Bookman Block Light Rear

The Bookman Block Rear Light is a basic 'be seen' light that's bright enough to get you noticed. It's extremely simple to operate and quick to recharge. Its size means it's easy to squeeze onto short seatposts and it's perfect for keen roadies who count the grams, but slacker seat angles will leave it pointing too far down.

This is, unsurprisingly, very similar to the Bookman Block Front Light I reviewed previously – but with one unique, unfortunate flaw of its own. The mounting is not angled to allow for your seatpost leaning backwards, so unless your seat tube is at 90 degrees (spoiler: it's not) the Block will point downwards. The more laid back your seat tube, the less effective the light is.

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Beyond this, it has all the benefits of the front version, though it's (deliberately) less powerful at 18 lumens. The low power mode is 5 lumens.

The four modes are navigated via the large button, and it's easy to operate even in gloves. A prolonged press switches the light on or off, and quick clicks cycle through 100% (power) steady, 100% flashing, 25% steady and 25% flashing. There's no memory mode – it always starts at 100% steady.

Actual run-times all exceeded Bookman's claims and, as with the front light, by a good way. I got just over the claimed 1.5 hours in 100% steady, and 5.5 hours in 100% flashing against a claimed 3. At 25% output I got 7 hours steady (claimed 5) and 30 hours (claimed 25) flashing. These times stayed consistent throughout the test period.

I found it consistently recharges from flat in under two hours, either directly or via a computer.

Light is certainly visible from the side (Bookman says visibility is 180 degrees), but it's not as junction-friendly as some. The low battery warning could be better, too. Turn the light off or on as it nears empty and you get a flashing orange warning, but in order to see it (it's very small), you have to look directly into the light.

I was initially sceptical about the mount – the channel isn't that deep and it feels like the band could jump out, but I tested it on a variety of seatposts including aero designs and it never shifted. I also mounted it on my helmet.

Bad weather doesn't seem to bother it either (Bookman makes no claims about waterproofing) and while the USB port's rubber seal is fiddly, it works well. It's a well-sealed unit that can handle heavy rain.

The Block rear costs the same as the front, and like the front it's outshone slightly by brighter options for the same money: the Vel 20 Lumen is also £20 but slightly brighter and has a better mount, and while the Giant Recon TL 100 is £5 more, it's slightly smaller (it's a 3cm cube) and a whopping 82 lumens brighter than the Block. Lezyne's KTV Pro Drive 75 is also £25, slightly bulkier, but well waterproofed with 270-degree visibility and a 75-lumen output.

> Buyer’s Guide: 17 of the best rear lights for cycling

The Bookman Block has simplicity, low weight, good run-times and quick recharges in its favour. It's also usefully bright, if massively outperformed by many similarly priced lights. However, the mount leaves what light it does pump out at the mercy of your seat tube, meaning it will rarely, if ever, sit at its most effective angle.

Verdict

Bright, simple and very useful, but it's stuck at the angle of your seatpost