Dropper Seatpost - Shim?

bungalballs

Im getting a new frame front triangle on warranty replacement. The replacement is 1year newer, having changed from 27.2mm seat post to 30.9mm.

I have a thomson dropper in 27.2mm. Is there any reason why I can't use a shim with the seat post to size it up to the new frame?

(By the way, the bike is a Whyte. I took the frame to my LBS where i bought it, who have been dealing with Whyte for me. Even though I am well over the 5yr frame warranty, the shop rang me to say Whyte have not only sent the frame front end anyway, but because of a change in colour schemes between the years, they have also sent new colour coordinated pivot bolt caps, linkages, seat post and saddle. Big fat thumbs up and thank you to Whyte!)

cooldad

Shim will be fine, I have a 27.2 post - cheap mechanical post, in a 30.9 tube. Post is shit but the shim is fine.

The Rookie

To keep clamp loads sensible I often use some gripper paste with shims, even more important as some droppers don't like high clamp loads very much!

bungalballs

Yeah thats the bit I'm worried about - clamping properly without damaging anything. I know the dropper goes a bit funny/clicky if I over tighten. Just want to make sure don't compress something and stop it working properly or damage it long term.

ilovedirt

I used a reverb with a shim in my old nukeproof mega frame for a good while and did no harm. I did have to be careful with clamping force which made the post bind-up if over-torqued slightly, which I've never had before or since, presumably because of the smaller clamping area. As I said though, it was fine.

bungalballs

Ok thanks guys. I'll try it and if I have problems, I'll eBay it for a reverb!

The Rookie

Use some gripper paste between post and shim (Shims seem slipperier inside than seat tubes) and I'm sure you'll be fine.

I align the split in the shim with that in the seattube, but always put the gap in the clamp opposite that so you get more radial compression and not pinching the tube.