How to Size a Bike

Are you trying to figure out what size bike you need? A lot of people think this may be quite the task, but in fact it's pretty easy and I bet you can do it yourself — especially after reading my how-to. ;)  Being hardly 5'8 but with a lengthy inseam of 35" myself, I've had my fair share of sizing issues. But after being taught the proper and simple steps it takes to size yourself, I've had zero issues . Knowing how to properly size yourself for a bike is a major plus —especially when looking to purchase online. 

Did you know you could be a size in one model, and a different size in another? For example if you're a size L in an Orange Bike, it's likely (but not definite) that you'll be a size L in a brand like Surly or Diamondback Bicycles. Sizing isn't straight across the board. Do you have gazelle legs with a super short upper body like me? Maybe a Michael Phelps torso with some stubby legs? Unless you're perfectly proportional, you're going to want to dive a little deeper than just referencing your height to a size chart. But don't worry! It's as simple as measuring your inseam and a wee bit of math. (If I can do it, you can. Trust me when I say my math skills aren't up to par). 

Ready to figure out your size? Here's the rundown: 

1). Buy the right frame for your style of riding. There are so many different frames available, but the frame shape (geometry) is drastically different depending on what type of riding the bike is intended for. Will you be casually riding around town or hitting the singletrack? Maybe neither and you're a roadie. Keep in mind — there are just as many variations of models of  bikes as there are styles of riding. 

• Mountain Bikes
• Typically have a lower center of gravity to help with balance while riding over roots, rocks, mud etc. 
• Center triangle is more compact
• Top tube typically angles down, away from the handlebar
• Frames are (typically) measured in inches
• Road Bikes
• Frames are usually large, isosceles triangles with the top tube parallel to the ground
• Frames are (typically) measured in centimeters
• Racing bikes typically have smaller frames while touring or commuter bikes will have larger frames 
• Hybrid Bikes
• Combined features of road and mountain bikes
• Street riding or casual riding
• Frames (typically) measured in centimeters
• Cruiser Bikes
• Usually have S-shaped or curved frames allowing you to sit upright while riding
• Handle bars are high and slightly in front of you
• Often called "city bikes" or "commuters"
• Fit is based more on comfort than measurements 
• Kids Bikes
• Smaller frames, similar to mountain bikes 
• Helps with keeping balance with lower center of gravity
• Very adjustable to compensate for quick growth
• Frames are (typically) measured by wheel size 

2). Take the most important measurement: Your inseam. Standing with your feet about 6" apart, take a measurement from the inside of your foot up to your crotch. 

• If you are sizing a mountain bike, measure in inches. 
• If you are sizing a road bike, measure in centimeters 

3). Use your inseam to decide the best size bike for you based on standover height. Now it gets tricky (kidding!) You'll want to convert the measurement of your inseam (either in inches or centimeters) and convert it to millimeters. Ah! Math! Google makes this very easy. ;) The reason you are converting your measurement to millimeters is because you will want to compare this to the standover height (which is in millimeters) on the bike you are wanting. You can find the standover height under the size guide on each bike product page. 

• Mountain bikes: 
• You want a minimum of 2" of clearance between the tires and the ground when standing over the top tube. (*More aggressive riders may prefer up to 4-5 inches*) 
• For example, if your inseam is 34", you will want a bike with a standover height around 32".  
• If the bike is full suspension, it's okay to have less initial clearance (1"-2") as the suspension compresses under your weight while sitting on the bike. 
• Road bikes:
• Sloping top tube: Ideally you want 2" clearance or more between the ground and the tires when you lift the bike while straddling it. 
• Straight top tube: Ideally you want 1" of clearance
• Hybrid bikes: 
• City commuter? Use road bike guidelines
• Beach cruiser or step-thru style? No need to worry about standover height! Most of these have very sloped top tubes that make it a breeze to easily step thru and place your feet flat on the ground. 

4).  Check your reach.Handlebar reach is simply the distance you reach from your saddle to your handlebars. In more specific terms, reach is the horizontal value between the bottom bracket and handlebars. Having a proper reach to the handlebars plays a key role in bike comfort. Whether the bars are too close or too far, you may experience neck, shoulder, back and wrist pain. On most bikes you can easily adjust your reach by replacing the stem. To check your reach at home, take a ruler and measure from your armpit to the palm of your hand. Once you determine your reach, convert this to millimeters as you did with your inseam.  You can find the reach measurement listed under the size guide on each bike product page. A comfortable reach should: 

• Let you rest your hands comfortably on the handlebars. Your fingers should be free to move around.
• Keep you elbows slightly bent, not locked nor pressed up.
• Allow you to reach all parts of the handlebars, especially gears and brakes, easily.
• You can bend from the waist, not the back, to reach down
• Generally, casual riders prefer higher handlebars while racers will want a longer reach. 

5). Use wheel diameter to help with deciding a size for a kid's bike. Most every kid's bike is extremely adjustable to accommodate to random growth spurts that kiddo has ahead of them (this also helps so you don't have to buy a new bike every year, score!). However, you still want to make sure the fit is right. 

• Child's inseam is 12-17 inches
• 12-inch wheels
• Child's inseam is 18-22 inches
• 16-inch wheels
• Child's inseam is 22-25 inches
• 20-inch wheels

6). Always check the bike over and make any final adjustments before going out for your first ride. All is not set in stone. You can still easily make many adjustments to your bike if you're still not liking the fit or feel. Start with the saddle. The height of the seat is easily adjustable and even on the right size bike, it may feel wrong if your seat isn't positioned correctly. You'll want to fine-tune a few things depending on personal preferences. 

• When sitting on the bike with one foot at the very bottom of the pedal's rotation, you want a *slight* bend at the knee. 

7).  Something still feeling off?

• Upper body position
• Aim for a position that gives you a good amount of bend in your arms without having to reach too far to apply the brakes. 
• Road Bikes
• Ideally your torso will form a 45-degree angel with your hips and a 90-degree angel with your arms. 
• Tight hamstrings or short arms?
• Try swapping stem to bring handlebar closer
• Mountain Bikes/Hybrid Bikes
• Aim for the same angels but they are not as critical since riding style is more relaxed than on a road bike
• Knee pain?
• Back of knee: Seat is too high. Try lowering it.
• Front of knee: Seat is too low. Try raising it. 
• Seat angle
• Women typically tilt the seat down for comfort while men tilt seat up

That's it! My *simple* ;) guide to sizing yourself for a bike. Keep in mind, every body is different and in the end it comes down to your own comfort and fun. And as my father-in-law said, it usually takes some time to get used to the flow and feel of a new dancing partner— try to think of your new bike in a similar way. Your first few rides may not feel right, but you'll quickly get to know each other. 

Still unsure what size you need? No fear, we are here! Carl and I are always happy to help you determine the best size bike you need. And, not to brag, but I did have a customer call me an expert the other day....  

Happy riding! -Kathryn