Bicycle Mechanics - Chain wear

I was out for a cruise today in the bad weather, and I noticed sometimes that when I coasted and then pedaled, the chain would go CLUNK like it had slipped off the cog or something and was re engaging........ I checked my computer and it's done nearly 5,000km and its a SORA chain that came on the bike. HG 51 perhaps?

I took the tape measure to the chain, and measured 1ft. I found that the pin that should be in-line with the 1ft line was nearly 1/8th of an inch past it. I need to replace the chain huh?

Brendon
:beer:

The chain and possibly a few other things. I'd be having a closer look at your cogs too.

oh well lube it up and ask the guys in the bunch ride in the morning what they think.

Brendon

1/8th of an inch wear is enough to warrant replacing the chain. As stated before, you should also check cog wear before you replace just to be sure the cassette isn't severely worn as well.

Chuck

I thought that was the case - was just checking. I'm not riding the bike until I can get a new chain on, and I will check for tooth wear, and then see how shifting etc behaves with the new chain.

Any ideas as to the life of a SORA 8spd cassette?

Thanks guys,

Brendon

I'm probably not a good recommendation here, but my Merida roadbike is more often my commuter. It's just ticked over 9,500km on the same chain, cogs and chainrings (Sora ders) in 20 months of riding.

I knew the rear cogs were on the way out ages ago, but I figured that the chain and gears were all wearing together, and I would just keep riding until something gives (chain slip on the cogs, broken chain, chainsuck on the rings, really bad shifting). I'm figuring 15,000km and I will probably renew everything, anyway. The chain has been cleaned five times, washed out by wet weather about 10 times, and relubed in each case with Castrol GTX motor oil. The chain bends laterally by a LOT (lol). By the way, I have downtube shifters with SIS on the rear and friction on the front. I probably wouldn't have been able to go this far with STI shifters, though.

I'll report back on the final outcome and replacement costs when the time comes.

As a general observation, 12-1/8" is the limit for a chain to wear and you may just get away with putting a new one on without replacing cogs. If you had caught it at 12-1/16" you would have done better. You will know soon enough if you have to replace the rear cogs if the new chain slips on any of the gears, or won't shift properly.

There is a tool for testing if the rear cogs are too worn, but if you have a chainwhip, you can do just as well. Wrap the loose end of the whip around a cog. Apply pressure to the handle so the leading end of the chainwhip is snug in the teeth. Then move the tail of the chain whip in and out of the teeth -- I think three or four half-links must remain engaged with the teeth. If the chain links move smooth in and out of the teeth, you're Ok. If the links catch, the cog is beyond redemption. Move on to the next cog and do the same thing.

Depending on how much time you spend riding in various cogs, you may find more wear on one or two than others.

FWIW

R

I have STI changers, and I ride HARD quite often as I am competitive. I have been getting a little bit of chain suck when changing down on the front DR. I would upgrade to 105 and get a new bike with full 105 if i could afford it. but $$ is an issue! I'm getting a new chain tomorrow so it should all be good, and the teeth on 4th/5th look fine and they are the ones I use most. I shall see!

Brendon