Shim or not to shim: 26.8 to 27.2?

[H]

Thoughts please. Is it practical or safe? Or should I hold out for another NOS post instead? Thanks H.

 

[Rampage]

Hold out.

 

[raidan73]

+1

 

[daugs]

Re:

there was a thread on shimming a while back and if done should be done properly I think, so even from a practical sense its probably possible to find the right size (unless you've already got a quality shim), so why wouldn't you ? it's not the most obsure size to find ? you'll just have to resist the temptation to use it as a short cut to get it finished ?

 

[02gf74]

I'm voting no. Only place I'll use shim is for front mech, not for bars or seatpost. Is the 27.2 mm version difficult to obtain or expensive?

 

[hamster]

No problem with using a shim at all, provided the bottom of the shim comes at least 10mm below the bottom of the top tube and/or seatstays. This reduces the risk of a stress concentration which could be a source of frame cracks.

However, 27.2 is about the commonest size out there so I'd probably wait - simply to avoid the hassle.

 

[Thias]

0.2mm shim, what would that be? Coke can cutout?
I would totalky do that until something 27.2 comes around.

 

[02gf74]

0.2mm shim, what would that be? Coke can cutout?
I would totalky do that until something 27.2 comes around.

try another can, possibly beer can, as coke can is 0.1 mm

 

[hamster]

Drinks cans have incredibly tight tolerances and make good shims. Cut out with scissors, then hammer flat and finally dress the cut edges with a file along the flat side (not the edge). This removes any high points.

Hacking it out without preparing carefully is asking for the thing to wrinkle, stick or slide. It takes time and care to do a decent job. With a typical drink can it's 1.5-2 turns.

 

[millsm]

Re:

Shims work just fine. You can search online for shims to work for your frame/fork. I have a 30.0 seattube, but wanted to use a 27.2 XT seatpost (the biggest size they make), so I found a Cane Creek 30.0 to 27.2 shim, and it works just great. Depending on what size seatpost/frame you have, you may be able to find a proper shim online - usually around $10.