The £10 gadget cyclists use to avoid a repeat of that 75 mph bike horror story

The rear light footage is awful to watch, even when you know the rider survives.

A dual carriageway, an HGV edging out, a cyclist holding a clean, predictable line on the left. The wind noise from the camera drowns out almost everything, until a horn blares, far too late. In the police report, the officer estimates the closing speed at around 75 mph. In the rider’s own words: “I did everything right. I just wasn’t… noticed.”

Months later, in a bike shop car park, that same rider is pointing at a tiny, blinking plastic square on his seatpost. Ten quid, thumb-sized, flashing like an angry lighthouse.

“It’s boring,” he shrugs. “But boring things that make drivers see you are suddenly very sexy at 75 mph.”

Why “being visible” is not the same as being seen

Most cyclists think they’ve ticked the visibility box the day they buy a hi-vis jacket and a cheap red light. You clip it on, it glows vaguely, you feel responsible. Job done. Until you ride in the real world: sodium streetlights, wet tarmac, brake lights, bus adverts, LED shop fronts all shouting in the same red-orange palette.

To a driver at 50, 60, 70 mph, your steady glow is just one more red dot in the noise.

Human vision is lazy and biased. We pick out motion, contrast and patterns more readily than static blobs of light. A constant, weak red LED can disappear against the blur of tail-lights and the reflections off a wet windscreen. Add fatigue, drizzle on the mirror and a slight bend in the road, and you’re suddenly in the statistical margin where “I never saw them” lives.

Tom, a commuter from Leeds, learned this the hard way. His near miss came on a dry evening, well-lit A-road, full set of legal lights. The dashcam from the car behind shows it clearly: you can see every reflector on the lorry, the sodium wash on the kerb, the green sign ahead… and then, late, very late, a faint, steady red glow, barely pulling free from the background. The driver who passed him cleanly described it perfectly:

“You were there, but my brain filed you with the tail-lights. You only popped out when you moved.”

The problem wasn’t that Tom was invisible. It was that his light behaved like everything else on the road.

The £10 box that hacks drivers’ attention

Ask around any club run or long-distance event, and you’ll hear the same bit of kit mentioned in passing, like it’s no big deal: a proper flashing rear light with a focused beam and a pulse pattern that cuts through the clutter. Not a novelty laser, not some disco ball. A simple, bright, well-designed flasher.

For about a tenner you can get a USB-rechargeable rear light that does three subtle but important things differently:

1. It’s bright enough to matter. Not a dull glow, but a clear, defined point that still shows up in daylight and from a long way back.
2. It uses a pulse or irregular flash pattern. That tiny unpredictability yanks it out of the mental “background lights” folder.
3. It throws light in the right directions. A narrow-ish core beam for distance, plus some side spill so drivers on a slight angle still pick you up.

On paper, it’s just another accessory. On a grey bypass with an overtake starting behind you, it’s a quiet negotiation with a driver’s lizard brain.

One rider who commutes year-round between Cambridge and Newmarket swapped his old steady light for a £10 pulsing one with a daytime mode. In his words:

“The first week, I could literally see cars giving me more space earlier. It felt like I’d gone from ‘oh, there’s a cyclist’ at 30 metres to ‘something’s flashing up ahead’ at 100.”

Is that a controlled study? Non. But if you ride long enough, you feel the difference in how often you’re “surprised” by a vehicle suddenly close.

Why the “boring” details of a cheap light matter at 75 mph

Ten pounds of plastic and LEDs doesn’t sound like much of a safety plan. The nuance lives in small design choices that most product pages hide under buzzwords and lumen numbers.

A decent rear flasher does a few unglamorous jobs well:

• Holds a consistent output as the battery drains, instead of fading to a useless ember half an hour from home.
• Mounts solidly, so it doesn’t sag down towards your tyre or point at the sky after a pothole.
• Offers at least one mode that isn’t an epileptic rave, but still breaks rhythm enough to be noticed.
• Survives rain, winter salt and the occasional knock without sulking.

