magnets on bike frame to change the traffic lights.

[1800 spec 3]

Originally Posted by Alan Hawk

In Boise, a VTX 1300R simply does not have enough ferrous metal on it to trip most of the lights in town. In fact, Idaho has a law that says if you are on a motorcycle and sit through one complete light change for everyone else and your light did not trip, then you are legally allowed to run a red light.

It's still VERY annoying, and I've discovered that quite a lot of drive through resturants use magnetic mass detectors also, and my VTX won't trip them. However, many bicycles will.

For the person who mentioned running your rims over the dector several times to make it trip, aren't the rims on a VTX 1300R aluminum? Either way, this doesn't work. First of all the detectors close to the surface of the road are in the approach to the light, not where you stop. The dectors where you stop are burried further, below the pavement, so there is no scar on the pavement indicating where they cut into it to place or adjust the sensors. Instead, they paint 4 yellow 3x3 inch squars in a rectangular pattern over where they think the sensor is, and you are supposed to place your bike in that rectangle. The drivers manual for the state of Idaho says that if you are on a motorcycle you are supposed to stop at the thick white stop line, and then ease your bike forward until the white line is in the middle between the front and rear tires, putting your front tire in the cross walk. Doing either or both of these still doesn't work. I usually have to wait until another car comes up behind me, tripping the sensors as it approaches.

I suppose each state does it their way. In NC, you can see the "asphalt snakes" where the pavement has been cut, strips put down, and then filled with tar. Very easy to spot.

[Redjack]

Quote: I can see where the confusion over magnets comes from. In quite a lot of cities the detectors are called "Magnetic Mass Detectors". What that means is that they detect ferrous metal, or metal a magnet will stick to. So people see magnet and they think it detects magnetic fields rather than detecting the mass of metal capable of being attracted to a magnetic field.


Also known as a MADMAN in some circles....

[jamaga]

The inductance theory is correct and rolling over any portion of the buried wire detector will induce the same signal strength for the Loop Detector in the control box. Setting the sensitivity of the Loop Detector control box is a very easy operation however some "Loop Detectors" can only be changed to a high, or low sensitivity and cannot necessarily be set high enough for a motorcycle. Then the only course of action is to replace the Loop Detector to one with more sensitivity. I have seen where the sensitivity has been set to high and causes lights and gates to short cycle and that is far worse than not cycling at all. There I shot my wad.........

[sherjimcarp]

A lot of cities are very polite when you call them and tell them they need to up the sensitivity of an intersection. They WANT them to work for motorcycles.

_____
i called the city where i live to tell them about the sensor near my house and the engineer’s secretary called me back in like 10 minutes and said the it will be adjusted. she even thanked me because her and her husband ride and she did not know that this was possible. he told her to tell me to stop on the middle line of the sensors that have three lines in the direction of traffic flow. something about a figure-eight and most points of contacts.

this is cool, because i've been at this light for over 10 minutes before. if no cars come to the light crossing the main road, i'm screwed.

[Tombstone]

Originally Posted by Rezin

They absolutley DO work. I have used them for years. They trip the 2 stubbon lights near my old house, and also actuated the gate at the apartment I used to live at.

They have nothing to do with the weight of the bike, it has to do with the size of the magnetic feild caused by the FERROUS metals in your bike. Aluminum and plastic and such do nothing. a magnet however does emit a field, and if you are moving along the edge of the loop sensor, it will see the disruption, and change the traffic signal.

Some loop sensors are so out of whack, a freigt train would have a hard time tripping them, but a magnet will help in most cases. Been uing them for 10+ years, and pretty much everone I know uses them too. They definatley make a difference. They don't change every light every time, but it's enough of a difference to use them.... Not like it is expensive or difficult to install or maintain.

CURSES! Foiled by Plasti-Chrome yet again!

[Frybie]

Originally Posted by jackandangie

Most traffic signals don't work on the principle of magnetism, they work on the principle of inductance. If putting a magnet on makes them change faster then it's the mass of metal that make up the magnets, not the magnetism. You'd have better luck if you strapped a manhole cover to the bottom of your bike.

Jack

Jack

New Floorboard mod???

[Alan Hawk]

Maybe someone makes steel floorboards? I wonder how much steel you have to add to make the bike more likely to trip the sensor. Engine guards? New floorboards? I already added a backrest and brackets and rear carrier and I'm pretty sure those are steel (to heavy not to be), but that's not enough. Steel floorboards and engine guards might help.

