K11 Owners Group

[malcolmt]

Last winter I started using my bike for work and struggled to keep my fingers warm on the 35km trip, so I made up some heated gloves. They worked brilliantly so this winter I’ve converted my jacket liner to electric. Here is how it was done.

The heating element is a little unusual, I used a very thin, nylon coated, stranded stainless steel wire intended for necklaces. It has a high resistance and being stranded makes it very flexible. Best of all its cheap.
All the info below uses Beadalon 0.46mm dia, 7 strand wire. Just a word of caution... the Beadalon wire is not intended for use as a heating element, the manufacturer provides no electrical data for the product. Use it at your own risk.

The wire can be bought from Beads Direct in Irene , this is a link to the wire on their website..... http://beadsdirect.co.za/zen/index.php?main_page=product_info&cPath=139_142&products_id=3283

Their product code is BP071866.

After a couple of tests I found a 2meter length was an ideal length for the element. This length has a resistance of around 35 ohms and produces 5watts of heat at 13.8volts. My elements were made of two 2meter pieces connected in parallel producing just over 10watts. Each of these elements draws 0.8amp from the bike. My jacket used nine elements and will produce around 90watts of heat. So before you dive in and get busy… make sure your bike electric’s can handle the extra load.

This pic gives an idea how the elements are arranged in the liner.



My jacket used nine elements, two in each sleeve (front and back), one on each side of the jacket front, and three in the back, nine elements in total. There is sufficient for two elements on a spool of Beadalon, five spools were needed.

Material
5x spools of Beadalon, 7 strand, 0.46mm dia
2doz small ‘Boot Lace’ ferrules, any electrical wholesaler
2doz dual ‘Boot Lace’ ferrules, any electrical wholesaler
2m 0.5mm wire, red, any electrical wholesaler
2m 0.5mm wire, black, any electrical wholesaler
1m heatshrink tubing to fit over the dual ferrules, any electrical wholesaler
1x two way connector , Roleen Instruments, Boksburg
1x fuse holder
1x spiral cable (Outdoor Warehouse)
1x power socket (on the bike), (Outdoor Warehouse)
1x power plug (on the spiral cable) , (Outdoor Warehouse)

Tools
Large darning needle
Soldering iron with large tip
Small wire cutters
Small pliers
Multimeter, handy but not essential
Heatgun, not essential
Cigarette lighter

Making the elements
Take 4m off a Beadalon spool.
Thread the darning needle down the wire.
Hold the two free ends together and burn off approx 15mm of the nylon coating
Make sure the wire glows red for a couple of seconds to be sure all the coating is removed.




Put the two ends in a ferrule and crimp it tight. Note: it is very difficult to solder the stainless wire, crimping is the best method to get a reliable connection.




Sew the wire through the jacket liner making sure all the two meters are used, DO NOT CUT IT SHORT. When planning the position of the elements make sure the element wires do not touch other wires or double back on themselves and touch. The nylon coating may rub off and cause a short circuit with possible serious results. My jacket liner has stitched ‘cells’, these were used to keep the element wires apart.

When all the wire is sewn snip the loop at the needle and fit a ferule as per the opposite end. I wrapped a small piece of masking tape around the ferrule with element number.
Repeat for all the elements.



Connecting the elements
Decide the best side to fit the wire connector. Mine is fitted close to the jacket bottom and 90 deg from the front centre.
Starting where the connector will be fitted make a hole in the liner with the needle and push one wire through.
Work it through to the first element.
Leave a loop and continue to the next element. The wires are better being a little too long rather than too short. There must be no stress on the connectors when the jacket is worn.
When all the elements are done repeat with the second wire.
Next connect the elements. I cut the wire at an element, stripped off the insulation and fitted the two ends PLUS the heater ferrule in the dual ferrule and crimped it. Each connection should look like this before the heat shrink.



Slide a piece of heatshrink tubing over each dual ferule and shrink with the heat gun or lighter. It is a good idea to protect the jacket with card while heating the heatshrink.

Fitting the connector
Strip the ends of the wires in the jacket, also strip the connector wires. Fit some heatshrink over the wires and keep it well away from there the soldering will happen.
Solder the connector wires to the jacket wires.
When cool slide the heatshrink over the joint and use the heat gun or cigarette lighter.



