KCNC Expander Plug Issue

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KH1
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by KH1

My KCNC expander plug on the CAAD9 has been regularly coming loose causing play in the steerer. Has anyone else experienced the same or similar issues with this part?
What if any solutions might there be other than just going with something else?
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devinci
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by devinci

extralite ultrastar 2, does the job perfectly and is light as hell

em3
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by em3

devinci wrote:extralite ultrastar 2, does the job perfectly and is light as hell



+1
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djconnel
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by djconnel

+1

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lechat
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by lechat

The plug only loads the bearings. The stem keeps everything tight. If the stem is tightened correctly, you should be able to remove the plug. If you wish.

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djconnel
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by djconnel

But then if your stem comes loose on a ride, it's SOL. Never happened to me yet, but....

lechat
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by lechat

Yeah, i know. Wouldn't remove mine. Just saying that it's not his bung that's to blame. (or maybe it is).

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theremery
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by theremery

carbon build paste between the stem and steerer. Use a torque wrench and a tiny amount of LOW STRENGTH (the yellow one???) loctite on the thread of the expander. Job done.
Some steerers MUST be run with the expander in place.......I'm not sure about your one tho.
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prendrefeu
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by prendrefeu

Not all steerer tubes accommodate the Extralite Ultrastar 2 though.

This past weekend 4 (FOUR!) forks I had on hand did not have an ID large enough to even fit the ultrastar in snuggly (before tightening).
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KH1
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by KH1

I might revisit the stem bolt tension. It could be that. Just never had this problem before mounting the KCNC. It has a weird tightening mechanism that requires the expansion part of the part to be adjusted before locking the whole thing in place - it seems to work okay during install but none of my other expanders have used this design. :noidea:
Don't let the truth get in the way of good story...
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trikobe
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by trikobe

Is the OD of the ultrastar vs the ultrastar 2 the same? Or is it just a modification of how it tightens that differs? Only reason I ask is because I couldn't use version 1 with my colnago C59 and for my caad10 I had to bring the dremel out to reduce the OD to get it to work

Ypsylon
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by Ypsylon

I've used various KCNC expanders on different bikes and I can't remember one rattling lose, neither in carbon steerers nor in an aluminium one. I've always used dynamic paste when using it with cf.

Is the expander coming lose, or the bolt holding the top cap?
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bikejunkie
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by bikejunkie

I had the Kcnc one, it too kept coming loose so I ordered a Extralite Ultrastar 2 and haven't touched it once since It was fitted 7 months ago. very light yet stays in. soild. :D

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KH1
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by KH1

Ypsylon wrote:I've used various KCNC expanders on different bikes and I can't remember one rattling lose, neither in carbon steerers nor in an aluminium one. I've always used dynamic paste when using it with cf.

Is the expander coming lose, or the bolt holding the top cap?


To be honest I'm not sure. But every 5 or 6 rides I need to undo everything and re-tighten to stop the rattle in the steerer.
Don't let the truth get in the way of good story...
2023 Propel Advanced SL (Growing in the Petrie dish)
2022 Trance Advanced Pro 1
2021 Revolt Advanced 1
2020 TCR Advanced SL 0 (Dead)
2019 Fathom 1 29er
2017 TCR Advanced Pro 0

by Weenie


Visit starbike.com Online Retailer for HighEnd cycling components
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Ypsylon
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by Ypsylon

I find that very strange.

Do you use carbon paste? How large is the gap between the spacer and the steerer?
"Nothing compares to the simple pleasures of a bike ride," said John F. Kennedy, a man who had the pleasure of Marilyn Monroe.

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