Help me install my brand new carbon fiber fork please.

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RRSODL
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Help me install my brand new carbon fiber fork please.

Postby RRSODL » Sat Oct 27, 2012 12:46 pm

I have now identified the fork I need to buy and it's full carbon.

I've been doing some reading and watching a few videos on how to cut and fit a headset but I'm now a little confused.

The things that I've learnt are:
- not to use a pipe cutter but a saw with small teeth - makes sense.
- not to use a star nut.

How am I supposed to secure a headset if I cannot use a star nut? Obviously, I've never done this job before, hence the question :)

I could ask the LBS to do this for me but I want to learn to do it myself, I think it's more fun that way, picking the components and building it up.

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Ber Nard
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Re: Help me install my brand new carbon fiber fork please.

Postby Ber Nard » Sat Oct 27, 2012 13:04 pm

Use an expansion bung. There's plenty to choose from.

Image

Rob

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Ber Nard
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Re: Help me install my brand new carbon fiber fork please.

Postby Ber Nard » Sat Oct 27, 2012 13:12 pm

Worth noting that the cap on a bung like the one above sits on top of the steerer reducing the gap between the top of the steerer and the top of the stem. You may need to trim the steerer a little shorter to compensate.

Rob

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sungod
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Re: Help me install my brand new carbon fiber fork please.

Postby sungod » Sat Oct 27, 2012 13:17 pm

you use an expander bung, there are a few on this page...

http://www.chickencycles.co.uk/index.php?cat=4&sub=106

...note that there are many different ones available, and sizes vary, you need to get one that is correct for the inside diameter of the steerer tube

personally i like bungs that are long enough to cover the full length of the steerer that will be clamped by the stem

*ideally* you should follow the instructions for your specific fork, if there are none then this will be close...

typically you also need a small spacer above the stem - otherwise the top cap can foul on the bung, a 3mm spacer is good, again you'll see some on the above page as examples

you cut the steerer, so that with the correct number of spacers below the stem, plus the stem height, you will end up with the steerer tube just about level with the top of the stem, a couple of mm either way is usually ok, then the thin spacer, then the top cap

if in doubt, err on the long side, you can always add a higher spacer above the stem, or lop a bit more off the steerer

to cut the steerer, you can get a very fine hacksaw blade designed for cutting cf etc., a cutting jig is best as it allows a square cut, but you can improvise

you need to avoid splintering the cf, the fine toothed blade is part of that, but also avoid excessing force or angling the blade, wrapping the area to be cut in tape helps
my bike - faster than god's and twice as shiny

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RRSODL
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Re: Help me install my brand new carbon fiber fork please.

Postby RRSODL » Sat Oct 27, 2012 15:53 pm

Thanks to both guys that posted with some new and very important information.

I had never seen an expansion bung in my life :) first time I'm using a CF fork too.

Now that I'm clear about how to fix the headset, fork, expansion bung, stem and headtube together I can relax for a bit :)

Cheers


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