Rear radar - any good?

[PaulSB]

Where a radar will not show a vehicle behind is when it has dropped to your speed. Made that mistake of not looking back thinking it was clear behind and getting a horn blast.
They are also useful approaching a narrowing in the road so you can time your arrival there after the rear approaching car has passed.
Very useful on a busy A road where I have to turn rught as you know when its pointless to look back.

My Varia shows a solid green line when the road behind is clear. When there is a vehicle behind me travelling at the same speed then a car icon, or icons if more than one car, will show.

 

[ebikeerwidnes]

No, it really is great fun riding up behind and making the radar beep!


If I wouldn't normally be looking behind, I don't need to know what's there and it's not worth getting more gadgetry just to add unnecessary information.


Shouldn't rely and should look, but it seems like users do rely and don't look as well.


Complete tosh. When did you last have a proper hearing test? Do you ride with headphones in/on, or with straps in front of your ears? If you can't hear a 2000 kilo brute's tyre noise and tell the difference between it on your road and on a major trunk hundreds of yards away (and if in doubt, you could always look), then I think something's up.

if there is traffic coming towards you on a road and there is wind noise (there is always a head wind!)
and there is otehr noise around
Then I have often not heard the car coming up behind until it is almost level
especially if they are going at a highish speed

and bikes coming up behind can be totally impossible to hear until they are level unless everything is very quiet

 

[PaulSB]

1. No, it really is great fun riding up behind and making the radar beep!

2. If I wouldn't normally be looking behind, I don't need to know what's there and it's not worth getting more gadgetry just to add unnecessary information.

3. Shouldn't rely and should look, but it seems like users do rely and don't look as well.

4. Complete tosh. When did you last have a proper hearing test? Do you ride with headphones in/on, or with straps in front of your ears? If you can't hear a 2000 kilo brute's tyre noise and tell the difference between it on your road and on a major trunk hundreds of yards away (and if in doubt, you could always look), then I think something's up.

1. You may find it great fun to me it sounds like very childish behaviour.

2. The point that users make is the radar gives additional information which is useful to have. It's no different to glancing in a car mirror to know what's happening behind one. It seems the only time you shoulder check or mirror check is when you think you need information. This means you are less aware of any given situation than other road users. Regular shoulder checking should happen whether or not one needs information prior to a manoeuvre

3. All I've read in this thread indicates users don't rely on the device. One did so, probably in error and we all make errors, and admitted this

4. Far from complete tosh. Ever since radar was introduced I have noticed users are aware of approaching traffic well before I've heard the vehicle. It's particularly noticeable in group rides when radar users always call a car before non-users.

I have some hearing loss, enough to make hearing aids useful. If I wear the aids while cycling all I can hear is amplified wind rushing by my ears. Modern cars are very quiet, the advent of electric vehicles has increased this making it more difficult for all of us to hear them. This applies in many situations, not exclusively cycling. There are many factors which can influence whether or not I hear an approaching vehicle, most of them have nothing to do with the fact I have some hearing loss.

I was very sceptical of these devices until autumn 2024. Following a major RTC in June 2024 I was returning to riding, friends commented I seemed nervous of approaching vehicles - I was hit from behind by a tractor at 35mph. One lent me an old Varia to try. One ride and I was convinced.

Radar devices are a significant step forward in rider safety, quickly and safely providing us with information on approaching vehicles. I wouldn't be without one. I doubt you will but you should try one before writing off other people's experience.

 

[ktmbiker58]

Errr, riding in the gutter is not safe.

I think your comment is missing context. It is a safer option than staying in primary position when you are on a narrow rural road and you have no idea if the vehicle bearing down at high speed has seen you - it's all about risk management

 

[Dogtrousers]

I have one because hey, it's a gadget, and I love gadgets. Gotta have them all!

Mind you last weekend I forgot to switch it on, or maybe it didn't connect to my GPS, I forget. Anyway I didn't notice its absence for about 20 minutes of riding through the relatively busy streets of SE London. I'm not sure what that says On the other hand I notice if my mirror is missing (say I've taken it off to transport the bike) immediately when I set off.

One feature of the radar I do like is that it gives you an indication of how many overtakers to expect. I may know there's a car about to come past, but knowing that there is a series of three of them is useful info, just to be prepared.

I wouldn't call it a game changer, and I'm not sure that it makes a significant difference to safety but it does help to improve overall situational awareness. I'd rather have one than not.

 

[mjr]

I think your comment is missing context. It is a safer option than staying in primary position when you are on a narrow rural road and you have no idea if the vehicle bearing down at high speed has seen you - it's all about risk management

It still isn't safer. If there's still time and likelihood that they can see you and react, it's safer to ride where they're most likely to see you, aka primary position. If it seems like they've not seen you and there is no time left then it's safest to hit the verge/hedge, as I have a few times over the years, mostly with bike. The gutter is almost never the safest place to ride.

 

[Alex321]

Shouldn't rely and should look, but it seems like users do rely and don't look as well.

It "seems" does it?

Complete tosh.

As in completely true

When did you last have a proper hearing test?

February.

Do you ride with headphones in/on, or with straps in front of your ears?

No, but I do ride without my hearing aids in, because they get crackly if I sweat a lot, or in heavy rain, and they really don't help much on teh bike anyhow, because the wind noise is what they pick up ,most.

