Safe Reliable Performance
Ride coast to coast with Donny’s performanced engines, transmissions and drive trains
At Heavy Duty Cycles, we know what is safe and what is not.
After all we have been hopping up Harley Davidson’s since 1974.
The vast majority of our customers want problem free riding and that is what we give.
We give big percentage horsepower and torque gains with our work.
We feel fully confident in giving a 1 year parts and labor warranty with most performance applications
How can we do this?
It’s simple.
Twin Cam and late Sportster metallurgy and fitment are the best ever. These engines are a platform for increased power.
The parts and methodology we employ are the best available.
We know how to do it and we know how to do it right.
Evolution V2 and early Evo Sportster are very reliable and we know how to stay within their reliability parameters.
We do not unduly stress engines and their components.
Shovels, Pans, Knucks and Ironhead XL’s are more temperamental as metallurgy and fitment is from another era’s technology.
Again, we know where to tread and where to avoid.
Donny defines performance as increased and/or more efficient engine breathing…true street performance is all about increasing efficiency.