On NZ motorcycle forums at least, one of the regular topics is radar detectors - do they work, what make is best and so forth.
I've used a detector since 2005 so thought I'd take the opportunity to share my personal experiences about what they will and won't do. There's clearly things I'm not aware of but the experiences and knowledge listed here will hopefully be a good starting point. These are in the New Zealand context but apart from legality of use issues, the technical aspects will largely apply to any country. Legality of use varies from country to country and state by state. In NZ, they are legal but if you get pulled up and the enforcement officer sees a detector, don't necessarily expect a sympathetic response! Interestingly though, an academic research study from Western Australia on the use of detectors shows that there is a strong international correlation between the use of detectors, safer driving habits and reduced serious injuries.
Before going any further, a radar detector merely confirms the presence of transmitted signal activity. It is only an aid, not a guarantee of avoidance and relying on your situational awareness in combination with a detector is still essential. Too much reliance on a detector will still see you in a world of grief! Active countermeasures will also be commented on further on in the post.
Why would you want a detector?
Owning a detector doesn't automatically mean that you're Public Enemy #1 who has no control over his or her right wrist! Most riders like a good blast from time to time but choose an appropriate time and place to do it. It's not normally these circumstances where a detector is really useful. It's where speeds are over but closer to the legal limit where your attention is perhaps temporarily diverted from your speedometer. The trigger for me getting one was in 2005 when putting in an entry for the Southern Cross round NZ in 5 days endurance ride. I doubted that I'd be hitting hyper velocities on the ride but a detector could be a useful warning when, for example, overtaking slower traffic at "perhaps" 20-30km/hr above the legal limit to minimise overtaking time. Get the drift? I can also say in all honesty that having a detector on the bike and being paranoid about it going off has increased my overall situational awareness.
What do detectors detect?
There are several radar bands used to detect vehicle speed, the most common of which are X, K, Ka and Laser. Most quality detectors will emit a different signal for each type of band. Personally, I only look at the detector visual display AFTER I've hit the brakes as scrubbing speed off is a sight more pressing than knowing what band has been picked up! Similarly, the rate of beeping and intensity will increase as the emitter gets closer but that's academic for the same reasons.
X band is largely outdated these days but most detectors will pick it up. Unfortunately, X band is commonly used for automatic door openers and other security systems in shops and offices etc, so any X band signal is likely to be a "false" warning. Good detectors will allow X band detection to be turned off, cancelled or muted to stop it becoming an annoyance, particularly in town.
K Band is similar to X Band in that it has commercial uses although some K band mobile speed cameras in unmarked vans have recently appeared in NZ. Consequently, I've re-activated K band detection and simply switch it to mute in town.
Ka band is the most commonly used form of microwave radar used by the police in NZ and is fitted to Highway Patrol vehicles as well as most mobile speed cameras. It's early detection of this band which has saved me multiple times more than the cost of a detector! The broad signal beam (or scatter) paints a large area and good detectors have 360 degree signal detection. Microwaves will pass through objects like windscreens and the human body. Consequently, you can pick up Ka signals from other roads but that's no bad thing anyway. OH, AND THERE ARE NO PRACTICAL MEANS OF JAMMING Ka SIGNALS WITHOUT TOWING A VIRTUAL TRUCK LOAD OF ELECTRONICS!
Laser band is less common in NZ than Ka band and as far as I know, can only be used statically as opposed to on the move like a Ka microwave radar. Once you've been hit by a laser particularly if you're not in traffic, it's likely that you're going to be a goner if you're above the legal limit as the beam width is very narrow and therefore very specific in its aim! A laser beam won't penetrate a solid object and is also affected to some extent by tinted screens and the like so the positioning of a detector for good pick-up is more critical than with microwave radar. The good news is there are laser countermeasures, although there are a few considerations which go with them - more on that later.