None of this is sexy. All of it is the difference between a gadget that quietly works every Tuesday, and one that impresses you in the kitchen then dies in week three.

The 75 mph horror story that did the rounds on cycling forums a while back had a depressing footnote. The investigating officer noted that the rider’s rear light was on, but angled slightly down and set to a steady, low-output mode to “save battery”. In the rider’s own GoPro reflection, you can see it, glowing bravely at his rear hub instead of the car grille.

It’s not about guilt. It’s about how many of us roll the dice on tiny, fixable details.

Turning a gadget into a habit, not a talisman

The danger with any safety device is superstition. You buy it, you fit it once, you mentally tick the “safe now” box and stop thinking. The real win is treating that £10 light as part of a small, repeatable ritual around every fast-road ride.

Before you head out on a route with any 50+ mph stretch, you give yourself two minutes for a “visibility check”:

• Is the rear light charged enough for the full ride plus a margin?
• Is the beam aimed level, at about car-bonnet height from typical following distance?
• Are you using a flash or pulse pattern that’s visible in current conditions (mist, full sun, dusk)?
• Is there mud, road grime or a jacket strap partially covering the lens?

It sounds fussy when written down. In practice, it’s a glance and a thumb press while you fill a bottle.

Some riders go one step further and run two cheap lights instead of one fancy one: one on a steady low mode, one on a pulse. Redundancy buys you time if a mount fails or a battery goes flat, and the twin pattern is harder for the eye to ignore. As with most good habits, you only feel its value on the rare day something else goes wrong.

Think of it not as gear obsession, but like checking your tyre pressure or your quick-release before a descent. It’s the tiny, repeatable stuff that quietly reshapes your risk.

From horror story to quiet confidence on fast roads

If you ride long enough, you collect your own “that was close” stories. A wing mirror brushing your sleeve. A horn you didn’t know was for you until the car passed. A driver at a junction swearing blind they looked, they just didn’t see.

The £10 gadget isn’t a force field. It won’t fix texting drivers, bad infrastructure or a blind bend. What it gives you is a cheap, practical nudge in the only battlefield you can influence in seconds: other people’s attention.

Once you’ve ridden with a proper rear flasher on a grim dual carriageway at rush hour, it’s hard to go back. You see how early lorries move out, how often cars hang back a little instead of diving between you and a refuge island. It doesn’t make you invincible. It makes you slightly less dependent on luck.

And that’s the quiet lesson hiding in that 75 mph video. You can’t control the whole story, but you can stack a few boring, plastic odds in your favour.

Key point	Detail	Why it matters for cyclists
Visibility vs being seen	Steady, weak lights blend into traffic noise	Helps explain why “legal” isn’t always “safe”
The £10 flasher	Bright, pulsing rear light with smart beam	Affordable, simple upgrade that changes driver behaviour
Habit, not talisman	Regular checks, correct aim, battery, mode	Turns a gadget into a reliable layer of safety

FAQ:

• Is a flashing rear light actually legal in the UK? Yes. UK regulations allow flashing lights on bicycles as long as they flash between 60 and 240 times per minute and meet minimum brightness standards. Many mainstream bike lights fall within this range by design.
• Should I use flash in daylight as well as at night? A strong daytime flash mode can help drivers pick you out earlier on bright roads, especially on rural A-roads. In dense urban areas at night, some riders prefer a steady or softer pulse to avoid annoying others while staying visible.
• Are two cheap lights better than one expensive one? Often, yes. Two decent £10 lights give you redundancy and pattern contrast. A single high-end light is great, but if it fails, you’re dark. The ideal is one solid, reliable main light plus a backup.
• Where is the best place to mount a rear light? On the seatpost or rear rack, roughly at car-bonnet height from a following driver’s perspective. Avoid tucking it under saddlebags or jackets where fabric can block or dull the beam.
• How bright is “bright enough”? You don’t need to blind people, but you want a light clearly visible in daylight at typical overtaking distances. If a friend can’t spot you easily from 100–150 metres on a dull day, your current light or mode is probably too weak.