Gen II ground spider discussion (bench racing)

[RZ350]

Boy, I thought I put enough disclaimers in my last posts...

I was just trying to be fair here. If someone wants to provide the actual resistance value in the original harness ground loop, road-runner's 4 extra 16ga ground wire paths, and Brodie's extra 10ga wire ground path, I will be more than happy to calculate a more precise current flow in each path for each case.

Until then, please use these numbers as a guideline only.

 

[JamesK]

Boy, I thought I put enough disclaimers in my last posts...
I was just trying to be fair here. If someone wants to provide the actual resistance value in the original harness ground loop, road-runner's 4 extra 16ga ground wire paths, and Brodie's extra 10ga wire ground path, I will be more than happy to calculate a more precise current flow in each path for each case.

Until then, please use these numbers as a guideline only.

Sorry RZ, yes the disclaimers were pretty abundant, unfortunately reading comprehension was never one of my strengths :blink:

 

[RZ350]

IMHO, RZ's numbers for Brodie's spider harness are a little too conservative, I would hazard a guess that with the Brodie harness the spiders are seeing less current, since Brodie's harness uses much bigger gauge wiring to ground for each of the spider junctions (since electricity, like water will take the path of least resistance, the Brodie ground wires will be carrying more of the current than OEM ground wires).

I agree with you 100%, JamesK, but you were being too kind - "a little too conservative" is an understatement. I was being EXTREMELY conservative with my 50/50 split.

I think in the case of both solutions, the new ground paths are taking a lions-share of the current since the resistance in these new paths are so much lower than the original (maybe even as low as 1/4 of the original path resistance???). I just don't have resistance numbers to put on it right now. It probably is a waste of time to get too detailed (did I just say that? :blink: ) since the highest current in both cases is already below 10 amps with the 50/50 split, and that seems acceptable for the original wiring. Any further reduction is just icing on the cake.

Everyone should keep in mind that the chart numbers highlighted in yellow (amps through the original ground wires) will most likely be much lower than those stated with either of the grounding solutions installed.

 

[dbx]

I was being EXTREMELY conservative with my 50/50 split.
I think in the case of both solutions, the new ground paths are taking a lions-share of the current since the resistance in these new paths are so much lower than the original (maybe even as low as 1/4 of the original path resistance???).

What is the basis for saying the resistance in the new paths is lower than the resistance in the stock wiring harness? Are you assuming the spiders are oxidized or otherwise corroded?

If the spiders are not already corroded, I would assume the resistance to be near zero, the same as I would expect for the new paths, and therefore the current through each path would be equal. What am I missing?

 

[olsonm3915]

What is the basis for saying the resistance in the new paths is lower than the resistance in the stock wiring harness? Are you assuming the spiders are oxidized or otherwise corroded?

"since Brodie's harness uses much bigger gauge wiring to ground for each of the spider junctions "

 

[dbx]

What is the basis for saying the resistance in the new paths is lower than the resistance in the stock wiring harness? Are you assuming the spiders are oxidized or otherwise corroded?

"since Brodie's harness uses much bigger gauge wiring to ground for each of the spider junctions "

My understanding is that bigger gauge wiring provides more current carrying ability, but not lower resistance, hence the current will be split equally between the two paths.

 

[olsonm3915]

My understanding is that bigger gauge wiring provides more current carrying ability, but not lower resistance, hence the current will be split equally between the two paths.

Your understanding is wrong. The reason why larger gauge wire can carry more current is in fact because the resistance is lower per unit length, hence the amount of power dissipated in the wire due to I squared R loss is lower, meaning lower heat.

 

[chivvalry]

My understanding is that bigger gauge wiring provides more current carrying ability, but not lower resistance, hence the current will be split equally between the two paths.

Your understanding is wrong. The reason why larger gauge wire can carry more current is in fact because the resistance is lower per unit length, hence the amount of power dissipated in the wire due to I squared R loss is lower, meaning lower heat.

Correct.

 

[RadioHowie]

I STILL like pie!

Had to contribute somehow!

 

[dbx]

My understanding is that bigger gauge wiring provides more current carrying ability, but not lower resistance, hence the current will be split equally between the two paths.

Your understanding is wrong. The reason why larger gauge wire can carry more current is in fact because the resistance is lower per unit length, hence the amount of power dissipated in the wire due to I squared R loss is lower, meaning lower heat.

We're talking about what, 10 feet of wire per leg, at the most? I don't buy the premise that there's a significant difference in resistance in such short lengths, and certainly not on the order of 4:1. The two parallel branches will carry equal current.

