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Discussion Starter · #1 ·
I need to get a seatpost shim soon (27.2 -> 31.6) and was just wondering what the lightweight options are. I've only found a Cane Creek for $8 and a USE for $13. Are they all made of aluminum and basically the same weight?

I know the USE shim is aluminum and Nino's USE 27.2 -> 31.6 shim weighs 17 g for 65 mm length. Is 65 mm the stock length or cut?

Also, if anyone has one that they no longer need, please let me know. Maybe a Giant shim is an option?
 

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bikerpilot
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I would think that the USE might be the lightest, but I'm not sure. But I don't see how one could be any lighter than the other, if they're both the same thickness, and they both have to wrap almost all the way around the seatpost, and they should be a minimum length. The only variable left is their material compostion. And the 65mm shim, I would think that's too short. I think in most frames you should have around 80mm of seatpost inserted, and for the seatpost's sake as well. Check your seatpost and frame, and look for a minimum insertion. Whichever is greater, that's how long your shim should be, since the shim is the only contact point between the two.
 

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Recovering couch patato
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If you manage to sell your 27.2, a 31.6 may be lighter than even the 27.2 without shim. At least my Thomson is 235/410mm dropping some 35-40g from 27.2. My USE 31.6 is 18g more than the 27.2 though, some 230g.
I was in the same boat recently, but someone offered me a Syncros 425/31.6 which we'll trade when we see each other. The bike with my shim in it got nicked :-(
 

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Discussion Starter · #4 ·
I agree. Sometimes the weight gets reduced such as with Thomson, which to me indicates that the stiffness remains about the same as the smaller diameter. But this scenario would only apply to overbuilt seatposts really. Or sometimes the larger diameter is heavier such as with USE which probably means the smaller diameter post is less stiff. (more comfortable?)
 
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