Touring - Chain & gear replacement

How many miles/km should we get from a chain and gears? I took my Cannondale T800 into the shop for a routine tuneup and they recommended that I replace the chain and rear cluster. I have 7000 km on the bike and have never had any problem with it. I don't like the prospect of troubles during a tour so I had them proceed with the work, and used the opportunity to get a cluster with a lower gear (34-tooth). I have since ridden it twice and have a problem now when riding on the small chain ring. The shop call it "chain-suck", a term I have never heard before. The chain does not release after it has travelled around the chain ring, and jams. They say the gchain and old ring wore at the same rate and therefore had no problem, but the new chain and old chain ring don't quite mesh properly. The solution is a new chain ring for another $100 - $150.

I trust my bike shop, though I think they are a bit conservative. I rode my old 10-speed for 25 years without ever replacing the chain or gears. Are today's 27-speeds made to finer tolerances that require more frequent replacement? How many miles should we expect to get?

If it was a road bike I think I would wait until there was a problem before replacing, but I don't like to take chances with a touring bike. Thinking of buying a road bike for Sunday rides and saving the touring bike for touring.

I also had a 27 gear T800 and had the problem from new. I rode this bike across America and constantly had chain suck I installed an anti chain suck device on the frame which kicks the chain back on the granny gear. Watch your shifting. Do the shift slowly and do it early. Problem went away
With a 27 gear the tolerances are very tight. If I had to do it again I would change the 27 speed to a 24 gear. With a 11-32 rear and 24 granny on the front , you can conquer almost any hill.
You might want to type "chain suck" into a search engine. There are many web sites that deal with this problem

100 -150$ chainring? Unobtainium? Chainrings are 'a buck a tooth' average retail.
I must be missing something?

http://www.bikeforums.net/showthread.php?t=97623 Is a post I did recently, it may have some relevent info....or not.
I have a new chainring, but to replace the chain, I have to do the cluster as well.

Chain and cassette have to be replaced once in a while (and at the same time)... speed shifting is not as smooth after a few thousand km...

Chain and cassette have to be replaced once in a while (and at the same time)... speed shifting is not as smooth after a few thousand km...

I'm under the impession that if you change chains regularly, you can do several on the same cogset.
Wear it, and your stuck with riding it out or replacing both..and maybe the rings too.

100 -150$ chainring? Unobtainium? Chainrings are 'a buck a tooth' average retail.
I must be missing something?

Good point! I said they were honest, not cheap. They said about $50 per chainring, but talked me into replacing the crank (unit price comes down & labour is less). Perhaps I should replace only the ring that sucks, but the middle ring has the most wear and maybe it will be needed soon.

You can do chainring replacement yourself, get the ring (nashbar: http://www.nashbar.com/profile.cfm?category=81&subcategory=1032&brand=&sku=9279&storetype=&estoreid=&pagename=), get a crank extractor, and do it youself. Should be about $30 with shipping and everything.

http://www.bikeforums.net/showthread.php?t=97623 Is a post I did recently, it may have some relevent info....or not.

Jeff, that is helpful. It tells me that there are lots of theories and no right or wrong one. Change the chain once a month? Yikes! Don't tell that guy about my old bike with the same chain for 25 years.

Jeff, that is helpful. It tells me that there are lots of theories and no right or wrong one. Change the chain once a month? Yikes! Don't tell that guy about my old bike with the same chain for 25 years.

Well, that might be much, but the idea is that replacing the chain before it stretches and wears = no need for new rings or cogs. This will depend on how much you ride.
Problem is, if the chain does stretch -you need a whole new drive. So it's $20 every couple months or a whole drive when it does start failing.

It would be interesting to hear from a pro race mechanic how often chain and drive are replaced on pro bikes.
And roughly how many chains a drive can go through before the cogset and rings get replaced (depends on how clean you keep it I guess is one factor.)

This is my first 'ridden out' drive, and it was to some degree intentional as it is a 7 cluster. When this cluster\ chain is repaced it will be an 8.

I think most tourers change their chain every 4000 to 8000 km depending on personnal preference and availability of spare parts... Most usually change the cassette at the same time but never heard of someone changing rings that early... but then, all the people I know are a bit thrifty. ;)

I am sure there are better ways of keeping your bike in good shape and Jeff's comments might help youmake a better choice there.

Cheers