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Each month I put this space to good use by complaining about the ins and outs of riding, racing, building and tinkering with bikes. Normally, you get a hefty dose of my personal opinion, but this month I’m veering off this well-beaten path to write about something that I’ve seen a lot of lately: ill fitting bikes.
All I’ve written about building the perfect bike and all the reviews you’ve read about high-end bikes is useless if you can’t get a proper fit. An ill-fitting bike turns even the most advanced and fastest race bike into a clunker and can even result in nagging pain and an increased risk of injury. Even if your bike feels good and you like how it feels, it’s important to check these measurements. You could be riding in a bad position and doing some microscopic damage to your joints, ligaments and muscles without even knowing it. Read on for the secrets of a professional fitting and learn how to avoid the most common bike injuries and tap the most power out of your body and out of your ride.
Come prepared
You’ll need a trainer, a plumb line or some kind of string with a heavy object tied on the end and a good hour to relax, work and test. Grab a friend too, but that should be an easy find, especially if you offer to buy the beer.
Standover
First off, when you’re looking for a bike, you want to ensure that you have adequate standover height. Remember this as you buy the bike; you’re not going to be correcting this later, and it could cause a severe pain in the *beeeeeep* if you ignore this measurement. The greatest thing about standover is the ease of measurement. Toss on your bike shorts (chamois included) and stand over the bike in front of the seat. Lift the bars. You should be able to get the front wheel about 4” off the ground before it cranks you in the grundle. Once that’s squared away, get on a bike that feels reasonably good (have a LBS help you out) and pick the correct size.
Assuming you bought the correct size for your body (I’m going to assume that this is the case from here on out,) the rest of the fitting will be very easy.
Cleat positioning
The first thing to consider is cleat positioning. Get your cycling shoes on and hop onto that bike. Clip in and rest your foot in a relaxed, neutral position. Have your buddy feel for the balls of your feet; there’s a bump on the outside of your foot where your little toe joins the foot, and the same thing on the inside. Those are your landmarks for fitting the cleat, so make a small mark on the shoe dead center at each of those points. You’ll want to set the cleat right in between those two points for a good balanced cleat position. Now, you’ll need to sit on a high chair or counter with your feet dangling off. Note the position your foot turns (toe in or toe out) when just hanging relaxed. Now adjust your cleats so they face forward when your foot is in this relaxed position. With those adjustments, your feet and ankles should feel much better on the bike.
For proper knee alignment, the first thing you’ll want to do is climb on the bike, clip in, and spin on a trainer for a couple minutes to settle into your regular positioning. Stop, and then drop one foot to the absolute bottom of the crank stroke (Bottom Dead Center). Your knee should be almost fully extended at this point, so hold it there and have your friend measure your knee angle. Draw an imaginary straight line through the lower leg from the outside ankle bone up through the center of the knee joint. Draw another imaginary line from the large bump on the outside of the hip joint ( to the center of the knee joint. Where the two intersect, you’ll want to estimate the angle on TOP of the knee. You’ll want an angle between 30 and 40 degrees for proper knee extension. Imagine putting a slice of pizza on top of your thigh; that line through your lower leg should line up with the edge of that hunk of cheesy goodness. Raise and lower the saddle to increase or decrease the angle as needed until you get something that feels good and comes close to that magic number. The smaller the angle, the more power you’ll be able to put to the pedals.
Seat positioning
The second (and probably) the most important measurement is knee placement over the pedal. Spin on the trainer to get your comfy position down, then stop with your feet at 9 o’clock and 3 o’clock, and hold them there, dead even. Have your friend drop a plumb line from the tip of your kneecap down below the pedal axle. You want that plumb line to go right through the pedal axle. If it’s not, you’ll need to slide the seat forward and backward to compensate. Re-measure the plumb line and adjust until you’ve got the proper positioning.
Stem positioning
For stem positioning, you’ll want to have a 45 degree angle between the ground and your upper body. Adjust your stem length as necessary to adjust to that positioning. Note that a 45 degree angle is probably the best for a weekend warrior type; the more aggressive a rider, the steeper the angle can be.
Bar width, shifters and brake levers
For bars, unless you’re a wicked downhill junkie, you’ll be best off with some bars that are about shoulder width wide. Cut them down if you need to, but do it a little at a time to get a feel for changing the width. That will give you the ability to get down and open your chest up to breathe easy on climbs and control the bike easily on downhills. If your bars are too wide, steering can get twitchy on the downhills, and you’ll just eat dirt in a bad way, and that sucks. Once you’ve got all these measurements down, you can fiddle with your brake levers and shifters to put them in a comfy place for your hands.
And you’re done, so…
Now you need to go out and ride the hell out of that bike. Adjust things as you need to for comfort, or if you have problems with some skills (getting behind the saddle may require you to lower the post a bit.) With a good fit, you’ll have a hell of a better time, produce more power, have better balance, and have a lot more fun. And there’ll be more energy left after the ride for beer and pizza, and that’s always a good thing.
Questions? Comments? Love letters? Send 'em to Techeditor@mountainbiketales.com.
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