jodyonekenobi
Member since May 2020 • Last active Sep 2023- 0 conversations
- 13 comments
Most recent activity
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aaand the other one:
Dad's Audax. Columbus Nivacrom; Veloce on Open Pros; Campag Veloce, Mirage mix, including mostly worn out right shifter; Sugino something cranks; my ancient M737 SPD's, boat-anchors but I love them; an equally ancient Rolls. Fun to ride on squidgy tyres, they're Rivendell somethings.
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Slightly better pics of my Roberts from an earlier post, on a nice ride today.
It's made from Columbus EL OS; Record hubs on Open Pros (re-rimmed once so far); mostly 2004-ish Campag Centaur/Record; Chorus Ti seatpost, Arione saddle; Thomson stem, Cinelli 64 bars.
@mattyc- that was a hell of a find. Looks great. Hope you love it.
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Sadly, I think the manufacturers themselves- at least their public facing departments- don't understand the causes of these failures either, and thus their blame of the operator is not generally dishonest (though still wrong!).
There used to be a rich collection of similar failures, with insightful commentary, here:
http://pardo.net/bike/pic/fail-012/000.html
It seems to have lost a few pages though. Still, an interesting read.
Edit- ah, here you go:
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I’m finding this Rivendell/Panaracer 33mm slick is lovely to ride in 700c form- here it is in 650b for £15 each:
https://www.planetx.co.uk/i/q/TYPAMF/maxy-fasty-folding-tyre
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Nearly all these pictures show fatigue failures. They had to have occurred over some time, and will have begun with a crack, invariably at a stress raiser - some sharp point in the crank, or a casting/forging error.
Looking at the broken surfaces, you can see where the face is dirty, is where the crack has been developing over weeks/months/years. The two halves fit back together neatly, also. The bright surface is a ductile failure, and shows how little material the component was still hanging on by. It’s surprising the story that these things tell.
The cause of these failures is virtually never rider error, or overload. If you tried to overload a new crank to destruction- by clamping it in a large vise and levering it with a breaker bar, say - it would bend, rather than crack. This persistent line from manufacturers that ‘you did something wrong’ is erroneous and unfair.
This junk gets "invented" every few years. The Alenax was the most well-known, but I bet Kickstarter has a few variations in the graveyard.
https://www.sheldonbrown.com/brandt/alenax.html