click upper image to enlarge
1977 RC500 motor is nearly the same as the 1976 model. The
updates include a different cylinder and head. The lower
end is nearly the same. There are holes all the way thru
the cylinder fins to access the cylinder mounting nuts.
This identifies the Type ll motor. 1976 and 1977 were the
only two years to use this type of motor. Note the head
stay, this was designed to use the motor as a stress member,
tying it into the chassis for extra rigidity. Also note the
special stover nuts on the motor mounts.
Engine case screws and kick start boss are titanium.
Unlike the titanium motor mount bolts on the 76 model, these are
machined steel. The pipe now takes on a more simple route.
Increased cylinder head fining and radial design were aimed at
curing the cooling problems that plagued the 76 bike. The
ignition is slightly different for 77. The carburetor is the same
magnesium one as 76. Notice how close the carb is to the
back of the cylinder. Big time horsepower here.
The rear hub is sand cast magnesium and only slightly changed
from 1976. The wide 2.50 D.I.D. rim is retained. Note the
massive Dunlop 500x18 rear tire. Swing arm construction is
similar to the 76 bike but the dimensions are different to
compensate for the frame changes. Note the flat aluminum
stock that wraps around the inside of the swing arm. This
made for a very stout rear end. Wheel spacers are titanium
and now the chain adjusters take on a more conventional
Special hand made Fox Shocks, made just for this bike are over
18 inches in length. Rear brake is cable operated for a
more progressive feel. The backing plate is sand cast
magnesium with a titanium brake pivot. Note the spring mounted
to the rear brake lever near the pivot. Details, Details.
The rear sprocket is machined from billet and held with titanium
allen bolts. The chain guide is made with aluminum plates
and actually has an aluminum chain roller.