Bicycle Mechanics - Request thoughts on compressor top caps vs. cap & star nut

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rideon7
12-27-07, 10:01 AM
I would like information or informed opinions about use of something like the FSA compressor top cap (see links below) vs. the traditional top cap and star nut.
Standard:
http://www.jensonusa.com/store/product/HS408Z19-Fsa+Compressor+Top+Cap.aspx
Carbon fiber:
http://www.jensonusa.com/store/product/HS408Z20-Fsa+Carbon+Pro+Compressor+Top+Cap.aspx
Thoughts on function vs. the traditional set-up? Advantages/disadvantages? No effective difference?
I am asking because I just bought a new frameset and while a headset was included, the top cap and bolt were not so must buy one and am deciding which to buy. The frameset has a carbon fiber fork.
Ex Pres
12-27-07, 10:04 AM
If your carbon fork has a carbon steerer you must use a compression cap. Star nut = possible failure.
roadfix
12-27-07, 10:06 AM
You must use the compressor cap if your fork steerer tube is carbon.
Soil_Sampler
12-27-07, 10:48 AM
Cannondale and another company I can't remember are the only carbon steerers that can use a star nut.
http://www.cannondale.com/asset/iu_files/techcenter/2006_carbon_road_fork_starnut_stem_headset_technote_en.pdf
Use an expander, and you can use any topcap you want.
http://www.universalcycles.com/shopping/product_details.php?id=17005&category=1695
http://www.universalcycles.com/images/products/medium/17005.jpg
HillRider
12-27-07, 11:18 AM
For a steel or Al steerer, a starnut and bolt are lighter and cheaper. For almost all carbon steerers, a starnut is absolutely not to be used and a compression plug is essential.
The construction of the Cannondale forks and topcap that allow a starnut to be used in a carbon steerer is not the norm and their topcap is a special design with a reinforcing sleeve. They even specify NOT to use a spacer above the stem due to this design. Most other carbon steerer benefit from a small spacer above the stem so Cannondale has a very different set-up. You can't follow their recommendations with any other fork.
capwater
12-27-07, 11:31 AM
And the starnut used on the C'dale Slice fork is proprietary for that application, not just a regular one as in an alloy steerer.
rideon7
12-27-07, 03:21 PM
Thanks to all who answered my question about compression top caps vs. top cap and star nut. You saved me MUCH aggravation. Also, thanks to Soil Sampler for the link, although product is currently back-ordered by seller but looks good.
Thanks Again!
Bob Dopolina
12-27-07, 04:33 PM
Thanks to all who answered my question about compression top caps vs. top cap and star nut. You saved me MUCH aggravation. Also, thanks to Soil Sampler for the link, although product is currently back-ordered by seller but looks good.
Thanks Again!
I believe DEDA uses the exact same compression cap (don't know who actually makes it). Try searching for it under the DEDA brand and maybe some other on line retailer will have one in stock.
I just used the sample that I had on my desk for the last 3 months and it worked like a charm.
Ex Pres
12-27-07, 06:06 PM
I bought a compression set-up from Nashbar for <$8 on sale earlier this year for my new all carbon fork and it worked just fine. Don't know if they still have 'em.
Soil_Sampler
12-27-07, 07:16 PM
I believe DEDA uses the exact same compression cap (don't know who actually makes it). Try searching for it under the DEDA brand and maybe some other on line retailer will have one in stock.
I just used the sample that I had on my desk for the last 3 months and it worked like a charm.
Deda is different, but equally as good. http://www.bikeparts.com/search_results.asp?ID=BPC121257
http://www.bikeparts.com/pimage/BPC121257.jpg
OP:you can find the Cinelli, if you look around.
http://www.speedgoat.com/product.asp?part=129286&cat=160&brand=51
HillRider
12-27-07, 08:16 PM
Here is a link to Bike Tools Etc's listing of steerer compressors.
http://www.biketoolsetc.com/index.cgi?id=92531081272&c=Repair-Parts&sc=Headset&tc=Compressor-Plug
Bob Dopolina
12-27-07, 08:36 PM
Deda is different, but equally as good. http://www.bikeparts.com/search_results.asp?ID=BPC121257
OP:you can find the Cinelli, if you look around.
http://www.speedgoat.com/product.asp?part=129286&cat=160&brand=51
That one works well,too. The one I have we got it with our sample order so maybe I have the '08 or '09 version. It is exactly the same as the picture posted above.
I just checked the Deda website and the one I have isn't shown. Opps.
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