• Required reading for all forum users!!!

    Welcome!
    Register to access the full functionality of the GSResources forum. Until you register and activate your account you will not have full forum access, nor will you be able to post or reply to messages.

    A note to new registrants...
    All new forum registrations must be activated via email before you have full access to the forum.

    A Special Note about Email accounts!
    DO NOT SIGN UP USING hotmail, outlook, gmx, sbcglobal, att, bellsouth or email.com. They delete our forum signup emails.

    A note to old forum members...
    I receive numerous requests from people who can no longer log in because their accounts were deleted. As mentioned in the forum FAQ, user accounts are deleted if you haven't logged in for the past 6 months. If you can't log in, then create a new forum account. If you don't get an error message, then check your email account for an activation message. If you get a message stating that the email address is already in use, then your account still exists so follow the instructions in the forum FAQ for resetting your password.

    Have you forgotten your password or have a new email address? Then read the forum FAQ for details on how to reset it.

    Any email requests for "can't log in anymore" problems or "lost my password" problems will be deleted. Read the forum FAQ and follow the instructions there - that's what we have one for...

  • Returning Visitors

    If you are a returning visitor who never received your confirmation email, then odds are your email provider is blockinig emails from our server. The only thing that can be done to get around this is you will have to try creating another forum account using an email address from another domain.

    If you are a returning visitor to the forum and can't log in using your old forum name and password but used to be able to then chances are your account is deleted. Purges of the databases are done regularly. You will have to create a new forum account and you should be all set.

(General) Diameter of electrical cables

roeme

Forum Mentor
Past Site Supporter
I'm about to order a chunk of cables for various electrical work on my bikes. Aside from the beefy ones (starter,...), what's the general diameter used?

1mm? or 1.25mm? ?
 
You will have to understand that there are different methods of measuring wire size. While you are obviously using surface area, we use a numeric wire gauge size.
Here is a chart that compares the two:


I would suspect that most of the wires on the bike are 16 or 18 gauge, depending on what they are powering. 18 gauge is a bit smaller, allowing smaller bundles, but 16 gauge will handle a bit more current safely.

The wires that have to carry the most current (except for the starter, of course) would be from the battery to the MAIN fuse, then from the MAIN fuse to the ignition switch and back to the fusebox. Those wires will have to carry up to 15 amps at times. After the fuses, each circuit will only have to carry a maximum of 10 amps, so 18 gauge wire is plenty adequate.
 
I've often pondered this. Being a Japanese company, why would Suzuki use American Wire Gauge? And indeed, upon careful inspection, most of the wiring you'll find in a GS appears to be thicker than 18 AWG but thinner than 16 AWG.

Here's a conversion chart from AWG to diameter and surface area in mm. From what I can find, the Japanese motorcycle manufacturers used wire area in square mm (remember, you're measuring the conductor, not the insulation).
http://www.global-electron.com/wiresizes.htm

More info here:
http://www.engineeringtoolbox.com/awg-wire-gauge-d_731.html

According to this page, these are the wire gauges normally used in Japanese machinery
Japanese sizes
mm? mm?
0.75
1.25
2.0
3.5
5.5
8.0
14
etc...

Some info in relation to BMW motorcycles, along with some charts to further illuminate/obfuscate the issues:
http://bmwmotorcycletech.info/wires&codes.htm


Stare at all this for a while, it looks like much of the wiring in a GS uses the 1.25mm? (square mm) wire size, which is indeed between 16 and 18 gauge. I'm not quite sure how to account for GS battery cables, which are thicker than 8awg, but thinner than 6awg. (When I need to make new ones, I use 6awg wire.) That list jumps from 8 to 14mm?, but 10mm? wire would slot right in between 6 and 8awg, and I suspect that's what was used.



Anyhoo, since most of us are here in the metrically challenged US of Damn A, where everything in the year 2017 is STILL based on barleycorns, drams, fewmets, and other medieval impedimentia, AWG wire is pretty much all we can get. So we have to muddle through as best we can when making repairs.

Generally, I look at the normal load on the wire and use what makes sense. As a rule of thumb, there are very few things on a motorcycle where you'd need to upsize to 16 gauge wire, so 18 is fine for just about everything.

Here's one hand-dandy little calculator (there are many charts and calculators in t' intarwebnets). Remember, your wiring runs on a bike are pretty much all less than 6 feet, so make sure you take that into account.
http://www.wirebarn.com/Wire-Calculator-_ep_41.html

Thicker than needed wire is pain in the rear to work with, plus it may not fit where it needs to go. And you may run into added issues in areas that flex frequently. Bigger is only better if it's needed.

