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Oxford Hot Grips - The "Computer Power Cable" Grips

Discussion in 'Electronics' started by ferkel, Jul 29, 2016.

  1. I like to install a motorcycle product that not only works good, but looks good. For people who have no electrical/electronics experience, that want a functional product they can DYI, don't care how it looks, and like gadgety looking controls, then I recommend Oxford Hot Grips.


    For people who can use a soldering iron (even just partially), a passing awareness of the wire loss rule, and like a neat job, then choose something else. When I install heated grips, you can't tell that I have installed them. So this is the standard I expect from a product. I like to flaunt my workmanship at the rare ride group I attend now days. Sadly, I am embarrassed to show people this job.

    "Heat Grips with computer power cables"
    This product functions well, but looks ugly. They have used computer power cables for the grip cables (hence the title of the post and the reference to the IT Crowd).

    "AS/NZS 3112 anybody ??"
    Not only does this make the product look cheap, but make the cables hard to conceal. At $150AUD, Oxford are cheap skates for doing this. There is smaller, more flexible, neater cable available that isn't expensive and has the current carrying capacity of computer power cables.

    The grips feel nice, but they have these bulky cable supports on the end of the grips. I personally don't like the feel of this... at all !. I'm struggling to get used to them. For minimum impediment, I have set them up so that this cable support is on top. I have lost access to the beam dip button, but I don't use this control anyway (I prefer to use the switch to do this function). I've tried a few orientations (even breaking and regluing and retest riding). Having this cable support up the top is out of the way. Any other position, these either catch my thumb, or get in the way of the levers.

    Bulky cable support​

    The controller uses Pulse Width Modulation to regulate heat. Basically, the controller switches the grips on and off about once a second. That 4 Amp rushing of current, and stopping of current could cause Electro-magnetic interference (EMI) to the bike's existing electronics. This is a big problem for high-tech vehicles now days, as it can cause uncommanded operations. The instructions mentioned keeping the cables away from the bikes electrical cables (See Section H, Para 6 Oxford Hotgrips Instructions V.8). I can see why !. Unless you have a very low-tech bike (ie: anything pre-EMI), then definitely do as they say. The draw (as mentioned in the manual and measured by me) is 4A at 14V. Section H of the Hotgrips Instructions talks about emission standards and intends to downplay this effect, but unless they have tested their product on my bike with a specific wiring configuration, the jury is out IMO !

    The so called "power saving feature" of the product does not kick in until 2 minutes after engine shutdown or when battery voltage is under 11.7V. This is a problem for my bike as I have an under rated battery, and need it at fully capacity (especially in cold weather). 4A draw for 2 minutes will end up increasing the failure rate of my battery.

    The Intelligent Heat controller is good in theory, but too has many buttons when needing to adjust the heat level through twists in a pinch. I fondle around with the control and end up looking down at it. This isn't a good habit :(. I definitely prefer an ON/OFF switch. A dial would be better than buttons IMO.

    Install notes:

    - KTM SMT specific: Throttle grip very tight. Removed lip. Had to cut about 2mm of grip away to prevent contact with bark-buster.


    - KTM SMT Specific: The left hand grip needs glue. However, The throttle grip is very tight and does not need gluing IMO.

    - KTM SMT Specific: Due to possible EMI risks, I have ran the heat grip power cable down the right hand side of bike (well away from bike's electrics). Any bike's electrics that this cable did pass, I made sure it crossed it at a right angle (see below). My bike has an accessory plug for accessories like this located beneath the cluster. I would prefer to use this point, but won't risk it due to the EMI issue mentioned above as the accessory lines are in the bike's electrical loom !

    "Heat grip power cable right angle to bikes existing electrics"​

    - KTM SMT specific: As mentioned above about the power save, I have used my old heat grip switch (located on the left control) to isolate hear grip when bike is not running.


    - The grips use the batteries + as a common. This means that most of the grip's cabling is alive all of the time. Not a big deal, but it's not how I would've designed it. It's more live wires around the parts of the bike that are susceptible to damage (ie: dropping the bike and the handle bar controls breaking, grips being damaged etc). There is the heat grip fuse to save the situation, but still... :/

    Pictures and comments:

    "all the bits.."

    The Intelligent Heat Controller with half of it's sheath removed. Red is Battery+ (it's the common), Black is Battery -, White is the switched (-).

    The equivalent circuit.

    Cable route (from bars to battery):
    • Informative Informative x 5
  2. #2 barry_mcki, Jul 30, 2016
    Last edited: Jul 30, 2016
    Good writeup and photos ferkelferkel . Interesting way you had to mount the grips, I think my OCD would be in overdrive knowing "OXFORD" is written upside down, luckily your gloves are covering them most of the time.

    Strange they have programmed the cutoff for 2 minutes, a couple of seconds would have been sufficient time to know the motor is off considering they are suppose to be monitoring "ignition noise" on the 12v line.

    I assume the 4amps is only when on max heat, so if you have set a lower temp, then the PCM circuitry should mean a lower power consumption (i.e. no sacrificial load resistor or potentiometer). I also agree with you about controlling the negative lead, having 12v "live" all the way to the grips at all times is a pretty silly design, I'd much prefer an IGN controlled relay to power things up.
  3. I have not heard about anyone having emi interference issues with oxfords before. I have myself fitted these to a KTM Duke 390 and a MV Agusta Brutale. Both I have routed along existing wiring and the KTM is wired into the accessory power lead in the wiring harness.

    The MV picks up within 5 seconds that the bike is switched off (green light goes on.to indicate battery saving mode).

    I agree on the wiring - the connection to the controller where the plastic sheath fits over the moulded entry point looks el cheapo. I used some heatshrink there.
  4. You've got the left and right grips mixed up, but not bad otherwise.
  5. not
  6. barry_mcki: When setting is 100%, it's a constant 4 Amp load. On settings between 100 and 0%, it's a pulse width modulated current (ie: 4 Amp, 0 Amp.. 4 Amp... 0 Amp... etc)

    GeorgeO: Me neither. I ride my bike pretty hard in the hills, I don't want a fault condition that would cause me an accident. The manufacturer does compatibly testing with their bike's electrical systems. Then we go and plop a high current accessory like this on to it with no investigation. A 4 Amp pulsing load is lot of current from the bikes power rail IMO. You have no problem with that, but I'm sceptical.

    Dark Angel: The clutch grip (inside diameter 22mm) fits on the clutch side bar, the throttle grip (inside dia 25.6mm) fits on the throttle barrel.

    Another pic I forgot to add. Splicing the conductors: