Originally Posted by
Bethany
...the entire pedal came out while he was riding and something else clanked when it hit the ground. My son is 15 and rides hard, but not crazy. He does the usual bunny hops, wheelies, curbs, but nothing I would consider abusive to a mountain bike I know his chain doesn't work on the cogs right, but he didn't tell me which ones..
Everything on a bike that screws in can come loose with vibration (of course more easily if not properly torgued in the first place). Pedals and cranks typically make a clicking sound under hard pedaling or standing on the pedals before they get very loose. ANY out of the ordinary sound on a bike should be checked as soon as possible. Wheelies are
not considered normal usage, and if done carelessly can cause significant damage to the headset and fork.
Originally Posted by
Bethany
...my Fargo has problems with the chain and cogs. It's a brand new bike and has been looked over several times, both by competent mechanics, and said it was the cable stretching as it breaks in. That's fine, but if after it's been looked at, get home, go up a hill and realize it's not shifting right with the same problem, something else is going on. The chain has problems shifting up to the largest gear. It gets up, can't seem to catch right, or catches for a second and comes back down..
To help we need to know for sure what you are talking about, which means some terminology rules. The front gears are called chainwheels or chainrings, the rear are called cogs. It's probably best to refer to cog size when discussing gear problems, either relative size or even better, number of teeth. Not everyone means the same thing when they say "I shift to a larger gear." So, with the above I think you mean that you have trouble shifting to the largest chainwheel. To shift properly to that chainwheel the derailleur needs to:
- Be properly aligned with the chainwheels
- Have the proper gap (~2mm) between the derailleur cage and the outer chainwheel.
- Have the proper limit screw adjustment
- Have sufficient cable tension to reach the large chainwheel.
The first two MUST be checked before any other adjustment is attempted, and I am assuming no damage to the cage.
Originally Posted by
Bethany
Then I realized the other day it doesn't go down to the last cog ...but stays on the 2nd smallest.... First thought was to put make sure chain was aligned with the bar shifters/and gears. That fixed the small cog but it still can't catch on the biggest cog. It does have problems with some of the middle rings but I can't give details of which ones until I put it back up on the stand. Only happens when going up and I think it happens in the middle and large ring
Really need a better explanation here. After you get it back on the stand please explain in proper terms whether it's a chainwheel or cog problem or both, and which middle rings (chainrings) with which gears. It really looks like you will need to return this to the shop. As I advise
everyone who reports stubborn shifting problems, derailleur alignment needs to be checked. That means the 1st two items listed above for the front deraileur and the hanger alignment for the rear.
No shop mechanic or service manager (I have been both) should feel insulted if you tell them that you were advised to make sure that those items have been checked. I dont care if an "experienced" mechanic or a novice assembler tries to fix it. Without confirming correct alignment with the rest of the drive train further diagnosis is futile. Only when those items and standard adjustment fail should one proceed to replacement of parts.