- The Magnets: The magnets in a motor are one half of the torque-producing system - they produce the magnetic field which the coils act against. The stronger a field you can fit into a small space, the better. Heinzmann only use the best quality rare-earth magnets, for the highest possible magnetic flux density.
- The Coils: The coils are the other half of the system - and the trickiest bit! The trick is to fit as many coils in as possible, able to carry the largest current you can manage. Heinzmann’s coil designs are very sophisticated (and very secret!), but manage to squeeze in a lot more power than all the textbooks say is possible - up to 3 horsepower in some motors!
- The Bearings: The bearing which a motor and gearbox run on are vital - they are going to get a lot of abuse and no maintenance! Heinzmann only use genuine SKF sealed bearings, not cheaper far-eastern imitations.
- The Gears: The gears are the only real wearing parts in a motor and gearbox, so they have to be good. Heinzmann’s are made out of hardened steel, with a helical tooth pattern to reduce wear. I have NEVER seen a worn out set of steel Heinzmann gears! In the lower-power motors, Heinzmann make the intermediate cog out of tough nylon to reduce noise - even these last three years or more of daily use. As a comparison, I once took a set of steel gears out of a Schachner motor which had been used for just 3 months - they were already worn almost completely away.
- The Castings: Although it’s bigger than a standard hub, there’s no superfluous metal in the Heinzmann hub - everything is machined down to save weight without sacrificing strength. I’ve never seen a broken one (apart from one the couriers drove a truck over!).
- The Thermistor: This is the bit almost all other systems miss out! The Heinzmann motor has a built-in thermistor which keeps an eye on the motor temperature - see the Power System page for more info on the Heinzmann’s safety systems.
For exact motor measurements, have a look at these PDFs:
Front motor dimensions: front view, side view
Rear motor dimensions: front view, side view Note - the difference between Peak Power and Continuous Power:
This is sometimes a bit confusing, and to be honest I sometimes talk about peak and sometimes continuous when I’m talking about motors. Here’s the difference: Peak Power: This is the maximum power the motor can happily produce - the motor will be able to put out this much power for a couple of minutes, but will then start to get warm so the controller will power down a bit. I usually talk about peak power when I’m talking about the high-power (non-legal) motors because you really want to know how much “grunt” it has, don’t you? Continuous Power:
This is the power that the motor will happily put out for ever, without getting even slightly warm. Obviously this is lower than the Peak Power. I usually talk about this for the legal motors because this is what the law asks for - the continuous power not the peak power. There is a lot more technical detail, for those who are so inclined, in the technical guides section - have a look... | 
All Heinzmann motors are built to the same basic plan, and come in two versions, for front or rear wheel fitting. The motor is spoked directly into the rim, and can be fitted to any size from 16� to 28�.