Detector in waterproof case mounted on left handlebar
Hearing any warning
Most detectors have a an inbuilt speaker with volume control but even on maximum, it's largely inadequate for motorcycle use. I started off using a small speaker attached with velcro inside my helmet and connected to the detector via a jackplug and cable. Whilst it worked well enough, there were times when I'd accidentally disconnect the jackplug or break the lead by forgetting about it when I dismounted the bike! Bluetooth is another approach although I have no personal experience of this
Another alternative is a commercial system called H.A.R.D. which uses a helmet-mounted LED on a small stalk just within peripheral vision. Connection to the detector is by radio frequency and when a signal is detected, the LED flashes red. The system works well although there are two potential downsides. The first is that it is battery-powered and it's essential that the batteries are kept charged and the unit switched off when not in use. Secondly, a visual cue is less effective than an audible one in terms of the brain's reaction time.
I use a device called a "screamer" which is of proprietary manufacture. It emits a scream similar in intensity to a domestic smoke alarm at the loudest setting and I'm told **grin** that it's perfectly audible at well over 200 km/hr! It's compact, hooked directly to the detector and powered by the bike electrical system. It's the round black object in the picture below mounted on the right of the Blackbird top yoke. (Not the heated grip control on the left). It's mounted behind the twin headlights on the Street Triple. It has 2 volume settings and an "off" position, all easily reached by the thumb via a switch mounted next to the left handlebar grip. I haven't found any significant disadvantages with this system. It's also worth adding that a friend built his own version, using the internals from a smoke detector.
"Screamer" is black circular object to the right of the headstock
Practical experience to dateI've only been lasered once and was travelling at legal speeds so all that can be reported is that the signal was picked up at about 100 metres with no other traffic around. However, with Ka microwave detection, the number of potential "saves" have been numerous. The terrain has a bearing on detection distance but in flat, uncluttered countryside, my maximum known detection range was around 5km. On twisty, hilly roads, range has been as low as 100 metres but still provided adequate warning in those conditions. Camera vans using Ka band are usually picked up at 100-400 metres. This is probably due to the beam being angled across the road and perhaps the strength of the signal itself.
The biggest influence on early detection is how the Ka signal emitter in the police vehicle is being used. If the radar is left running in target acquisition mode, then it's easy to pick up a long way out and this is a relatively frequent occurrence from personal experience. I guess that members of the Highway Patrol can be as lazy or forgetful as other sections of the community. More of a problem is when police are using the "instant on" technique and then there's almost no warning unless you pick up the ground calibration pulse and react immediately. Your best chance of "instant on" detection is when it is is being used on traffic further down the road and the wide microwave beam scatter and reflection off solid objects allows it to be picked up by your detector.
It's worth adding that as with most things, you get what you pay for and there are plenty of detectors on the market which perform poorly. The Escort, Bel and Valentine brands consistently score highly in independent tests (available on the 'net). I've used an Escort Passport X50 for several years. You really do get what you pay for.
Laser countermeasures are a bit of a minefield for two reasons.
Firstly, from the legal perspective. Technically, they are legal in NZ as well as some other countries. However, the understanding is that it would be possible to bring a prosecution under perverting the course of justice or a few other legal avenues. Even so, no known prosecution has ever taken place, perhaps because they can be discreetly located and also, because not many people have them.
Secondly, product performance. Independent testing has shown that a number of so-called countermeasures simply don't work - a rip-off in other words. The only two I'm aware of that have solid credentials are the Blinder and Escort jammers although there may be more. There's no intention on my part to buy one because of the relatively low frequency of use of lasers in NZ. Besides, detection and active jamming are rather different issues.
So there we are.... detectors are a very useful device but personal vigilance is still required. My Escort X50 has saved me from trouble countless times, not from hyper velocities but those times when you're "a bit over" the limit. It has certainly paid for itself many times over. They are also a genuine aid to better riding which is only fully appreciated after you've owned one for a while. Hope that the post has been of interest.
And one more thing...... in NZ advertisements for radar detectors, you will frequently see "Tuned for NZ conditions". This is marketing nonsense presumably aimed at deterring you from buying from overseas often at a significantly lower price. The "tuning" is simply turning off the bands which are not used by NZ law enforcement to reduce the risk of false alerts. This is a job you can do yourself in about 5 minutes or less by following the detector instructions, so don't be fooled!