Why use silicone insulated high strand count wire?

[Bicycle365]

Silicone insulated wire with high strand counts usually cannot be found at the local hardware store. Why not use " regular " wire ?

• High strand count wire conducts better with less resistance (i.e higher performance).
  • False
  • The measurable difference between high strand 10 AWG wire and a 10 AWG solid core is minuscule at the lengths that bike builders use. By definition it is the total cross section of the copper that determines the rating.
• High strand count wire is more flexible and less prone to breakage.
  • True
  • The smaller individual strands are better suited to repeated flexing without breaking and the soft silicone insulation is more pliable than most wire covering materials. In an eBike environment where wires are plugged and unplugged stuffed in bags and cases ,and vibration can be an issue, this is a desirable material property.
• High strand count silicone insulated wire is also higher temperature rated.
  • True
  • Heat is the enemy in most eBike scenarios so why outfit them with high temperature wire? Because when you use a lot of heat to make a strong solder joint in larger current carrying runs, such as between 10 AWG wire and an XT-90 connector a lot of the soldering heat can creep up the wire, standard insulation can melt or shrink back exposing more of the conductor. This makes for a sloppy looking connection and can create a short hazard if that exposed conductor is not re-insulated with shrink tubing or other means.
• Are there other benefits to using this type of wire?
  • Yes
  • Silicone is an excellent insulator and has excellent moisture resistance properties. This is especially true at connectors where the ability for moisture to "wick" up under the jacket and cause unseen corrosion is almost non-existent in silicone insulated products.

Luna cycles currently has several gauges of silicone wire available at this link:

Product Link: Silicone Insulated High Strand Count wire at Luna Cycles

*** Just a personal comment here, I shop for this stuff a lot and Luna is selling it at what must be their cost because these prices (06-2016) are VERY competitive with having to buy it in bulk. Thanks Luna !

[MichaelT]

I was taught that the electricity flows on the outside surface of most any given object (Better to be struck by lightning when wet than dry) as traveling internally in an object there is greater resistance, and resistance causes heat. So the total surface area of high strand is greater than the 16 strand used on the BBSHD lead wires, as finer wire fills in gaps and compacts tighter. Tin plating the strand prevents oxidisation and the resulting resistance it causes.
This is even truer when wiring audio equipment, and the the use of Oxygen Free Copper(100% OFC) wiring. Oxidization causes resistance frequency filtering and this degrades the response of the speakers.
So 184 strand 12Ga flat braided OFC wire will perform better than 16 strand 12Ga round untreated wire.

The 1st thing I would have done is replaced the factory 12ga leads on my BBSHD, with better wire. Unfortunately, this isn't easily possible.
Anyone know of a POT solvent that will not affect the circuit board and components?

[ykick]

Skin effect is mostly an VAC thing and really nothing to worry about for an eBike, IMO.

[ykick]

Quoted for truth and agreement.

The only practical downside I've found regarding silicone insulation is that it doesn't tolerate mildly sharp edges or pass throughs in equipment boxes, etc. For those situations I tend to go with PVC. But for majority of eBike wiring I find the flexible multi strand silicone wire to be the most useful. And yes, I've bought it for years from RC suppliers and Luna has a very competitive price.

PTFE or Teflon is another useful wire insulation because it's very thin and useful passing through hub motor axles but it exhibits "cold flow" properties and doesn't like to be tightly cinched using wire tie wraps. It may eventually deform the insulation and thin it out in those places.

Silicone insulated wire with high strand counts usually cannot be found at the local hardware store. Why not use " regular " wire ?

• High strand count wire conducts better with less resistance (i.e higher performance).
  • False
  • The measurable difference between high strand 10 AWG wire and a 10 AWG solid core is minuscule at the lengths that bike builders use. By definition it is the total cross section of the copper that determines the rating.
• High strand count wire is more flexible and less prone to breakage.
  • ​True
  • The smaller individual strands are better suited to repeated flexing without breaking and the soft silicone insulation is more pliable than most wire covering materials. In an eBike environment where wires are plugged and unplugged stuffed in bags and cases ,and vibration can be an issue, this is a desirable material property.
• High strand count silicone insulated wire is also higher temperature rated.
  • ​True
  • Heat is the enemy in most eBike scenarios so why outfit them with high temperature wire? Because when you use a lot of heat to make a strong solder joint in larger current carrying runs, such as between 10 AWG wire and an XT-90 connector a lot of the soldering heat can creep up the wire, standard insulation can melt or shrink back exposing more of the conductor. This makes for a sloppy looking connection and can create a short hazard if that exposed conductor is not re-insulated with shrink tubing or other means.
• Are there other benefits to using this type of wire?
  • Yes
  • Silicone is an excellent insulator and has excellent moisture resistance properties. This is especially true at connectors where the ability for moisture to "wick" up under the jacket and cause unseen corrosion is almost non-existent in silicone insulated products.

Luna cycles currently has several gauges of silicone wire available at this link:

Product Link: Silicone Insulated High Strand Count wire at Luna Cycles

*** Just a personal comment here, I shop for this stuff a lot and Luna is selling it at what must be their cost because these prices (06-2016) are VERY competitive with having to buy it in bulk. Thanks Luna !