Forum menu
Hi all,
Still looking at the ti hardtails.
A few decisions to be made.
Still looking at Kinesis Sync's and have noticed they have a 31.6 post.
Got a couple of posts lying around,1 Syntace and a Giant dropper.
Don't really want to replace these straight away but they are 30.9 diameter.
Is a shim a good idea in a ti frame?
I noticed USE do a long plastic one that mite do the job.
Some people say it's ok others not so much so.
Any experience?
In the meantime photos of Sync's or ti hardtails are much appreciated for inspiration!
Thanks,
Max
Any experience?
Thanks,
Max
I've hade a shim in one of my bikes for about 3yrs now with no issues. Same reason as you; hade a 30.9 dropper that I didn't want to get rid of and a new 31.6 frame to put it in.
It's a pita when using a qr which you won't be.
I've seen the plastic ones deform over time, I'd use metal and grease it up.
My Ti Salsa had a factory inserted shim - alloy pressfit into a Ti tube. Never had any problem with it other than it was a little creak prone. Grease sorted it.
cynic-al - Member
It's a pita when using a qr which you won't be.I've seen the plastic ones deform over time, I'd use metal and grease it up.
+1
My experience with plastic shims is that they deform plastically under pressure. Kind of obvious in retrospect.
I used one in the 'Puffer and had 4 laps of slipping seatpost before I changed bikes. I had tried it out beforehand and it seemed ok.
I blamed the residual grease on my seatpost from a previous use. Anyhow, with it completely degreased I used it again for last weekend's Forth Fat, again after a brief test.
Two days of slipping seatpost and riding "with my knees hitting my chin like a teenager on a stolen kids BMX bike". Not fun, and exhausting - I was stuffed by the end. Although I'm sure there must be some training benefit in there. 🙂
It doesn't seem to slip when the weather is dry, but a tiny bit of moisture in the air and it slips.
I won't be using plastic shims again.
All I'll say is that the only Ti frame I've ever had, a Kona Hei Hei, cracked at the top/seat tube join directly because of a shimmed post. I'll never ever use a shim ever again.
I'm using a metal USE shim on my Bfe, again already had a 30.9 reverb. As said above it's a pain in the backside with a QR (I have a 31.6mm post for when the reverb is off) so I swapped to a bolt up seat post clamp and it's been fine. Just make sure it's all thoroughly degreased and maybe use some carbon paste.
make sure the sim extends far enough to be below the top tube / seat
tube joint to avoid peterpoddy's issue !
Thanks for the advice guys.
A metal shim of decent length sounds like a good idea.
An allen key fitted coller will be used.
Would buy some more seatposts but when the Syntace is a Hi flex and retails above 150 quid or so you can see my dilemma!
Thanks again,
Max
I use a cane creek Al shim in my Al bike for about a year.