On a GS, wiring troubles are almost always corroded or damaged connectors and sometimes damage to the wires (from rubbing or from thumbfingered POs bumbling around in the wiring).
 
I just love this forum, you shoot off a quick question before festivities, and you get a buttload of information, both metric and medieval (you made me laugh for a good minute there bwringer) :D

Anyhow. We don't really use AWG on my continent, hence my question posed in conductor surface area - that's what generally is used around here. It's no foreign concept to me though, as ordering from all places around this globe requires me to convert from time to time.

Building codes here are very stringent re. electrical installations and make it illegal to install wiring below a certain diameter. My memory's a bit fuzzy, but I think its 1.5mm?. This has the effect that smaller diameters aren't readily available, so the last time I quickly grabbed some wire from the next shop, it seemed to bulky on the bike.

Nothing wrong electrically with it of course...but yeah, some of the harnesses are bulky enough as is, and I don't need to lug around more copper than necessary on my 550s ;) And yeah, especially at the backside it just becomes a PITA to work with.

Tefzel wire seems nice...naturally, I want nothing less than MILSPEC on my bike :D

Anyway, I think imma hunt for some 1.25 now.
 
Pffff, it's surprisingly hard to source an assortment of cables with many colors...

Then again, Suzuki did use ~26 different colors, so it looks like I'll need to update the wiring diagram anyway with the fewer colors I'll be most likely using.
 
This is a great thread with good timing. Winter projects include regulator update and starter relay update. Since I am I.T. challenged, if someone could post links to those threads and any other needed electrical updates, I would be sincerely grateful. What size wiring would be correct for charging systems and there grounds?
 
From the info on that BMW page, it looks like euro vehicles skip from 1mm2 to 1.5mm2, so yeah, it's probably going to be tough to find 1.25mm2 wire in Switzerland. I haven't found a source for the stuff in the US, either.

The best source for the correct wire in the correct colors, plus an assortment of connectors, is often an old wiring harness or two. You can pick them up dirt cheap, especially if they're damaged. Wiring harnesses are mostly model-specific, but there's a lot of commonality. If you get a harness from any model GS within a year or two of yours, you'll find most of it is useful -- one of the hallmarks of Suzuki engineering is that they didn't change anything unless they really, really had to.

If you inspect the connectors carefully, you'll see tiny slots where you can insert a terminal tool and extract the terminals from the connector shells, so quite often you can piece together what you need to make repairs from a scrap harness, or at least to make a splice in a more convenient location. The insulation is generally very high quality stuff and doesn't seem to deteriorate.
 
I have burned the whole afternoon on this topic by now.

Holy bezeejus there is so much to wiring:

- Insulation is important. It defines heat resistance, effective O.D. of the cable, and flexbility.
- ISO 6722-3 defines diameters of insulation, conductor (and some materials IIRC).
- Apparently, there are "thick wall", "thin wall", and "ultra-thin" wall insulator thicknesses defined
- There is a sh!$tload of more standard publications
- Conductor sizes are defined differently depending on the conductor alloy
- Modern automotive industry uses standardized codes to refer to cables. Closest to what I/we need seem the "FLRY-B" from the "ze germans", "GXL" from 'murica, and "AV" from the japs.
- Even the angle and thickness of the color stripe for two-colored cables is standardized in modern wiring.
- The colors of these cables generally tell their function, regardless of the vehicle.

As said earlier, I found it next to impossible to get a color assortment of cables online. Either the lengths are way too short, very few colors are included, or it's simply too pricey.
I also couldn't find reliable information on insulator thickness. Either you get AWG, or mm?.

I was able to find a source for FLRY-B cables here locally, so I went down this rabbit hole. For now.

FLRY-B:
"FL" stands for Fahrzeugleitung (vehicle wire) and is a prefix common to all these cables.
"R" means reduced insulator thickness (that's what I want on my bike).
"Y" designates plasticized PVC. The "tefzel" (EFTE) wire that bonanzadave was referring to would have a "7Y" in this place.
Finally the "-B" version is more flexible than the "-A" version, by defining thinner strands (consequently, -A is rated up to ~220Volts, while -B may carry no more than 60V).

I just hope I can finish ordering today :D

bwringer, you're right, 1.25mm? seems to be an odd-ball size around here. Also, recycling old harnesses is a neat idea.
 
Last edited:
Taking voltage drop and product availability into account, I have now ordered both 1mm? and 1.5mm? FLRY-B wires, 2 colors of each, as a starting point.

