If you ever find yourself at a shortage of ex-friends -- I usually run at a 20% rate, whether I mean to or not -- start up a conversation about torque, horsepower and their relative importance as measurements of motorcycle engine performance.
First of all, no one really knows what either really is. The more they insist they do, the less they really understand. This, as we all know, is the first ingredient for a heated discussion. Add second opinion and stir.
OK, so maybe there are some people out there who can rattle off equations, ratios and empirical tests that adequately describe torque and horsepower. And maybe these people actually understand what they're talking about. But, really, how far is that going to get you with the guy holding the can of Busch Lite sitting on the cooler?
Busch Lite guy: "Hell, that CR250 ain't fast! My first cousin, Cleft, has a quad that's puttin' out 90 horse! He's got one of them boost bottles on that sucker and a bigger jet. That quad'll haul!"
Chances are, Busch Lite guy will not understand a retort involving: "HP = (RPM x Torque) / 5,252".
Chances are, after the glaze evaporates from his eyes, he'll then proceed with a lengthy explanation of how his cousin also installed an aftermarket powerband.
I once had a guy explain to me how torque is useless as a measurement of power with something along the lines of: "So what if a big diesel engine puts out 650 ft. lb. of torque. A Camero engine that puts out the same 300 horsepower will pull the same load. Just put a 10-foot diameter rear tire on it."
Somehow, I don't think "just" is the right modifier for that situation. More like, "Holy shit, Bubba, look what Chester did to his Camero! Call the wacky wagon!"
However, you will always encounter idiots. That's no reason to forsake your own mental grasp of a difficult concept. But at least in this case, even if you do understand what the equations mean in mathematical terms, can your brain honestly convert that information into reality?
For an example, let's pick on horsepower, the most quoted and often abused of the two.
If you're shown a horsepower curve for a YZ125 and see it tops out 35 ponies at 9,000 RPM, is that information really of any use without also knowing the internal gear ratios, sprocket sizes, terrain, type of tire, suspension settings, cleanliness of the jetting, the bike's rake and trail, the butt rash quotient of the seat foam and, of course, the torque curve? Even if we assume ceteris peribus, as we should, will 35 horsepower really feel different to you on the track or trail than 32 or 37? If it doesn't, than we submit that those numbers really are useless.
Aha! But what about big differences, you say? The 2.5 horsepower put out by a PW50 surely is much different, on paper and in reality, than the 44 horsepower put out by a KX250!
If you need a number to tell you the difference between the power output of a PW50 and a KX250 -- or the power output of an XR200 and an RM125 -- than Congress should pass special legislation banning you from contact with all two-wheeled vehicles.
Furthermore, dynamometers ("dynos"), the machines that measure horsepower, aren't very consistent. That means you can't compare the horsepower numbers from one dyno with the horsepower numbers from another dyno.
So, if horsepower is useless in measuring power in small increments, except for in an academic context, and if large differences are self-evident and beside the point, then what are we to do? The terms "horsepower" and "torque" are far too ingrained in our social verbiage to abandon.
To save these special words (and friendships everywhere), we propose the following test for horsepower and torque. It's called the "Ass test" and is based on the notion that any ass can know more about torque and horsepower than any equation-spouting know-it-all.
To pass this test, your ass must have:
- ridden a bike with little horsepower and little torque,
- ridden a bike with lots of horsepower and lots of torque,
- ridden a bike with little horsepower and lots of torque, and
- ridden a bike with lots of horsepower and little torque.
Any ass that has accomplished these four relatively simple feats is hereby accredited with full and proper understanding of horsepower and torque and shall receive all the benefits and privileges of said accreditation, including, but not limited to, the right to discuss the two measurements around a fire, drinking beer with their riding buddies.
The second part of this rule is almost as entertaining: Any egghead who ever again tries to explain anything about a dirt bike with an equation must bunk with the Busch Lite guy.
