The Blackburn Mars 4.0 is the brightest rear light in the range from Blackburn. It features a single super bright red LED pointing directly backwards and two smaller orange LEDs for visibility from the sides. It’s a compact lightweight unit and offers a number of mounting options.

Manufacturers specifications

Blackburn’s most powerful rear flasher
1 Watt Ultra Bright Red LED
2 Amber Side LED’s for lateral visibility
50 hour run time steady; 150 hour run time flash
No tool battery installation
2 AAA batteries included
3 mounting options included: belt clip, seat post clamp and reflector/rear rack mount
Lifetime Warranty


Best Rear Bike Light - Blackburn mars
Best Rear Bike Light – Blackburn mars

The Blackburn Mars 4.0 is about the size of a small matchbox which weighs only 58g including batteries. It’s made of tough plastic appropriate for the rough conditions these lights need to endure in daily use. Opening the case to change the battery will cost you a penny – a quick twist of which in the slot at the base of the unit prizes the case apart. A rubber seal is effective at keeping out the rain.

Mounting Options

Best Rear Bike Light - Blackburn mars
Best Rear Bike Light – Blackburn mars seatpost mount

A number of options exist for mounting the light to the bike. Most people will choose to mount the light on the seat post. The included mount wraps around a seat post of any shape or diameter. The vertical angle can be adjusted and it’s worth spending a little time getting the angle just right to ensure maximum visibility to a range of road users from cars to lorries. The clip on the rear of the light used for attaching to the seat post mount doubles up as a belt clip. A further mount is also included which allows the light to be attached to a rear rack.

The Mars 4.0 is an excellent choice for Brompton owners. It fits nicely to the seat post and doesn’t affect the folded package apart from the seat post protruding an extra centimetre.

Operating Modes

The Blackburn Mars 4.0 light is operated by a single push button on the top. The button is quite small and is tricky to operate with gloves – though with some practise it can be done. One press of the button switches the light on in steady mode. A second press puts the light into flashing mode. A third press switches the light off. All nice and simple!

Beam Pattern and Brightness

Blackburn Mars Beam Patterns
Blackburn Mars Beam Patterns

The light has a circular beam pattern which is bright over quite a wide viewing angle. With fresh batteries the Mars 4.o is at least as bright as our benchmark Cateye TL-LD1100 from the rear but while it does include side LEDs is not as bright as the Cateye from the sides. None the less it kicks out an impressive light for one so small.

Battery Life

As always I recommend the use of rechargable batteries and with AAAs, make sure you get a pair with a rating of 800mAh or greater. In my test using a pair of 850 mAh batteries (which had a measured capacity of 700mAh), the batteries lasted for approx 35 hours on steady mode before the light has finally extinguished. The brightness dropped off quite quickly though so I would say that you would probably want to be recharging the batteries after around 12 hours use (longer on flashing) to maintain maximum visibility. When I was using this light last winter for an hour a day I got into the routine of charging the batteries every two weeks. To get the most from your batteries, be sure to use a good charger.


The Blackburn Mars 4.0 is a great little light and would be a good choice if you want something smaller and lighter than the TL1100 but don’t want to compromise on brightness. It’s our recommended rear light for Brompton users and is our choice for best lightweight rear light.

Where to buy the Blackburn Mars 4.0 Light

The Mars 4.o can be purchased from here or here.

The Official manufacturer website page for this light can be found here.

Moon Shield 60 Review

Moon Shield 60 Video Review
Moon Shield 60 Review
Moon Shield 60 Review

I must admit I wasn’t expecting much from this light when I received a model for review. It’s pretty tiny and I was anticipating a correspondingly small light output from the diminutive package. I was wrong – It’s a great little rechargeable light capable of an insane light output, has a decent mounting bracket and great build quality and weather sealing.

Moon Shield 60 Manufacturers Specifications

Up to 60 lumens light output
Tool free quick release bracket
Constant & flashing modes
Water resistant
Vertically adjustable
Low battery indicator
3.7V Lithium polymer battery
USB rechargeable
Up to 6 hours runtime
2 hours charge time
Weight 38.4g
Dimensions 5.5cm x 3.5cm x 3cm

Package Contents

You don’t get much in the package but you get what you need – the light itself, a USB charging lead, a rubber seat post mount and an instruction leaflet. If you don’t have a USB socket in a convenient place for charging, you’ll need to buy a mains adaptor.