To help distinguish the cables, I'm going to use cable markers like these:



Since I don't yet rewire the bike(s) from scratch, but rather fix PO botches and make various small-time mods, I deem this sufficient for the time being.

I will then select the wire according to the current it will have to carry. From what I have learned so far it seems that 1mm? FLRY-B will/must be able to carry 16.5 amps, and 1.5mm? 21 amps. Glancing from posplayr's SSPB thread, this seems plenty. I'd even go down to 0.75mm? (~AWG 20) for the dash, but let's not get ahead of myself just now.

Will update this thread with install experience when the cables arrive.
 
This topic is perfect timing for our little GT250 cafe racer project.
The bike has all LED lights & will have a from-scratch wiring harness.
I would like to use the same colors & tracer colors that Suzuki used.


That kojaycat website looks interesting.
Does anyone have a link for a US retailer of the thin-wall wires that includes tracer options?

It's gonna get seriously expensive... here's thin-wall Tefzel in all the colors of the wiiiiiind...
https://www.prowireusa.com/c-59-m22759-32.aspx

If you're building from scratch, you'll probably want to settle on Deutsch or Weatherpack connectors, so you'll need an assortment of these ($$$) and the correct wire strippers and crimpers ($$$$), not to mention heat shrink breakout boots ($$), heat shrink tubing, etc.

Another place with lots of supplies:
http://www.riwire.com/

If you're looking for replacements for the OEM connectors on your GS or other motorcycles, a couple of places to look:

http://easternbeaver.com/Main/Elec__Products/Connectors/connectors.html <== mostly the stuff used on newer Japanese bikes

http://www.vintageconnections.com/ <== supplies for older bikes, like our Suzukis.
 
Try Z1 Enterprises for wiring, connectors and the tools for the connectors. They have a wide assortment. I changed many of the old bullet connectors to weatherproof spade connectors.
 
Try Z1 Enterprises for wiring, connectors and the tools for the connectors. They have a wide assortment. I changed many of the old bullet connectors to weatherproof spade connectors.

Nice! I didn't know they had this stuff.
https://www.z1enterprises.com/store/category/suzuki/electrical/connectors
https://www.z1enterprises.com/product/RI11-001
https://www.z1enterprises.com/product/KL35-9266
They don't tell you what gauge the wire is or what the insulation is made of, so you just have to make a few assumptions...

With wiring, it's easy to go down a bit of an expensive rabbit hole and go overboard making everything NASA grade. You have to find a good middle ground between the often crappy stock connectors and something suitable for an interstellar oceanic mission.
 
One simple point to bear in mind, with bike (or any vehicle wiring) is the vibration resistance of the wiring. I don't know how many vehicle wiring harnesses I've seen repaired with the wrong type of cable - ie, too few strands in it. Finely-stranded cables are more flexible and tend to resist cracking for far longer, even if installed incorrectly. Of course, making sure the harness isn't allowed to flap about is important, too.
 
One simple point to bear in mind, with bike (or any vehicle wiring) is the vibration resistance of the wiring. I don't know how many vehicle wiring harnesses I've seen repaired with the wrong type of cable - ie, too few strands in it. Finely-stranded cables are more flexible and tend to resist cracking for far longer, even if installed incorrectly. Of course, making sure the harness isn't allowed to flap about is important, too.

Agreed:

If you look at power cables on LiPo batteries for Drones they have very fine stranded cables. I don't know what the count typically is but Automotive grade wires is usually adequate for a motorcycle but it is very important to keep the wires wrapped so that individual strands have not only the support of the individual cable, but also the wrapped cable group. Securing the wrapped cable group then provides a very good support that can be used to minimize any "flapping around".

Of course you have to make sure you don't have soldered joints with solder wicked way up a wires that is subject to flapping. It will break off in short order.

Wire to wire soldered butt joints need to be stabilized inside of the harness wrap as an absolute necessity.

This is one area at least that house wiring twist caps are an improvement if you can't actually do a proper job :).
 
Last edited:
Nice! I didn't know they had this stuff.
https://www.z1enterprises.com/store/category/suzuki/electrical/connectors
https://www.z1enterprises.com/product/RI11-001
https://www.z1enterprises.com/product/KL35-9266

They don't tell you what gauge the wire is or what the insulation is made of, so you just have to make a few assumptions...

Perfectly timed thread. I had the same question regarding gauge of wire from Z1 Enterprises so I emailed them.... The response was 18 gauge. Hope this helps! Thanks so much for all the insight!

For reference, I asked about the wire in general but referenced part#KS001-1015 so the rep from Z1 had something specific to go on.
 
Last edited:
Back
Top