Wired Cateye v Wireless Cateye

matiny2k

Hi,

My work colleague and I have just bought Trek road bikes and did our first long distance trip yesterday. We're not quite sure how far we went because my 'wired' cateye said 74 miles but his 'wireless' cateye said 82 miles !

Is it usual to have such differences ? Are 'wired' devices more accurate ?

Thanks


Mat

alfablue

Either computer could miss some data if the wheel magnet and the sender on the forks are poorly aligned, alternatively it is feasible that the receiver of the wireless one misses data because of interference (though this is unlikely with current digital wireless ones). LED lights sometimes interfere, but these tend to cause over-reading, with crazy high speeds. More likely is that your wheel circumferences are inaccurate. Don't bother with the values in the handbook, not all 700x23 tyres (or any other sizes) will be equal. Measure the wheel circumference by rolling the wheel one complete revolution along the floor and measuring that distance (start with the valve perpendicular to the floor, mark floor, roll till valve is again perpendicular, mark floor, measure, enter that in the computer. If the computer has provision for two wheel sizes, make sure you are using the correct one).

tlw1

any difference in speed showing on the computer as you are side by side?

pbracing

I've got a wireless strada, did a 50 mile out and back ride, recording 2 miles less on the return run. A bit more extra than the long way round a roundabout :?

landrew

alfablue wrote:

More likely is that your wheel circumferences are inaccurate. Don't bother with the values in the handbook, not all 700x23 tyres (or any other sizes) will be equal. Measure the wheel circumference by rolling the wheel one complete revolution along the floor and measuring that distance (start with the valve perpendicular to the floor, mark floor, roll till valve is again perpendicular, mark floor, measure, enter that in the computer. .

I agree with the comments above. You may not get accurate results using the standard fugures from the instructions.

landrew

alfablue wrote:

More likely is that your wheel circumferences are inaccurate. Don't bother with the values in the handbook, not all 700x23 tyres (or any other sizes) will be equal. Measure the wheel circumference by rolling the wheel one complete revolution along the floor and measuring that distance (start with the valve perpendicular to the floor, mark floor, roll till valve is again perpendicular, mark floor, measure, enter that in the computer. .

I agree with the comments above. You may not get accurate results using the standard fugures from the instructions.

matiny2k

Thanks - yes, we were side by side and the speeds were different.

Having done the trip by car I think my wired reading (distance) was more accurate.


Mat