 

[olsonm3915]

My understanding is that bigger gauge wiring provides more current carrying ability, but not lower resistance, hence the current will be split equally between the two paths.

Your understanding is wrong. The reason why larger gauge wire can carry more current is in fact because the resistance is lower per unit length, hence the amount of power dissipated in the wire due to I squared R loss is lower, meaning lower heat.

We're talking about what, 10 feet of wire per leg, at the most? I don't buy the premise that there's a significant difference in resistance in such short lengths, and certainly not on the order of 4:1. The two parallel branches will carry equal current.

All I can say is, when you find yourself in a hole, a good strategy is stop stop digging. The ratio of resistance per unit length of 10 gauge wire vs. 16 gauge wire is almost exactly in the ratio of 1:4. You can look it up. I just did.

I really can't get too worried about your failure to understand basic electrical concepts. That's OK- most people don't, and it doesn't hold them back.

I do this stuff for a living, and I KNOW you are 100% wrong about the specific point that the resistance difference between the two wire gauges does not affect how much current each wire carries when they are hooked in parallel.

I will say, I agree with you that the percentage of current carried by the 10 gauge (?) wire vs. the existing 16 gauge (?) wire is practically irrelevant, What really matters is decreasing the total current carried by the individual connector pins, which adding additional grounds to each spider junction takes care of. That has been the problem all along, aside from the fact that a 16 gauge wire is not an appropriate size for carrying large currents. Question marks added since I am using those gauge numbers from memory and not by reading previous posts.

 

[dcarver]

What my man Olson said. :clapping:

 

[RZ350]

I STILL like pie!
Had to contribute somehow!

RadioHowie - PI (~3.14) will be used in calculations a little bit later on, but thanks for mentioning it now.

 

[RadioHowie]

I STILL like pie!
Had to contribute somehow!

RadioHowie - PI (~3.14) will be used in calculations a little bit later on, but thanks for mentioning it now.

Jes keepin' ya honest. :thumbsupsmiley:

 

[RZ350]

We're talking about what, 10 feet of wire per leg, at the most? I don't buy the premise that there's a significant difference in resistance in such short lengths, and certainly not on the order of 4:1. The two parallel branches will carry equal current.

dbx,

It appears your mind is made up here no matter what people are saying. I'm not a debater - I'll leave that to the politicians. If you (or anyone) truly want to understand some of the engineering laws behind their comments, I will be happy to elaborate or find a good website that explains it better. Otherwise, if you still think there is an equal split, then my recent charts should be just perfect for you - an equal split was originally assumed to keep it simple. It is by no means what's really happening here, however.

 

[Scrib]

Or better yet, simply don't install these fixes on your bike if you don't think it helps. I believe these guys since it is apparent they understand it better than I do. Yes, I am a lemming jumping off the cliff here, but at least I don't have a spider bite on the way down.

 

[road runner]

Holy- Moly

I'm sure that Brodie's harness will bring the current way down, because with his all the loads go back to ground in parallel, or each item goes directly to ground, and not in series like the factory harness does. So there is no stacking up of amperage going from one spider to another.

Mine will bring it down also, but not as much. The factory harness is still in series with all the spider connectors in place. Mine just cuts the load in half, and adds 4 ground wires to the 1 factory wire. It adds 2 ground wires to the S4, and 2 ground wires to the S6 via the S7&S8 spiders.

I don't know the exact #, but seeing as the bike worked stock, either one of these solution will be more than enough. And yes Brodie's is definitely better at lowering the amperage, lower than it needs to be. But that's not a bad thing.

Art

 

[MartyA]

Got bad news from the dealer. He ordered the front and main harnesses - there are 2 front headlight harnesses in Japan, and he may get one of them, and no main harnesses anywhere, and they are back-ordered "indefinitely."

I asked them to install road runner's harnesses and button it up, and call me when the harnesses get in. I really need to ride!

 

[chivvalry]

Gosh... I wonder why they are out of harnesses? What ever could be causing those to be used up quickly?

Installed roadrunner's two fan harnesses the other day. I didn't do all four (the two lights) 'cause I'm a cheap bastidge when it comes to farkle money but I'm pretty confident tripling the ground paths is sufficient.

 

[Burnspot]

Gosh... I wonder why they are out of harnesses? What ever could be causing those to be used up quickly?
Installed roadrunner's two fan harnesses the other day. I didn't do all four (the two lights) 'cause I'm a cheap bastidge when it comes to farkle money but I'm pretty confident tripling the ground paths is sufficient.

In some industries, the "indefinite" lack of supply sometimes indicates a new version coming down the pike. Perhaps Yamaha smelled the coffee? One can always dream...