Sydwaiz

Decided to dust off my bike today and go for a ride. It's been a few months and I'm feeling the affects of sitting on my butt too much at home! Anyway, the chain is a Shimano HG73 off my Trek 2200. I've only got a few hundred miles on the drivetrain. I was in the middle chain ring in front and 23 in the back at a stop light. When I tried to start off, it just popped on the intial downstroke! The rivet is still there but the link just exploded on both sides! It's like the rivet pulled straight through the link. This chain isn't stretched or worn at all and was well lubed.

Was is just a crappy chain to begin with or what? I'm only 150lbs so I don't think I could put that much pressure on it especially in that gear. Can I just remove the broken link and put it back together with no problems or should I get a new, better chain? Thanks.

same time

Shimano chains have a special pin that should be used for assembly - it is longer than the others, and you put the chain together with it, then snap off the extra bit.

All of the failed Shimano chains I have seen (on road bikes) broke because that special pin was not put in correctly, or the chain was disassembled and reassembled using a normal pin, and one side plate ends up bowed out a little. When you put pressure on the chain (start pedaling), the link explodes apart like you describe.

I like to use SRAM chains because there are no special pins, and you don't have to use the special connector link if you don't want. Any old chain tool works fine, on any link, and I've never had one fail. That's my experience, but lots of people use Shimano chains with no problems, too.

mechBgon

Another vote for SRAM chains. Now would be a good time to switch, while the drivetrain is still fresh.

bccycleguy

Sometimes when you buy a chain (which is probably cut from a bulk length), the old connecting pin at the break is still in place on 1/2 of the link. It's probably tempting for some people, including some at an LBS, to just push that pin back in place, rather than use one of Shimano's $1.00+ pins.

I also endorse the SRAM chains and look forward to them coming out with a 10-speed version. In the meantime you can use a SRAM connector gold link with a Shimano 9-speed chain.

Sydwaiz

For what it's worth, it didn't break at the special pin. It was one of the factory installed rivets where it broke. I guess I'm in better shape than I thought! Gonna pick up a new chain tonight, probably go with the SRAM like you guys recommended. Thanks!

LóFarkas

Scary.

krazyderek

sounds like it was rusted out, and if you were cross chaining a little bit up to the big cog on the back that's probably all the leverage it took to break the chain first hard pedal stroke you took.

mechBgon

He says his bike's almost new, so hopefully it's not rusted out. For the record, I cross-chain like a fiend with my SRAM chains, big-to-big combo for stoplight launches, and even with a winter's worth of wear & abuse behind them, they don't blow plates off the rivets. Ok, I guess I did blow one about a year ago but they're pretty good chains.

Ironically, back when I was trying to humor Shimano and use their stupid chains, I had them break more at the special pins than anywhere else! Forget it, PowerLink > Crazy Pin.

Ny Cykel

Know what else too, both my bikes got SRAM, got the sticker on my hard hat, seem like a good product, never tried anything else.
Before I wasn't 248lbs anymore I used to make the back wheel pull out of its place on hills, and have abused the heck out of these chains,

Thanks you all for writing here, I will stick with SRAM.

oilman_15106

At least you didn't get trashed like I did over posting about breaking a chain.

Al f R

Another person who can't follow simple instructions

krazyderek

Well i was thinking it might have rusted out sed link pin since the bike was sitting doing nothing for a couple months. I know i start to see rust the next day after a rainny day ride, so if there was a little moisture where the bike was stored or just that link in particular was a little dry on lube when stored then it could weeken/corrode the tiny little rivet on the pin.
Anyways, plenty of 9spd chains out there, so best of luck with something else