Headlamp shell grounds
- Thread starter rgrigutis
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I don't have turn signals on either of my Commandos, but I put a longer bolt on one of the headlamp mounting points, and use a ring terminal on 14 gauge wire back to the battery. A thin nut and a star washer keep in in place. I've never thought that push in bullet thing for a headlamp ground wire was up to snuff, even by wanky Lucas standards. I might also add that both of my bikes have purpose built wiring harnesses with a separate harness just for the grounds. Never let me down, and my headlamp is bright.
I think that the push in bullet receptacle on the headlight shell is made out of the same metal they used for all the other bullet connections on the bike. Modern versions that I've seen are also stampings from sheet but the metal seems to be spring steel, so it's able to do a better job of getting a good grip on the bullet part. I've heard there was a time when some bikes didn't run a ground at all and relied on the bearings in the headstock to do the job providing a ground path to the headlight.Brithit said:
On a related issue, could someone tell me what a ground loop is?
Thanks.
http://en.wikipedia.org/wiki/Ground_loop_(electricity)
On a bike, there is no need to worry for most devices.
Jean
On a bike, there is no need to worry for most devices.
Jean
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Here's one version:bpatton said:
It's when there is a separation between the positive and negative conductors in a circuit which allows a magnetic field to be generated.
This is why twisted pairs are used; to minimise the magnetic coupling - if the earth return is the chassis it's more difficult to manage, especially where multiple equipments are being powered, hence the use of dedicated earth returns.
Fortunately, the Norton Commando isn't particularly susceptible to RF emissions :mrgreen:
Has been known to play havoc with aircraft compasses though.
Do I get my Anorak now?
I saw the term used, apparently incorrectly, to describe a situation when a guys rpm's went up and down with his turn signals. He had an electronic ignition, probably a Boyer. His battery was good and it went away when he grounded the Boyer/coils directly to the battery.
On an unrelated note, I just got back from a trip down to San Francisco. I was amazed by the way people ride in traffic. Scooters and baggers splitting lanes on the freeway and surface streets. Cage drivers seemed to be well trained to it but the skill level of the riders was quite high. But then I guess you'd only see the ones who'd gotten the hang of it quickly.
On an unrelated note, I just got back from a trip down to San Francisco. I was amazed by the way people ride in traffic. Scooters and baggers splitting lanes on the freeway and surface streets. Cage drivers seemed to be well trained to it but the skill level of the riders was quite high. But then I guess you'd only see the ones who'd gotten the hang of it quickly.
DogT
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Ground Loop:
Imagine you have your radio plugged into your computer with a shielded wire, center conductor and shield. All should seem to work well. However, your computer also has a grounded AC plug which is also attached to the ground of the computer. Your radio may or may not have the ground wire to the AC also. Doesn't matter, what does happen is the ground on your radio is a different potential (voltage) than your computer because of the different places it is grounded and with different length wires. This means that you will have ground currents (ground loop) on the shield of the audio input and the computer and the radio, usually showing up as a hum. It can be fixed by isolating the grounds.
Dave
69S
Imagine you have your radio plugged into your computer with a shielded wire, center conductor and shield. All should seem to work well. However, your computer also has a grounded AC plug which is also attached to the ground of the computer. Your radio may or may not have the ground wire to the AC also. Doesn't matter, what does happen is the ground on your radio is a different potential (voltage) than your computer because of the different places it is grounded and with different length wires. This means that you will have ground currents (ground loop) on the shield of the audio input and the computer and the radio, usually showing up as a hum. It can be fixed by isolating the grounds.
Dave
69S
The first time I mounted a MkIII Boyer on my bike I couldn't get it to start. It coughed and sputtered. I took the box off from under the backbone and laid it on a chair next to the bike and jumpered the connections. It started right up. I replaced the leads from the stator to the box with a shielded 2 wire cable and it ran fine. But then I've heard of plenty of bikes that have never had a problem.B+Bogus said:
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One effective way to deal with grounds is to construct the harnesses with three multiple-connection ground points; one at the headlight shell, one on the frame at the battery case, and one at the tail light. Each oif these points is connected to the frame and then to each other via a dedicated ground wire running the length of the bike. Each return point in the harnesses is then connected to one of these three ground points, whichever is closest. My headlight shell and battery case points, for example, each have 6-8 ground wires attached to them. This avoids daisy-chaining, allows for a fully redundant grounding system (the frame), and minimizes ground loops (although b+bogus got it right; ground loops are only important in rf applications, say 100 MHz, where current loops can "see" each other). The two grounding exceptions to the above scheme are the ignition secondary and ES circuits, each of which demand a ground through the engine case.
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