To measure a BMX bike frame, you will need a measuring tape and a friend to help you. First, stand the bike up on its wheels and have your friend hold the top tube level with your waist. Then, use the measuring tape to measure from the center of the bottom bracket to the top of the head tube.
Write down this number and then repeat the process for the other side of the frame. Finally, measure from the center of one seat stay to the center of the other seat stay. This is your seat tube length.
- Decide which type of measurement you need
- There are two types of measurements for BMX bike frames, top tube length and stand over height
- Top tube length is the horizontal distance between the head tube and the seat tube
- Stand over height is the vertical distance between the ground and the top tube
- Place the frame on a level surface
- If you are measuring stand over height, make sure that there is no tire attached to the frame
- Measure from the center of the headtube to the center of the seatube for top tube length
- For stand over height, measure from the ground to the top of the top tube
- If you are measuring an old school style BMX frame, then measure from where the headtube meets the down tubes (halfway up) to where they meet again at the bottom bracket shell (center)
- This will give you your chainstay length measurement 4bIf you are measuring a new school style BMX frame with integrated or semi-integrated headset bearings, then measure from where one side of the bearing cover meets the down tubes all way across to where it meets again on other side (at bottom bracket shell)
BMX BIKE FRAME MEASUREMENTS AND GEOMETRY!
What Size is My Bmx Bike?
There are a few things to consider when trying to determine the size of BMX bike that is right for you. The first is your height. You will want to stand over the top tube of the frame and have about 2-3 inches of clearance.
If you can not comfortably stand over the frame, it is too big for you. The second thing to consider is the length of the seat tube. This measurement will give you an indication of how tall the bike will be once built.
Typically, BMX bikes have a seat tube length that is about 2-4 inches shorter than their actual height (measured from the ground to the top of the headtube). This allows riders to get low and aggressive when riding. Finally, take a look at the wheelbase of the bike.
This is the distance between where the two wheels sit on either side of the frame. A longer wheelbase will provide more stability while riding, but may make tricks more difficult to perform. A shorter wheelbase will make tricks easier, but may sacrifice some stability.
With all this in mind, here are some general guidelines for choosing a BMX bike based on your height:
Rider Height (in) Frame Size (in)
4’10” and under 13-14
4’11” – 5’2″ 14-15
5’3″ – 5’6″ 15-16
What Age is a 20 Inch Bmx Bike?
There is no definitive answer to this question as it depends on a number of factors, including the rider’s height and ability level. However, we would generally recommend a 20 inch BMX bike for riders aged 8 years and up. If your child is particularly tall or advanced for their age, they may be able to ride a 20 inch BMX bike from as young as 6 or 7 years old.
Conversely, if they are on the smaller side or still learning the basics of riding, they may need to wait until they are 10 or 11 years old before progressing to a 20 inch BMX bike. Ultimately, it is best to consult with your local bike shop or experienced rider to get guidance on what size bike will be best for your child.
What Size is a 20 Inch Bmx?
20 inch BMX bikes are the industry standard for racing. The wheels on a 20 inch BMX are smaller in diameter than those on a mountain bike or a road bike, which makes them lighter and faster. Most BMX riders prefer to ride a 20 inch bike because it offers more maneuverability and control than a larger bike.
How Do I Find My Bike Frame Size?
Assuming you don’t already know your frame size and want to measure for it, there are a few different ways you can go about finding your bike frame size. One way is to measure your inseam. You can do this by standing against a wall with your shoes off and measuring from the ground up to the crotch of your pants.
Once you have this measurement, multiply it by 0.67. This will give you an estimation of what size frame would be best for you based on stand-over height (the distance between the top tube and your crotch when standing over the bike).
Another method is to measure the length of your torso.
To do this, find the bony protrusion at the base of your neck and measure from there down to your waistline. Again, once you have this measurement, multiply it by 0.67 to estimate what size frame would be best for you based on reach (the distance from the seatpost to the handlebars).
If possible, it’s always best to test ride a bike before purchasing it so that you can make sure that both the stand-over height and reach feel comfortable for you.
