twowheelstom wrote: Mon Feb 23, 2026 12:37 am
What if a person were to put an XT1 into the 12v XT3 cradle? I'm just wondering since you can put an XT3 into a 5v XT1 cradle what will happen if an 5v XT goes into a 12v XT3 cradle
It is impossible to do it. The rear of the XT2 has 4 recessed slots around the outside of the 6 metal contacts. The XT2 mount has 4 solid ribs / ridges that fit precisiely into those four slots. The ribs / ridges are a tad less then 2mm high - which doesn't sound much but it is enough.
You can see that the mount recess (surrounded by the red waterproof seal) is the same size on both the XT1 and the XT2. So when you try to put the XT2 into and XT1 mount - it fits perfectly and the latch secures it in position. The bottom 5 contacts on the XT2 match exaclty with 5 pin positions on the XT1 mount. So the XT1 mount provides 5 volts to the contact which is 3rd from the bottom on the back of the XT2.
That isn't theoretical. I have an XT1 mount sitting next to me on the desk. It is powered with a mains transformer which supplies up to 4A at 12v to the XT1 cable - just as if it was connected to the bike battery. The XT2 works perfectly, stays on all of the time and charges up while it is on - just like onthe bike. I can take the XT2 out and insert the XT1 without doing anything else.
- XT1 & XT2 Rear comparison.jpg (428.28 KiB) Viewed 1452 times
The XT1 is the image at the top, the XT2 is underneath.
But If I try to put the XT1 in and XT2 mount - well look at the back of the XT1 - it is smooth. No recesses surrounding the 5 contacts. So although you can mate lower the groove inside that red seal frame , the top of the XT1 cannot be pushed to lock under the latch - because those 2mm ridges prevent it from doing so.
Those ridges also prevent the top pin in the XT2 mount (which supplies 12 v) from making a passing connection with any of the 5 brass contacts on the back of the XT1 stanav. Even if you wanted to give it a go and ground down those ribs/ridges on the XT2 cradle, yes the XT2 would probably lock into position under the latch. But it even if you avoided doing permanent damage with the 12v pin - it still wouldn't work, because the XT1 requires 5v of power on the 3rd pin from the bottom. The XT2 cradle doesn't have a pin in that position. The 12v pin in the cradle would mate up with nothing - there isn't a contact in that top position on the back of the XT1.
To complete the earlier comments - here are the mounts for three Zumos. Click the image to see a larger version.
- Compare XTn Mounts.png (1.03 MiB) Viewed 1452 times
Left - The XT1 - Note 5 pin position, only 2 pins. Middle is +5v, lower is 0v. There appear to be two ridges either side of the pins. These are soft rubber which squash against the rear of the Zumo
Middle - the original XT2 - as provided with the XT2. 3 pins, 6 locations. The bottom 5 match with those on the XT1. The top one is additional, and it is that which provides +12v. Note the long ribs down each side and the two shorter ribs top and bottom. These are hard plastic.
Right - the XT2 mount that is supplied with the power cable for the handlebar controller / group ride radio. This has two extra pins (2nd and 3rd from top) - for data signals from (say) the handlebar controller. The bottom 2 pins are both 0v - I guess one is for power, the other for data - but they are both show as being connected togther.
This means that if you buy the H/bar controller and the modified new lead and cradle, you have a spare XT2 cradle to fit on your spare bike that doesn't have the H/bar controller.
