Carbon steerers - a...
 

[Closed] Carbon steerers - anyone use a glue in insert instead of a bung?

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Somthing like [url= http://www.3tcycling.com/small-parts/fork-kit ]this[/url] which replace the need for a bung and lets you use a starnut by gluing in a thin alu sleve in to the steerer

I know its designed for a 3T fork but I have one in a planet x fork I have hanging around. Safe to use, or will I die?

Only concern is that it may put additional stresses on the steerer, but then again I'm not sure that it would be any different than a standard bung kit, ie [url= http://www.planetx.co.uk/i/q/FSPXFCENT/planet-x-carbon-fork-bung-centre-pull-system-fits-px-team-alu ]this[/url]

any thoughts?


 
Posted : 24/12/2013 6:27 pm
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Mine was replaced on my Ibis carbon and the LBS glued in the insert. Don't recall what kind of glue it was, but one recommended by Ibis. Solid as a rock
Edit: think it was an epoxy that they mixed


 
Posted : 24/12/2013 6:31 pm
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if you use a good quality "bung" you should not have any problems, and it doesn't require any glue?


 
Posted : 24/12/2013 6:37 pm
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Hope bung, Quality bit of kit


 
Posted : 24/12/2013 7:45 pm
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Hope bung doesn't work in all steerers, it's not very adjustable so if the walls are thick, it doesn't fit. Still, glue-in part makes a lot of sense, but what if you change bikes and want to shorten the steerer?


 
Posted : 24/12/2013 7:49 pm
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All cervelos come with an insert which you glue in place. Uses a 2 part epoxy resin. Just ensure the whole thing is coated and plenty used!


 
Posted : 24/12/2013 7:49 pm
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Yep mines been glued in well enough, so no chance of cutting down the steerer.

I thought the insert may cause uneven stress in steerer, particularly at the end of the bung, but theres no real logic round this thinking, more just paranoia.

Merry chrimbo everyone...


 
Posted : 24/12/2013 9:13 pm
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The bung is only used to give the stem top cap tightening bolt something to pull against in order to take up play in the steering head bearings and the force to achieve this is small. Once this has been achieved, the stem bolts take the major tightening stresses in clamping the stem to the steerer. So long as your bung allows you to take up any play in the headset bearings, it will have done its job and won't compromise the safety of your front end.

You could buy a bung for carbon stems such as the one listed on this page, if you don't fancy the Hope Head Doctor:

http://www.ceeway.com/carbon%20forks.htm

Happy Christmas!


 
Posted : 24/12/2013 9:33 pm
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I'm going to glue the next one on my best roadie build. Just to save a few grams really.

Has anyone seen a cheap weenie solution? Just a light alu insert which I can epoxy in place will do the trick.


 
Posted : 24/12/2013 9:39 pm
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Head doctor wouldnt fit in my SID WC's had to use the shitty looking one they provided...

Wouldnt want to use a nut, i assumed the logic of using a bung in carbon sterers was to provide some couterforce to stop the steerer overcompressing and cracking during tightening?


 
Posted : 26/12/2013 2:13 pm
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A quick google indicates that on the cervelo fork at least the alu tube is there for structural strength.

[url= http://weightweenies.starbike.com/forum/viewtopic.php?f=3&t=92744 ]Advice from cervelo designer[/url]

My concern is around the requirement for the sleeve to extend past the bearing race, which mine doesn't. I'm not using a cervelo fork, I'm using a planet x one, but it still raises questions around will a glue in sleeve, if not extending past the race actually weaken the steerer by putting additional loads aroud the bearing race area.

I've not used the fork yet, but given my other carbon steerer looks to have developed a crack I'm in need of a short term replacement. Not at the expense of my teeth however.


 
Posted : 26/12/2013 8:26 pm