The 5 Key Elements of a Perfect Bike Fit
Master bike fitter Dave Luscan outlines the essential points to consider when seeking out your best bike fit.
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Whether you’re a newbie who just purchased your first bike or a veteran with a stable of steeds, getting a proper fit on a bike is a must-do for any triathlete. A bike fit is a technical and tedious process–most sessions can take at least two hours–but an important one to set you up for an ideal, efficient, and comfortable ride. “Just like effective golf swings, high jump technique, and methods to roll a bowling ball, there are fundamental characteristics of excellent bike fits,” says Dave Luscan a professional bike fitter who has completed over 3,000 bike fits in his career and has a forthcoming book, The Misfit’s Guide to Basement Bike Fitting. Here, Luscan, who is based in Richmond, Va. and services cyclists at M3 Bike in Vienna, Va., outlines the primary fit coordinates that serve as a foundation for a bike fit.
The Focus: Saddle Height
Why it’s important: The wrong saddle height is the leading cause of overuse injuries on the bike, says Luscan. “Proper saddle height cultivates a balance between over and under extension of the knee, hip, and ankle joints. Too high and we may feel like we make good power, but we may not notice the stress on the hamstrings and back of the leg until it is too late. Too low and we can also sacrifice power and risk patellar pain.”
What to look out for: Monitor ankle flexion and hip movement. If your toe starts to point further down or the hips start to rock, the saddle is likely too high. And, when playing around with position to find the just right saddle height for you, go with your gut. “Intuitive, quick, seat-of-the-pants assessment is what we want, says Luscan. “Your body is smarter than you. Keep your brain out of the way.”
The Focus: Setback
Why it’s important: Setback–the horizontal distance between the center of the bottom bracket and the nose of the saddle–can make the difference between a relatively comfortable ride and one that’s riddled with pain, discomfort, and numbness around your pelvis. A proper saddle setback, which is adjusted by moving the saddle slightly forward or backward, can alleviate pressure on your pelvis while increasing your power.
What to look out for: When in doubt, move the setback forward, says Luscan. “There is rarely any downside to very steep positions, and a whole lot of upside including more open hips, better aerodynamics, and, for some, improved runs off the bike.”
The Focus: Cockpit Distance or Reach
What it’s important: Your cockpit distance–that is, the tip of the saddle to the middle of the elbow pads on your aerobars–is the primary driver of comfort on the bike, says Luscan. Not only that, it can impact your bike handling (if you’re reaching too far, you’ll have less control) as well as your power output (a too-short reach will put you in a more upright, less-aerodynamic position).
What to look out for: Cockpit distance can be difficult to dial in, and often takes a few rides–plus some trial and error–before you can determine if you’re in the right spot. However, a general rule of thumb according to Luscan is that if your bike immediately doesn’t feel right, it is usually a problem with your reach. Then, as you ride pay attention to what precisely which part of your body became uncomfortable first. Is it your lower back? That’s a sign of too much reach. Upper back and shoulder? The reach is too short. “As you ride, be sure to keep your position on the bars constant as you make changes,” says Luscan. “Your elbows should rest on the pads and your hands should grip the extensions in the same places as you adjust the bars.”
The Focus: Crank Length
Why it’s important: Crank length directly affects both the thigh to torso and knee flexion angles at the top of the pedal stroke, both of which can have significant impact on the efficiency of your pedal stroke. Typically, says Luscan, shorter cranks help you produce more power and higher cadence, minimize range of motion of overused joints, and can can lead to a stronger run off the bike.
What to look out for: Does your bike have stock parts? Most likely you’ll need shorter cranks. “When modifying crank lengths on aerobar equipped bikes, I almost exclusively making them shorter than the lengths commonly delivered on stock bikes,” says Luscan. To gauge if a rider is “overly-cranked,” he looks for tell-tale signs like too much knee flexion at the top of the stroke. “The knee joint needs to be ‘open’ to a certain degree before you can produce close to maximal force, and cranks which are too long flex the knee joint past this point at the top of the pedal stroke,” says Luscan.
The Focus: The Drop
Why it’s important: Having a significant drop between the saddle and the cockpit is key in racing triathlon, because, as Luscan bluntly puts it: Lower is faster. “Going lower is the best way to reduce drag. Countless wind tunnel tests have verified this premise,” he says. Plus, the perfect drop can help you avoid riding with too tight of a hip angle (AKA how bent over you are), which impinges your pedal stroke.
What to look out for: Getting “aero” is ideal as long as you’re not too low, which can compromise your comfort and your ability to breathe. “If you bend over too far and your upper leg is too close to your torso, your pedaling suffers and your hip flexors burn,” warns Luscan. The ideal angle varies from person to person, but generally, you do not want your back to be table-top flat when you’re in an aero position. “Ideally, it’s just a bit, like 5-10 degrees higher, than completely flat,” says Luscan. That’s a position almost all athletes can tolerate.”