Friday, December 6, 2013

Moon Comet Rear Light Review

Yet another new rear light for my bike! It is obvious that having more lights on the bike will make you more visible to the traffic. If you have a strong rear light that can be seen from far away, this makes it much easier for the vehicle behind you to spot you from a greater distance. The driver will be more willing to move over to the next lane, as they have plenty of distance and time to execute a proper lane change.

On the other hand, if you only have a dim rear blinker, the driver will only be able to spot you when they are quite near. This gives them very little time to properly change lane when overtaking, making it more likely that they will pass close to your bike.

With that in mind, I decided to add on a rear light for my Avanti Inc 3. Although the current NiteRider Solas 2 Watt rear light is very good, an additional light will complement the Solas and make my bike even more visible.

Another reason is that using both at the same time will practically eliminate the chance that my bike has no rear light if one of the lights suddenly spoils. There is such a possibility as my Avanti is a wet weather bike, and riding in the rain may cause the lights to spoil (even though they are advertised as rain resistant).

I am a fan of the Moon Comet series of lights, mainly because these lights use COB LEDs, which gives off a really nice organic glow which I like. They are also small, lightweight, and have a decent battery life. The rubber strap mounting provided is really versatile and easy to use, with quite a bit of room for adjustments. For more details on COB LEDs and the Moon Comet Front Light which I have on my Dahon Boardwalk, just check out this link!

Moon Comet Rear Light. 35 lumens compared to 100 lumens for the front light.

The various modes and the estimated runtime for each mode

Viewing angle and the range of the light

The rear light comes with an additional saddle rail mount, which the front does not have

Looks exactly like the front light, except that the LED is red in colour. For more details on the light, check out the Moon Comet Front Light review.

What's inside the box: The various mounting options that come with the rear light

Saddle rail mount. Useful if you are not using a saddle bag, and don't have enough seatpost length to attach the light onto the seatpost.

Even though I did not attach a saddle bag onto the saddle of my Avanti, I am still unable to use the saddle rail mount for the rear light, as the rear-rack-mounted-saddle-bag gets in the way. The picture below shows what I mean.

No way to use the saddle rail mount or the rubber strap mount on the seat post as the saddle bag on the rear rack will block the rear light

To overcome this issue, I decided to mount the rear light onto the tail end of the rear rack instead. That was my original intention for the NiteRider Solas 2 Watt rear light, but unfortunately I was unable to engineer an elegant and unobtrusive solution for that.

With this new Moon Comet Rear Light, it has different mounts, and after some experimentation, I was able to fix up something that looks simple and works well. Check out the pictures below!

Light clip (shown on bottom left) is taken from the saddle rail mount. That is the part that I need to fix the rear light to whatever DIY jig that I have.

I used an L-shaped stainless steel plate as my DIY mounting. It was sprayed black to match the colour of the bike. Mounted onto the rear rack with some standard bolts, nuts and washers. Nylon locknuts were used to prevent self-loosening.

When mounted, the Moon Comet rear light is positioned exactly in the middle! Just what I wanted.

The Moon Comet rear light nestles nicely on the rear rack, protected by the saddle bag and the rack itself. This prevents me from kicking the light accidentally when I swing my leg over the rear of the bike.

On/Off/Mode button is easily accessible on the top, and the light can be removed easily for charging. This is what I mean by a simple and elegant solution! It is also very secure and does not droop down on bumpy roads.

With this additional rear light, I feel much safer as there are two very good rear lights doing the job of lighting up the rear. I normally set the NiteRider Solas 2 Watt rear light to blinking mode, and put the Moon Comet into the steady mode. This gives me both an eye catching blinking light and a constant rear light.


  1. I like your solution for mounting the light on your rack. I've just bought one of these, and was thinking of doing the same, but I don't think my DIY skills are quite up to your standard.

  2. Can the rack mount bracket be affixed to a rear rack using the standard 2- or 3-screw configuration? I have a Bontrager BackRack Lightweight, which has a place to mount a reflector or light. I'd rather use that than clamp onto the rack's top rails. Also, what rear rack do you have in these photos? It looks nice.

    1. I don't have a way of fixing the light to the rear rack using the rubber mount. That is why I used the L shaped bracket to fix the light.

      The rack is from RackTime, I forgot the exact model it is matte black and with double rails.

  3. hi, is it possible to install the saddle mount the other way? (as opposed to the picture) so that the light is closer to the saddle?


    1. Most likely it is possible, but the location of the mount is very much limited by the width of the saddle rails, as there are grooves on the mount that needs to be fitted to the rails.
      Another problem i foresee is that it will be difficult to tighten the bolt when the bolt head is facing upwards. There is very little space to insert the Allen key and turn.

  4. Thanks for this post. Love the INC 3.
    If it helps your readers, I learnt recently (i.e. in March 2016) that Moon has a rack mount bracket (product code RB-19, see which may fit the Comet light to some racks.
    The three holes in this RB-19 bracket are each 25mm apart (centre-to-centre measurements). Outer holes are 50mm apart.

    1. I can confirm that the RB-19 is a great way to mount a moon light to a rear rack using the standard 50mm spaced holes. I'm probably going to buy another RB-19 and mount it to the front fork brake hole to put my front light there.


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