The course you choose is another factor that controls the character of the event and how it is run. Normally there will be a reasonable gradient so that the carties can roll from the start to the finish though gravity alone, although this is by no means mandatory. There are several successful events where the carties are pushed some or all of the way.
Generally speaking, the course you have will be pretty much fixed, since it is some local feature that naturally lends itself to the idea of a soapbox cartie race. In fact it is often the inspiration for the event in the first place - perhaps the main street though your village or a local landmark. However, if you are trying to find a hill to use or assessing the suitability of several candidates then the things you are looking for would include;
- Reasonable gradient - enough to freewheel on a bike or in a car, but not so steep as to allow dangerous speeds.
- Good run off areas, especially on corners.
- Reasonable length - anywhere between 100m and 10 Km...
- Space at the top and the bottom for marshalling carties, turning tow vehicles around, etc.
- Safe areas with a good view of the course for spectators.
- Parking for competitors and spectators.
Other issues to consider include;
- Access for businesses and residents.
- Access for emergency services.
- Noise and nuisance effects.
What constitutes a "reasonable" gradient depends on what you are trying to acheive. If you want a relatively low speed event suitable for novices and children, then it doesn't need to be very steep at all. If you want to run a full on gravity race, however, you'll need a steeper course. The table below gives some ball park figures for terminal velocity (in mph) of a typical cartie at various gradients on tarmac. Note that some carties may be faster than this and some may be much slower, and that the course might not actually be long enough to reach the terminal velocity in some cases.
| Typical terminal velocity (mph) for a given gradient and total mass|
|Mass (Kg) ||1 in 30||1 in 25||1 in 20||1 in 15||1 in 10||1 in 5|
There are usually several things you will need to do to the course to make it safe for competitors and spectators alike, and also other options - such as chicanes and slalom sections - that you might consider to make things more challenging.