The BASICS Of Proper Fit
NOTE: I realize persons of good will might feel differently. Some question what is important. I have done my best to list these in order of importance. They are also the easiest ways to get a better fit.
There is a lot more to determining proper fit than just the correct frame size. If your bike is not properly fit to you, it probably isn’t going to be comfortable. You won’t ride it much.
Size is a good place to start. First and foremost, the DTC standard of using your height is never correct. My wife is 1-2″ taller than I when standing. She’s about 3″ shorter than I when seated. I cannot safely ride a bike properly sized for my wife. She would be cramped on one sized for me (yes, I am a lucky guy).
Any decent mfg has diagrams showing the measurements of their bike in different sizes. You should know your pants inseam. From the ground to the top tube, or where it would be on a diamond frame, it should be close to, but no more than, your pants inseam. It would be 1-2″ shorter than your actual inseam. Do not assume that it does not matter with a step through frame. A bike that is too large is dangerously hard to handle and too small will keep you from being able to take advantage of your full muscle range.
The temptation may be to think this isn’t as important on an e-bike. It is though. Range and comfort on longer rides is all about efficiency. Everything that makes a traditional bike more efficient and comfortable applies to an e-bike. Everything that makes a traditional bike less comfortable or less efficient applies to an e-bike as well..
There are niggling quibbles about some of the following. Certainly people have found ways to live with measurements that aren’t perfect, but if you are uncomfortable, one or more of the following may make all the difference in the world.
If your bike still isn’t comfortable, even with the proper size, it is because your bike does not fit. Suspension or an over stuffed saddle are just band-aides. Without meaning to, I have sold a lot of cushy saddles, that people really love, just by putting the new saddle in the proper position vs their old saddle. BTW, the nose of your saddle almost always should be pointed at the top of your stem. Road bikes level to slightly down. Mtb’s level to slightly up and commuters up, to keep your sit bones on the widest portion of your saddle (there’s no sense in having a wide or padded saddle if you are riding the nose like a cleaver all the time).
There are roughly a dozen ways to determine proper saddle height. BTW, you sit ON a saddle. You sit IN a seat. Shops are full of know-it-alls like me that will take you more seriously if you know the difference (no, I do not know why saddles are mounted on seat posts).
Some say to multiply your actual inseam by .883 to determine proper saddle height. Others say to multiply by 109%, both are to determine the proper distance from the top of your saddle to the bottom of your pedal stroke, with the ball of your foot between the pedal axle and front of the pedal. The Zwift diagram above says to measure the same by setting the saddle height to where your leg is straight with your heel only on the pedal. A very easy way to get close, is to rest the back of your saddle between the top of your thigh bone and bottom of your hip. The end result of all of these and a few others, is that your knee will have between 1 & 2″ of play at the bottom of your pedal stroke (as shown above). A saddle too high not only makes your bike dangerously hard to handle, but can cause pain at the back of your knee and a dead spot in your pedal stroke. It will also likely cause you to rock with each stroke. That wastes a lot of energy. Too low and you may have front of knee pain. You won’t be able to take advantage of all the muscles in your leg to pedal (more work and/or less range).
Even these measurements aren’t worth a lot if others don’t match. Rarely do shops bother and never do DTC retailers care enough to make sure the above setting doesn’t cramp or extend your knee at the power position of your pedal stroke. If it is wrong, not only can it keep you from getting the most from your pedaling effort, but can cause knee, hip and ankle pain. To get this right, ideally your knee will stay directly above the ball of your foot throughout the pedal stroke. Forward will cause front of knee pain. Backwards will cause back of knee pain. Both force fewer muscles to power your bike with less of their range. To check it, have a friend run a string from your knee cap to the ball of your foot at the 3 o’clock position of the crank. Normally, you can adjust this by moving the saddle forward or back on its Rails.
Now, the reason even some really great shops don’t bother with the setting above is that it can mess with your proper reach (saddle nose to the handle bars). Most people are more concerned about their back or sore hands than marginally better performance. The further you ride, the more this matters.
Adjusting your saddle fore or aft can impact proper reach. If you have to reach too far it rotates too much of your weight on to your hands, wrists, elbows and shoulders. It can hurt your back too. Sometimes your fingers or even your privates will go numb. If that reach is too short, you throw too much of your weight on to your lower back and you will be cramped pedaling (especially if you are fat like me). Ideally, your reach should be your cubit (tip of elbow to tip of fingers). That is, the nose of your saddle to the point at which your hands meet the bar (for women, it is a good idea to be a knuckle or two shorter…I hope I don’t have to explain why). On flat bars, that are not straight, to an imaginary line between the insides of your handgrips. Sometimes, there is enough play in your knee to just move the saddle, but often you need to change stems to get proper reach. A proper stem can be as little as a trade to as much as a couple hundred dollars for a suspension stem (plus $45 labor). Ask anyone that has ever made the change. It is worth every penny.
Reach can also be impacted by the width of your handle bars. Nearly all e-bikes come with flat handle bars. Since these have traditionally only been used for mtb’s, they tend to be extremely wide. Obviously, the further out your hands are placed, the further you are reaching. This is important for control off road. You want that extra leverage. For the street, especially on long rides, you want your bars no more than 2″ wider than your shoulders (or as close to that measurement as you can get). Bars that are too wide often hurt your elbows. Your outside two fingers will go numb and you will often have pain at the base of your neck, between your shoulder blades.
It is so funny to write this as a senior citizen. Back in The 70’s all the rage was narrow, drop bars to reduce wind resistance. You’d almost hit your knees on the bar ends (I did hit my knees on the bar end shifters I had).
Those of us paying for e-bikes, as well as those purchasing a better bike from a local bike shop, deserve a proper fit. It is amazing how often a person will choose the wrong bike because, of the two or so they test ride, the wrong one is closest to being properly fit to them.
Even little things like brake levers, adjusted to your fingers and handle grips small enough to wrap your fingers properly, can make a huge difference in your comfort and confidence. Even if you have to pay a little more to make your bike just right, it is a lot more affordable than purchasing a bike that then sits unused in your garage.