advice please - Front cog damage

[eviking]

I've just bought a GT Avalanche 3.0 (1/2 weeks ago), I've only ridden it less than 30kms and just noticed some of the Suntour XCC-252 front cog teeth are worn quite down, if not broken down on all 3 gear cogs. The worst damage is mostly on 3rd gear (two teeth) , which I don't ride on, and only have used to test for a few seconds.

On day one, my front deraileur has been coming out of gear, aswell as not shifting properly, and has already gone for adjustment by my LBS. Even after the adjustment it still slipped out of 2nd and could not reliably shift up or down. So much so, I have had to stop the bike and make sure it goes into gear. I had only noticed after my second ride after this adjustment the broken teeth. My rear shimano cassette is perfect.

I have only ridden on sealed roads, and have not trashed the bike (I'm not fit enough yet to trash it anyway).
Can the shifting / slipping out of gear problem has caused the teeth to break? or are the front cogs so cheap that they were going to break under the stress of slipping/shifting out?

I'm thinking if I should go to my LBS and get it fixed under warranty, or try and push for a bike with better running gear? I'm loosing confidence in the bike, as I've only had it less than 2 weeks.

 

[tyler_derden]

Those teeth aren't worn down. They come that way from the factory. They are cut that way to make shifting the chain on the chainrings "snappier".

Cable stretch in the first few weeks of a bikes life is common. Your LBS will be happy to tune up the derailleur for you, and they shouldn't charge you anything for the work (a few seconds with a screw driver). When they make the adjustments, ride the bike a little and check it out. if it still isn't 100% right, have them tweak it some more.

You will save yourself a lot of frustration and wasted time if you learn a bit about bike maintenance. There are lots of books out there (and plenty of web sites) that will teach you how to adjust derailleurs, fix flat tires, lube bearings/chain, and etc. Most jobs don't require a lot of expensive tools, but there are a few you should get (consider it part of the cost of the bike) and learn how to use. You don't need to be a rocket scientist, either.

TD

 

[eviking]

Those teeth aren't worn down. They come that way from the factory. They are cut that way to make shifting the chain on the chainrings "snappier".

Cable stretch in the first few weeks of a bikes life is common. Your LBS will be happy to tune up the derailleur for you, and they shouldn't charge you anything for the work (a few seconds with a screw driver). When they make the adjustments, ride the bike a little and check it out. if it still isn't 100% right, have them tweak it some more.

You will save yourself a lot of frustration and wasted time if you learn a bit about bike maintenance. There are lots of books out there (and plenty of web sites) that will teach you how to adjust derailleurs, fix flat tires, lube bearings/chain, and etc. Most jobs don't require a lot of expensive tools, but there are a few you should get (consider it part of the cost of the bike) and learn how to use. You don't need to be a rocket scientist, either.

TD

Thanks for the info, I was freaked out when I saw it, I understand the reasoning now

 

[peet9471]

Turn the bike around. The cogs are on the rear. Chain rings are on the front.
Good luck!