Wednesday, September 13, 2006

Non-Engineer Engineering Analysis

A little analysis of an innovative little mechanical dalliance (that may or may not have wandered into my garage recently). (If so, yes, it didn't take very long.)



I love that a small company can still innovate in a world where big, corporate factories and design houses hold sway. Design might still be, fundamentally, a human endeavor, and not something entirely taken over by computer. Erik Buell began building motorcycles for racing in his garage and eventually built up quite a respectable operation. That operation was bought up and made a subsidiary of Harley-Davidson a number of years ago, but he's still basically running his own show, with a mere 170 employees at the factory in East Troy, WI (a couple hours from my house). It's entirely to his credit that his machine is bristling with so many innovative details relative to the mainstream of motorcycle design. Some of my favorite details:

1) Front brake. This is the most important single piece of equipment on any motorcycle, in my opinion. And Erik Buell's idea is brilliant. Most modern motorcycles have two brake discs attached to the front wheel hub, and the act of braking causes great stress to the entire wheel rim since the outer portion (where the tire is) is trying to rotate, while the hub, with brakes applied, is trying not to rotate. Forces collide. The whole wheel assembly must be made very strong to withstand this stress. Buell's idea is to replace the two standard discs with one huge disc attached to the perimeter of the wheel--out by the rubber--and have the caliper grab it from inside. Voila! Only a single caliper is now needed, only a single disc (though of a greater overall surface area than the two smaller discs it replaces, which is better for heat dissipation), and a lighter wheel. Total weight savings: six pounds! This is HUGE. Weight savings typically accrue in ounces.

2) Belt drive. He didn't invent this, of course (though they're still not in widespread use), and the general principle is not different from the chain drives used on most every other motorcycle on the planet. But the differences from a chain are significant. A belt is very light weight, makes no noise, requires no lubrication (and does not throw that lubricant all over the place), needs no adjustment. And it's warranted for the life of the motorcycle. It's been torture-tested to withstand rocks and things that might get thrown up and into the sprockets. My BMW had a shaft drive, which is also quiet and clean, and the new ones need very little maintenance. But I think it's a maxim of good engineering that the simplest solution is the best one, and shaft drives are heavy, they require several u-joints, they need lubrication, and they involve bending the power output 90° at least once in every application, which sucks up energy. The belt is simply the better idea.

3) Exhaust components contained entirely beneath the engine. Oddly, no one has done this before (at least that I've seen). Most motorcycles route the exhaust under the engine, but only enroute to the muffler canister which extends out beyond the rear wheel. In this latter position, the hot components are near to riders' legs, and it's a lot of weight extending like an arm away from the bike's center of gravity. Plus, exhaust canisters up beside the rear wheel interfere with saddle bag placement. Buell's solution is to keep the whole muffler down beneath the engine, away from burnable human parts, with its considerable weight down very low and right on center. Another brilliant idea.

4) Fuel and oil reservoirs. He keeps the fuel inside the frame, instead of in a standard fuel tank, and the oil reservoir is inside the rear swing arm. These decisions make for brilliant multi-use packaging, and enable components to be more easily placed where they are wanted, rather than where there is room for them.

What I'm not particularly sold on so far:

1) The whole association with Harley-Davidson is a big turn-off for me. This issue is, admittedly, not one with Buell but rather an axe to grind with Harley-Davidson. I think Harley riders are typically in pursuit of very different things than the riders of more modern machinery. A Harley-Davidson is a fashion accessory, an attempt by many people to be "bad" by association. Please. I don't mean to pee on everybody's parade, and indeed there are a whole lot of Harley riders who are passionate about riding. But much more prevalent, I think, is this lifestyle association stuff, and I haven't quite figured out what it has to do with motorcycling. The whole emphasis on how the bike looks, and most ludicrously, what riding position is supposed to be cool, seems entirely off the topic of engineering excellence. As an offshoot of this, Harley has for years and years resisted developing more technologically-advanced machinery (to satisfy the wants of a gigantic market of buyers who currently buy Japanese or Italian or German machinery) because it would offend "the faithful." Nobody said, of course, that the more advanced machine had to REPLACE the antique! But such is the mind of the faithful that such offensive developments as... liquid cooling have been kept at bay. It is to his huge credit, to my mind, that Erik Buell was able to show Harley the way forward in many of these areas. As I understand it, his association with Harley came about because he was trying to make an all-American machine and their engines were the only extant developed motorcycle engine / transmission made in this country. Good for him, but I still feel a bit as though he's tethered to some ugly thing, and his machines would be so much the better with a modern powerplant.

2) As for that powerplant: Buell has gone some ways to civilize the H-D narrow angle v-twin, but it just feels cruder and less refined than the engines I've had in past bikes. There's a reason that nobody else is using this 45 ° air-cooled, pushrod configuration; no, this configuration has been dictated by a nostalgia obsession and not any sound engineering motivation, but it's what Erik Buell has to work with. My BMW engine was about the same displacement, had the same number of cylinders, was also air / oil cooled (and also had pushrod-activated valves, though for legitimate space reasons). But it just felt better-mannered. Having said this, it must be noted that this Buell motor is more powerful than my BMW was, and while it shakes quite a bit at idle (as one would expect from a 45° angle), it is as smooth as my BMW was once it's off idle. I've ridden the bike all of eight miles; my mind may yet be turned about the motor.

It is said that some of these oddities are the quirks one falls in love with, that a Buell gets under one's skin. I'm open to the idea, loving quirkiness and all, and I may yet come to appreciate things toward which I am presently skeptical. For now, I'm thrilled to immerse myself in something different, and Erik Buell seems to have put together a very high quality product. More to follow.

3 comments:

Jeffy said...

Sounds like a pretty awesome machine. It will be interesting to hear how it compares to the BMW.

It does seem a bit disappointing that in an effort to build an entirely 'American' bike Buell has stuck with the HD engines. I would assume that there are other options out there, and some have got to be more advanced and generally better. It just seems to be a shame to go to all the effort to create a bike that is re-thought and redesigned in nearly every way, and then have to toss in an engine whose primary virtue is that it is made nearby.

Anonymous said...

Good posts on several subjects. I found you by your comment on the "Postards From Somewhere site."
I'm not a motorcycle guy, so have no real experience on them (other than nearly "buying the farm" once on a Triumph Bonneville.)
I am sure H-D will disagree with your statement that "...Harley has for years resisted developing more technology advanced machines...".
The V-Rod received considerable publicity by H-D and magazines' reviewers based on the advanced technology.
The V-Rod is certainly a big step away from the "hog" mentality, and seems to me that it has moved closer to the Buell Sportster concept.

wunelle said...

I must concede this point to you. I am conveniently forgetting the V-Rod. Still, I might assert that the V-Rod is advanced for H-D, but doesn't stretch any envelopes outside the company. But you're right that a much more advanced engine (designed wth help from Porsche, no less!) HAS sprung from the HD loins, and that the V-Rod is a step toward the sporting motorcycling mainstream (following in the footsteps of the Yamaha V-Max).

I would certainly have considered one if there had been no Buell, but I think the chassis stuff he's done is more important overall than the much better motor in the (to me) still-overweight V-Rod. JMO.

Thanks for the comment! :-)