Assuming the wheel is working right.... probably u need to add some tension to the cable. Do you know how to adjust the thingy that is attached to the wheel??? it has a cable that goes to the gear lever, if the tension is off the gears wont work right.
The second option is that the cable is getting stuck somewhere. Is pretty simple to find out, move the lever or have somebody to move the gear lever and the cable will move and the thingy (which i forgot the name in english) will move also, of you notice that the cable kind'a bulge somewhere and the the cable doesn't move or the thingy doesn't move, then you found the problem. Obviously that if the cable is all rusted that could be your problem also.
Just look how it works and see why is not doing what it suppose to do. Again, I'm assuming is not a problem in the hub ok?
Not rocket science.
ps: u said "The wheel is new though", u mean the whole wheel is new? the tire is new?? I believe to change those wheels u have to deattach the cable thingy that goes in the wheel and re adjust aftwer wards, i believe thats all u have to do.
Last edited by ultraman6970; 06-09-11 at 08:07 AM.