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cyclocomputers and magnets out there!

SpinSis2010-04-28 19:14:46 +0000 #1
Does anyone else experience this (and do you have a solution/recommendation)?

I have a basic, Nashbar brand wireless cyclocomputer. It records speed, time, average speed, max speed, and distance, and then has an odometer. It uses a magnet on the front wheel to track it's info (pretty standard, I think), and I've got it calibrated (checked by riding with others for comparison).

I am VERY frustrated, however, by how magnetic fields out there in the world constantly mess with it, and screw up my data! I work at big hospital complex with Lord knows what for radiation and magnetics. And I regularly ride through technology central (aka. Kendall Square at MIT) which also messes it up. And by "messes with it" I mean: I'll be at standing at a stop light going 75mph! As you can imagine, it messes with average speed and distance and time. It even does this if I hold it near a computer.

HELP! Is this normal, or is it just my cheap device?


DebW2010-04-28 19:26:43 +0000 #2
I suspect it's not the magnet, but the RF signal between the wheel sensor and the computer. I've not heard of such problems with wired computers, even in Kendall Sq. Wireless units seem much more susceptible to interference. There was a thread several months ago discussing wireless computer problems.
DeniseGoldberg2010-04-28 19:36:52 +0000 #3
That sounds totally frustrating.

Have you talked with other cyclists who are riding through the same areas? I remember seeing a bicycle parking area at MGH (I didn't make that up, did I?) - can you talk to some of the other riders at the hospital to see if anyone else is having the same problem?

It also might be worth trying a step up from your inexpensive Nashbar device. I've been using a Cateye wireless computer and I've been happy with it. I just checked online, and the model is the Cateye Wireless CC-MC100W. It has the same functions you mentioned, nothing fancy. I picked mine up at REI, but I imagine you can find them at a local bike shop too.

--- Denise
Eden2010-04-28 19:42:26 +0000 #4
I used to use a Cat-Eye wireless, but I had too many problems with it not picking up or going haywire so I switched to a wired Sigma Sport.

The problem you get at stop lights is from the induction loop sensor that is used to change the light. Wired systems aren't affected by them. My heart rate monitor is affected by some things too - invisible dog fences most notably.



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