Review – Backtracker Radar Watches Your Back on the Bike

Cycling Safety Roads Radar

The Backtracker is an innovative cycling accessory which has an integrated radar and provides visual alerts for the bicyclist on the distance and speed of vehicles approaching from behind. The radar unit mounted on the the seat-post includes a flashing rear light which increases in frequency the closer the vehicle is. We introduced the Backtracker in early July with an interview with Franz Stuwig, the managing director of the South African team (iKubu) who launched crowdfunding for the Backtracker.

At the time of writing, the team have reached just over half of the $194,500 (USD) crowdfunding goal. An Australian distributer has already been appointed and I was fortunate to be able to trial a prototype Backtracker unit, one of only 10 units in the world.  I was asked not to get it wet, though the production version of the Backtracker will, of course, be waterproof.

Despite the terrible Sydney weather, a few dry days allowed me to trial the Backtracker on different roads in various locations and to get a feel for how it works and can help bike riders.

 

On the road with the Backtracker
The Backtracker radar works by detecting only vehicles approaching from behind. It ignores parked cars, stationary objects and vehicles traveling in the opposite direction. Experiencing this first-hand and seeing the display showing a vehicle approaching from behind is enlightening. While the novelty of this new idea wears off quickly, the practical value of being more aware remains.

Nolen van Heerden of Backtracker was able to provide a more precise explanation “Only cars with closing speed are detected (this is speed relative to the cyclist). Vehicles with speed lower than the cyclist or going at the same speed as the cyclist are ignored.”

Backtracker Car Bike Radar Display
Handle mounted Backtracker display unit fastened with O-Rings

Backtracker Radar Traffic Car Detection
The radar and light unit mounted with O-rings on the seat tube

 

I was initially surprised to see how the Backtracker would highlight multiple vehicles approaching, an obvious feature perhaps but useful information. The display unit indicates the distance of the vehicles, the LED lights moving up the display as the vehicle comes closer. A colour LED also provides an indication of speed and my judgement was that vehicles faster than 70 km/h were given a red light while slower vehicles have an orange light.

The second component of the light is the frequency of the flashing rear red light, it speeds up the closer the approaching vehicle. When setting up the photo and video shoot it gave me the opportunity to observe vehicles and their reaction. It appeared that vehicles were slowing as they came closer. This observation however may be distorted as the approaching vehicles were also seeing an unfamiliar situation, a stationary bike with a flashing light and no rider – and nearby a person with camera and tripod.

 

How accurate is it?
The direct answer is that the prototype unit is fairly accurate, but not perfect. It picked up approaching cyclists while the unit was stationary, but was not fooled when I walked around in the path of the radar. I found that over 90% of vehicles from behind were picked up, but there were situations in which it didn’t work and I asked Backtracker about this.

Van Heerden acknowledges,“The prototype unit that you have tested has poor performance for close-range vehicles that are at a distance of less than 8m. We have seen a few cases where a vehicle that starts accelerating past you from a distance of 8m is not detected. This is something that we are working on improving for the final unit and we are confident that the steps we are taking will improve the close-range performance significantly.”

As the Backtracker records approaching vehicles, in situations where the vehicle maintains exactly the same speed and isn’t closing-in, it may be ignored. For example at traffic lights, if you accelerate faster the traffic behind then vehicles may not show up, or may show up unexpectedly. The other situation in which I experienced some vehicles being ignored by the prototype Backtracker was when the road situations changed, such as when turning corners.

Bike Video Traffic Following
The Backtracker accurately detects approaching vehicles, even on winding roads

 

The Backtracker was consistent in locking-in on vehicles in the far distance approaching while I was cycling along on winding as well as straight roads. Around curves the vehicles were obviously ‘lost’, however when they become visible, the Backtracker quickly picked them up again.

A situation I didn’t trial was inner-city cycling, for example on a dedicated cycle-lane where you pass congested traffic, as I would argue this is probably not a riding situation best suited as a bike rider is already anticipating traffic. While Backtracker are fine-tuning and improving, after my trial the technology appears best suited on routes where traffic is infrequent or inconsistent, this provides information not previously available.

Backtracker Display Lights
Part of the start up sequence, connecting to the radar and running through all LEDs
The potential
One of the inherit difficulties with the Backtrackers is that as a rider, you are usually gazing out ahead and have to look down to notice the display unit, though this is no different to a bike mounted rear view mirror. True, the Backtracker does face competition from a humble helmet mounted rear view mirror, however the Backtracker offers the rider more detailed information: the distance of the approaching vehicles, an indication of speed, and the rear light which flashes with increasing frequency as vehicles draw closer.

