Shim Converter?

[syplam]

Hi, im getting a frame for 31.6 seatposts...am thinking if its safe to use a shim converter so that i can use a 27.2 seatpost? anything i should be careful of if i use a shim converter?

[F45]

I use an aluminum one. I used a deburring tool to radius the top lip so it wasn't so sharp.

The K Force seatpost is on a hardtail xc bike so it sees some stress. The carbon is cracking, but not around the shim.

[Rick]

I did that for a while. I used a thomson aluminum shim.
It is perfectly safe.
There were only a few mnor downsides:
1. It adds weight, so you don't really save any weight over going to a larger seatpost.
2. It creates an additional gap where the shim doesn't quite close, that could be a path for water intrusion. Fill it with grease.
3. I could never decide of the top rim of the seatpost clamp should go over the top rim of the shim, or under it. I think I ended up keeping the shim up just the thickness of the seatpost clamp so that the clamp sat just underneath the shim's lip. If the clamp is over the shim's lip, it might create a stress concentration on the seatpost.
4. When you adjust the saddle, everything slides around, so it is a little more inconveniently fiddly.

[syplam]

thanks for the info, guess i will just sell my old post and get a new one :S