Motorcycle Ergonomics: Trouble In the Fitting Room

Motorcycle Ergonomics: Trouble In The Fitting Room

ROUNDUP

DAVID EDWARDS

Quick! What’s your inseam measurement? What was it five years ago? Or ten?

Assuming you’ve passed through the usual adolescent growth spurts, we suspect that your inseam, along with most other measurements a tailor might care to make, has been fairly constant over the past few years. But you’d never come to that conclusion by studying motorcycle ergonomics.

Each year it seems that motorcycle seats get lower, footpegs higher, the room left for the rider less. While this isn’t a problem for short trips, the cramped quarters on some recent motorcycles can be truly uncomfortable when the time spent on the bike is measured in hours instead of minutes.

This is particularly true on sportbikes, which generally place the footpegs directly under the rider’s seat. And as cornering prowess increases each model year, the footpegs move higher so they won’t drag. The resultant footpeg/seat relationship is so close that it forces a knee bend that can turn into a painful experience after 50 freeway miles. And this isn’t limited only to the footpegs; handlebars on new sportbikes seem to be evolving into clip-ons. And the forward lean they impose can translate into lower back pain, and, along with the footpegs, force a tuck between legs and torso that can lead to hip-joint cramping.

This is not to say that all sportbikes are uncomfortable for long rides. But the trend is for new models more and more to closely resemble roadracers, and that trend is leading to motorcycles that are suitable for one task only: roadracing. And while they may be faster around a road course, these GP replicas are also becoming less suitable, and less fun, for most ordinary street riding, all because their riding position has been optimized for 150mph speeds and full-tilt lean angles rarely, if ever, used on U.S. roads.

Sportbikes aren’t alone in these departures from human suitability. There are custom-style motorcycles whose footpegs aren't appropriately located, or whose handlebars lean you back too far without back support. While the prototypical customs from Harley-Davidson manage expansive seating positions and are comfortable on long trips if you have a dufflebag or such to lean against, some of the motorcycles that emulate H-D styling haven’t copied the seating position. Most Harleys have their pegs low and very far forward, which causes the pegs to drag during moderate cornering speeds. To avoid that dragging, some of the Harley clones have their pegs mounted higher; and to seem less chopperesque, or simply because their wheelbases are so much shorter, some of these bikes also have their pegs mounted further aft. So what was expansive becomes, once again, slightly cramped.

Solutions to these problems? We can suggest a few. First, footpeg height shouldn’t be set so high that the pegs don’t drag during 1 g cornering; most riders don’t ride that hard, and even those who do don’t do so all the time. Better to place the pegs where they’re reasonably comfortable, put a replaceable rub strip on the end of the pegs, and let the fast riders make some sparks. Second, not every motorcycle needs a minimum-height seat; there ought to be bikes out there for people with long legs as well as short legs. Perhaps Kawasaki’s example with the KX-series motocrossers could be followed: Kawasaki offers taller seats as

continued on page 26

continued from page 22

options for the KXs. Finally, perhaps the industry should reconsider the use of GP racebikes as models for street-going sportbikes.

This last suggestion is the most radical, but consider this: In every motorcycle sport where the speeds are much below 100 mph, or where motorcycle control is placed at a premium, the riding position is full upright. Even such roadracers as Eddie Lawson describe how much easier a Superbike (with its wider,

higher handlebars) is to ride than a GP machine. And both Lawson and Kenny Roberts have suffered muscle tears manhandling lightweight 500cc GP bikes, injuries that have to be at least in part the fault of clip-on handlebars that offer inadequate leverage. For street riding, where speeds are usually low by roadracing standards and where a premium is placed on maneuverability, perhaps true GP replicas aren't the answer.

— Steve Anderson