Words From The Pros... Fanthom Racing

http://www.fantomracing.com/tips/mm.htm

CHOOSING THE RIGHT NUMBER OF STRANDS

To give you a simple explanation, the number of strands you choose, i.e. single, double, triple, quad, quint, or hex, determines the power band of the motor. For example, a single produces its’ maximum horsepower in the lower RPM range, while a quad produces its’ maximum power in the mid to upper RPM range. In other words, a single will feel like it has more “punch” coming out of a corner, while a quad will seem to kick in around mid straightaway. Only you can determine what best fits your driving style, but a good place to start is with doubles. Normally speaking, a good system to follow is to base your decision on the current track conditions. Usually tight technical tracks are more suited for singles and doubles, while big open tracks may require a triple or quad. Also, traction can play an important role. For instance, if there is a lot of traction, you can get away with running a single. If the traction is sketchy, where you can’t hook up well coming out of a corner, you might be better off using a triple.

And this is the rationale that they have for "why" this actually happens... which is interesting...

http://www.fantomracing.com/cstm_mod.html

With today’s high voltage/long runtime batteries, the most common winds now being used are singles and doubles, however, there are situations where multi-strand armatures can still be utilized effectively. In simple terms, there are two main things to consider when choosing a wind; MCA and SA. MCA is the abbreviation for Mill Circular Area, and SA is the abbreviation for Surface Area. MCA is the area measurement of wire, viewed from the end, 1 mill thick, meaning larger gauge wire equals more MCA. For example, larger gauge wire, such as 15awg, 15.5awg, etc. is used on singles. SA is the amount of surface area measured around the circumference of the wire. Generally speaking, by adding multiple strands of wire the SA can be increased significantly with the more strands of wire being used. You can go even further by winding split winds (i.e. one large and one small wire), with which the smaller wire helps fill in the gaps allowing for finer tuning of the MCA/SA combination. Typically we don’t run many split wind armatures, but they are interesting to experiment with in certain situations. In very simple terms, more MCA produces more torque, and more SA produces more top end performance. Given the same MCA, more SA will move the power curve up, but use more battery at the same time.