Paying the price of procrastination

AlanW

Maximum Pace
Jan 30, 2007
1,214
436
103
Tokyo
#1
This may be familiar to a couple of you....
Recently I've changed the chains on both my road bike and my MTB. The road bike, with about 5000 km on it, took the new chain no problem, and the drivetrain is silky-smooth.
The problems came with my mountainbike. The chainrings were obviously worn after a couple of years being hammered around various courses, even in mostly dry conditions, so I replaced them along with the chain. But one sprocket on the cassette (the smallest of the four titanium cogs) was also too worn to take the new chain and would slip as soon as I put power on the pedals. Of course it is impossible to buy a single sprocket as they are riveted onto the carrier. So, one large bill and a week of waiting later (bizarrely, the XTR cassette is cheaper in the UK than here) and I got my bike running properly again.

I've learned my lesson the hard way and will be keeping a watchful eye on my chain wear from now on with one of these:

proxy.php?image=http%3A%2F%2Fwww.cyclestore.co.uk%2Fimages%2Fproducts%2FXtra%2F14691.jpg&hash=faa1b478814f743891eb6b7da648c362
 

kiwisimon

Maximum Pace
Dec 14, 2006
2,681
494
103
Japan
#3
makes sense. sprockets have less teeth so they will wear faster than chainrings. a 12 tooth sprocket has 4 times more contact with the chain than a 48 tooth chainring. Chainwear indicators are a good idea but you will still need to replace your rear cassette about twice as often as your chainrings, just not so often.
 
#4
so, instead of buying a "chain cleaner" thing, I should first get the "is your chain stretched?" thing and see if it's worth cleaning? I put 3000km on it this year and it's five years old (though had only been used sporadically for the middle 3 years or so...)

I'm not a racer or into the fanciest lightest stuff... but I do want my bike (Bianchi Brava) to work well and last a long time. How do I know when to change the chain? Is the "is your chain stretched?" thing the right indicator for me?

I know upgrading can be a slippery slope and I'm a bit scared....
 

Phil

Maximum Pace
#6
so, instead of buying a "chain cleaner" thing, I should first get the "is your chain stretched?" thing and see if it's worth cleaning? I put 3000km on it this year and it's five years old (though had only been used sporadically for the middle 3 years or so...)
With chains, you have two choices.

1. Leave it on the bike and ignore it until it starts slipping on the rear cogs. At this point, you have to replace the chain AND the sprockets (20,000 km? 30,000 km?)

2. Regularly check for chain stretch, either with an imperial ruler or a tool like the one AlanW posted above, and when it is worn a certain amount (1/16" inch or whatever the checker tool says) replace the chain, and only the chain (5,000 km to 15,000 km?). The sprockets should still be good with the new chain (of course, they still wear, but at a much slower rate).

With method #2 you change chains more often but your sprockets last longer, and this is more economical in the long run.

In either case, cleaning your chain regularly will help it and the sprockets last longer.

As always, the Sheldon Brown legacy is a good place to read up on this stuff:

http://www.sheldonbrown.com/chains.html
 

jdd

Maximum Pace
Hardest Crash
Jul 26, 2008
2,517
644
133
Kanazawa
#12
another way

Here's how I check for wear now and then. This is a simple way to eyeball wear/stretch.

Put the chain in the biggest chainring. Naturally, it's engaged from top, around the front, to the bottom of that ring. Use two fingers to grab a link of chain at the front of the ring (3 o'clock position) and check how easily/far you can pull it away from the ring. If you know how a new or relatively new chain feels when doing this, it's pretty easy to ID one that has a few thousand km on it.

Still, I'm in the regular replacement camp, and mostly get a new one every year or so.
 
#13
Phil GOOD points. Either NEVER change your chain or do it often. You can guess what your bike shop is going to say about that.
I recently had the chain skip blues on Tom R. Turns out it was from transporting a big freaking heavy box on my handlebars that clicked my changer adjustment barrel a bit. I just thought which way it would have gone and dialed it back in.
I also once rode a Pugeot that had such a whippy frame each time I put some power down shifted gears. TODO


With chains, you have two choices.

1. Leave it on the bike and ignore it until it starts slipping on the rear cogs. At this point, you have to replace the chain AND the sprockets (20,000 km? 30,000 km?)

2. Regularly check for chain stretch, either with an imperial ruler or a tool like the one AlanW posted above, and when it is worn a certain amount (1/16" inch or whatever the checker tool says) replace the chain, and only the chain (5,000 km to 15,000 km?). The sprockets should still be good with the new chain (of course, they still wear, but at a much slower rate).

With method #2 you change chains more often but your sprockets last longer, and this is more economical in the long run.

In either case, cleaning your chain regularly will help it and the sprockets last longer.

As always, the Sheldon Brown legacy is a good place to read up on this stuff:

http://www.sheldonbrown.com/chains.html