[ervin260]

Here is a little additional info, how loop sensors work at traffic light:
http://www.humantransport.org/bicycl.../detection.htm
http://marshproducts.com/pdf/Inducti...Write%20up.pdf
http://www.magneticsensors.com/datasheets/new_pers.pdf

To make it short:

"There is a common misconception that an object must be ferrous (include iron) to activate a traffic signal loop sensor, or that a ferrous object will perform better.
A number of variables affect the degree to which the introduction of a conductive object will change the effective inductance of the sensor loop. These variables include:
The size, shape, and conductivity of the object
The 3-D orientation of the object with respect to the wires in the loop
The 3-D position of the object over the loop
The size and shape of the sensor loop
The nominal operating frequency of the circuit "
In other words, the mass (weight) of the vehicle doesn't matter, but the size of the (horizontal) surface of conductive material on your vehicle does and its distance from the loop too. Lower (but less weight) vehicles with the same size of conductive surface will trigger the sensor easier than a heavier, but higher clearance vehicle (sports car vs. SUV).

And how it works ?

"Theory of Operation
Inductive-loop traffic detector systems operate by sensing disturbances to the electromagnetic field over a coil of wire built into the roadway. When a conductive object (typically made of metal) enters the area over the wire loop, the magnetic field generated by alternating electrical current in the signal detector circuit induces weak electrical currents in the conductive object. (The AC frequency may be between 10,000 and 200,000 Hz, typically around 20,000 - 30,000 Hz.) The electrical currents induced in the object generate their own magnetic field that works in opposition to the magnetic field generated by the sensor coil (due to Lenz's Law). This opposition changes the resonant frequency of the sensor circuit by reducing the effective inductance of the sensor coil. This change in resonant frequency (an increase in frequency as the inductance decreases) is detected by the circuit instrumentation in the signal controller cabinet, which then tells the signal control electronics that a vehicle is present."

My conclusion is: A magnet on your bike (with its magnetic field similar to the magnetic field generated by the sensor's coil in your vehicle's conductive material) can help triggering the sensor. (Maybe a magnet itself (without your bike) over the loop sensor or your bike's conductive material itself is not enough, but the two together can trigger the sensor.)

Ervin

[Alan Hawk]

well according to that, the right magnet, located in the right area sure should work.

But I don't see why they say there is a misconception about needing ferrous metal. Not only is ferrous metal able to respond to a magnet, it is also conductive. Aluminum isn't able to respond to a magnet and is not conductive. You need steel, or something a magnet will stick to. Or if you are just concerned with how conductive the metal is, then copper or gold. But not aluminum.

[ervin260]

Originally Posted by Alan Hawk

well according to that, the right magnet, located in the right area sure should work.

But I don't see why they say there is a misconception about needing ferrous metal. Not only is ferrous metal able to respond to a magnet, it is also conductive. Aluminum isn't able to respond to a magnet and is not conductive. You need steel, or something a magnet will stick to. Or if you are just concerned with how conductive the metal is, then copper or gold. But not aluminum.

Aluminum is conductive.

Ervin

[jbs89]

Originally Posted by 12RPilot

One time I put a huge magnet from a paper recycling conveyer belt under my bike. This thing picks up small cars if one could fit on the conveyer. On my way to the nearest traffic light I was stopped over a manhole cover and couldn't move. Burned up the clutch trying to get away. .......

I gotta tell you - that was one of the funniest things I've read in awhile. [smiley] [smiley] [smiley]

[Alan Hawk]

Aluminum is only conductive if you force a lot of electricity down it. So is human hair, or cotton. Not the same thing. Aluminum is not conductive enough to create the return electromagnetic field when passed over an induction loop, not unless the loop is WAY overpowered, to the point of being dangerous.

[snush]

Wonder if steeled toe boots will work ?
SNUSH (blue thumbs up smiley)

[ervin260]

Originally Posted by Alan Hawk

Aluminum is only conductive if you force a lot of electricity down it. So is human hair, or cotton. Not the same thing. Aluminum is not conductive enough to create the return electromagnetic field when passed over an induction loop, not unless the loop is WAY overpowered, to the point of being dangerous.

You are wrong. Aluminum more conductive than iron, steel, bronze, brass, zink or nickel and less than gold, copper or silver.

Ervin

[Alan Hawk]

Ok, I admit that I can be wrong, I didn't know that about aluminum, BUT, if you run electricity through aluminum, will it create an electro magnetic field? I don't think it will, which is why the wheels on a VTX won't trigger the sensors, unless they are spoked, the spokes on spoked wheels are steel.