If you can't hear a 2000 kilo brute's tyre noise and tell the difference between it on your road and on a major trunk hundreds of yards away (and if in doubt, you could always look), then I think something's up.

"Something" in this case being that I am a normal human. I will almost always hear if a car (very few of which are 2 tonne brutes) is close behind me, particularly if it is coming fast. But by then it is too late to react much to it, if a reaction is needed.

And on those roads, cars more often than not aren't coming up fast behind me, because it just isn't safe to drive fast on them.

 

[Happy_Days]

One feature of the radar I do like is that it gives you an indication of how many overtakers to expect. I may know there's a car about to come past, but knowing that there is a series of three of them is useful info, just to be prepared.

Undoubtedly, that’s helpful info. It’s one reason I’m considering getting radar.

I love the new Lezyne radar’s lack of reliance on a bike computer (I don’t have one). However, it’s unclear if the Lezyne radar indicates how many vehicles are behind. I’d like to know.

 

[Binky]

I'll say from outset I don't have a rear radar and not tried one. A few I ride with who do say they are game changing.
I do have a discrete bar end mirror which I find brilliant, especially for right turns as well as checking traffic behind.

My point is though even if the radar alerts you to a vehicle(s) behind I'm not entirely sure how that helps if said vehicles are going to close pass etc anyway. Example you are riding along a road with traffic fairly frequently overtaking. So, I assume as vehicles approach you get an alert which tells you they are approaching etc but what then? Do you then check over shoulder for every vehicle, surely that's not feasible on a busy road. Do you alter line every time?

I'm not being negative or down playing how useful some find the radars, just wondering about effectiveness against bad drivers.

 

[Gwylan]

I'll say from outset I don't have a rear radar and not tried one. A few I ride with who do say they are game changing.
I do have a discrete bar end mirror which I find brilliant, especially for right turns as well as checking traffic behind.

My point is though even if the radar alerts you to a vehicle(s) behind I'm not entirely sure how that helps if said vehicles are going to close pass etc anyway. Example you are riding along a road with traffic fairly frequently overtaking. So, I assume as vehicles approach you get an alert which tells you they are approaching etc but what then? Do you then check over shoulder for every vehicle, surely that's not feasible on a busy road. Do you alter line every time?

I'm not being negative or down playing how useful some find the radars, just wondering about effectiveness against bad drivers.

It's the satisfaction of knowing what hit you

 

[fossyant]

I'm not being negative or down playing how useful some find the radars, just wondering about effectiveness against bad drivers.

Nothing will stop a bad driver hitting you.

 

[Dogtrousers]

which tells you they are approaching etc but what then? Do you then check over shoulder for every vehicle, surely that's not feasible on a busy road. Do you alter line every time?

You do whatever you think is appropriate to the situation - it's exactly the same as your bar end mirror (and ears and eyes) but you have a bit of extra information.

Also can be handy if an indication disappears. Has that vehicle that I know to be behind me turned off? Time for a quick shoulder check.

And yes, I do find that in certain circs riding in the gutter, or pulling off the road altogether, can be the most appropriate action.

 

[Ajax Bay]

Shouldn't rely and should look, but it seems like users do rely and don't look as well.

Agree. Looking is mitigation for the risk of an unseen/unheard(electric?) vehicle behind before manoeuvre. Any rear radar device should be a catalyst for looking, never a partial substitute.

if something is coming in hot and fast I move right into the gutter to be safe even if they haven't seen me.

As @mjr says:

riding in the gutter is not safe.

I think your comment is missing context. It is a safer option than staying in primary position when you are on a narrow rural road and you have no idea if the vehicle bearing down at high speed has seen you - it's all about risk management

Sorry: don't agree. On a narrow rural road I always stay in primary position. Getting in a "narrow rural road's gutter" will make the rider marginally less conspicuous and minimally mitigate the risk. In fact "getting in the gutter" actually opens the way for the impatient motorist to "squeeze by" increasing the risk. I will manoeuvre to allow vehicles to pass safely at the earliest opportunity (road widening, gateway etc - as @Dogtrousers says: "pulling off the road altogether" if necessary and certainly not straightaway) but until then they are staying behind me. Finally riding in a "narrow rural road's" gutter increases the risk of uneven surface, gravel, potholes forcing unexpected manoeuvre.
Hope that offers you the context.

 

[ebikeerwidnes]

I have one because hey, it's a gadget, and I love gadgets. Gotta have them all!

Mind you last weekend I forgot to switch it on, or maybe it didn't connect to my GPS, I forget. Anyway I didn't notice its absence for about 20 minutes of riding through the relatively busy streets of SE London. I'm not sure what that says On the other hand I notice if my mirror is missing (say I've taken it off to transport the bike) immediately when I set off.

One feature of the radar I do like is that it gives you an indication of how many overtakers to expect. I may know there's a car about to come past, but knowing that there is a series of three of them is useful info, just to be prepared.

I wouldn't call it a game changer, and I'm not sure that it makes a significant difference to safety but it does help to improve overall situational awareness. I'd rather have one than not.

The point about knowing there are several cars is a good one

sound wise there can be nothing different
and if I look in my mirror then I often only really see the first one
then it goes past and suddenly there is another one there - especially if they are a "bit close"