lightest Fork expander

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PK
Posts: 168
Joined: Fri Oct 04, 2002 4:45 pm
Location: UK

by PK

Can anyone advise on a good lightweight fork expander/bolt+cap... I dont know the proper name for the parts...the gear which pulls the a-head stem down on a threadless steerer(Alu). Any help welcome, PK :?:

by Weenie


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Desperado

by Desperado

What kind and size fork do you have (1" or 1-1/8")? Integrated headset or standard?

PK
Posts: 168
Joined: Fri Oct 04, 2002 4:45 pm
Location: UK

by PK

1-1/8 ALu, with standard HS.

Desperado

by Desperado

Brunetti Cycles (Italy) makes a carbon expander very light (I can't remember the weight offhand, but I had trouble ordering from them direct because of the language problem. However, I have discovered that they do have a US outlet now at brunettiusa@hotmail.com

Another source is Andrew at info@cyclinginnovations.com He is the new US distributior for TISO in this country and they make an 18 gram carbon expander. I should get one from him next week. He, however, just left for Asia on business so I don't know if you'll get him right now. Cost was under $15 without shipping.

As far as a lightweight top cap goes, contact poshbikes in the UK: info@poshbike.com They sell a very light (5gm I believe) Storck carbon top cap with a titanium bolt. Fairly inexpensive and the shop was very cooperative. They also have Tune 10 gm. carbon water bottle holders (must be used with Tune slightly concial bottles, but work great)

Good Luck

PK
Posts: 168
Joined: Fri Oct 04, 2002 4:45 pm
Location: UK

by PK

Thanks for the info. Talking of TISO, have you seen their new rear mech? On TISO web site under news..weighs 183g ... POSHBIKES will be selling at £190, can you see what your contact in the US will be selling them for. :wink:

HK

by HK

When you tighten the stem, the fork is locked in the right position.
Why can't these parts be removed to save weight for free??? :idea: :?:
Just glue the cap on?

stuka666
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Location: portugal

by stuka666

Use heavy expander, remove heavy expander, no need for a top cap or if you don't like the hole in there, just put some foam to prevent mud.

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corky
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by corky

stuka666 wrote:Use heavy expander, remove heavy expander, no need for a top cap or if you don't like the hole in there, just put some foam to prevent mud.


Should stem/headset work their way loose during the ride, no way to tighten up....unless you carry one with you, which defeats the object
+ a top cap keeps everything locked down + an expander can strengthen/firm up a steerer that maybe needs a little help from being crushed by a stem........

But the choice is yours......obviously

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madcow
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by madcow

I know this is an old thread but since it's been revived it seems like a good chance to mention some of the lightest current options.

Carbon-Ti, 13.6 grams
Mcfk, 11.4 grams
Tune Gum Gum, 8.9 grams
Extralite, 5.9 grams
EE Cycleworks, 5.2 grams

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rmerka
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by rmerka

EE Cycleworks makes an expander?

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madcow
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by madcow

Oops, I guess I shouldn't have mentioned that just yet. The top cap and bolt has been released but the expander not yet. I've had a couple different prototypes of them and the latest works quite well. I thought they were released at the same time as the top caps, but turns out they weren't. Shouldn't be too much longer though.

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Calnago
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by Calnago

HK wrote:When you tighten the stem, the fork is locked in the right position.
Why can't these parts be removed to save weight for free??? :idea: :?:
Just glue the cap on?

It depends on a couple of things, one being the strength of the steer tube and how much it might "give". The clamping force of the stem works with the expanding force of the "expander", sandwiching the steertube in between. I wouldn't even think of not using a good expander in a carbon steertube. Try this, tighten the expander quite a bit, while the stem is not on the steertube. Then try to put the stem on... can you even get it over the expanded area of the tube? Sometimes you can't, indicating how easy it is to expand the steer tube or conversely, crush it. Well, same thing in reverse... if there's no expander in there, the stem can come loose and work it's way up so much easier since there is nothing on the inside pushing it against the stem. The top cap is just there to provide initial preload until the stem gets tightened down. Once the stem and expander are both tight, it does nothing. It only provides a preload prior to torqueing the stem in the right spot.
So it's very dependent on the design of the steertube... was it intended to used without an expander, like an alloy steer tube, where just a startnut is used to provide an anchor for the top cap bolt and provide preload, or is it a light carbon steertube where the expander serves the dual purpose of preload AND reinforcement. Come to your own conclusion on your specific bike, but don't lightly dismiss what the original manufacturer has supplied.
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rmerka
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by rmerka

madcow wrote:Oops, I guess I shouldn't have mentioned that just yet. The top cap and bolt has been released but the expander not yet. I've had a couple different prototypes of them and the latest works quite well. I thought they were released at the same time as the top caps, but turns out they weren't. Shouldn't be too much longer though.


:) I won't say anything but I'll keep my eyes peeled for it!

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sugarkane
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by sugarkane

I'm running one of Craig's EE expander and it's pretty darn good! Trouble free insterlation and unlike the new extralite expanders ( just getting too light :cry: ) there has been zero issues with it not holding nice and tight. Will be available in 6-8 weeks I'm told and no I won't post a better picture :mrgreen:

https://instagram.com/p/BAG3hXIHL-F/

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mythical
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by mythical

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by Weenie


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