

Alternatively anyone know where to look for one of the correct diameter?

[ScotRoutes]

Shims work fine. An application of carbon assembly paste can help stop any slippage.

FWIW a thinner seatpost will generally be less stiff and therefore more comfy on long rides.

[Mart]

Thanks Colin - I do find when riding that I sit down and have broken a carbon post with my weight (85kgs) and seatpack weight
Current set up is a Thomson post (stiff) in a Ti frame so hoping it cold help soften the ride a little

[benp1]

I used to use a USE shim, it worked great

[FLV]

Hi,

I currently use a USE aluminium shim in a steel frame with an aluminium raceface seatpost.
Assembled with a small amount of copperslip, no slippage so far in 600km

Works fine, It was going to be a temporary fix until I got a correctly sized post but I see no reason to change it now.

[Lazarus]

shims workfine - think i have about 4 now collected over the years for various sizes and all worked fine with no slippage

[drjon]

you'll struggle to find a ti post in 31.6 - mostly the biggest is 30.9. I have used moots and eriksen - both are good (and similar for obvious reasons) ive used them with USE and cane creek shims. both of which are also good. not all ti posts are created equal - in either the construction or clamps. id generally stay away from cheap Chinese ti components...

[Ray Young]

On another post I blamed the shimmed seat post for letting water run down the seat tube into the bottom bracket.

[Dyffers]

Looking for a special Ti seatpost (layback) in 31.6mm diameter, with a good seatclamp (something like a Thomson)...Alternatively anyone know where to look for one of the correct diameter?

Ahem viewtopic.php?f=9&t=14859&p=184343#p184028

(maybe not as layback as you want but 31.6)

[Mart]

i did see that and was sorely tempted, but I really need the layback as a straight post puts my saddle position too far forward on the rails

[Dyffers]

Fair enough.

On the topic of shims, I use a USE one to adapt a 30.9 Reverb to my newer frame that is 31.6. Had to change to a bolted seatclamp with a better design (captured nut rather than just threaded CNC collar) so I could mungo it up to stop it moving. Would try and avoid a shim in the future.

[paramart]

i did see that and was sorely tempted, but I really need the layback as a straight post puts my saddle position too far forward on the rails

surly a lay back post will push it further forward mart, if you are to far forward now maybe look for a longer seat

[Mart]

No quite the opposite mart
The seat in the correct position, is clamped too far forward on its rails
by having the layback you move the clamp point backwards
The seat position isn’t changing. the clamping point is

[Alpinum]

Waltly will make you one as described.
Should be about 80 USD.
The linked Kingdom post's clamp looks exactly like the Waltly one (which it likely is).

But why not go thinner and work with a shim. Flex of seatposts for comfort is likely getting forgotten nowadays it seems. Some (non trail) bikes will surely profit from some flex.

If you use shims, go with the longest option available. I've came across frames and sestposts with min insertion of 12 cm, some sleeves only have 10.

Cheep chinese... well, I just had a frame custom made (for some change) and got photos post welding (prior any treatment) and there was simply no discoloration. Never seen that before on ti. My other cheep chinese frame (from the same company) has now lasted me 6 years and is going to another happy owner. In 6 years I mostly would've cracked my frames. This goes for steel and aluminium (cracked carbon too, but that was with hard crashing). Yet, I mist admit I hardly ride fatbikes on dirt

[BreninBeener]

Ive just got an Al shim from Evans. It was 31.6 to 27.2. Its 140mm long and was £5.99.

Brilliant

Ian