Using a radar detector?

Discussion in 'Spare Parts, Tools & Product Developement' started by Motorizedbikarguy, May 14, 2010.

  1. Motorizedbikarguy

    Motorizedbikarguy New Member

    Has anyone used a radar detector (police alert) on their bike?

    If you have how did you run it?


    I'm thinking about adding one on my 2 cycle MB :grin5:


  2. jared8783

    jared8783 Member

    never heard anyone say this before

    it would be fairly simple

    just get a small 12v rechargable battery like a moped or scooter battery and mount it on bike somewhere
    wire radar to that
    mount radar somewhere like the handlebars
    and there you go
  3. Fabian

    Fabian Well-Known Member

    Hi Motoredbikarguy

    Yes, i want to install a radar detector on my motored bicycle, because they are setting up speed cameras in the 40 k/ph (25 m/ph) zones in almost every location now.
    At the moment cyclists are not required to wear a number plate on their back, but Vicroads is looking ito legislation that will require cyclists to have positive identification carried on their body, just like they want to bring in legislation to make all cyclists pay registration fees for a bicycle, even for your 3 year old child riding his/her bike in a local park - it's government going insane.

    The private operators of mobile speed cameras are not required to give the public, the government error margin or 3 k/ph (1.5 m/ph), as per the fixed red light/speed cameras.
    So 40.1 k/ph is classified as 41 k/ph and it's almost a $200 speeding ticket.

    How do you know the speed camera isn't correctly calibrated or deliberately miscalibrated to increase their revenue - you simply don't know, so need to take preventative measures to protect yourself.

    I've done my research and want to get the new Escort Redline Radar/Laser detector and a mount to install it on my bike - it's small, compact and totally undetectable to the newest spectre 3 radar detector, detectors.

    Last edited: May 20, 2010
  4. loquin

    loquin Active Member

    Still may not help.

    If you were traveling at 20 kph, and a car, 50-100 ft. back were traveling at 50 kph, their speed, being the larger radar cross-section (at ten times the distance,) could show up when you crossed through the radar 'zone'. In effect, you could be getting their ticket. Think about it. The amount of metal that can reflect back at the radar gun is miniscule. Probably 5-10 square inches, max (and under most conditions, a couple of square inches) The metal which is not aligned to bounce the radar signal straight back at the radar receiver bounces it away in other directions... And part of the signal will be bounced off spokes, which are either at speeds from the bike speed down to zero, or at speeds up to twice the speed of the bike (it depends upon how far from the hub the spoke portion is.)

    What this means is that the speed recorded by the radar, is actually the speed of the largest radar target in range and general direction as you are, of the gun. So, a car 10 times further away could easily have many times the cross section as you on the bike do. A person's body doesn't reflect radar - it absorbs it. (Which is why microwave ovens work...) The fork and frame tubes are all positioned at an angle, which would tend to bounce any signal up into the air. Plus, they have a round cross-section, which means that only a tiny 'strip' of the tube could bounce the signal back at the radar anyway. About the only portions of the bike which normally could return a signal are the handlebars, the spokes, and possibly the hubs. But, they're ALL a round cross section...

    Only if there is no other traffic in range of the radar, would the radar speed measurement of a bike be accurate. And, maybe not even then, because of the spokes...
    Last edited: May 20, 2010
  5. Fabian

    Fabian Well-Known Member

    In the case of the fixed speed cameras, the device takes two photos at a measured time delay, so you can prove time over distance.

    At the very least, the radar detector gives an allert and allows you to get on the footpath when travelling past a speed camera.
    It's a stupid concept to attach a radar detector to a bicycle, but that's how bad things are getting in my state of Victoria (Australia).
    California has nothing on Victoria and New South Wales for revenue raising measures.

    Last edited: May 20, 2010