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A friend lend me his dropper post to test but his dropper is 30.9 size and my frame is 31.6. Is there a shim that I can get or does people just DIY a shim (i.e coke can 😆 ), coke can which I tried but slips 😆
Is it a good solution to secure a seatpost?
A proper one works fine*, ideally metal IME. If you can get enough layers of can in there it may work.
*0.7mm is kind of thin tho, I'm not sure how well either would work
The plastic from a 4l milk container is also exactly the right thickness if you're in a pickle.
Have used one on my HT for years, did it as a bodge and it was great. never touched it since.
I think if you use a bit of old can it may work fine but you may just lose a friend if your homemade marvel of engineering scratches up their seatpost. I think maybe you owe it to them to use the right tool for the job in this case `:-)
Calling all London Road v1 owners...
😉
@avdave2
Haha yeah except that he gave me permission to use can 😆 it didn't scratch the post in any way.
@butterbean
Really? Good we have some empty milk bottles around haha, was it easy to bend it around? can't cut any at the moment as I am not at home 😆
My only worry is that if the can or plastic shim slips down the tube haha.
I used a USE shim for around 12 months until I swapped my seatpost to a 31.6mm and it never caused any issue, and came out fine when I was finished with it - not a stealth ad, honest!
A Coke can is 0.1mm thick (so 0.2mm on diameter) so you’d need three wraps at least to make up the 0.7mm difference. Is this what you did?
I have a 30.9 seatpost in a 31.6 frame. I bodged it whilst I was waiting for my USE shim to arrive, but the shim is perfect and quite remarkably thin for a piece of machining. Get one, problem solved.
ONly thing to consider if using a shim, is that the shim sticks up about 10mm from the top of the seat tube (stops it slipping down inside) - might be an issue if using a dropper that is slammed way down at the lowest point.
USE shim here. Works fine.
"ONly thing to consider if using a shim, is that the shim sticks up about 10mm from the top"
Really? sticks up a centimetre?
Mine has a lip to stop it slipping inside but it's 2mm max.
The coke can wasn't a good solution by the way. One layer wasn't enough, two was too much, so I had to have one and a half, which wasn't good for evenly supporting the post.
ONly thing to consider if using a shim, is that the shim sticks up about 10mm from the top of the seat tube
USE one doesn't. It's only a couple of mm, you'd be hard pressed to tell just by looking at the bike.
ONly thing to consider if using a shim, is that the shim sticks up about 10mm from the top of the seat tube ...
And that the depth of the shim needs to meet the minimum insertion depth of your frame - most frames have a minimum insertion depth for a seatpost to protect snappage of the seat tube (it's usually a CM or so below the lowest point of the seat tube/top tube weld but may vary); any seat post that protrudes below the bottom of a shim isn't in contact with the seat tube and, therefore, doesn't count.
My USE one DOES have around 10mm showing above the top of the shim, but it is plenty long enough for the minimum insertion.
I guess USE change the shims they use a bit.