Bicycle Mechanics - Chain pops off on rocky steep climbs, delayed shifting!

Alright, on my ride saturday, on tough small climbs that were rough and bouncy, my chain popped off. I few times its happened, the chain is in the smallest ring - so there is something to that, but is my chain to loose? The chain has 500 miles on it, not many stress miles - so Im thinking its not stretched? Also, cleaned my chain and relubed, now I get delays in my shifting? Sometimes a fantom shift under pressure, any ideas?

Check your front derailleur.

Is there a rubbing noise while you are riding as if the front der. is out of adjustement? Even if there is no noise, there could be enough misalignment to cause poor shifting. Are you trying to shift down to the small ring when this happens on the trails? If so, it coul be that the combination of pedaling pressure and an improperly adjusted derailleur is causing the chain to skip right over the small ring and onto the BB shell. Check out the Barnette's manuals online here - it will give you an idea of what the front der. should be adjusted to , and gives step by step insrtuctions on how to correct the problenm.

-Moab

It is easy to test for chain elongation/"stretch" -- if 24 half-links are longer than 12 - 1/16", you need a new chain. Loose chain tension at the rear derailleur cage (worn or misadjusted spring or excessively long chain) could also contribute to you problems.

Your derailleur spring might also be stretched.

There are some after-market add-ons which are designed to keep tension on the chain during bouncy sections... they all have names that include one or more of the following: a hairy animal, some form of mental illness, death. I have seen them advertised in magazines but since I'm a roady I haven't paid much attention.

I had the same problem and I did the following things to correct it:

Got a new front derailleur and readjusted the stops.
Shortened the chain by 2 links.

I suggest you do the second one first, then test the capacity of the chain. Refer to Ch 32 of Barnett's Manual for the testing procedure.