Failure modes and the Titanium Fat Chance

This month, I’ve broken two Shimano XT cassettes (11-32, CS-M771-10-bL). The smaller cog carrier, #Y1YR98040 (18,20,22), has failed in exactly the same way both times. This is something that is very rarely seen and even rarer to see it the same way so soon for one person. This is certain to be an engineering or manufacturing issue. Shimano did a great job getting replacements out in short order. Sadly, they also contain the exact design flaw.

We can see the failed desing below on the new parts. A very thin section, not enough support for the rivet and no stress releifs. Hopefully this will be fixed soon.

Also, this past weekend, I showed a couple of my bikes at the Bicycle Fabrications framebuilder show at The Sandbox Warehouse. It was a nice little show that was more encouraging to people showing there work rather than a trade show. Here’s the Bike Radar story for the show: http://www.bikeradar.com/news/article/san-francisco-custom-builder-show-35589/

I showed the WarBird and the Gemini (Alpha).

The show came to a stop suddenly when one bike came into the room. A brand new – UNRIDDEN – 1st run 1993 Titanium Fat Chance with 1st generation Shimano XTR. Everyone was in awe of seeing a legendary bike, 20 years old, in unrestored new condition in front of them. It was very cool. Even more cool was the fact that I worked at Fat City Cycles when this bike was made and was able to describe what went into it with a group of very knowlageable framebuilders. I even sent Chris Chance a pick of the bike from the event and he was stoked.