Should I put a Shim in my frame?

[tim3638]

I have the less common 34.9mm seat post tube size on my dual suspension aluminum 130mm bike. I would like to move into modern times and try a dropper post. Should I find a dropper that is available in 34.9 or get one that is 31.6 and run a shim? Do shims really damage frames?

Thanks all for your help.

 

[JTmofo]

I have the less common 34.9mm seat post tube size on my dual suspension aluminum 130mm bike. I would like to move into modern times and try a dropper post. Should I find a dropper that is available in 34.9 or get one that is 31.6 and run a shim? Do shims really damage frames?

Thanks all for your help.

No. Put a shim in or find a 34.9mm post.
Either way.... life will be better.

Sent from my SM-G955F using Tapatalk

 

[smitho]

I have the less common 34.9mm seat post tube size on my dual suspension aluminum 130mm bike. I would like to move into modern times and try a dropper post. Should I find a dropper that is available in 34.9 or get one that is 31.6 and run a shim? Do shims really damage frames?

Thanks all for your help.

I’m guessing you have a Specialized given the seatpost size. They make a 34.9 dropper post. Other wise there’s no issue with running a shim.

Specialized released 34.9 seatpost bikes in 2017, and they came stock with a shim and 31.6 seatpost, before they released a 34.9 dropper in 2018.

Do everyone a favour and get something else though and don’t support Specialized’s own-brand sizing fuckwittery.


Sent from my iPhone using Tapatalk

 

[tim3638]

Thanks for the reply Smitho, actually it is a GT. Was thinking Rockshox or x fusion. Preferably something cheap and efficient!

 

[JTmofo]

Thanks for the reply Smitho, actually it is a GT. Was thinking Rockshox or x fusion. Preferably something cheap and efficient!

Rockshox are utter shite.
Not had an xfusion dropper, but like the Vengeance fork I once had.

I've recently put a OneUp dropper on my bike, and gotta say (after initial friction that was sorted with some lubing of the bushing) it's been awesome.

$260 plus some coin for a decent lever and you're good to go.


Sent from my SM-G955F using Tapatalk

 

[smitho]

Rockshox are utter shite.
Not had an xfusion dropper, but like the Vengeance fork I once had.

I've recently put a OneUp dropper on my bike, and gotta say (after initial friction that was sorted with some lubing of the bushing) it's been awesome.

$260 plus some coin for a decent lever and you're good to go.


Sent from my SM-G955F using Tapatalk

Also running the OneUp, and super happy with it. Has one of the shortest insert lengths, which means can run max drop.


Sent from my iPhone using Tapatalk

 

[ctguru]

Just make sure it’s a longish shim


Sent from my iPhone using Tapatalk

 

[Tim_the_Clyde]

+1 for one up....rockshox was a pain to maintain, more expensive and I didn’t rate the standard lever.


Sent from my iPhone using Tapatalk

 

[moorey]

Running shims for years without issue.
I’d get 30.9 post though. Leaves more options for later frame swaps

 

[John U]

Ran shims for a while without any frame issues.

 

[wkkie]

No issues with shims here in the past. Go for it!