Originally Posted by bboseley
I have a Cateye 7 computer that performs well – but I can’t seem to get it calibrated exactly. I suspect a cordless is not intended to dead on. On a premeasured bike trail, when I cross the 20-mile marker, my Cateye will show about 19.2. Does this throw the current and/or average mph off also? In which direction?
Anyway, my real question concerns average mph. First, when riders go out and talk about riding a 20mph pace – won’t the average mph be somewhat less? Even a pace-line will have occasion to slow for various obstacles, but they can still say they are riding a 20mph pace. The computer on the other hand is going to penalize them on average mph.
Lastly, and maybe this isn’t all the information needed, but say I am beginning the last 5 miles of a 40 mile ride. The computer shows me at 14.8 Ave mph. Based on my ride yesterday, it seems I would need to maintain virtually 19 mph all the way in to bump the Ave to 15. Actually I did almost that, and was perturbed to see my final average at 14.9. As George is fond of saying – “This is hard work!”
By the way, anyone with a Cateye know if I need to adjust the circumference number up or down?
Tyre size as measured and not from the quick data given on the sheet will give you a computer that is set for your tyre size. The correct tyre circumference, or incorrect, will affect all the readings for the computer.
To my thoughts, a 20mph pace will ocacsionally drop below 20mph, hence lowering that average---but it will also occasionally go above the 20mph so should even itself out over a ride.
I have used Cateye cordless for many years now, and other than breaking the sensor on the Cateye 2's, have never had a problem with them so wise choice on your part. As to whether they are accurate enough, I think they can be when correctly set up, but there will always be a minor discrepancy on any computer.