Bell 4Forty Air MIPS - MTB Helmet

The right size of your hardtail mountain-bike:

The Inside leg length is multiplied by 0.226 and thus you get the theoretical value of the frame size in inch. One inch equals 2.54 cm.
If the theoretical value is in-between two sizes, the following rule of thumb can be applied:

• choose the smaller size when riding athletically
• choose the larger size when riding tour-orientated

How to determine your Inside leg length:

The Inside leg length or stride height is the length of the inside of the leg. The most accurate way to measure your stride length is to use a spirit level and a tape measure or folding rule. Stand barefoot on a flat surface, clamp the spirit level horizontally between your legs and measure the distance from the upper edge of the spirit level to the ground. This value corresponds to your stride length.

Alternatively, you can also determine your frame height based on your height, see the table below. However, the method using inseam length is more accurate.

If you need help, please call us at +49 (0) 2641 -89 00 0.
We will be happy to advise you!

The right size of your fullsuspension-bike:

The Inside leg length is multiplied by 0.226 and thus you get the theoretical value of the frame size in inch. One inch equals 2.54 cm.

If the theoretical value is in-between two sizes, the following rule of thumb can be applied:

• choose the smaller size when riding athletically
• choose the larger size when riding tour-orientated

How to determine your Inside leg length:

The Inside leg length or stride height is the length of the inside of the leg. The most accurate way to measure your stride length is to use a spirit level and a tape measure or folding rule. Stand barefoot on a flat surface, clamp the spirit level horizontally between your legs and measure the distance from the upper edge of the spirit level to the ground. This value corresponds to your stride length.

Alternatively, you can also determine your frame height based on your height, see the table below. However, the method using inseam length is more accurate. If you need assistance, please call us at 02225-8888-222. We are happy to advise you!

The right size of your Sport-Touring Cycle:

Frame-size in cm: multiply your Inside leg length by the factor 0.61. Frame size in inch: multiply your Inside leg length by the factor 0.24.
If the theoretical value lies between two sizes, the following rule of thumb can be applied:

• Rather the smaller frame size when riding sportsmanlikely
• Rather the next frame in size when riding tour-orientated
• Deduct approx. 5 cm (or 2 inches respectively) of the theoretical size when using spring-mounted seat posts.

How to determine your Inside leg length:

The Inside leg length or stride height is the length of the inside of the leg. The most accurate way to measure your stride length is to use a spirit level and a tape measure or folding rule. Stand barefoot on a flat surface, clamp the spirit level horizontally between your legs and measure the distance from the upper edge of the spirit level to the ground. This value corresponds to your stride length.

Alternatively you may select the right frame size according to your height with the help of the chart below. This only serves as a rough guide though.

If you need help, please call us at +49 (0) 2225 - 98 90 590.
We will be happy to advise you!

The right size of your road bike and triathlon bike:

The right size of your road bike and triathlon bike:

• choose the smaller size when riding competition-orientated
• choose the larger size when riding tour-orientated

How to determine your Inside leg length:

The Inside leg length or stride height is the length of the inside of the leg. The most accurate way to measure your stride length is to use a spirit level and a tape measure or folding rule. Stand barefoot on a flat surface, clamp the spirit level horizontally between your legs and measure the distance from the upper edge of the spirit level to the ground. This value corresponds to your stride length.

Alternatively you may select the right frame size according to your height with the help of the chart below. This only serves as a rough guide though.

If you need help, please call us at +49 (0) 2225 - 98 90 590.
We will be happy to advise you!

The right size of your Trekking or Touring Cycle:

Frame-size in cm: multiply your Inside leg length by the factor 0.66.
If the theoretical value lies between two sizes, the following rule of thumb can be applied:

• Rather the smaller frame size when riding sportsmanlikely
• Rather the next frame in size when riding tour-orientated
• Deduct approx. 5 cm (or 2 inches respectively) of the theoretical size when using spring-mounted seat posts.

How to determine your Inside leg length:

The Inside leg length or stride height is the length of the inside of the leg. The most accurate way to measure your stride length is to use a spirit level and a tape measure or folding rule. Stand barefoot on a flat surface, clamp the spirit level horizontally between your legs and measure the distance from the upper edge of the spirit level to the ground. This value corresponds to your stride length.

Alternatively you may select the right frame size according to your height with the help of the chart below. This only serves as a rough guide though.

If you need help, please call us at +49 (0) 2225 - 98 90 590.
We will be happy to advise you!