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would you run a 30.9 dropper post in a 34.9 seattube with a shim?
ive done it with 30.9 into a 31.6 without any problems, but 4mm seems like an awful lot!
I used 27.2 GravityDroppers in 30.9 frames for many years. As long as the shim is a snug fit and at least 100 mm long, I can't see what difference it makes.
I've got three frames, 27.2, 30.0 and 31.6.
I have two conventional posts and one dropper. The dropper is 27.2 and is swapped between bikes without any problems, had to get the smallest so it fits all of them. Didn't fancy shelling out for three Thomsons, even at the second hand price!
27.2 in 31.6 is about the same step in absolute terms as the OP, less proportionally so should be fine. As above, get a long one.
Ill let you know
im waiting for my 34.9 shim to be delivered
Length of shim for load spreading will be very important. Long as you can get/fit and it’ll be fine.
I’m using both 31.6mm and 30.9mm droppers in Liteville 301 Mk 10 frames, which are 34.9mm seat tube diameter. The shims are made for the job (by Syntace) and are 140mm long - you’ll be fine if you get one of those.
No issues what so ever with syntace shims
this is nice. i was expecting a torrent declaring madness!!
however, its turns out my current post is too long anyway...
No problem as long as the shim is long enough,shouldn't think the diameter difference matters
no prolem. my old crank bros kronolog dropper post actually came with a shim so i could run it in a 34.9 seat tube.
We have four Specialized which have been shimmed from new. The shim comes as standard on the carbon frames. Enduro's and Stumpjumper.
Anyone got a source (in the UK) for 30.9 or 31.6 to 34.9 decent (ie long) shims?
I've done it as a temporary measure with 27.2 dropper into 31.6 tube. Worked fine.