R26 Loud Whining?

Hi guys - i have a loud rotational whining noise coming from one of my wheels when im driving at low speed in my R26. Could this be a wheel bearing?

 

Yeah it doesnt do it at first when its cold - but gets worse when running for a while. How much on average is to get a new one? And is it dangerous to drive with it?

 

cheers,il get it looked at the garage tomorrow.

 

Is this just down to wear & rear? cos it had its MOT in the summer and nothing was wrong.

 

ok,so i took it to a garage and he said all bearings etc are ok - he said the reason is the rear tyres,they have an uneven worn sufrace to them - does that lead to a metallic sounding whine??

 

Its a sticking rear caliper.