Problem with rear gears

Goldcoin79

I have got a Trax mountain bike which I bought from Halfords and it has a shimano derailleur. The reason for my post is to see if any one can advise me on a problem I'm having with my rear gears. Last week I noticed that I could not get from gear 6 (the smallest cog) up to gear 5 so I tightened up the rear derailleur cable a bit and it then moved from gear 6 to 5 fine. I then found that at the other end it did not go from gear 1 to 2 so I loosened the cable a bit till it dropped from gear 1 to 2 but then I had the same problem as before going from gear 6 to 5. I have now got it set where I can get it to move from 6 to 5 and from 1 to 2 but with a real struggle. It doesn't seem be to do with where I've set the cable tension as if I move it, it will either stop gear 6 to 5 working or gear 1 to 2 working.

Ive only had the bike since November so I didn't think it would need a new cable so soon so I am well confused at this point. Any ideas or advice would be gratefully received.

cooldad

Re index properly - see Parktools link, if that doesn't work - try new cables. Six months of rain is plenty of time to destroy cables.
If you replace them, replace inners and outers, and get stainless steel cables.

The Rookie

Make sure all the bolts are tight, any loose bolt will introduce some slack.

The Trax is a bargain basement bike with bargain basement parts so longevity is not a strong point.

Have a read up on Parktools.com and go through the full indexing procedure for the rear mech, it could be you are fighting the stop at the first gear position.