You are reading a single comment by @Pasty_Spumante and its replies.
Click here to read the full conversation.
London Fixed Gear and Single-Speed is a community of predominantly fixed gear and single-speed cyclists in and around London, UK.
This site is supported almost exclusively by donations. Please consider donating a small amount regularly.
Pasty_Spumante
For all the chat about whether your teeth should be that shape, it's actually the bending it back into shape which is the real issue. Chainrings, like most aluminium alloy bicycle parts, are made from precipitation hardened alloys. The price you pay for high yield strength is very poor ductility. When you try to apply large cold deformations, you usually are not flowing the alloy as you might in a highly ductile metal, you're just moving the cracks around. Material which has suffered this kind of abuse is seriously weakened, and is likely to fail catastrophically under peak loading conditions, which is exactly the moment when it can do the most damage to the rider.
As a general rule, any component made from one of these alloys (which is basically all the ones used for bicycle parts) which has been bent far enough to stop functioning as designed should be binned immediately, because bending it back into shape just makes the crash you have when it breaks worse than the one you had to bend it.