Sermons On The Mount

With the inundation of new fit terminology and event-specific geometries, the crusade for the perfect fit can get confusing. We asked two of our most experienced bike fitters to shed some light on how much really changes and what will always stay the same.

Glenn Dussl, buyer, and Todd Cravens, QBP’s director of national accounts, have both spent a little time with an angle finder and a plumb bob. When we told them we wanted to put together an article about bike fit, Dussl quipped, “Why don’t you just make it about religion?”

Finding the perfect fit on a bike really is about putting your faith in someone else when you haven’t been able to figure it out on your own. Even then, your beliefs can be shaken to their very foundations by a random comment on a club ride like, “Is that seat kind of low?”

A solid knowledge of mechanics is essential for getting a rider headed in the right direction, but Cravens states, “The bike is just the backdrop. Fitting a rider is so much about listening and looking, asking more than answering, and being keenly observant. The person being fitted wants to be more efficient; ride longer, harder, and farther; and most importantly not hurt any more. The human side to fit is so critically important.” 

Here are some basic tenets of a good fit and where to get started.

Ask Questions

Get the “state of the state” of the rider.

  • Find out what kind of riding the rider currently does, and what the rider aspires to
  • Are there disconnects between assumptions, desire, actual fitness, and how much time the rider can/will make for cycling?
  • Are there any injuries (old or new), or issues with flexibility? This helps determine if there will be areas requiring more attention. The rider may have something from an old injury that is causing discomfort or limitation

Observe The Rider

See the rider in action on the road or on a trainer. Look for or ask about:

  • An appropriate leg extension and knee alignment while pedaling. When the pedals are at 11:00 and 5:00, the extended knee should have a slight bend in it and the heel of the extended leg should be level. This makes for efficient pedaling and full use of the quadriceps
  • Shoulders should be squared, not rounded or compensating for a stem that is too long 
  • Hand position on the tops of the bars, hoods, and in the drops. Ask about hand pressure as well
  • A bar drop that is too deep, or bars that are too wide
  • A toptube that is too long
  • Look at whether the person is rocking in the saddle with each pedal stroke, which is a sign that the saddle is too high
  • Triangulation between stem/bar height and seat height. The curve of the back and pelvis position give a sense for where the person is actually sitting on the saddle
  • Wear marks from the rider’s saddle contact points
  • RPM riding style. Is the rider is a “masher” that pushes a bigger gear, or a “spinner” with a more supple low gear and high RPM?

Make Adjustments

Many riders seek something between a “race” fit and an “endurance” fit for longer rides. For either style of fit, the customer should be communicating how the adjustments affect his ride as he trains towards his goal. Ultimately, the fit may change if discomfort occurs somewhere down the line.

Race Fit

A    KOS (Knee Over Spindle)—Drop a plumb line from the bump just below the kneecap to determine this position. In front of the spindle allows a more explosive snap for top end sprinting; a little behind supports muscling a bigger gear during longer efforts around the rider’s maximum sustainable watts
B    Bar/seat relationship—Generally you end up with a greater disparity between the amount of stem and exposed seatpost, with the seatpost being significantly higher
C    Arm position—A rough range for elbow bend is approximately 30° on the hoods, 40° to 45° on the drops or hooks, and 35° or so on the lower flats. Shoulders and hands/wrists should be in a neutral position; they should not look like they’re reaching or cramped
D    Back angle—The rider’s back is flatter on the hooks and lower flats. The pelvis is rotated slightly forward, but not onto soft tissue
–    Bar width/position—Race bars should closely match shoulder width, and the drops should be usable and allow the rider to tuck even lower while still maintaining comfort and the ability to generate power

Endurance Fit

A    KOS—For endurance riding where sprinting and muscling big gears is less frequently required, the position is more or less neutral to maybe just slightly behind the spindle
B    Bar/seat relationship—The bars and stem are closer to level to provide a more upright position
C    Arm position— Like with race fit, shoulders and hands/wrists should be in a neutral position; they should not look like they’re reaching or cramped
D    Back angle—The rider’s back is more upright on the hoods and lower flats. The pelvis is rotated slightly back, with more weight on the sit bones
–    Bar width/position—Endurance bars are sometimes wider than shoulder width to offer the rider more varied hand positions, as well as for increased leverage for a hilly all day effort. The drops are usable for an additional position but with less emphasis on an aero tuck or for sprinting

Keep in mind:

The rider really dictates how the bike is adjusted. Look at the customer’s abilities, flexibility, and limits. Riding a crit versus a century should not dictate how a rider’s body is positioned; rather, the body dictates how the bike should be adjusted. If you position a set of bars and create a great amount of saddle to bar drop, but the rider’s flexibility can’t handle the position, the outcome will be an uncomfortable ride that equates to a loss of power and efficiency.

Just because you can make adjustments doesn’t mean you should. If something has been working well and your tweaks make things worse, then go back to the original placement. Nobody has all of the answers. Get to know other fitters, physical therapists, kinesiologists, etc., that can help you. There’s always something to be learned.

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