However, if this isn’t possible, measuring yourself as described above should give you a pretty good idea of which size bike will work best for you.
Credit: odysseybmx.com
Bmx Frame Size for 5’11
If you’re 5’11” and looking for a BMX frame, you have plenty of options. Here’s a rundown of some of the most popular frame sizes for 5’11” riders:
-20.5″: This is one of the most popular BMX frame sizes for 5’11” riders. It provides a great balance between being nimble and maneuverable, while still being stable and comfortable at speed.
-21″: This is another popular option for 5’11” riders. It offers slightly more stability than the 20.5″ frame, while still maintaining good maneuverability.
-21.25″: This is a great option if you’re looking for a bit more stability than the 21″ frame.
It’s also a good choice if you want to run bigger tires (up to 2.4″).
So, what’s the best BMX frame size for 5’11” riders? Ultimately, it comes down to personal preference.
Try out a few different sizes and see which one feels best for you.
Bmx Bike Size Chart by Height
Bmx Bike Size Chart by Height
In order to find the perfect BMX bike, you will need to know your height and inseam measurements. You can use this chart as a guide to find the right sized BMX bike for you.
BMX Bikes come in many different sizes. The two main variables that will affect what size frame you should get are your overall height and your inseam (inside leg) measurement. Once you have these numbers, you can consult a sizing chart to determine which size frame is right for you.
For example, if you are 5’6” tall with a 29” inseam, according to the chart below, you would need a 20” top tube length frame. However, it is always best to try out a few different bikes before making your final decision since everyone has their own preferences.
Size Top Tube Length Frame Standover Height Rider Height Suggestion
Mini 20″ 16-17″ 4’10” and under
Junior 20″ 17-18″ 4’11”-5’3″
Expert XL 21″ 18-19 5’4″-5’7″
How to Measure Bmx Wheel Size
When it comes to BMX, wheel size is everything. The wrong sized wheels can make your bike feel sluggish and uncomfortable to ride. Conversely, the right sized wheels can make your bike feel fast and responsive.
So how do you know what size wheels to put on your BMX?
There are a few different ways to measure BMX wheel size. The most common way is to measure the diameter of the wheel, which is typically done in inches.
For example, a 20″ BMX wheel has a diameter of 20 inches.
Another way to measure BMX wheel size is by measuring the circumference of the wheel. This is often done in millimeters and results in a slightly different number than measuring the diameter.
For example, a 20″BMXwheel has a circumference of 63.5mm.
The last way to measure BMX wheel size is by looking at the width of the tire. This measurement is important because it affects how wide your handlebars are (among other things).
Tire width is typically measured in millimeters and ranges from about 1.75″ all the way up to 4″.
Knowing what size BMX wheels you need starts with knowing what kind of riding you want to do. Are you looking for speed or maneuverability?
Do you need wider tires for stability or narrower tires for easier Trickster moves? Once you have an idea of what you need, then you can start thinking about sizing up your wheels!
Bmx Bike Size Calculator
For those of you who are looking to buy a BMX bike, one of the most important factors to consider is what size bike you need. There are a few different ways that you can go about finding out what size bike you need, but the best way is to use a BMX bike size calculator.
There are a few different BMX bike size calculators available online, but our favorite is the one from BikeRide.com.
To use this calculator, simply enter your height and weight into the fields provided. Once you do that, the calculator will give you four different bike size options to choose from.
We recommend starting with the middle option and then adjusting up or down based on how the bike feels when you ride it.
If it feels too small, go up to the next largest option. If it feels too big, go down to the next smallest option. With a little trial and error, you should be able to find the perfect fit for your new BMX bike!
Conclusion
When measuring a BMX bike frame, you will need a tape measure and someone to help you. The first step is to measure the top tube length. This is the distance from the center of the head tube to the center of the seat tube.
Next, measure the seat tube length. This is the distance from the center of the bottom bracket to the top of the seat tube. Finally, measure the chainstay length.
This is the distance from the center of the bottom bracket to where the rear wheel axle meets the frame.