Build Quality

A number of the latest lights on the market today have pretty rubbish build quality suffering in particular from either poor mounting brackets or poor weather sealing or both. I’m happy to say this isn’t the case with the Moon Shield 60 and it has a pretty solid feel and is better sealed than most rear lights I’ve seen in a while. The weakest point is the rubber USB charge socket cover which is attached by a very thin strand of rubber. I don’t think it would break in normal use but you do need to be a little careful when removing the USB cable. The mounting bracket is made of a stretchy rubber which can fit round pretty much any shape or size of seat post.  This can be fitted with no tools.  Embedded into the mounting bracket is a simple plastic slot into which the light itself is mounted. Once attached, the light’s vertical tilt can be adjusted.

On top of the light is a well sealed rubber push button that definitely wont get accidentally pressed when the light is carried in a pocket or bag. Consequently it can be a little tricky to operate with gloves but it can be done.

Battery Life and Light output

When I turned the light on by a press of the button, I was pleasantly surprised to find the light was just as bright as the Blackburn Mars 4.0 and the Cateye TL-LD1100 that feature on my best bike lights list. Then I realised that was merely the minimum light setting. Pressing the button again raised the light output to a level exceeding that of pretty much all rear lights I’ve ever seen. There was worse to come. A further press of the button caused yet another step up in intensity to a frankly bonkers level. Unless you ride regularly in thick fog, the brightest setting is way more intense than necessary and I imagine most people will use the light on one of the lower settings with longer run times between charges. In addition to the constant light output modes there are two flashing modes, the first has a rather unpleasant strobe effect, the second a more bearable slower flashing. These can be seen in the video below.

While there are not separate side LEDs the central LED generates a wide enough beam to give very good visibility from the sides as well as the rear.

Specified battery life is 5 hours 40 mins on the lowest setting, 3 hours 50 mins on the medium setting, 2 hours 30 mins on the highest setting and 7 hours on the flashing modes. My tests showed these to be accurate to within a few minutes. Considering the size, weight and brightness it’s actually pretty decent and will be plenty for most commuters. In all modes the light output maintains its same bright level throughout the run time but then cuts out suddenly. There is a low battery warning light but it is not much use. One, it can hardly be seen right next to the bright main LED and two there is just not enough warning from when the warning  shows to when the light cuts out. (15 minutes if you’re lucky). Really with this light you’ll just need to be organised and remember to recharge it on a regular basis.

Charge time for the light is approx 2 hours. There is a charging indicator LED that shows when charging is complete, and unlike the low battery warning light, it is useful.

Compared to Cateye TL-LD1100

In an attempt to make the rear light beam shots more useful, I’ll now be showing the beam alongside our benchmark rear light, the Cateye TL-LD1100. Here we have two photos showing the output from the two lights side by side. In the first, the Moon light is set to its lowest brightness setting, in the second it’s at the highest setting. In both, the cateye light is set at its maximum constant light output. As can be seen the Moon light (on the left)  is both brighter and has a considerably wider beam pattern than the Cateye on the right.


All in all I really like the Moon Shield 60 light. Apart from the daft low battery warning light I can’t find anything bad to say about it. Highly recommended and an easy choice for our best bike lights page.

The light is fairly widely available. For example it can be purchased  here or here.

Cateye TL-LD650 Rapid 5 Review

It’s time for us to take a look at another rear light. Here we test the Cateye Rapid 5. This is also known as the TL-LD650 and is the latest of Cateye’s popular tail lights. The light follows on from the successful and immensely popular TL-LD600 and TL-LD610 lights but has updated styling for the 2011 / 2012 season.

Cateye Rapid
Cateye Rapid


Dimensions: 104 x 28 x 38mm

Weight : 72g (inc batteries & mounting bracket)

Batteries : 2 x AAA

Modes : Rapid (50 hours), Pulse (50 hours), Flashing (100 hours), Constant (15 hours).

