Traffic Light Trigger for Your Bike

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Introduction: Traffic Light Trigger for Your Bike

Not feeling ferrrous enough to trip the induction loops that trigger green lights? No problem - just epoxy a rare earth magnet to your shoe! Inspired by a product marketed to motorcyclists, which is basically a big neodymium magnet to stick under your ride. I thought it might be better to get a slightly smaller magnet closer to the road.

Step 1: Dremel As Needed Between the Lugs of One Heel

I always put my right foot down, so I ground out a little extra space on my right heel. Luckily, my Sidis have tall, widely-spaced lugs, so I didn't have to remove much material.

Step 2: Epoxy the Magnet, Backed With a Washer, to the Shoe

I used PC-7 heavy-duty epoxy paste and coated the entire magnet, both to protect it and to stick it firmly to the heel. Backing the magnet with a washer helps to focus the magnet field, aiming it down (and not up into your heel, not that it should do anything to you anyhow).

Step 3: Using the Magnet to Trigger Lights

Look for the round or diamond-shaped cuts in the asphalt that show where induction loops are buried at intersections, and set your heel down near the tar lines. Here in Portland, some lights helpfully have a small bike between two hashmarks which you're supposed to line your wheels up with, which is a the perfect spot (and more sensitive, too).

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    user

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    81 Comments

    Will it work if I attach it on bottom of bike? I do not want to dig a whole in my shoe.

    heres another idea check out yr local flea markets u might find a whole computer that up 4 sale

    I have a bunch of eraser - on - the - end - of - a - pencil size earth magnets. I almost always wear work boots on bike. If I stuck a few of those in the space just in front of the heel, do you think that'll work?

    or better yet with hard drive idea but cable tie the them to the spoke of the wheel near the rims.

    No drives laying around.

    More images would help with this, but it's such a cool idea.

    I am quite amazed at the amount of comments this posting has generated. I have seen intersections where I live in Southern California that have the sensors in the bike lane, sized smaller (about 18" across) for bicycles. They even have a pictogram of a bicycle painted in the center. I hope this is a trend that continues to grow.

    user

    I'm also from SoCal. I've seen those bike lane sensors, one up on PV and some in Santa Monica. Here in Torrance where I live, new traffic light installations have the camera type triggering and I've found these to work very well with bicycles. No magnets!

    By the way- Sweet idea!

    i didnt read all the comments, so this may be repetitive info: if you put the magnet in your shoe, then you will be picking up all types of metal shavings and what not. these may come off as you walk into your home, and reside in your carpet. and then some how they make their way into your skin as a splinter. or scratch up a nice wood floor. if you get an old hard drive, crack it open and get those magnets out. tape it to one of your spokes as far away from the hub as you can. put one one each wheel, or two on the rear wheel, spaced 180 degrees apart, for maximum coverage. depending on your wheeels/tires, these magnets will come within 1 to 3 inches away from the road, for those magnets, that is close enough to trigger the loop. i had this work when i stacked 2 of these magnets together, and hot glued them to my frame, below the bottom bracket.