Bicycle Tutor

1. The gears are sram x4. When I put pressure on my pedal to move off, there is usually a loud snap noise and it will tend to jerk forward (the pedal).

2. When I'm jumping down gears (front derailleur) it makes a long clicking noise (rubbing along the derailleur and not jumping down I think), in-order for me to jump down a gear I have to use the rear derailleur to go into the lowest gear then it gives.

What's the problem with these two?

1. Could be the chain jumping over the teeth on the rear cog indicating worn chain and cassette. But I wouldn't assume that until you rule out of the basic adjustments.

2. Sounds like you need to check all the front shifting adjustments. (Watch the video on this site). Short answer is either your inner limit screw is too tight on the front derailleur or front shifter cable has too much tension. But you should go through the full process of checking the shifting adjustments for both derailleurs regardless.

I have this exact same problem! I've just installed a new Sram PC971 9 Speed Chain, but not replaced the Cassette. Am I asking for trouble?

First gear is fine but when I apply pressure whilst in all other gears my gears bang!

The cassette physically looks fine though...Weird!

(Jan 30, 2013 09:28 PM)neo36uk Wrote:  I have this exact same problem! I've just installed a new Sram PC971 9 Speed Chain, but not replaced the Cassette. Am I asking for trouble?
......

yes.

(Jan 30, 2013 10:12 PM)nfmisso Wrote:  

(Jan 30, 2013 09:28 PM)neo36uk Wrote:  I have this exact same problem! I've just installed a new Sram PC971 9 Speed Chain, but not replaced the Cassette. Am I asking for trouble?
......

yes.

just this second ordered a Sram PG970 9 Speed MTB Cassette 11-32T...just hope this fixes my problem...was fine with old chain and old cassette