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  1. #1
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    Bike Computer Gain Miles on My Car

    I've been noticing that my computer gains mileage on the ride home on the hitch rack. I probably wouldn't have noticed it, but after a ride a few weeks ago I was looking at my stats from my ride and I noticed that my max speed was over 60 MPH. I started paying more attention to it and today I gained about 1.3 miles in the 8 mile ride home, and my max jumped to 70 MPH. Before I left the trailhead the numbers were normal.
    What do you suppose is causing the interference ?
    It's a cateye micro wireless, and I'm pretty sure the magnet wasn't right on the sensor while on the rack.
    Anyone else seen this? I've seen my heart rate monitor freak out going over railroad overpasses...

    WRFB

  2. #2
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    your wheel spins while on a hitch rack style that allows the wheels to dangle. it's an effect of the wind and your spokes. put a bungee through your wheel to prevent it from spinning if this matters to you.

  3. #3
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    nope, wheels don't turn. the rack's an Xport flatbed...wheels sit in hoops

  4. #4
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    Quote Originally Posted by WillRideForBeer View Post
    nope, wheels don't turn. the rack's an Xport flatbed...wheels sit in hoops
    there's something magnetic going on causing the switch in your wheel sensor pickup to go off. flapping webbing straps anywhere? is there a piece of the rack that passes near the wheel sensor? pics of how your bike sits in the rack might be helpful.

    if there is an electric current passing through the rack due to some wonky electrical issues on the car, it could potentially be inducing a magnetic current that might be enough to trigger the wheel sensor to register.

  5. #5
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    I also have a Cateye wireless, and the same thing happened to me this past weekend. I had taken the front wheel off and laid the bike in the back of the car (an Audi A4 Avant, FWIW) for the dozen or so mile drive to some trails. For the drive out, I put the bike in rear-wheel first, and it didn't register extra mileage. But for the return trip I put it in fork-first, and the odometer registered about an extra mile and a half and a peak speed of 64 mph.

    Just wondering if the OP ever figured out what was causing this. My guess is that there's something electronic towards the front of the car (at least in my case) that either the sender is picking up and thinking it's the wheel magnet or the computer itself is reading as a signal from the sender. Next time I'll pop the computer off, at least that'll tell me which one is picking up the interference.
    Last edited by jjaguar; 08-15-2012 at 09:58 AM.

  6. #6
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    Most likely a design flaw with the unit itself. Probably not worth a recall but I bet they know about it.
    2012 Fianceť
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  7. #7
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    Quote Originally Posted by jjaguar View Post
    I also have a Cateye wireless, and the same thing happened to me this past weekend. I had taken the front wheel off and laid the bike in the back of the car (an Audi A4 Avant, FWIW) for the dozen or so mile drive to some trails. For the drive out, I put the bike in rear-wheel first, and it didn't register extra mileage. But for the return trip I put it in fork-first, and the odometer registered about an extra mile and a half and a peak speed of 64 mph.

    Just wondering if the OP ever figured out what was causing this. My guess is that there's something electronic towards the front of the car (at least in my case) that either the sender is picking up and thinking it's the wheel magnet or the computer itself is reading as a signal from the sender. Next time I'll pop the computer off, at least that'll tell me which one is picking up the interference.
    Vibration can cause the reed switch in the sensor to close repetedly, sending a signal to the head unit. I have had it happen on rough downhills, giving me max speeds over 70mph.

    Remove the head from the bike during transport and it will not record anything.
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