Mobile bike repair, and the density the round needs.

Before you build it, four documents about it: who else is already selling to a mechanic who would rather not pay for a shopfront, one price you can defend, a money model with every guess labelled, and where the first customers are.

What it checks first, for this one.

1. What the fixed-premises shops charge for the four most common jobs, since that is the ceiling
2. What the parts distributors require before they will open a trade account
3. Whether the employers and estates in the area already buy cycle-to-work servicing as a benefit

How many jobs a day does the round need before the van beats the rent on a shop?