One of the unexpected results of recently poring over the comments below the DC Rainmaker review of the Wahoo Roam was that I (and it’s clear I’m not alone here) came away thinking “maybe a radar unit would be useful after all”.

Are they?

I’ve always thought the whole thing was rather pointless—the radar’s user interface as it stands is quite basic and can’t help predict someone ploughing into you from behind—but the numerous comments in its favour made me think maybe there’s some benefit. Being able to tell you how many vehicles are approaching, for instance. (In my experience a driver who’s close behind another is much more likely to close-pass, and is probably also more likely to have failed to see you at all.) And being able to identify vehicles before you detect them by ear, which in some situations can be quite limited.

Thing is, I currently often use a Fly6 camera on the seatpost, which serves a somewhat related role: it can’t tell me anything about what’s behind me, but it’s there to record either anything exceptionally dangerous, or to provide evidence should the worst happen and someone needs prosecuting (or life insurers need boxes ticked) in my absence. Which the Varia won’t do (it would be nice if it did record its data, though: as a general point, to be able to see that someone completely failed to slow down before impact would surely be useful evidence in some cases). So I’d be swapping the camera for something that might give me more peace of mind in the moment, but less value should I need anything after the event.

So how do you find it? It seems that people who’ve used it don’t want to be without it, but it’s hard to discern how much of that is actual usefulness, how much is peace of mind, and how much is people having misplaced faith in powers it doesn’t have. The first two are great—they just need to more than offset the same qualities of the Fly6.

Two things, it can be set up to get brighter as things get closer so it might raise their awareness of your presence.

Secondly I think it’s useful having it if you are pootleing along somewhere quiet and it makes you aware of something behind you. In and around town areas where there is lots of traffic as it’s constant you become a bit blind to it.

I have taken mine off when I changed bikes and never got round to added back on again and can’t say I missed it.

It’s brilliant. I’ve not been able to use mine since changing to a Wahoo ELEMNT, and I miss it every time I ride.

Sure, it won’t stop someone ploughing into you but it provides a degree of situational awareness that is incredibly valuable. It’s also handy in groups, as riders behind you can tell if a car is approaching because the light changes from solid to flashing.

Wahoo are going to support it later this year, and it can’t come soon enough. Garmin won’t sell the Varia head unit separately so my radar unit has languished in a box for the last 12 months.

I really like mine for when I’m on the road bike.

It is great for making you aware there is something behind you on less busy roads, especially if you are going into a head wind or descending so the wind noise is preventing you from hearing. The little chirp is often a timely wake-up call.

As Bez mentions it’s really useful to know that there is more than one car behind you, as this makes me conscious of avoiding drifting out after the first vehicle has passed (which I otherwise sometimes unconsciously do).

My main gripe is that mine (original RTL 500) doesn’t have a big enough battery. Only get about 5 hours out of it and it also runs the battery down in my head unit (Edge 1000) more quickly. It is possible to connect it to an external USB battery, although I’m not a fan of having cables all over the bike.

riders behind you can tell if a car is approaching because the light changes from solid to flashing

This is one point I’m curious about. How far (in terms of time, not distance) in advance of the pass does it start flashing? Or is it distance based, ie flashes really early for someone driving slowly and/or really late for someone driving fast?

If they are coming up quick the edge display goes red. If they are approaching more slowly it stays green. Not sure about what the drivers see.

As said above handy in wind it allows you to glance back, maybe get some eye contact or just stop! It tracks multiples well and I am not aware of it being wrong during my usage.

I’ve got one of the older ones and yes, I do like it. It’s a pretty convinving rear light in its own right, even before the “escalating” output (I have no idea what it actually does – might try mounting it on the bars one day to see)

It’s good for my fairly rural then suburban commute because cars are fairly rare. Not sure it’d be so useful in a city centre as it’d always be “alerting”.

(I used it on the TT bike the other day as well – handy there as you’ve much less opportunity to look around or listen for engines’n’shit)

I wish the beep could be made louder but seems it can’t

I wasn’t convinced about the idea either. Mainly for the same reasons as you. I got one anyway because (a) it was cheap, (b) other people said they loved them, and (C) new toy.

I really like it a lot. Often does give me more warning than my ears otherwise would, and does indeed show that there are e.g. 3 cars coming not one. Also helps to wake me from my daydreams on quiet country roads. I would now not buy a head unit that didn’t support it. If mine died today then I’d have ordered a new one before tomorrow.

I also fine the battery life on mine (old version) a bit borderline. I got just over 8 hours out of mine on a long ride a few weeks back. Normally charge before each ride.

Same as the above for me really, great for giving you a heads up on quiet roads and indicating how many vehicles are actually going to pass you.

I wouldn’t buy one for busier roads but if you ride out in the sticks they’re worth having.

Hmm. Yesterday Halfords had 15% off this and now they don’t. Typical 🙂

😉

Bumpity bump.

