Topic: Anyone ever try to make their bike's EM field larger?

[eideteker]

Most of the traffic lights around here are signalled to change by an electromagnetic induction coil-type sensor.  Cars and trucks trip them just fine since they are giant hunks of ferrous metals (for the most part).  On the bike, I've had to sit at several lights that are triggered in such a manner until a car pulls up behind me or across the intersection opposite me.  Has anyone ever had any success adding magnets to their bike to increase the "EM size" of their bike?  If so, how large of a magnet did it take and where did you mount it?  Is this even worth looking at?  I could dig something up around here and try it for myself, just curious if it's been done before and what the effectiveness was.

[CycleRanger]

Does it work?  I've always wondered.

[markb]

When I run into this problem I just look both ways and go.   

[Duke McDukiedook]

By law if you don't trigger the loops as long as you check all directions before you go, you can go.

Same applies for bicycles, that's why I like the video trigger systems.

[74cb750]

Really? Well I was stopped for doing just that, at 3 am.
Must not be a law in New Hampshire.

[Trav-i]

By law if you don't trigger the loops as long as you check all directions before you go, you can go.

Same applies for bicycles, that's why I like the video trigger systems.

+1 on video systems.  Our city just started putting them in, it has made life on a bike so much better,

[markb]

Really? Well I was stopped for doing just that, at 3 am.
Must not be a law in New Hampshire.

Did you get a ticket?  Not to be a smartass but how long did he expect you wait?

[mystic_1]

The "Green Light Trigger" product is just a magnet in a plastic housing with a zip-tie.  Way over-priced for what you're getting imho.

I like to recycle the magnets out of old hard drives, if you can lay you hands on an old 5 1/4" hdd they usually have big honking magnets neodymium magnets inside.  Newer hdd's have good magnets too they're just smaller.

Forum member MoTo-BunnY had the great idea of mounting them into the feet of her centerstand and this seems to have worked for her.

http://forums.sohc4.net/index.php?topic=35872.msg372019#msg372019

mystic_1

[ieism]

Good plan, but it won't work. I did a little research into this, as my car has the same problem (don't make fun of the size of my car please
I have a Smart car, and it's mostly made out of plastic.

It seems a magnet is not what you need at all, the sensor "feels" conductive material not magnetic fields. It also senses metal surface area, not mass. So a large heavy clump of metal is no better than a thin sheet of metal. It picks up metal closer to the ground, so part of the problem is the height and surface area of your engine with a bike.

So you need a large area of conductive metal, close to the ground where the loop is build into the pavement. For cars they ussually install  and design the loops so they pick up your front axl.
Try this: stop right over the side of the loop (you can see the cuts in the pavement were they intalled it, and lean your bike towards the centre of it, it may work.
Or try bolting aluminium sheets under the soles of your shoes

[Duke McDukiedook]

You need ferric metals that will induce an EM field in them when the inductance loop is charged, aluminum won't cut it.

I would have fought that ticket, I hope you didn't pay the fine on that without a bloody fight at the traffic court.

Any cop that would ticket you after you waited for the light to change for 1-2 minutes at 3AM needs his badge stripped, period.

[Gordon]

I've had success with stopping my bike so the crankshaft is directly over a concentrated section of the loop.  I don't usually have too much trouble with the 750, but the 550 is less noticeable to them and requires more precise positioning. 

[eideteker]

You need ferric metals that will induce an EM field in them when the inductance loop is charged, aluminum won't cut it.

I was wondering if it really had to be ferrous or just conductive.  What's going to happen as automobiles go further toward Al and plastics as major construction elements?  Will there be enough ferrous material left to trigger induction loop-type sensors?

I would have fought that ticket, I hope you didn't pay the fine on that without a bloody fight at the traffic court.

Any cop that would ticket you after you waited for the light to change for 1-2 minutes at 3AM needs his badge stripped, period.

That cop must have been bored out of his mind, or had to fill his "non-existent" quota. 

[Kframe]

I've also heard that if you 'blip' your starter while directly over the field coils in the pavement it may trigger the light.
Not sure if this really works, as I stop, wait a bit, look both ways and go.
In MN we have the "affirmative defense" law regarding motorcycles and red lights. 

Minnesota Red Light Law. Sec. 42. Minnesota Statutes 2000, section 169.06, is amended by adding a subdivision to read: Subd. 9. [AFFIRMATIVE DEFENSE RELATING TO UNCHANGING TRAFFIC CONTROL SIGNAL.]

 

(a) A person operating a motorcycle who violates subdivision 4 by entering or crossing an intersection controlled by a traffic-control signal against a red light has an affirmative defense to that charge if the person establishes all of the following conditions:

 

(1) the motorcycle has been brought to a complete stop;

(2) the traffic-control signal continues to show a red light for an unreasonable time;

(3) the traffic-control signal is apparently malfunctioning or, if programmed or engineered to change to a green light only after detecting the approach of a motor vehicle, the signal has apparently failed to detect the arrival of the motorcycle; and

(4) no motor vehicle or person is approaching on the street or highway to be crossed or entered or is so far away from the intersection that it does not constitute an immediate hazard.

 

(b) The affirmative defense in this subdivision applies only to a violation for entering or crossing an intersection controlled by a traffic-control signal against a red light and does not provide a defense to any other civil or criminal action.

-K

[Gaither]

In TN if a light doesn't change in a "reasonable" time [whatever that may be], a motorcycle is, by law, allowed to proceed with caution if no traffic is approaching "on the green light" [greatly simplified]. We rednecks do it all the time, legally - very carefully.

This may or may not be a Fed law [?]. May be state-by-state.

[Spanner 1]

Think it's State by State, Gaither.... also we TN rednecks move thru' a 4-way stop 'en-masse' , at least up to 4 bikes in one 4-way 'go slot'..

[Brown Bomber]

I salvaged the magnets from some old speakers, and wired two of them to the center stand of my Concours, and lights that wouldn't change for me before, change now.

[Gaither]

Spanner!

Thanks - didn't know about the 4-way stop thing.

[eideteker]

I've also heard that if you 'blip' your starter while directly over the field coils in the pavement it may trigger the light.

I heard that as well and tried it a couple times, with no effect.  I don't really want to replace my starter anytime soon either.

[tramp]

never had the problem
perhaps moving the bike around would help