In my opinion it always ends up being way more of a headache. Those on the inside know the product better and are more driven/passionate etc to sell it than a hired salesforce will ever be. In the end it ends up taking more of your time for direction, supervision, etc. Add that to the fees your paying them and you just become frustrated. I just glanced at your site quickly, but why wouldn't you go form strategic alliances with the bike companies, give their staff a free case and incentivize them for selling your bike related products when they sell a bike? Motivate the person standing in front of your potential customer and sky's the limit.