Originally Posted by
rm -rf
I like the
Park Tool Repair Help pages for learning repairs. Sometimes, a youtube video helps on complicated repairs.
The
rear derailleur adjustment page starts from the beginning, setting the
high and
low limit screws, then adjusting the shifting. Do the whole thing so you know it's correct. Then you'll understand how to adjust it quickly in the future. It's easy after you do it the first time.
If the low limit screw is set too far, it'll allow the chain to go past the large cog, into the spokes. Then the derailleur catches on the spokes, and rips it off the bike. It'll need spokes, derailleur, and often the frame is damaged too. An expensive problem.
this is is one of the best resources out there on adjusting your rear derailleur. Your description really sounds like a derailleur adjustment problem - if you find that you can switch gears very quickly going up but it's very hesitant going down the gears then chances are that it's your rear derailleur cable tension. The little barrel adjuster that sticks out of the derailleur can be turned clockwise or counter-clockwise and makes small adjustments in where the chain is positioned relative to the cogs.
the only other piece of advice about switching gears while riding is to change gears earlier than you need to - if you're trying to change from a harder to an easier gear while pedaling very slowly with a lot of force, you will not make a smooth shift. Shifting gears while pedaling more quickly is the way to go.
good luck!