Tools

Wheel circumference
Frame size calculator 2
Frame size calculator 3
Windchill

To set up the cycling computer the exact wheel circumference is needed..

The wheel circumference will vary depending on the rim, the pressure and the weight load. The most exact results will be archieved by rolling off the wheel with the cyclist in the saddle.

A computed result is possible with the following circumference calculator. The needed values are ETRTO information on the wheel's edge (see sample pictured).

Value 1: 
Value 2:

Result:     mm wheel circumference

Zoll	ETRTO	Zoll	ETRTO
16"	50-305	26"	50-559
	35-349		54-559
	37-349		57-559
18"	40-355		60-559
	50-355		37-590
20"	35-406	28"	20-622
	40-406		23-622
	47-406		25-622
	50-406		28-622
	54-406		30-622
	60-406		32-622
24"	47-507		35-622
	50-507		37-622
	54-507		40-622
	57-507		42-622
	60-507		47-622
	62-507		50-622
26"	35-559		54-622
	40-559		60-622
	47-559		32-630
			40-635

Sample pictures

55-559

57-559

62-559

The ETRTO (European Tire and Rim Technical Organization) size marking shows the width and the inner diameter of the wheel. 57-559 = 57mm width and 559mm inner diameter).

Calculation of the frame size with the Body-Index-Frame-Sizing method.

Another possibility to find your best frame geometry is the Body-Index-Frame-Sizing method. This method was invented by the magazine „Mountain BIKE“. To calculate your personal frame size there is a little bit more effort to do. Therefor you get detailled information to find the bike which fits you the best. The determination base differs from the so far used formulas of the various providers. The tendency is more towards somewhat smaller framesizes. Three measurements are needed.

Body lenght - The body lenght is measured from the ground to the sternum (small v-shaped notch below the throat).
Arm length - The arm length is measured from the start of the collarbone to the middle of your clenched fist.
Inside leg - To measure your inside leg you place yourself barefooted against a wall, put a level between your legs and push it slightly upwards. The distance between the ground and the upper edge of the level shows the inside leg.

Please put your personal values into the first three boxes.

Frame size calculation

Five measurements are needed.

The correct frame size is the most important element for maximum driving pleasure. Only those who feel comfortable on their bike will ride it regularly. In order to calculate the correct frame size, several factors must be considered.

Windchill factor

Wind-chill or windchill, (popularly wind chill factor) is the perceived decrease in air temperature felt by the body on exposed skin due to the flow of air.

Wind chill numbers are always lower than the air temperature for values where the formula is valid. (Source Wikipedia)

Windchill Calculator

5 measurements are needed
mm shoulder width
mm shoulder height						Measuring point outside of the clavicle
mm body length						Ground to sternum (Notch at the lower end of the throat)
mm fist heigth						Ground to knucklebone with clenched fist
mm inside leg
Gender:
Range of use:
Results
						mm seat length
						mm stem length
						mm top tube length
						mm head tube length
						mm seat tube length
						zoll seat tube length

Body length (ground to sternum)	mm	Caution!!! Values need to be in millimeter
Arm length	mm
Inside leg	mm
for	Cross-Country	Tour	Enduro
Seat tube length	mm	mm	mm
Head tube length	mm	mm	mm
Stem length	mm	mm	mm
Reach	mm	mm	mm
Seating length	mm	mm	mm
Top tube length (male)	mm	mm	mm
Top tube length (female)	mm	mm	mm

Air temperature
Wind speed

Windchill temperature = perceived temperature

5 measurements are needed

Results