Rake and Trail Numbers Do Matter

 

I get kidded a lot because of my obsession with rake and trail settings on modern motorcycles: most of them steer too damn fast! Other things affect steering like front to rear weight bias, center of gravity, wheel base, wheel size, etc. But the guy who first uttered the expression, “More trail, less flail” knew what he was talking about.

Back in the last century I had a deposit down on a soon to be released Honda XR400. Fortunately the specs were released before the bike arrived and I was able to get my deposit back. The sales manager exclaimed, “Aren’t you even going to ride it?” I replied, “I don’t need to. With that quick street bike steering, I wouldn’t go near sand or ride at high speed off-road on that critter!” I made the right decision because the XR400 later became famous for its head shake at speed and its treacherous behavior in the soft stuff. As I remember the rake was approximately 27 degrees and trail was about 3.7 inches. That’s a long way from my very stable old “C and J”, Curnutt, Honda which had 30½ degrees rake and 5 inches of trail.

I suspect that motocross bikes, which are equipped with quick steering, have something to do with the problem, but motocross bikes run on groomed turf with good traction, a long way from the loosey goosey sand of Baja.

I have a street DR650SE and a dirt DR650SE in the garage. Both are set up very differently, as I’ll write about later. I run the street bike with stock 28 ½ degrees by 4.37 inches steering but different wheel sizes. With more rake and trail, the dirt DR is better off-road than any other DR650 or KLR650 I’ve ever ridden.

The so-called ADV bikes, which are actually nothing more than sport-tourers with semi-knobby tires, are not only too heavy for serious off-road work, but most of them have quick, street-like steering. A good example is the Triumph Tiger 800XCX which has 24.3 degrees of rake and 3.8 inches of trail. Wow! Mount me some AM-26 Road Rider street tires and point me towards California Coast Highway 1.

It’s doubtful that the motorcycle industry is going to back away from the quick steering characteristics that exist in modern street and off-road motorcycles. Everything is moving toward more technical and more complex which is not all good. The answer may be to install adjustable rake and trail components on dirt and multi-surface bikes, but that may not be easy to do. Besides, no manufacturer wants to be at odds with our sue-crazy trial lawyers and their clients.

Oh well, lots of 80 year old guys are under the dirt and therefore past worrying about how well they can travel over it. Guess I’ll just quit bitchin’ and keep on ridin’.