There are a few problems using these on a bicycle. First and foremost they put the load very high up which is not such a good idea on a bicycle. It isn't really such a good idea on a motorcycle either but since motorcycles weigh a lot more than a bicycle it is not as big a deal. Second, they tend to be noisy when mounted to a bicycle rack. This can be really irritating. Three, notice they don't list the weight ... there is a reason for that.