Anybody break a chain while riding?

[Ken Robb]

I broke one on my mountain bike as I was standing to muscle up a short steep hill. I couldn't tell if it was caused by a stick by the time I picked myself, the bike and the chain off the ground.

[dddd]

Up until about ten years ago, it still seemed common for riders to break a chain and then fess up to having not used a correct pin or link to make a chain connection.

Shimano had created a new chain tool when their 10s chains first appeared at the Interbike seminars that they held. Where the previous widths of special pin had enough of a flange on their end to resist the final turn of a chain tool's handle, the 10s chain's special pin needed for the tool to come to a stop, to prevent the new special pin from pushing through the outer chain plate instead of coming to a hard stop. I have no idea how many chain failures may have been caused by use of earlier/other chain tools than the 10s one that they gave to us seminar attendees, but I myself have managed to push a couple of 10s special pins past the point of no return using older tools over the years.

Shimano now supplies even their low-end chains with connecting links, which I have found to be much superior in terms of length/pitch tolerance than the cheaper links sold by KMC. The KMC link adds a shocking ten thousandths extra length to the roller spacing at the connection point compared to the Shimano link, which is equivalent to being far off the charts of traditional chain wear measurements. I first noticed this when joining a C11 chain (so felt I had to replace it with the expensive Shimano link since I have no Campagnolo-specific chain tools). The Shimano link corrected the issue. And I've since measured/noticed the same thing when joining Shimano and SRAM 11s chains.