And if aluminum is so conductive, how come wires for electronic equipment only come in 3 types, copper, gold and steel?

[snush]

Originally Posted by Alan Hawk

Ok, I admit that I can be wrong, I didn't know that about aluminum, BUT, if you run electricity through aluminum, will it create an electro magnetic field? I don't think it will, which is why the wheels on a VTX won't trigger the sensors, unless they are spoked, the spokes on spoked wheels are steel.

And if aluminum is so conductive, how come wires for electronic equipment only come in 3 types, copper, gold and steel?

Because of the Beverly Hills Supper Club in Southgate Ky. New laws were imposed on ALL electrical components throughout the country. Aluminum will melt and burn when a excessive load is passed through it.
SNUSH

[Alan Hawk]

so maybe we have a different idea of what a "good" conductor of electricity is. If steel can handle a higher load while creating less heat than aluminum, then steel is a better conductor.

The questions still remains though, will an induction coil cause aluminum to create an electromagnetic field? At the same voltage as steel? I don't think it will, because if it did, the aluminum wheels on a 2007 VTX1300R would certainly set it off, they are almost solid aluminum.

[W9VD]

Aluminum is actually a very good conductor of electricity. Many transformers have aluminum windings in them. However, aluminum is not a ferrous metal so a magnet has little affect on it.

[Frybie]

Originally Posted by W9VD

Aluminum is actually a very good conductor of electricity. Many transformers have aluminum windings in them. However, aluminum is not a ferrous metal so a magnet has little affect on it.

Aluminum is actually a very good conductor of electricity. agree

magnet has little affect I'd say little to NO affect
just my 2 cents

[W9VD]

Originally Posted by Frybie

Aluminum is actually a very good conductor of electricity. agree

magnet has little affect I'd say little to NO affect
just my 2 cents

About aluminum and magnetism, take a magnet and install it on the spin side of the press drill and take aluminum on the bottom, and make spin the drill, you will see that the aluminum will heat even if there is no contact...So there is an effect between aluminum and magnetism some how.

Same thing if you use a ball shape magnet and put it in an aluminum tube you will see some restriction when the magnet ball is dropped.

http://www.pureenergysystems.com/os/...ets/index.html

[Frybie]

Yes in a case like that,,,I agree.

[ervin260]

Originally Posted by Alan Hawk

so maybe we have a different idea of what a "good" conductor of electricity is. If steel can handle a higher load while creating less heat than aluminum, then steel is a better conductor.

The questions still remains though, will an induction coil cause aluminum to create an electromagnetic field? At the same voltage as steel? I don't think it will, because if it did, the aluminum wheels on a 2007 VTX1300R would certainly set it off, they are almost solid aluminum.

If you want to know the details, check out the links provided in post #38.
You can find the answers there.

Ervin

[trucktrain]

Originally Posted by 12RPilot

Sometimes I will pull forward and wave the car behind me to pull up onto the loop.

One time I put a huge magnet from a paper recycling conveyer belt under my bike. This thing picks up small cars if one could fit on the conveyer. On my way to the nearest traffic light I was stopped over a manhole cover and couldn't move. Burned up the clutch trying to get away. Had to cut it loose and leave it there. An hour later I saw a Ford Fiesta sitting over that manhole with a bunch of people gathered around. Poor fella couldn't move either. The wrecker couldn't tow the car off there because that would leave an open hole. They had to wait until the city could bring a replacement manhole cover. I read in the paper the next day that there was a reward by the police department for information leading to the arrest of the person responsible for the magnet. I heard through the grapevine that I was a suspect since the magnet was traced to the recycling center were I worked. So I went to a payphone and called in a tip that terrorists use huge magnets to get manhole covers off so they can plant dirty bombs under the city. This upset the local police so much that many government spooks were called in to verify the entire sewer system was free of dirty bombs. Naturally, this took the attention away from me. However, the latest revision of the Homeland Security Bill calls for registering magnets over a certain power. The recycling Center can no longer just throw away it's old magnets. They must be broken into small pieces in the company of a federal Homeland Security agent. True story. Spread it around.

Story time??

[Alan Hawk]

Originally Posted by ervin260

If you want to know the details, check out the links provided in post #38.
You can find the answers there.

Ervin

I don't have the time to get a doctorate so that I can understand all of that. The simple fact is that MY aluminum wheels do NOT cause the light to change, or the drive through to recognize me. But the kid next door's bicycle will cause the light to change and the drive through to recognize him.