Why does my bike jump through the gears?

Question

I bought a mountain bike, 21-speed, 7 gears, dual-suspension. Everytime I shift from the first gear to the second, it doesn't shift. Then, when I shift from second to third, the chain shifts to third gear. Why doesn't it go to the second gear? I always have to go to third, and shift back to second for the chain to be on second gear. My old bike had the same problem, but on 3rd gear it skipped. Why is it like this?

Answer 1

I'm assuming this happens on your rear derailler.  Take your bicycle to the local bike shop as explaining how to fix this can be complicated unless showing exactly how it is done.  I have a hard time learning how to do something through reading, as I can understand mechanical things much better when I see how it is done.  This can be fixed.  Or you can google "how to adjust your rear derailler" and you can adjust this problem yourself by watching a video demonstration....BUT if you dont have any experience in this, you might end up having your bike not shift at all because the cable is too loose or too tight.  Its much more complicated than just telling you what those screws are for on your rear derailler.

Answer 2

You rear derailleur needs adjusted. Where the cable goes into the derailleur there should be a barrel adjuster, turn it 1/2 turn counter clock wise to tighten the cable just a little. Try it out, if it still does it try another 1/2 turn.  Should do the trick.

Answer 3

If the bike didn't do this just after you bought it, the cables have stretched. In any case, your derailleurs need adjustment. If you bought the bike from a local shop, they will usually do this for free. The local shop where I bought my road bike does this for 2 years after purchase. Other shops do it for one year. Performance offers free adjustment for life.

If you didn't buy from a local shop, one of them will adjust your derailleurs but you'll have to pay. My local shop charges $16 each for front and rear. If you want to try it yourself, check out the web pages at http://sheldonbrown.com/derailer-adjustm...

HTH