This is the HRC RC500 snap-ring crankshaft
that is talked about in my book "Legendary Motocross Bikes."
These cranks are tunable for different power-band
characteristic's by altering the rotating inertia. Steel,
tungsten and nylon inserts were available and gave the tuner the
flexibility to adjust the power-band simply by changing the
weights. The process to change the weights is very simple as
they are held in by snap-rings located in the crank flywheels.
This along with all the other available options that HRC
offered, made the RC500's some of the most competitive motocross
bikes ever produced. Ask any factory Honda rider that ever used
one of these crankshafts and he will tell you this was the
biggest improvement on the bike. Even though the crank flywheels
look like they are made from billet, they are actually made from
several machined pieces that are hollow in strategic areas and
then electro laser welded together. Very few of these were made
and the cost was well over $10,000.00 in 1980's dollars.
This is the HRC RC500 optional 40mm
sand-cast/hand machined carburetor.
Huge top end performance. Cost of about $5000.00.