Top Tube Length
The first thing most people think about when choosing their new frame is the length of the top tube. BMX bikes come in a variety of sizes and aftermarket frames come from 16" all the way up to 24". The length of your top tube will ultimately decide how your bike feels so getting it right is critical, too long the bike could feel harder to maneuver too short and the bike will be too small for the rider.
Less then 20"
Some 20-inch frames will not actually be 20 inches, having said this you will still use all 20-inch components. These frames are built for shorter riders making the step up off the 18 inches. These Kieran Riley signature frames from Tall Order are 19.8"
$349.00 USDRegular price
Most BMX frames will fall somewhere between 20" and 21". This size fits most BMX riders and feels the best for most styles of riding.
21" and up
Frames with top tubes longer than 21 inches are designed for the taller rider trying to get a little more room in the cockpit. It's important to choose the right size for your height so you don't look like your on a pit bike!
Chain Stay Length
Chainstay length is the distance from the centre of the bottom bracket to the centre of the rear axle. This length is important to consider when choosing a frame because it changes the way your bike will react in different situations. The standard chainstay length on BMX bikes is between 12.8-14 inches. Street and park frames are leaning towards a short more “snappy” back end. The shorter the back end the closer the bike is together allowing the rider to spin,...
Short Chainstay (12-13.4 Inches)
Manual 180's have never felt so easy! Shorter back ends bring the rear wheel in closer underneath you making the balance point closer to your feet. This makes it easier to pull up into a manual or can make spins go around faster.
Medium Chainstay (13.5 -14 inches)
A medium back end would lie somewhere between 13.5 inches to 14 inches long. This middle-ground for your chainstay length has been a popular choice for companies over the years.
Longer Chainstay (14 + inches)
A longer chainstay length will do the opposite to a short back end. The longer the chainstay gets the wider your wheel base becomes, this makes your bike feel more stable but harder to pull up a wheelie!
Head Tube Angle
The head tube angle refers to the angle at which the head tube rests. (90 degrees being vertical) Most BMX frames range between 74-76 degrees headtube angle. The higher the number the steeper the front end will feel, similar to fork offset, the steeper the more responsive it becomes. The more mellow the angle, the less responsive and more stable at higher speeds it will become.
Steep headtubes have become more popular with street and park riding with some frames getting to 76 degrees. (90 degree's being vertical) Steeper headtubes are more responsive depending on which fork/bar/stem combo you are running.
Most frames' headtube angles will fall between 74° and 75°. This angle only changes the feel of your bike in a minor way unless you are at the extreme end of the scale.
Mellow head tube angles are more traditional and are used more in frames build for large transition or trails riding. The mellow headtube angle increases the wheelbase and is there for the stability of your ride.
Stand Over Height and Seat Tube Angle
The stand over refers to the height of the tube that holds the seat pole. This height determines the height of the top tube in relation to the angle of the headtube. As trends have changed over the years companies have experimented with very low (6.5") standover heights whereas other brands have gone the other way making standover heights at 9.5". The angle of the seat tube does change the feel of the bike. This is why it is important to...
The lower your standover height the less "bike" you will have underneath you, meaning less weight, and more maneuverability. These types of frames are generally used for technical park riding, however, I'm sure we all remember the Colony Phantom frames.
Most frames will lay somewhere between an 8"-9" standover height. The angle of the seat tube will then impact the length of the top tube. This happy medium is popular across most brands as it has stood the test of time.
Taller standover frames are more of an aesthetic for some riders. if you are a taller rider you a probably going to like the look of a taller standover however it will make minimal difference to how your bike actually rides.
The talking point of every BMX riders bike should be their frame. For that very reason, the frame can also be quite a big expense. Most 20” BMX frames range between $350- $550 with an exception for American made frames that can go up to $900. Similar to forks, frames use a variety of methods during the manufacturing process that can impact on the cost of the frame. American made parts are more expensive and promote a higher quality product.
Frames in this price range will either be a combination of Hi-tensile steel and Cromo at the lower end or full Cromo at the higher end. Several companies will offer frames in this range. These Kink Cloud frames are great value for money!
Frames in this price range will start to include thicker tubing, tapered headtubes, built-in chain tensioners, more gussets and even invest casted joins. These frames are suited to the rider stepping up off his first complete frame.
Frames in this price range use more technology and can feature invested cast dropouts, bottom bracket bridges and seat stay bridges, and internal gussets and can use ovalised or thicker tubing to reduce dents.