How To Set Up Bicycle Speedometer

You accept bought a new bike computer and want to set information technology up correctly? At the step where you enter the wheel circumference into the bicycle speedometer, at that place are different procedures.

In this commodity you will learn 3 ways to set up your wheel calculator correctly.

✅ Calculate wheel circumference with formula
✅ Mensurate bike circumference
✅ Set up bike computer with table

The three methods are explained in this article uncomplicated and understandable. In improver, I explain the advantages and disadvantages of the methods.

If your bike reckoner is currently showing incorrect readings, then this article will most likely assist you besides. You volition also acquire how to bank check the right setting.

First, the wheel computer must be mounted correctly. Therefore, nosotros commencement first with the bicycle computer mounting:

Bike computer: The correct mounting

Almost all bike computers can be mounted without tools. Each bike calculator comes with a magnet and a sensor. This is how yous continue when mounting the bike computer:

1. Attach the supplied magnet to the spokes. It does not matter at which position the magnet is attached. Please annotation: The magnet and the sensor must exist at the aforementioned acme and the distance between them must not be also large. In practice v mm is a good distance
2. Attach the sensor to the fork at the level of the magnet.
3. For a bike computer with cablevision: Lay the cable from the handlebar to the fork (from the wheel estimator to the sensor). With a wireless bicycle computer this step is omitted

In the video, all steps are conspicuously shown using the popular Sigma BC 14.sixteen (with cable) as an example:

Tip: Cable ties are very helpful during assembly. Sometimes cable ties are also included. Most of the time, the wheel computer sensor is held in place with i or more condom bands. In the beginning, this usually works quite well. Afterwards a certain time, the rubber can then unfortunately become brittle. I or more cable ties will then hold the sensor securely in place.

Setting the bike computer correctly

If your bike computer is mounted correctly, yous tin at present ready the bike reckoner properly. For this I will show 3 possibilities and yous will learn the advantages and disadvantages of the methods.

I recommend y'all method 2 "Measure bike circumference with tire rotation". The issue with the wheel computer correctly ready here will exist the most correct. With this method your weight and also the tire condition including air force per unit area are included.

Summate wheel circumference with formula

The quick method for setting the bike speedometer! This method involves measuring the bicycle tire: The radius of the bicycle tire is determined with a folding dominion. With the formula U = 2 * pi * r (where the circle number pi = 3.14) y'all then calculate the wheel circumference.

The radius of the bike tire is measured from the outermost signal of the casing to the eye of the axle.

These are the steps:

1. Inflate tyres
2. Using a folding rule, measure out the radius from the bicycle tire.
3. The determined radius in mm into the formula U = 2 * pi * r.

Conclusion on the method (summate bike circumference with formula)

✅ Easy and quick way, to make up one's mind the wheel circumference and adjust for the cycle speedometer.
✅ Method includes the own bike circumference

Bad

The wheel circumference calculation method is relatively inaccurate. If you already have a folding dominion at hand, measure the tire circumference (side by side method).

Measure cycle circumference with tire rotation

This method is much more accurate. By measuring you directly make up one's mind the tire circumference:

1. Inflate tyres
2. At the point where the bicycle points exactly downwardly, make a mark on the bike casing and on the footing e.chiliad. with a slice of chalk. Alternatively, you tin can also use the bicycle valve equally a marker.
3. Roll forrard with the bike. Until the marking on the bicycle tire points exactly downwards once again.
4. Measure the distance travelled with a folding dominion. The distance travelled is the bicycle circumference in millimetres
5. Enter value into your bike computer

Echo the method a few times to go the almost accurate event.

In this brusque video the method is explained very understandably:

Your bike calculator is set correctly? Information technology is best to drive a precisely measured route. With this you lot can cheque the correct setting and check whether the bike speedometer setting was successful.

Conclusion on the method (measure wheel circumference with tire rotation)

For setting the bike computer, use this method. It is quick and like shooting fish in a barrel and the results are the most accurate.

Setting the wheel computer with wheel circumference table (ETRTO table)

To determine the correct bike circumference, you exercise not necessarily have to measure out. There is also a handy bike circumference chart. There you lot can easily read the value for your wheel circumference.

In a bike circumference chart, there are three important specifications:

• The tire size in inches: The number indicates the judge tire inner diameter in inches.
• ETRTO specification: ETRTO stands for European Tyre and Rim Expert Organisation. The ETRTO specification has the post-obit format: 47-406. The first number, 47, is the tire width in mm. The 2nd number, 406, is the inner diameter of the tyre in millimetres.
• approximate wheel circumference: This is the third and most of import size. With the help of the ETRTO specification, you tin can read the approximate bicycle circumference from the table.

If you have set the wheel circumference in your bike calculator, then the speed and distance can be recorded correctly from now on. Adjusting the bike speedometer was successful 😉

Wheel circumference read off the tire: Here information technology is 29 inch bore and 2.1 inch width – nevertheless works even with a dirty tire 🙂

Depending on the information on the tire, you can then read the tertiary important size in the tabular array, the wheel circumference in mm. This value must then exist gear up on the bike estimator so that the speed and distance are recorded correctly.

Depending on the tyre manufacturer, the wheel circumference is given slightly differently in the ETRTO table. The source for the tabular array below is the Schwalbe Tech Sheet. Manufacturers like Sigma Sports as well accept their own ETRTO tables for their cycle computers.

By and large the ETRTO table is included in the delivery and is for instance printed on the packaging or part of the manual. Set bike calculator with tabular array:

Customs	ETRTO	Wheel circumference in mm
26″	35-559	1990 mm
	40-559	2030 mm
	47-559	2050 mm
	fifty-559	2075 mm
	54-559	2100 mm
	57-559	2120 mm
	60-559	2160 mm
	37-590	2100 mm
27,v″	54-584	2195 mm
	57-584	2215 mm
	sixty-584	2240 mm
28″	20-622	2100 mm
	23-622	2125 mm
	25-622	2135 mm
	28-622	2150 mm
	30-622	2160 mm
	32-622	2170 mm
	35-622	2185 mm
	37-622	2200 mm
	forty-622	2220 mm
	42-622	2230 mm
	47-622	2250 mm
	50-622	2280 mm
	40-635	2250 mm
29″	54-622	2310 mm
	57-622	2330 mm
	60-622	2340 mm

On Mountainbike-Folio.de yous will observe a detailed compilation by tire manufacturer and tire blazon. With these tables yous tin determine the cycle circumference with the table method.

Conclusion on the method (setting the bike computer with tabular array)

✅ Quick and like shooting fish in a barrel method for determining the bike circumference
✅ many tire manufacturers offering individual tables

Bad

The wheel circumference table (ETRTO table) is not the most accurate method for determining your bicycle tire circumference. The values determined are only approximations. Many factors play a part in the exact determination of the bicycle tire circumference, east.1000. the condition of the casing and the rim and especially your tire pressure level. I therefore recommend measuring with the tire rotation to determine the wheel circumference.

Were you able to adjust your bicycle figurer? Do you have any questions? Then feel free to drop me a annotate – I'll be happy to reply.

Source: https://bikepacking-adventures.com/en/bicycle-speedometer-setup-wheel-circumference/

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