Just got a bike computer, which is asking for my (or rather my Dawes Horizon's) wheel size. The tyre is covered in numbers and I have no idea which to use - 622, 128, 350. The default figure in the computer is 155. What do I tell it?
Quoted message said:
Thanks,
Quoted message said:
Daniele
Sheldon Brown is your friend. Someone will come along in a minute with the URL.
155 as a default suggests this is the wheel circumference in cm.
If the bead seat diameter is 622mm (a 700c wheel) and the tyres are 35mm wide, (guessing from figures here) you will need to enter 217.
Just got a bike computer, which is asking for my (or rather my Dawes Horizon's) wheel size. The tyre is covered in numbers and I have no idea which to use - 622, 128, 350. The default figure in the computer is 155. What do I tell it?
Sheldon Brown is your friend. Someone will come along in a minute with the URL.
155 as a default suggests this is the wheel circumference in cm.
If the bead seat diameter is 622mm (a 700c wheel) and the tyres are 35mm wide, (guessing from figures here) you will need to enter 217.
Actually, the default was 2155, which I misread. And it's a weird system - my tyres are 25-622, which I eventually worked out means you enter 2146 as your wheelsize if you want to measure it in km/h, or 1333 if you want to measure it in mph. I guess that means I can't just press a button on the unit to switch between a readout in mph or km/h.
Just got a bike computer, which is asking for my (or rather my Dawes Horizon's) wheel size. The tyre is covered in numbers and I have no idea which to use - 622, 128, 350. The default figure in the computer is 155. What do I tell it?
Sheldon Brown is your friend. Someone will come along in a minute with the URL.
155 as a default suggests this is the wheel circumference in cm.
If the bead seat diameter is 622mm (a 700c wheel) and the tyres are 35mm wide, (guessing from figures here) you will need to enter 217.
Actually, the default was 2155, which I misread. And it's a weird system - my tyres are 25-622, which I eventually worked out means you enter 2146 as your wheelsize if you want to measure it in km/h, or 1333 if you want to measure it in mph. I guess that means I can't just press a button on the unit to switch between a readout in mph or km/h.
No; that seems to be their root calculation when you fire 'em up. But mine have always used the same wheel circumference which is around the 200 and something cm's whether they are m or km. I long since switched all mine to km's, it is vital for audax and no big deal to convert otherwise.
