First you said ur bike is crap, now ur saying this hmm.
Post your bike with full specs, then i will just simply write you what to swap so the it will be more bulletproof.
(not a good place to buy a bike i know..)

. New one costs 2,5 pounds, that's a lot of money.









).
) . You will be forced to be repairing it more than riding, but isn't that the best way to know something about bikes?