Finishing off the jacket
The jacket wiring is now done each of the wire joints needs stitching to the jacket to prevent it moving.
Stitch the wire connector to the jacket.

Making the spiral cable
I bought an auto power extension lead, it had a car cigarette lighter plug on the one end, a nice piece of coiled wire and a socket at the other end. The socket wasn’t really suited to mounting of the bike so I bought a separate socket with a clip on cover. My bike suited mounting the socket on the right hand handlebar. You need to sit on the bike and decide before climbing in.





The power socket
I made a mock-up of the mounting bracket with card to be sure it all fitted nicely then used the card as a template for the alloy bracket. The socket is wired directly to the battery via a fuse. Its VERY IMPORTANT to fit the fuse close to the battery in case any wires get damaged and short to the frame. My bike used 5mm wire from the battery to eliminate any voltage drops before the socket. I may modify my circuit and fit a switch next to the socket, we’ll see.




A couple of last words should you decide to make a jacket…
Make sure your bike electric’s can handle the load.
Do not take shortcuts
If in doubt ASK, I’ll only be too pleased to help.

MalcolmT
_________________
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A Bike on the road is worth two
in the shed
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[whyoldbill]

Excellent write-up Malcolm. You've inspired me to do the same.
_________________
'02 - GL1800


The desired effect is what you get when you improve your interplanetary funksmanship - George Clinton

[Tim (Midland Section)]

A popular misconception is to use resistance wire. IMHO the less resistance the better, within limits of course.
If one uses 30 feet of 30 Gauge hook up wire, you will get about 10 Degrees C above ambient temperature rise. As it will never glow, there is no need to use Nichrome wire either.
Using 30G wire means less joins & therefore less discomfort.
Here is the original :-

Wire is available in many thicknesses (gauges) and you need to select one, which will provide sufficient resistance to generate the heat you are seeking, yet without drawing too much power from your electrical system. I used a 100ft reel of 30awg (American wire gauge) wire from RS Components for £8.00; R.S. Part Number 177-0621, and here is the specification if you are really interested (you don't need to be):

30 awg conductor 7 x 0.1mm strands 4 amp maximum current Total thickness 0.81mm Temperature rated to 200 deg c - much more than you will ever see!

This is a relatively low resistance PTFE coated wire which is U.L. listed, so I didn't have to translate into swg (Standard wire gauge). The PTFE insulation on the wire is suitable for high temperature, and also has a slippery feel, which makes it easier to thread into any garment. This particular wire has a resistance of about 0.1 ohm per foot, and I started by cutting off a 40 ft length, then gradually cutting down two feet at a time until I reached my target of about 3.0 ohms. In fact, the 30 feet length I ended up using, provided 2.9 ohms, which was near enough to what I was looking for.

As the resistance is 2.9 ohms, the current draw is 13.8 volts/2.9 ohms = 4.75 amps.
Wattage is (13.8 x 13.8 volts) / 2.9 ohms = 65 watts
_________________
Regards Tim,

Grey haired riders don't get that way by pure luck
1996 Guzzi Cali3 LAPD
1972 750 Commando
G6HRN
#485

[malcolmt]

Tim,

I saw the notes on the copper wire while researching my solution.
Have you used the copper wire ?
I've got tons of the PTFE wire at work but didnt use it, I was concerned about breaking with the continual flexing.
_________________
******************************
A Bike on the road is worth two
in the shed
******************************

[Tim (Midland Section)]

Never considered anything else. Copper is the most malleable & therefore the most resistant (no pun intended) to flexing. The most likely breaking point is at the connector, not in the clothing.
_________________
Regards Tim,

Grey haired riders don't get that way by pure luck
1996 Guzzi Cali3 LAPD
1972 750 Commando
G6HRN
#485

[malcolmt]

Tim, Have you used this method?
I may add some heated pant's to my wardrobe?

The multiple connections wern't a problem in the facket, they fitted nicely between theliner and jacket, I reckon the single copper wire would suit the pants better.

Malcolm(t)
_________________
******************************
A Bike on the road is worth two
in the shed
******************************