Rim Failure

See other failures under 000.html.

From http://www.flickr.com/photos/brianwickman/314546026/in/set-72157594493374262 and http://www.flickr.com/photos/brianwickman/314546027/in/set-72157594493374262 as of 2007/09/26

Rim is of aluminum. Nipple bed failures occur for several resons including low bed strength (e.g., too thin a bed) high spoke tension, poor bed fatigue (e.g., stress risers), high working of the bed (e.g., low spoke count compared to rim stiffness), stress corrosion cracking (e.g., initiated by hard anodizing), and manufacturing defects.

According to http://www.spinergy.com/Bicycle/xaeroLite.html and http://www.spinergy.com/Bicycle/xaeroLite_specs.html as of 2007/09/26, the wheel uses 24 spokes, laced 2-cross to a rim of 24mm section. The rim weight is not listed.

According to http://www.spinergy.com/Bicycle/tech_specialFeature_PBO.html as of 2007/09/26, the spokes are made of "PBO" or polyphenylene bensobisoxazole, over 30,000 strands per spoke; and have three times the strength of stainless steel at half the weight. The stiffness of PBO is not listed. The manual at http://www.spinergy.com/Bicycle/pdfs/Manual%20Xaero%20Xyclone.pdf as of 2007/09/26 lists tension in terms of defelctions on a Park TM-1 tension meter, not in absolute tension.

Accompanying text says

marius "thor hushovd" eriksen breaks yet another wheel. this is the first time spinergy has seen such a rim failure, and they are promptly sending a replacement.

a comment says

[they have seen it before] When i worked in a shop, i saw that, two or three times.