Giant Bicycles Australia
The Backtracker and bike taking a refreshment break during testing in Sydney

 

Because you have to look down while riding to see the display, I would prefer an out-front mounted option to bring it closer to my peripheral vision. Thinking ahead into the future, a head-up display (think Google Glass) would be optimal. But a practical addition for now would be an optional audible beep. When there is little traffic, a single beep would alert you.

Backtracker are already on this as van Heerden explains, “The rear unit uses Bluetooth Low Energy (BLE) to communicate and we are going to release an Open API so that anyone can interface with it. We can actually interface with up to 6 BLE devices simultaneously, so this really opens up interesting possibilities. As a start, we are very keen to interface with existing bicycle display units (e.g. Garmin displays and smart phones) to help minimize handlebar clutter. We are also very excited about interfacing with technology like Google Glass and other wearables that can give a cyclist visual, audio or even haptic/tactile feedback.”

The Australian distributor also noted the possibility to trigger a video camera to start recording.

The two hardware components, the radar (with light) and the display, are well constructed and attractive. Charging is with standard USB cables, so both the display and the light/radar unit are separately charged. It is intuitive, as is the operation of the units; a button on the front and a button on the rear to turn on/off. It will only be a matter of time until they can be slimmed down. For example, the display unit could incorporate a front light and become more integral.

Bike Radar Track Safety
The Backtracker prototype unit showed high quality manufacturing standards

 

In summary, the Backtracker is an innovative first generation product, and I personally feel it is a important advancement in bicycling technology. While out riding it was good knowing that vehicles are behind you, although it is up to you to decide what to do with this information. I found myself being more conscious about when to move over and let vehicles pass, or to ride in the center of the lane and hold my position where I felt it was too dangerous for the vehicle to pass safely. It doesn’t replace human judgement and common sense, such as looking before turning, but it a useful accessory.

The Backtracker is however not yet a reality, although over half of the crowdfunding goal as been pledged. There are a couple of ‘early bird’ spots for USD $179 (plus $10 intl. postage) and the regular price will be USD $199. This does make it a small investment, however there is nothing cooler than telling your friends you have a radar on your bike.

Link: Backtracker crowdfunding project
Website: backtracker.io



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About The Author

Christopher Jones is a recreational cyclist and runs a professional design business, Signale. As the driving force behind Bicycles.net.au he has one of each 'types' of bicycles.

7 responses to “Review – Backtracker Radar Watches Your Back on the Bike”

  1. Thomas Houseman says:

    Is it true radar or ultrasonic or something else? Has it been emissions tested and passed? How comfortable are you be having a radar emitter so close to your manly parts for several hours a day?

    Will you be buying one or using one daily in the future?

  2. Angus says:

    Good question.
    I was riding behind someone with a backtracker, am I going to get slowly microwaved? Will my presence screw up the signalling of the unit? Does only the rear rider in a peleton get to turn their backtracker on?

    • Franz says:

      Angus, regarding your question of interference from other cyclists: From my experience with Backtracker, it doesn’t matter if there are a few cyclists behind you – it will still pick up the cars.

      Due to the nature of RADAR however, the signal will be degraded if there are lots of cyclists behind you…which means cars will be picked up later, i.e. not from the maximum distance.

      Its also important to note that Backtracker allows for multiple riders in a group to actively use a device without causing any interference with each other.

  3. Franz says:

    This is a very low power FMCW radar. It only emits a few mW, while your mobile phone can do about 2W!

    We are in the process of doing certification – we do not expect any hickups. Safety is very important to us.

  4. David Halfpenny says:

    If you combine this with a Fly 6 rear camera and the ability to write the speed of approaching vehicles to the video, you’d have a great evidence gathering tool. Maybe we can get the police departments to contribute to the crowd funding. I imagine having every cyclist as mobile radar trap would make a difference on the roads 🙂

  5. Steve says:

    Hi Franz,

    will it give false positives if you have a strong tailwind especially in rainy conditions. ie the way the doppler windspeed works (I think) at the Bureau of Meteorology?
    http://www.bom.gov.au/products/IDR71I.loop.shtml#skip

  6. fruit cake and bananas says:

    Interesting but a HELMET MIRROR is much more useful – vehicles coming, can tell to a good degree the speed they’re doing, if they’re too close to you, rego number if you want to make a Police complaint and other riders catching you(interesting while racing!).

    Spend the $20-25 and get a helmet mirror.