Finding the Perfect Size for Your Electric Bike According to Haibike
Electric bicycles are incredible for a number of reasons - one of them being that they have multiple sizes and styles to fit a variety of riders. But, what is the right size? How do you fit to a standard diamond or step-through frame? Let’s break it down between the two frame sizes with help from Haibike.
What are the benefits of right sizing?
Often enough, those who ride bikes hardly ever get their frames, saddles, and handlebars properly fitted. According to The Physician and Sportsmedicine journal, having incorrect fitting can lead to an increase in chance for injury. If you’re constantly reusing the same muscles incorrectly, you’re more likely to abuse your body (Kronisch, 1998).
The most common injuries for bicyclists is anterior knee pain and patellofemoral pain syndrome. Due to overuse and the increase of injury, the tissues around the knee and legs is traumatized, inflames, and damages surrounding tissues (Asplund and Pierre, 2004). Having proper bike fitting allows your body to perform at its peak.
Dr. Baker focuses is effort on the importance and nuances of proper bike fittings, and he has mentioned that riders who come to him with pain due to biking often feel relieved after being properly sized for their bike (2009).
Even if you’re purchasing an electric bike online, taking it to an experienced bike shop to get fitted could save your muscles from getting overworked - which means you can ride longer (extra bonus)!
Diamond Frame Sizing
You’ll notice the diamond frame on standard and mountain bikes. For example, this Stromer ST1X ebike:
Diamond frames consist of two triangles, one containing the top tube, seat tube, down tube, and a portion of the head tube. The other triangle is the rear triangle, containing the seat and chain stays. The Haibike Sduro Nduro 6.0 serves as a good example:
When it comes to sizing, you will want to consider your use for the bike, the terrain in which you’ll be riding, and your standover height. Haibike recommends checking for standover height by straddling the bike frame and bouncing on your heels repeatedly. When bouncing, if the top tube is touching your crotch, the bike is too big and you should try another bicycle. You’ll want a certain amount of clearance depending on your riding style and terrain.
Diamond Frame Top Tube Clearance Chart
|Riding Terrain||Top Tube Clearance (In.)||Top Tube Clearance (CM)|
|Paved surfaces only||2”||5cm|
When looking at this chart, think about where you’ll be riding. Make sure your top tube clearance meets this standard.
Another way to get an estimate for your ideal frame size, you can find a bicycle frame calculator online. You’ll want to know your inseam and height. Calculators and charts are helpful because they can give you an range of bicycle frame sizes that will fit, but you’ll ultimately want to test the bicycle before purchasing.
The step-through frame was famously used by women back in the day because the frame allowed skirts to be worn without having the indecency of flipping a leg over the frame.
Nowadays, you’ll see all genders, ages, and sizes on the step-through frames. They’re incredibly helpful because riders with back or knee injuries don’t have to worry about climbing over a high frame. By stepping through, the transition between standing and riding is easy. Also, riders who are shorter in height will enjoy the fit better with a step-through frame.
Bike pictured: Pedego Step-Thru City Commuter - 28"
Sizing for a step-through frame is different than a diamond frame. Instead, you’ll want to look at the saddle height and how your legs are positioned when pedaling.
To find the proper size, sit on the saddle, place one heel on a pedal and rotate the crank until the pedal is in the down position. Take a look at your leg...is it straight? Your leg must be completely straight to be properly seated. If you find yourself having to shift your hips or entire body to pedal, your saddle is too high. If your leg is bent, you’ll want to consider raising the saddle. Dr. Baker suggests having your leg around 30-degrees with your foot horizontal on the pedal (2009).
Remember, when raising the saddle, you’ll want to make sure you’re not raising it beyond the “Maximum Extension”. There should be a mark on your seat post or a sight hole in the seat tube to indicate where your saddle lies. Make sure you pay attention to your dealer’s recommendations and brand’s specifications.
You may also be able to adjust the saddle front and backwards as well as the angle of the saddle. You’ll want to make sure you’re fitting the adjustments within the brand’s specifications in your user manual.
Another way to help adjust the bicycle for your fit, you can adjust the height and angle of the handlebars. You’ll want to make sure you speak with your dealer about adjusting the handlebars, as different styles of stems can affect the adjustability. You may also be able to adjust the brake levers located on the handlebars.
Ultimately you’ll want to speak with your dealer about the perfect fit. You should look for a dealer that has knowledgeable staff who are ready to tweak and adjust your bike to make sure you’re riding comfortably and safely. Happy riding!
Asplund, C., & St. Pierre, P. (2004, April). Knee Pain and Bicycling. The Physician and Sportsmedicine, 32(4). Retrieved from Google Scholar.
Baker, A. (2009). Bike Fit (4th ed.). San Diego, CA: Argo Publishing. Retrieved from Google Scholar.
Kronisch, R. L. (1998, March). How to fit a mountain bike. The Physician and Sportsmedicine, 26(3). Retrieved from Google Scholar.