Too Overweight For A Bike

[peanut]

new cheap components are probably more likely to fail than older/used higher spec components.

absolutely and those bikes are bottom of the range with nasty cheap 'no-name' components

 

[Ademort]

What weight would be considered to heavy for a road bike/ mountain bike

A friend of mine recently bought a road bike and within a few days the sprocket packed up he weight is 17/18st was it his weight that caused the problem

Here in the Netherlands we have people of all shapes and sizes on all types of bicycle. Compared to some of the people i,ve seen, 18 stone is nothing. In fact i would think it almost impossible for something to break off a bicycle purely because of the weight of the rider. The chances are that the part that broke off was fitted incorrectly or a faulty part. As other members have suggested your weight would never be the sole factor in a major breakage.
Ademort