Jonahhobbes

Recently took my cross bike in to the LBS to have some work done and asked the mechanic to give the bike a full service. I reckoned the groupset still had about 6 months life in it before it needed a full replacement. The mechanic spoke to my wife about the work that needed doing and said exactly the same thing, he said it had 6 months life left in it and he knows I do a fair bit of cycling. When I got the bike back after about 40km I noticed the chain was being thrown on the inside of the chainrings when I moved into granny gears on a hill, (It's a double chainset).. No biggy I thought I'd adjust the the front Derailleur when I got home about 5kms away. Then on the hill the chain snapped.

Should I be aggrieved that after riding it for 40km after a full service the chain snaps? I'm obviously going to have to replace everything. Should I be pissed at the bike shop?

Marcus_Ti

Cross bike...how much are you used to shifting under load? I've done it and in retaliation I've snapped a chain or two myself.

Dropping a chain...bit hinky....but at the end of it--a chain is $20USD. Unless it was damaging the frame in the process-not something to squawk much about-for me.

AnkleWork

Why did it snap?

Kontact 

And did the mechanic remove the chain for service. Did it snap where he reconnected it or elsewhere? If where he did something to it, it doesn't involve the mechanic.


I've never heard of wearing out a groupset.

Andrew R Stewart 

The vast majority of broken chains I see are from rough shifting at some prior time. The challenge is that a chain can have a compromised pin in side plate fit and still work well enough to not notice that one of the over 200 fits is questionable until that one give out.

So as asked, how did the chain break? Did the side plate pull off the pin (the usual) or did the side plate crack (also happens but rather uncommon). Did it break when shifting or when JRA? Andy

ksryder

False.

Jonahhobbes

Side plate on a link is bent where it snapped. The bike is a Salsa La Cruz and is my main commute, it has panniers but nothing to much and I was on the hill near home so it snapped under pressure. The hill is pretty steep and bends.

So do you guys think he took the chain off and then reconnected it badly?

I can't talk to him until after the weekend. I'm not a bike mechanic, (hence the reason I'm here),

I just don't want to part with $40 - $50 NZ Dollars for a chain if the whole thing is going to need replacing anyhow and I'ts winter here already. The weather is bad and I can't be doing get stuck in the middle of nowhere trying to get to work for a night shift. I need a reliable bike.

Kontact 

The relevant information would be the brand and speed of the chain, whether it has a quicklink anywhere or whether the link pin that failed looks different than the other link pins, indicating a special Shimano replacement pin. Being able to find either of those would tell you if it is likely that your mechanic took the chain off and goofed up putting it back on.

If you'd like to keep using this chain, and SRAM or KMC quicklink could replace the broken one.

Jonahhobbes

I hadn't thought of that. Thank you.

AnkleWork

I don't think so but how could I possibly know? If you would relieve the vacuum of information, you might get better guesses for your questions.

Jonahhobbes

Sorry I forgot my electron microscope which I normally carry on my commute to identify my bike chain stress fractures.

I'm not asking for a fix I just asking for opinions on what to say to the bike mechanic.

AnkleWork

Not enough information to either answer your questions or offer a (possible) fix. So far there's no basis for you to say anything to the mechanic but "please fix this." Considering your posts, one wonders whether you are capable of saying that.

Jonahhobbes

So what information are you looking for?

I said I'm not a bike mechanic. I came here for advice.

This used to be a much more friendly place.

Kontact 

Anklework is usually unpleasant, but it doesn't take an electron microscope to say how many speeds you have and whether you have a quicklink.

Jonahhobbes

thank you - will get back I'm cooking at the mo. I'm not mech so I'll have to have a look at it. Chilli comes first though.

ksryder

Bicycle mechanics seem daunting at first, or they did to me at least, but when it comes down to it bikes are relatively simple machines.

Fix the chain with a quick link, or replace it. There's no risk if you replace it. If it turns out something else needs replaced too like the cassette or a chainring, you still have a brand new, usable chain. If shifting is clunky then you'll probably need to look at the cassette.

Groupsets themselves -shifters and derailleurs-don't really wear out... At least, they should be good for years. My educated guess is that your group is fine.

Andrew R Stewart 

As we spin off tangent...

Groups do wear out. They are made up of parts (ders, calipers, hubs...) that all can and do wear out.

But the different parts that make up a group usually don't wear at the same rate and what that wear means to function also isn't directly comparable between the various parts in a group. Case in point is the Terry TI road bike of about 23 years old in my basement. It's likely seen over 40,000 miles and some of the Campy group is what I would call past worn out. The BB, rings, hubs, ders all are past sloppy. The calipers are fine if battle scared, and the Ergo levers are rebuildable (and have been done before). The rider has wanted lower gearing then Campy supports on this old spec (8-speed/pointy hoods) so is considering switching to Shimano. Andy

Siu Blue Wind

This rudeness wasn't necessary...
Please leave this thread.

AnkleWork

You must not have read the OP's post and quote before the moderator edited them.

Kimmo 

That's still not clear - has a pin pulled out of the side plate, or has the plate opposite the bent one broken in half?

If the former, and if you examine the pin, you may be able to see it looks different from the other pins. If it's identical to the other pins, it was a relatively freakish failure (like a broken side plate) that isn't really anyone's fault except maybe the rider's, for giving the chain too much of a hard time while shifting. If it's the special joining pin that has let go, that suggests the chain probably wasn't joined very well, either in the first instance or upon refitting (if the chain has been refitted, there should be more than one special pin - you shouldn't use the original spot, IIRC).

Jonahhobbes

Pin came out of the side plate. The Mechanic is going to replace the link and it's free of charge. He didn't recommend putting a new chain on. Thanks all.

Koyote

I suggest that you take it back to the shop, tell the mechanic what happened, and see what she or he says. If the answer is, "That's weird, I didn't touch the chain," then leave it at that. Sometimes stuff just breaks.

I'm curious about why the groupset would be worn out. Sure, you might need a new cassette, and obviously a new chain. But if shifters or derailleurs were broken, you would know it now. How can you predict that something will fail in six months?