Bike Computer Set Up

[Del 80]

Anyone know what the excact circumference setting is, for a 26'' wheel, on a bike computer, this one says 2045, but I suspect that it is not accurate.......Del.

 

[benjy_a]

http://sheldonbrown.com/cyclecomputer-calibration.html

Scroll down to the chart of sizes, find your tyre size....it gives you the circumference.

Ben

 

[flecc]

Varies widely according to the tyre fitted Del, some much taller than others. Best to measure it. Make a chalk mark from tyre to ground, wheel the bike forward until the chalk mark is at the bottom again and mark the ground, then measure the distance from beginning to end.

Another way. Use a spirit level on a straight edge on top of the front tyre to make the straight edge exactly level, then measure the distance between ground and straight edge. Then multiply that by 3.14 (Pi). This needs a second pair of hands.

2045 would be for a very tall tyre, Kinetics calculator says 2016 for a typical 26" 559 tyre.
.

 

[Davanti]

... Make a chalk mark from tyre to ground, wheel the bike forward until the chalk mark is at the bottom again and mark the ground, then measure the distance from beginning to end. .

Just what I was going to suggest, flecc .......

 

[Del 80]

Thanks Guys, I will do a roll out in the morning.........Del

 

[GaRRy]

Best if you have room to do say ten revolutions (in a straight line) and measure that distance divided by 10. Helps to get it more accurate.

 

[NRG]

Better still, inflate the tyres to the correct pressure, sit on the bike and then mark the tyre and roll forward and measure as Flecc mentions above!

 

[GaRRy]

Better still, inflate the tyres to the correct pressure, sit on the bike and then mark the tyre and roll forward and measure as Flecc mentions above!

Better still do both

 

[Mussels]

I used the GPS speedo on my phone, see if they match and if not adjust the bike computer.

 

[Biker44]

Anyone know what the excact circumference setting is, for a 26'' wheel, on a bike computer, this one says 2045, but I suspect that it is not accurate.......Del.

Dunno - but I've struggled with this and will use some of the tips others have provided.

E-bikes especially need these cycleputers as a fuel-gauge.

 

[Del 80]

Just done the roll out.....2035 exactly.....so, now going to calibrate device, and test it.....fingers crossed....Del.

 

[Del 80]

Well, it works, now for a ride around the block.........

 

[Del 80]

Everything seems o.k. registered 14.5 miles an hour....on throttle only, then had to stop for lights, and registered 0.48 of a mile, which is about right.....marvellous, well pleased seeing that this is only a ''cheap'' one.........Del.