I have a Varia on the Hybrid of Doom that I really like, but the bracket is crap. Does anyone know of an alternative (possibly saddle rail mount). Supposedly the quarter turn mount is slightly different to the computer one…

Hijacking the hijack of my own thread to bring it full circle…

I bought a Varia, used it for a few months, didn’t find any benefit from it at all, sold it.

That’s my mini review right there.

Supposedly the quarter turn mount is slightly different to the computer one…

Nope, I used a rubber-O-ring computer mount on a little widgety thing to mount it to the pannier rack on my tandem when I used it on there.

They’re all the same mount. And I like mine, find it very useful on the relatively quiet roads round here. It’s completely useless (as a radar; it’s fine as a light) when the traffic’s heavy though.

I bought a Varia, used it for a few months, didn’t find any benefit from it at all, sold it.

surely the whole point is, you don’t really need it until you need it?

surely the whole point is, you don’t really need it until you need it?

If 99% of the time you’re not getting any value out of it, you won’t be paying attention to that 1%. And if you’re riding on roads with regular traffic you won’t get much value out of it – at least IME it’s most clearly useful when there’s not much traffic, and what there is is relatively fast moving and comes up with little warning.

I like mine – I ride on fairly quiet roads though. Not sure it’d be so useful in town as the bleep would be going off all the time

(… and the “display unit” I bought relatively recently doesn’t bleep (it should, and I’ll be asking Garmin for help there) – it’s surprisingly shit if you don’t get a bleep IMO/E

has anyone actually used it to take emergency, evasive action i.e. cos a car was barrelling right for them, or is it just “ah there’s something behind me, that’s nice to know!”

Am I correct in presuming that these are useful for alerting you that something is approaching fast behind you so you can take a look and decide if you need to take some defensive action or not?

has anyone actually used it to take emergency, evasive action i.e. cos a car was barrelling right for them, or is it just “ah there’s something behind me, that’s nice to know!”

For me it’s “ah there’s something behind me, I’ll have a quick look in the mirror and if need be turn round and look them in the eye”
I’ve not (yet) done the latter and seen a driver not looking at all (course, you can’t at night but it IS also a decent rear light). Could be coincidence but looking round does seem to start them moving out “immediately”

Thinking about one of these recently. I ride alot of country lanes that are mostly empty so often find myself drifting into the middle of the lane as they are quite narrow and being in the middle gives me a better view of what’s coming up ahead when approaching bends.The downside is that a few times I’ve been caught out as I’ve not heard a car behind me – cars are bloody quiet these days, so often don’t notice a car until the road widens a bit and they get a chance to overtake then give me a bit of a startle…but also not realising the car is there at all I could move to avoid a pothole and collide with it. So thinking a varia would be useful for this at least.

And on the mirror thing – got one on my commute bike…get sick and tired of adjusting it whenever it gets knocked – a bar end mirror on the end of my drops so sometimes gets knocked by my knee or moved when I lean the bike up against a wall. PITA and also takes a few seconds to focus on it as it’s quite small so takes a bit to focus and understand what you’re looking at. Find I don’t use it that often, certainly not on quiet roads. Would much rather have something that actively gets my attention. And hey…it is the 21st centre after all. No need for a pencil solution when an expensive pen will do the job.

I have the radar (with a edge 830). Really like it. Like wobbliscott I find it useful on country lanes, where you tend to ride more in the middle. It is also useful in giving you a good indication of how many cars are coming up behind you.

I have one on my gravel bike. It’s useful on towpaths if I’m bimbling to let me know if a cyclist is coming up behind when I swerve to avoid a dog/child etc that steps out. It’s mostly useful on not so busy roads – never used it to take proper evasive action (yet..) but it is very useful to know something’s there and might try and squeeze past between you and a central reservation that you can see but it can’t yet. That kind of thing.

I’ve got one of these on my road bike – unobtrusive and effective

It is also useful in giving you a good indication of how many cars are coming up behind you.

Sort of. If they’re close together then it seemed pretty unreliable at figuring out that there were two rather than one.

And given that the Venn diagram of “the sort of person who drives close to the vehicle in front” and “the sort of person who crashes into other people” probably looks like a hula hoop, it’s one area where you don’t want a false sense of security.

It’s definitely a good heads up that there’s something behind you, even if it flashes into view for a second then away again due to bends in the road you know something’s there.

I’ve never taken any particular evasive action after an alert but I do generally look back at the vehicle, move into the road a bit more if I’m approaching a pinch point, maybe put the bottle back in the cage if it’s a narrow road – little things like that.

I had one with a garmin then sold it when I moved to wahoo but as soon as they were made compatible I bought a replacement unit, when I ride without one I do miss it a bit.

You see the mirror comparison quite a bit and if the mirror shouted at me to let me know to look at it I’d probably have one of them instead but until then I’ll stick with the radar!