Mounting the Luxos U Light

The B&M Luxos is a fantastic light, arguably the best for long distance cycling. but it an be very difficult to mount if your bike does not have a calliper brake system. My friend Arran had some problems mounting his so thought I would show how I’ve mounted in on my aero bars, a technique that could be adapted elsewhere.  Be warned: this is engineering overkill but once done you will have a solid mount.

You need a few bits to do this:

  • A Profile Design universal mount (or similar)image
  • Some epoxy
  • A drill, screwdriver and pliers
  • A bolt long enough to go through the Profile Design mount with a washer and a nylock nylon nut (or some Loctite)
  • Some tenacious tape (or similar)
  • A small stainless steel screw

Step 0: Think about how far forward you want the light

I mounted the light with the bracket resting on the mount for extra stability, but you may want to do it differently.

Step 1: Drill a hole diagonally through the mount for the bolt

Be sure to do this carefully and not go off on an angle.

Step 2: Insert the bolt through the mount

Put a washer on the end of the bolt, the bolt through the mount and then the nut on the back with a washer. You now have the bolt through the mount.

Step 3: Fill up the Profile Design mount with epoxy

The mount is hollow so if you put too much pressure on it when tightening the bolt it will crack. Take the cap off the end of the non-threaded side and then fill up the interior with epoxy. Of course you let it dry before going to the next stage.  Your bolt is now permanently in the mount.

Step 4: Mount the Luxos Bracket

Take off the nut. Take some epoxy and put in area where the bolt comes out the back of the bracket, and on the bottom of the bracket where it rests on the mount. Slide the bracket over the bolt, put on a washer, and tighten the nut. Remove the excess epoxy.  You should now find that the open area where the bracket goes around the bolt is full of epoxy and everything is in there firmly/permanently.

Step 5: Cut off the excess bolt

You want the bolt flush with the end of the nut.

Step 7: Add some tenacious tape (or other)

This is really just to protect the bolt from rusting.

This is what it should look like without the tape.  Apologies for the bits of tenacious tape left on it the mount.



Step 8: Mount on the bike

You want to mount it on you LEFT aero bar as that way the natural weight of the light will serve to tighten rather than loosen the light. I tighten the unit and then, just for one last bit of engineering overkill, drill a small hole through the mount and into the handlebar threaded clip, into which I insert a small stainless steel screw.  You now have your mount ready to install and aim the light.


The photo below shows it with the tenacious tape covering the bolt.


Now that your light is mounted …

The new Luxos U have a different approach for plugging in the USB cable.  When first released, the USB socket was in the on/off switch. Now there is a small cable which you plug into another cable with the USB socket.



I’ve posted here about how I run the cables into my gas tank bag, as well as my complicated setup for running/charging three devices at once. Of course I wrapped my tenacious tape around the plug just to make it extra safe from any water intrusion! What’s nice with the new system is that the on/off switch can be mounted externally (see below—it is on the bottom, attached to my aero bar) and then the cable run into the gas tank bag. This sure beats searching around in the gas tank bag for the switch!



5 responses to “Mounting the Luxos U Light

  1. Doesn’t this light location completely prevent you from holding on to the bars? I would think you would want to rotate the mount just a bit to put the Luxos U below where your hands go. This would also reduce the amount that your hands block the side beams.

    I’ve been very happy with how much even light the Luxos U provides, but have found that even slightly blocking the light results in huge dark areas where I can’t see anything if there are no street lamps.

    I will be doing a similar setup as soon as the new Profile T1 bars show up on my doorstep.

    • Good observation. Yes, a more forward position gives you better illumination but last year I crashed my bike and broke the lens on the Luxos because it was out too front so hence my moving it back. I can still hold on the bars as I don’t have the bars too close together.

      Glad you like the Luxos. They really are a great light and the USB integration is wonderful.

      • lentamentalisk

        Thanks for the suggestion. I’ll make sure to keep the light recessed a bit and protected by the areo bars. I’m sure there is nothing worse than finding your self in pitch black after a crash, many miles from home. Originally I moved my light from the top of the crown down to one side of the fork to avoid interference with my handlebar bag. This is all well and good during the day, but at night the front wheel blocks a huge swath off to the right, leaving plenty of room for boogie men to hide.

      • Fortunately it was in the day time. I dozed off while riding! The bigger hassle was getting it repaired by B&M. Suffice to say that at that time they did not have a mechanism to repair cracked lenses. Cost me Euro 80 in the end. Depending on the size of your handlebar bag another option is to go for one of the versatile Minoura mounts. They have a number of configurations but this one – replacing one of the stem spacers – is an attractive option for some bikes.

  2. Pingback: Mounting the Luxos U Light – Part Two | Chris Bennett's Triathlon and Cycling Blog

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