Climbing and a new chain

Carrera said:

I just fitted a new chain but a mechanic advised me I may have left it a touch late. He says I have one or two slightly worn teeth on my cassette. I decided to take the risk.

Today I was climbing a big hill and unfortunately the chain slipped halfway up and ruined my concentration. The jolt sort of put my gears on tick-over and I feared a massive slip the rest of the way up. It nearly screwed my climb.
I've taken a bit of a risk and haven't had major chain-slipping problems since I fitted it. But certainly the cassette has noticed the newness of the chain and I'm getting minor slips when I work the chainring hard. It's just occasional.
Do you think I should give up the idea and put my old chain back on? Or is it probable my new chain will settle after a bit more use?

Best suited for the mechanics forum but I'll answer.

If you put the old chain back on you risk wearing the front chainrings just as you've worn the cassette and that gets expensive. At this point you're going to most likely need a new cassette with as much climbing as you do. Another option is to replace only the cogs that are worn but you'd have to be a little more drivetrain savy to pull that one off. 😉

If you didn't do the hard climbs your chain probably wouldn't be skipping and you could squeak by with the current cassette. The only downside to that is it will wear a new chain a little faster. However, if you weren't climbing you would be in a different gear/cog in the rear so you may not even use the worn cog much and thus wouldn't need to replace the cassette.

To avoid this in the future I recommend you get a chain checking tool such as the Park CC-3 tool. It's an easy go/no go tool to check chain wear/stretch. When it hits 0.75% you know to be making plans for a replacement. At 1.0% replace it no questions asked because you are now at the border of being out of spec and it's not worth it to try and squeeze a few extra miles out of an inexpensive chain.

http://www.nashbar.com/profile.cfm?category=99&subcategory=1234&brand=&sku=11164&storetype=&estoreid=&pagename=

Hope this helps, Carrera. 😄

Thanks for the imput. It seems to me my best bet is to hope the new chain will wear down to accommodate those slightly worn sprockets. It doesn't seem to be a serious misfit but I confess I wouldn't feel comfortable climbing a steep hill at this stage. I figure I should try and do as much cycling as I can on lesser hills and flats so the chain hopefully wears into my cassette. If you recall, I only fitted my new cassette a short time ago (you'll remember perhaps I raised a theme on the fitting of the cassette) so I'm loathe to buy yet another one.
Of course, I saved the old chain in case the jumping does become too much of a problem.
I'm not sure whether my fitting a new chain at this stage will protect my sprockets from excessive ware or whether I'd have been better off just letting the old chain and cassette ware out together and replace the lot.
Time will tell.

Doctor Morbius said:

Best suited for the mechanics forum but I'll answer.

If you put the old chain back on you risk wearing the front chainrings just as you've worn the cassette and that gets expensive. At this point you're going to most likely need a new cassette with as much climbing as you do. Another option is to replace only the cogs that are worn but you'd have to be a little more drivetrain savy to pull that one off. 😉

If you didn't do the hard climbs your chain probably wouldn't be skipping and you could squeak by with the current cassette. The only downside to that is it will wear a new chain a little faster. However, if you weren't climbing you would be in a different gear/cog in the rear so you may not even use the worn cog much and thus wouldn't need to replace the cassette.

To avoid this in the future I recommend you get a chain checking tool such as the Park CC-3 tool. It's an easy go/no go tool to check chain wear/stretch. When it hits 0.75% you know to be making plans for a replacement. At 1.0% replace it no questions asked because you are now at the border of being out of spec and it's not worth it to try and squeeze a few extra miles out of an inexpensive chain.

http://www.nashbar.com/profile.cfm?category=99&subcategory=1234&brand=&sku=11164&storetype=&estoreid=&pagename=

Hope this helps, Carrera. 😄

Carrera said:

Thanks for the imput. It seems to me my best bet is to hope the new chain will wear down to accommodate those slightly worn sprockets.

But it won't. The sprockets are going to keep wearing down. Even if the chain does "wear in" to the cassette, you're right back where you were before you shelled out good money for a new chain. You'll save yourself a lot of headaches by just replacing the worn sprockets.

I still recommend getting a chain checking tool. It's well worth a few bucks to keep from damaging a drive train. As long as you replace your chain when it goes out of spec (or slightly before as I do) you'll get considerably more mileage out of a cassette.

Even though I have five 105 12/23, two HG-50 11/25 and two HG-50 11/32 cassettes in my stash out in the garage, there's no reason to replace one before it's necessary. 😉 I stocked up on parts when I can get them super cheap.

I have to go with the good doctor, I have this debate with myself once before, it really is better to go ahead and buy the new cassettte. chains don't wear in, they simply wear out, just consider this cassette a learning curve and try something new. Gear jumping will also occur during stiff acceleration, and if you need to get out of a situation, you really need to know that the bike is reliable and will get you out of it.

As things stand, I may have gotten away with it. I was out riding and climbing yesterday and suffered no jumps. There is only one sprocket that does jump every once in a while (but not frequently). Maybe as I ride more, the jumping on that same sprocket will cease (maybe after 6 weeks or so).
I was just slightly late changing my chain and have suffered a little ware on a couple of sprockets.
The jumping sprocket is the second largest on my cassette and penultimate. Is this easy to replace and how do you buy single sprockets?

Carrera said:

.....how do you buy single sprockets?

In the USA,

For Shimano:

http://sheldonbrown.com/harris/k7.html#sprockets

For Campy:

http://www.branfordbike.com/cassette/cog.html

There are probably other suppliers and a good local shop can order for you.

John M said:

There are probably other suppliers and a good local shop can order for you.

QBP carries loose sprockets for both Campy and Shimano. Any LBS should be able to order them.