Mount Diameter : 12-32mm

Cateye TL-LD650 Design

Cateye Rapid 5 Review
Cateye Rapid 5 Review

The light contains five LEDs, the centre three point directly backwards and the outer two are directed out at about 45° to provide all-round visibility. The centre light is the brightest, the two either side being almost as bright (but are not used in all modes, see below). The outer two are not as bright or perhaps just not as focussed as the centre lights. All in all it provides a decent spread of light.

Cateye Bracket
Cateye Bracket

The supplied bracket is a seatpost mount which can be attached without tools. It works with pretty much any size of seatpost. It allows vertical tilting so the beam can be pointed at the optimal angle. The light attaches to the mount with a simple but effective quick release mechanism. Both horizontal and vertical mounting are possible though all round visibility requires the light to be mounted horizontally. Alternative mounts are available including a saddle rail mount and a rack mount. (Note these are not supplied).

Cateye Rapid 5 Batteries
Cateye Rapid 5 Batteries

The light takes AAA batteries so is a lightweight unit. The batteries are held behind a simple plastic cover. There is no sealing as such but the plastic cover has a reasonably snug fit. It doesn’t inspire quite as much confidence regarding waterproofing as some other lights I’ve tried (like the mighty TL-LD1100)  but that said I’ve used it for the last month in some pretty nasty conditions and haven’t experienced any problems. Like most lights, I would suggest taking it indoors when you’re not using it.

Cateye Rapid 5 Beam
Cateye Rapid 5 Beam

A single button switches the light on and off and switches between modes.

The available modes include:

Constant : Only the centre and outer two lights are on in this mode.

Flash : A simple flashing pattern using all 5 LEDs

Pulse : A gentler flashing pattern using only the centre and outer two lights. (Useful when riding with other cyclists as it’s less dazzling when riding close).

Rapid : A wild attention grabbing flash mode using all five lights.

The video shows the modes better than I can describe them:

Cateye TL-LD650 Rapid 5 Review


The Cateye Rapid 5 is a decent rear light and will appeal to a lot of people and is brighter than many lights on the market. To be honest I still prefer the older TL-LD1100 which is brighter, gives more light to the sides and has better sealing against the rain. However, the Rapid 5 is much lighter and is more compact and stylish.

The Rapid 5 is not widely available yet but this store has some in stock at the time of writing.

The official web page for this light is here.

Exposure Lights Announce 2012 range

A few days ago, Exposure Lights unveiled their 2012 range of bike lights. Unless you look carefully, you might not notice any difference between these and the 2011 range. Exposure have sensibly chosen to not to drastically alter the form factor or features of their already popular and successful range of lights and instead have provided a number of evolutionary refinements across the range:

The chargeport connector is now gold plated which provides a better connection.

I noted in my review of the Exposure Diablo that the charge port connector was the only potential place water could possibly get in and I thought a rubber bung would be a good addition. For the latest versions, Exposure now include a silicone cover to protect the port from the elements.

The circuitry within the light has been improved to optimise output from the LEDs across the temperature range. This patented technology is called ‘Intelligent Thermal Management’. Exposure says “combats the loss in efficiency of LEDs at elevated temperatures, maintaining optimum output keeping you shining ‘Brighter for Longer’ “. I had noticed a slight drop in battery life with my Diablo light on very cold (sub-zero) winter evenings last year so it will be interesting to see if this technology also improves battery life at low temperatures.

All the lights now use the new Cree XPG R5 LEDs. Compared to the 2011 range, this provides an increase in brightness of approx 25 lumens per LED. So the Joystick mk6 provides 325 lumens and the mighty Six Pack mk2 kicks out a blinding 1925 lumens. My favourite midrange models; the Strada mk3 and Diablo mk3 are rated at 645 and 975 lumens respectively.

All in all these are subtle but welcome additions. It’s great to see that Exposure are still investing in R&D to ensure their lights remain competetive.

Some of the lights in the new range are available now and the rest will become available through September. In my price comparisons, I’ll link to both 2011 models (which are being sold off on special offer) and the 2012 models until the 2011 models are sold out.