Trek has launched a new CarBack bike radar that warns you of vehicles approaching from behind at a distance of up to 240m, as well as offering a daytime-visible rear light. At £169.99, Carback goes head-to-head with the identically priced Garmin Varia RTL515, which offers similar functions.

If you’re unfamiliar with the concept, a bike radar scans what’s going on behind you and sends details wirelessly to a compatible head unit on your handlebar (or wrist) so you know what to expect.
“CarBack pairs [via ANT+] with most major GPS computers, GPS smartwatches, and smartphones, so riders can utilise the tech they already have,” says Trek. “Plus, riders who pair CarBack to their smartphone using the Trek Accessory app can enjoy even more features, including the ability to see the exact location of approaching vehicles in real-time.”
We’ve reviewed devices like the Bryton Gardia R300L Rear View Bike Radar Tail Light in the past, but Garmin dominates this market with its Varia RTL515 and the more expensive Varia RCT715 (£299.99) which features a camera too.
> Read our review of the Garmin Varia RCT715
Whereas Garmin says that its devices can detect vehicles up to 140m behind you, Trek claims “industry-leading” rear-approaching vehicle detection of up to 240m. Trek also says CarBack offers “best-in-class visibility with an interruptive flash pattern that’s daytime visible from up to 2km away” – although that’ll depend on conditions.

CarBack has an IPX7 waterproof rating and an LED power gauge.
“CarBack toggles between a battery-saving scan mode and a more energy-intensive detect mode that offers additional precision while a vehicle is detected,” says Trek. “The stated battery life of seven hours is based on radar being constantly active in detect mode, effectively simulating there always being a car present. Most rides will see a significantly longer runtime, up to 12 hours.”

Carback is rechargeable via USB-C and is said to fit both round and aero-profile seat posts. It’s priced at £169.99 and is available now.




















21 thoughts on “Trek sets sights on Garmin with CarBack bike radar”
Cool, battery life looks
Cool, battery life looks awesome. Worth noting that longer range is not necessarily a good thing with these radars. They already penetrate hedges for example….
Secret_squirrel wrote:
At least it’s not as long-range as the review I read yesterday that said it was 240 km! They since corrected it.
I’m a HUGE fan of my Garmin
I’m a HUGE fan of my Garmin rear light and radar. It took me ages to decide to get one, now I won’t ride without it.
Likewise, thought my visual
Likewise, thought my visual aid (1.5m white plastic pipe) does more to avoid close pass stupidity.
“Plus, riders who pair
“Plus, riders who pair CarBack to their smartphone using the Trek Accessory app can enjoy even more features, including the ability to see the exact location of approaching vehicles in real-time.”
Garmin has an app in connect IQ for this which installs on the device which is much better than trying to use a phone.
I’m not religious, but didn’t
I’m not religious, but didn’t (your) god already give human drivers two eyes in the front of their heads? And a connecting brain? Why should I worry about an approaching car?
….. God forgot to give me
….. God forgot to give me eyes in the back of my head.
And?
And? Your neck don’t work?
Some people’s necks don’t
Some people’s necks don’t have owl-like turning abilities.
Most bike radars don’t only
Most bike radars don’t only alert you to approaching vehicles, they change the flash pattern of the rear light to give drivers of approaching vehicles a better chance of seeing you sooner. I’ve been using one since the launch of the original RTL500 Varia Rearview Radar in 2015 (and the subsequent models RTL510, RTL515, RCT715) and on rural roads, there’s more often that not a perceptible change in engine note and vehicle speed (absolute & relative speeds and distance can also be seen on the My Bike Radar Traffic Connect IQ data field).
I’ve never had a problem
I’ve never had a problem seeing cyclists or pedestrians, even the mysterious night time stealth riders that Daily Mail readers simoultaneously can’t see yet still report sightings of. The ability of seeing other road users doesn’t prevent incompetent drivers from hitting you.
don simon fbpe wrote:
Neither does video camera evidence however it does enable you to hold them accountable depending on the police area that you cycle within.
Kent Police do act, including referral to CPS so Courts.
Lancashire do not..
But it does alert you to
But it does alert you to incompetent and dgaf drivers giving you 2-3 seconds to escape being a KSI.
mark1a wrote:
Does that mean that the standard flash pattern is ineffective?
I find rear lights such as the Exposure TraceR and Bontrager Flare have particularly good, attention-grabbing flash patterns without the need for this feature. My £25 Viz 100 will run for 15 hours in Daytime flash mode so I’m struggling to see how this thing is really much more effective. But Trek & co. all need to sell us new, betterer things…
Does everyone who uses these radar-style rear lights also choose their clothing for maximum visibility? Or do these kinds of ‘smart’ lights (and daytime lights in general) mean that dark clothing, preferably Rapha, should be worn when using them?
Simon E wrote:
I don’t think standard flash patterns are ineffective, no. But I’m sure that human perception of a change in flash intensity and frequency is better than no change on approach, so yes I think it’s more effective.
I’ve no idea what other people wear either, I don’t think clothing choice is relevant, unless that was a way of shoehorning in a sneer at people who wear Rapha.
In terms of whether it’s cost effective, I don’t really care. Rear end collisions between vehicles and bikes may not account for a large proportion of the total, but I’m willing to bet they account for the more serious ones. Most of my riding is rural A & B roads, where vehicles approach at 60mph+, so I’ll take my chances with a radar regardless.
mark1a wrote:
Clothing is extremely relevant. Lots of people praise gadgets like this as being some kind of solution then make no effort to wear a jersey or jacket that helps them be more visible.
— mark1aUnless you know it’s having an effect then it is as useful as Hirsute’s little prayer. I’d put more faith in defensive riding, a shoulder check, an inexpensive flashing light and a jersey colour that stands out.
I’ve ridden and driven on rural roads all my adult life and I know that black, dark blues, greens and grey tones are the absolute worst colours you could choose yet so many people continue to ride wearing those things.
Radar tells me their closing
Radar tells me their closing speed, if they are slowing and how far away. Then I decide to say a prayer. The change of light pattern is incidental.
Meanwhile, elsewhere on the
Meanwhile, elsewhere on the site:
https://road.cc/content/news/hit-and-run-driver-without-licence-jailed-year-307917
mattw wrote:
A selfish c**t with a history of drug use (and possibly drunk), who was already banned from driving, was speeding in Prestatyn.
Are you really suggesting that a fancy-schmancy flashing rear light would have prevented Nathan Brown smashing into the cyclist?
No-one is suggesting that.
No-one is suggesting that. Any more than being able to see folk in say car rear mirror affects other road users. However, you can take action to avoid any detected idiots which could save your life.
Simon E wrote:
No more or less than this in that particular example: