"BarryNL" wrote:
So the factory pin is possibly the problem. Then,
to expand my story slightly, I actually bought two of these bikes (for me
and the wife) and its actually her chain that broke. Should I be thinking
about replacing the factory joining pin on my bike as well with one of the
two stage pins? I have noticed that on my bike the pin sticks out slightly
further on one side and is virtually flush with the plate on the other.

Arthur Harris wrote:
Shimano make a special pin for joining the chain.
http://tinyurl.com/ba999

You're not supposed to reuse the regular pins (like we used to do before 8
and 9 speed chains came along). The fact that one side protrudes further out
is proof that it wasn't installed right.

I would be a good ide to replace the joining pin on your bike. But make sure
the side plate wasn't damaged when the chain was initially joined. I'd go
back to the LBS and have them inspect and make right at no cost to you.

Art's right that your uneven rivet is unsafe. I'd add a
snaplink rather than use a Shimano pin, especially where
side plate damage is likely.

--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971