How much is a chain strength weakened by removing and reinstalling a connecting pin?

I bought a new chain, and became tired of trying to get the SRAM powerlink to lock in place. Removed it and used extra plates and pin (from shortening the chain) to reconnect it via a chain tool.

Bad idea? Ok?

Thanks.

The general consensus 'round here is that's its a bad idea. New chains are assembled with a peaned head on the rivet rather than the old flush fit. Pushing the pin out removes the pean and thereby weakens the link. You should use the master link that you gave up on.

That said.

Before I knew about the above consensus. I lengthened a 9spd SRAM chain and used my old shop grade Park chain tool. That chain has now seen about 1500 miles and has been torqued going over some of the 'hills' 'round here.

Your decision. Out of curiosity, was this on a 10 spd SRAM chain? As alien as the thought may be. Read the instructions that came with the chain. It had me stumped too. But RTFM sometimes does work.

If your bike has STI or Ergo levers, and you'll be shifting while pedaling out of the saddle, you should not use that chain.

If you can locate the compromised link and replace it with a Powerlink, all is well.

For seated riding, you might still be able to dislodge one end of the sideplate while shifting under power, so it is possible that the link could then fail completely when you were pedaling steadily out of the saddle.

Having the chain fail while standing can cause an abrupt change in the bike's direction. Very, very bad if it fails during a sprint.
It is also not uncommon for a failing chain sideplate to snag solidly on the front derailer cage.

Re-assembling a modern chain's links with the pushed-out pin or pins reduces the sideplate's retention quite drastically.

Go back and try pushing the re-installed pin back out with the chain tool and you'll immediately see what I mean here.

This is a 10 speed chain SRAM-1031, with Ultegra STI 6600 shifters, 6700 11-28 rear cogs. I squeezed the plates, etc, they wouldnt lock more than half way. Basically destroyed them getting them apart. My only choices now are to live with it or get a new Powerlink (if I can find the used pins).

No problem there. My bet is the reused pins will reveal themselves in due time.

Dont the Shimano chains come with connecting pins? How are they any different from what I have done?

The Shimano connecting pins are different from the ones that you push out of the assembled chain links. For one thing the ends are pristine because they haven't been previously peened onto a chain.

The Shimano pins have little barbed ends which go through and lock into place. Your repair depends of friction alone, which isn't really enough when there's virtually zero overhang on the end of the plate.

Whether the chain holds up or not depends on your riding and shifting habits. Modern index shift systems allow shifting under load but it causes tremendous side pressure on the outer plates, thus the peened rivets. If you don't shift under load, you don't create the side stress and aren't as dependent on the peened rivets to keep the plates from coming off the ends.

Some people splice chains and ride for thousands of miles without problems, others break the chain within a few miles. If you decide to keep riding, or can't find the repaired link, cut a square notch out of a dead credit card and carefully file it open until the outer plates can just barely pass. From time to time, run your chain through this gauge and if a plat is spread it'll snag and you'll know not to ride the chain any longer, and which bad splice needs to be cut out an replaced.

Oh, crap.

I'm a Clyde, putting heavy pressure on my chain each and every ride. I have rolled with SRAM chains for years; each and every one, until this last one, was first connected with a Powerlink (9-speed). Each and every one snapped in the first month, was chain-tooled back together -- and only the one I'm using now didn't run trouble-free for two years. (It's 6 months old.) WHERE the chains broke was random -- but never at the Powerlink. My theory is a flaw in the chain that shows up in that 'break-in' period.

Chains at Walmart, on their BSO's, get lighter use; IME, the only time there was a significant chain problem was during a recent recall, when ALL the chains on a certain model had to be replaced. I've worked with those things for over 12 years, and chains breaking is near the bottom of the trouble list.

As long as the pin is re-inserted to the correct depth, you can ride with confidence.

Think what would happen if the chain broke while you were cranking up a hill. No chain mfg or experienced mechanic would recommend riding on that chain. Just get a new one and connect it properly.

Change would to could for this to be more appropriate or accurate.

Chain breakage isn't that rare (even when closed correctly), and chains almost always break at the worst of times (when tension is fairly high), yet there are not that many injuries arising from chain breakage. There are even fewer serious injuries, though they do happen occasionally.

Breaking a chain isn't fun, and it could cause an injury, but isn't likely to. The typical chain breakage injury is cuts to the calf from the chairing or the chain whipping forward. Actually the most common chain breakage injury is to the front derailleur, as the chain whips forward snagging the cage and tearing it off the bike.

Yes FB, you are correct. In fact, I've only ever witnessed breakage of two chains and neither rider was hurt. They could have had long walks home though, if someone had not provided replaceable links. Guess I'm guilty of overstating the risk I'd still get a new chain....

OF COURSE the chain mfg would recommend a new one -- you think they're more interested in saving YOU money, or making it for themselves?

And you're wrong about experienced mechanics -- you're talking to one.

28.3%.[SUP][citation needed][/SUP]

At first I was having a hard time picturing that, but then I realised you've got all this force on the cranks that are suddenly free to turn, until a split-second later the chain hooks up the FD, and then you crank it right off the seat tube!

Ugly.

I'll say it again, if you're in the sprinting position when any sort of chain incident occurs, your bike will immediately change direction like 20-degrees, wherever you're not wanting to go, at whatever speed you're going.

You might fly into the ditch, or you might fly in front of a bus or your riding bud's, or simply hit the ground, hard.

How safe this chain really depends on how and where it's used and by who.

For a mtn bike where hard, under power shifting routinely breaks even correctly riveted chains, I'd replace it pretty automatically (unless I could find the splice)

For a road bike, it depends on where it's used and the riders style. A spinner living in a relatively flat area could probably use the chain until it's stretched with no issues. In hillier areas, the nature and steepness of the hills becomes a factor. For the long grades of Colarado, someone with a spinning style might be OK, but in the choppy terrain of Pennsylvania or Connecticut, the rider is more likely to be caught unprepared and shift under power, which will break the chain if this link happens to be coming through at the time.

So there's no one answer, it's a judgement call and depends on who, where and how, balanced against the cost of chains.

In the OPs shoes and living where I do, I say chance it for a commuter or around town bike, replace it if doing centuries in the hills, and definitely replace if planning a multi-day tour.

Same thing could be said for a puncture, but I see your point. I agree it would be safer using a Powerlink and I have ordered one.

Just for closure purposes....

I ordered a new Powerlink,and did just as the first respondent said, RTMF, and it went on in 5 seconds. Amazing what following directions and recommendations will do. :-) All is well. Thanks everyone.

I broke a chain while grinding up one of the rolling hills around here. I remember waking up in the middle of the road dazed, but basically unhurt. Some woman stopped and asked if I was OK. I told her I was fine, but as she drove away, I remember thinking I'm fine, other than not having a clue as to who I was or how I got there.

Somehow, I did remember which way was home. By the time I walked the 1½ miles to the house, most of my facilities had returned. It was after I got home and saw my broken chain that I figured out what happened. I wasn't badly hurt, but it was a very close miss.

Oh, and I had pushed a pin to connect the 9 speed chain where it broke. Lesson learned. I heard some clicking just before the accident. The chain tried to warn me, but I didn't listen.