Heavy Duty – July-August 2019

the power to weight ratio, which is the core factor

in performance. Here’s how engineers describe it:

“A measurement of performance of a vehicle as a

whole, with the engine’s power output being divided

by the weight (or mass) of the vehicle.”

Translating this into motorcycle terms we can say

that a big engine in a lightweight chassis is going to

put a big smile on the rider’s dial.

So take a moment to run your eyes back over this

ride and see what heavy items have gone into the

recycle bin. Front disc, front caliper, front mudguard,

stock fuel tanks, mufflers, half the back guard, inner

and outer primary cover, primary chain, rear disc

rotor and caliper, chain guard, handlebar switchgear,

brake and clutch levers and perches – that’s a lotta

combined weight to dump.

The engine has been bored out to 80 cubes, or

1340cc, and runs a stock cam, stock pistons and

a stock 8:1 compression ratio, but enhancements

include S&S solid lifters, an S&S Super E carb and

it gets its spark from a Dyna 2000 ignition module.

These modules fit under the cam cover on 1970-

1999 engines and replace the mechanical compo-

nents found in the stock engines, with subsequent

performance enhancement and longevity. Air enters

via a Boyle Custom Moto air cleaner and exhausts

Lean and mean
is the in look amongst
the newer generations
of chopper builders
and we see it well
nailed here.