What's my wheel size setting?!

[slayer 83]

Hi, this is probably such a stupid question but I really cant sort this out.

 

I have a new polar cs200 speedometer on my road bike and I need to set my wheel size setting (mm).

 

In the manual they have a chart listing all the wheel diameters (ETRTO) with their corresponding wheel sizes in mm. But my ETRTO size isn't on this list and I cant find any info on the web.

 

My ETRTO is 622 x 15c.

 

I'm probably just missing something but I just cant figure this out. Any help will be much appreciated.

 

cheers

Polar chart.bmp

[TNT1]

dunno wtf an etrto is, but what's your wheel size? In inches?

[slayer 83]

dunno wtf an etrto is, but what's your wheel size? In inches?

I dont know, it doesn't give a size on the wheel and I dont have an imperial tape measure to measure the wheel if I could do that.

[owti1997]

Measure the circumference of the wheel (with the tyre fitted and inflated!) by rolling the wheel along a straight line and measuring the distance. Deduct about 10mm allowing for compression while riding. The circ of my 29r wheel with 2.25 tyre fitted is 2208mm.

[Captain Fastbastard Mayhem]

Have a look at the sidewall of your tire. The size is normally embossed on there. If it's a road bike, normally it's either 700*23c or 700*25c.

[Kranswurm]

Surely its worked out on the tyre size?

Thats on the side of the tyre

[TNT1]

Have a look at the sidewall of your tire. The size is normally embossed on there. If it's a road bike, normally it's either 700*23c or 700*25c.

 

There you go!

[slayer 83]

Aaha! Thanks alot, was so focused on the damn ETRTO size on the rim that I never checked the tyre! Idiot...

 

Thanks all

Edited March 14, 2012 by slayer 83

[Honkdonk]

Make a mark on your tyre sidewall with a piece of chalk, use the valve position as a starting point. Position your wheel with the valve/chalk mark on the floor. Make a mark on the floor that lines up with the chalk mark on your tyre. Roll your wheel along the floor one complete revolution in a straight line and make a mark on the floor at this point. Measure the distance between the 2 marks with a tape measure. Make sure that you use metric measurements and not imperial.

 

That is your wheel size setting

[TNT1]

Make a mark on your tyre sidewall with a piece of chalk, use the valve position as a starting point. Position your wheel with the valve/chalk mark on the floor. Make a mark on the floor that lines up with the chalk mark on your tyre. Roll your wheel along the floor one complete revolution in a straight line and make a mark on the floor at this point. Measure the distance between the 2 marks with a tape measure. Make sure that you use metric measurements and not imperial.

 

That is your wheel size setting

 

So much PT. The chart has the tyre sizes in it, just use that.

[Caerus]

Take piece of string, wrap around wheel and tyre to get the circumference and hey presto you are in business, mark the string and measure it on a ruler/ tape measure, this will give you your circunference. Then doing some simple arithmetic(with the newly aquired measurement) you can take the circumference to get the actual diameter of your wheel for your Polar. Here in case you not sure of the maths part.

 

Good luck

[Caerus]

So much PT. The chart has the tyre sizes in it, just use that.

 

Depends on how accurate you want to be

[TNT1]

Depends on how accurate you want to be

 

Yeah, I know a guy like you. Think he is a wanka as well...

[The Drongo]

So much PT. The chart has the tyre sizes in it, just use that.

 

Pfft. Took me 2 minutes yesterday. Just ran it valve to valve rev along a tape measure. 2,050. Presto!

 

PT my ass.

[TNT1]

Pfft. Took me 2 minutes yesterday. Just ran it valve to valve rev along a tape measure. 2,050. Presto!

 

PT my ass.

 

Oh, look, another one. Please collect your tapout shirt when you leave.

[NotSoBigBen]

dunno wtf an etrto is, but what's your wheel size? In inches?

 

Isn't that what I get a mail about very now and then .... 'ERTO will be implemented tonight at midnight and points will be deducted for traffic offences'