Are the pulleys made of steel?

Our motor pulleys are made out of steel. Drive wheel pulleys are made out of aluminum.

How do you attach the drive wheel pulley to the wheel

You can see these installation instructions located below:

The best way to assemble the drive wheel pulley kit is to use drill with a hex bit and drill from the pulley end and into the wheel.   STEP 1 - Drill 3 bolts from the pulley side into the wheel. This confirms that the pulley is 100% seated correctly. STEP 2 - With the Retainer plate, drill the 3 remaining bolts from the front of the wheel. STEP 3 - Remove the 3 bolts from the back and drill them through the front.   That should help with assembling your drive wheel pulley easier. It's best to use a power drill and a 5mm metric hex bit for our M6 Socket Cap Bolts.