You’ve got your dream bike, but after the first few rides, you may be experiencing some discomfort. Does your back ache a bit? Are your hands are going numb? There’s more to a proper bike fit than “how it feels.” Your inseam, arm and torso length, flexibility, and preference with regards to bike handling are all critical factors to account for when fitting your bike to your body. Here we’ve broken out a few tips that you can do at home in order to dial in the fit of your mountain bike a bit further.
Dial-In Your Touch Points
Your bike has three touch points: saddle, grips, and pedals. These points are crucial to a proper bike fit.
1. How to Set up Your Pedal Cleats
Of the three touch points, your shoe and pedal interface is arguably the most important. If you’re riding with clipless pedals and shoes, your bike fit should start with your shoes’ cleats and the shank, where they bolt onto your shoes. This position will affect comfort and pedaling efficiency.
Start by wearing your bike shoes, and on the inside of the soles, mark the ball of your foot with a pen or marker. Set the cleats in the center of the shoe along the marked axis. This is your starting point.
Cleats can be positioned fore and aft, and side to side. The side-to-side adjustment is key as it can alleviate knee pain when done correctly. Think about your riding style—do you pedal with your knees tucked in close to the top tube of the frame? Or are they set wide? If you ride with narrow knees, move your cleats toward the outside of the shoe. This moves your foot toward the crank and straightens your knee. If your knees run wide, do the vice-versa, and move the cleat toward the inside of the shoe, which will help align your knees.
As you hone in your fit over the next few rides, you can move the cleat forward or back, and side to side until you find the most comfortable, efficient pedaling position. Try sitting and standing while pedaling on a flat, smooth surface to gauge your comfort. And be prepared with a 4 mm wrench to make adjustments.
2. How to Choose a Bike Saddle
The first question to ask yourself is “why am I replacing my saddle?” Is the saddle torn or too heavy? If so, then replacing it with the same or similar style makes this process easier. But if you’re experiencing discomfort, buying a new saddle becomes more complicated. It takes careful observation of where you are feeling aches, pain, or loss of efficiency. Are you sliding around, experiencing chafing where your legs rub, is the padding too stiff?
Most saddles on new bikes come with generic, one-size-fits-all dimensions. This isn’t necessarily a bad thing but people come in all sorts of shapes and sizes. To make sure you’re using the right saddle for your body, start with your “sitting bones,” or the ischial tuberosity. The width of these bones is a critical measurement and will begin the narrowing process of selecting the proper saddle. Your saddle should complement and support this distance. This measurement is best done with the use of a tool or guide, and most bike shops will have such a device and be able to interpret this information to make a recommendation on the proper type of saddle for you.
These measurements only go so far. An additional saddle pressure scan that you would get at a professional bike fitting service would tell you additional information about how your sit bones actually interact with the foam and shape of the saddle.
The best way to find a saddle is to visit a professional shop and inquire about a saddle demo program. Have your sit bones measured and ride different saddles until you have found something comfortable. Investing in a precise bicycle fit will help you find the right saddle faster, but will be more expensive.
One last piece of advice: always mount your saddle flat. Saddles are designed around being flat and will offer the best support and comfort when mounted on your seatpost in this way. Only in certain circumstances do saddles call for being mounted at an extreme angle with the nose up or down. A professional bike fitter will be able to help you make that call.
3. How to Choose Bike Grips
Bicycle grips compliment your handlebars and allow you to hold on and improve handling. If you’re using the grips that came stock on your bike, and have never had any complaints, keep using them without a second thought. However, if you’re experience numbness in your hands or pain, you may need to swap the stock grips for something more ergonomic.
Hand pain or numbness is usually caused by pressure on the Ulnar and Median nerves. The Median nerve runs to the thumb, index, and middle fingers. While the Ulnar nerve runs to the ring and pinky fingers. Ulnar nerve pressure is the most common culprit of numbness. Choosing a grip with a more ergonomic shape and complementing that with a handlebar with more backsweep can relieve this pressure. One fix could be to move your saddle forward, which in turn moves your elbows out and your body forward over the bars. This position can relieve pressure and should be taken into account before purchasing new grips or bars.
Mountain bike grips also come in different sizes and foam densities. Some options offer a slim diameter with minimal texture, and others a larger diameter, or a more textured surface. Your hand size is most important here. If you have large hands, a larger grip is going to feel more comfortable plus offer a more secure hold and safety while riding. If you’re looking to upgrade, try and identify if there are any specific pressure points where you might benefit from a different grip shape. Then head to your local shop, grab a few different grips, and talk to the staff to see which ones are right for you and your needs.
Proper Bike Fit Measurements
A proper bike fit starts by looking at three different measurements of your bike:
The distance from the saddle to your stem
The stem and bar height
Saddle height
The human body is remarkably proportional, and key upper and lower extremity lengths are perfectly suited for bicycle fitting. It’s almost as if nature intended it. Because of their accuracy, we have adopted many of these simple measurement techniques in our own shops, in addition to more advanced fitting methods and measurements.
1. Saddle-to-Stem Distance
Put your elbow on the nose of your saddle with your arm pointed to your stem. With your wrist and hand outstretched, your middle finger should fall right on the top cap on the bike stem. If your outstretched finger falls in front or behind the top cap, you’ll want to move your saddle backward or forward accordingly.
2. Stem Height
This measurement is a bit tricky as it has a direct correlation with saddle-to-stem distance as well as your flexibility and core strength. This measurement also comes down to personal preference, as some riders prefer a higher handlebar for comfort or lower for more power transmission. To start, take your index, middle, and ring fingers and place them across the top of your head tube. The height of your fingers should not go over the height of your stem. This is a starting point, to get your stem in a ballpark range that you can hone in as you ride.
The next step would be to ride and take note of any back or neck pain. If you experience pain over the course of a few rides, try putting headset spacers underneath your stem or look into getting a higher rise handlebar. This will put you in a more upright position and take some of the pressure off your back and neck.
3. Saddle Height
Now that you have your saddle-to-stem distance and your stem height dialed, place your armpit on top of the saddle and extend your arm and hand down toward your crankset, which should be positioned at 12 and 6 o’clock. Your middle finger again should touch the middle of the crankset almost exactly. If not, adjust your saddle accordingly.
Saddle height and distance from saddle to stem can be adjusted relatively easily. However, if you’re looking to raise your stem but have found that your steerer tube is too short, look for a dramatic riser handlebar. This will provide the necessary lift you need without having to empty your wallet on a new fork or steerer tube assembly.
A Proper Bike Fit
Everything we listed here are considerations and adjustments that you can make at home. But nothing beats a proper bike fit done by a professional. Having a second set of trained eyes and someone to discuss pressure or pain with will alleviate many of these issues quickly. Bike fits usually start around $150 and will take 2-3 hours when done properly. Your fitter will invite you into the shop after a couple rides as well to reassess and ensure you are riding comfortably. Be sure to call ahead to schedule your time.