Right, Bike 2 Bike Communications. Its a Frequently Asked Question, and every-one tends to start at the wrong end, looking at the actual radios.... Bear with me, I WILL get there, meanwhile, an audiophile, many many years ago gave me a pair of head-phones and a bit of advice...... "Shit IN, you get SHIT out" doesn't matter HOW good the equipment is, if it don't have a decent signal, or a decent pair of speakers on the end, it will NEVER sound good.
When it comes to Bike 2 Bike radio, pretty much the same is true; but we have a few other things to consider, and the MAIN one is that the noises need to be in your hat. You are wearing a crash helmet, so you want speakers in it to hear what's said on the radio, and a mic so you can say things INTO the radio. AND, you can have the best headset in the world, if you have loads of wind noise over the top of it, you aren't going to hear it very well, and half of what you say will be lost on the breeze. Meanwhile, when you don't have anything to say or hear... you want to be comfortable!
THIS, is the kind of earpiece/mic you get as an accessory with many PMR Walkie talkies. These are NOT very good inside a helmet.
First of all, they are 'in ear' speakers, and perhaps 1/2" deep. With the crash helmet lining pressing them into your ear-ole they are uncomfortable... IF they even go inside the hat, and aren't plain painful. And if they aren't, then chances are your crash hat is too loose a fit to be worth a damn in an accident!
Next up, the microphone boom... well its short, and if you do pull a crash hat on over the top, its as likely to go up your nose, or poke you in the eye as sit anywhere near useful to talk into.
And they are cheap and nasty, and 'adequate' for 'hands free' operation of the radio, in 'normal' walking around kind of situations. They are not wonderful in 'noisy' environments, like inside a crash helmet.
First warning; idea that you can buy a pair of walkie talkies, with headsets for about £50, 'complete' and that will give you 'ALL' you need for bike to bike comms, well, if you are relying on this kind of headset, think again. I'll come back to the radio's later, but this kind of earpiece/mic is pretty much useless for bike 2 bike work.
On CBT or Rider Training, you may have had a School Radio, and that will have had an earpiece a bit more like this one.
Sometimes called a 'Jaw-Mic' or 'covert earpiece', the head-phone speaker doubles as the microphone, picking up your voice through the vibrations in your jaw bone.
Rider Schools use them, but PURELY for students, and purely as speakers, the microphone function normally disabled, so that the instructors don't have to listen to their screams.....
But if they did enable them, they are horrible, even when not used in a helmet they don't work brilliantly as a microphone, but inside a helmet, they pick up all the vibration off the helmet, as readily as they do your jaw.....
The Instructors will have a 'proper' dedicated designed for the job HELMET head set like this
Or more likely, as most instructors prefer flip front helmets, the version for the 'open face' helmet that has a microphone boom.....
These have a number of advantages, and the first one is that SIMPLY they are more expensive, and 'better' quality bits of kit.
The 'cheap and nasty' earpiece/mic that comes 'free' with your £50 PMR pair, is not much different to what you can get in the pound shop, to plug into a computer, just has a different plug on the end, and even at a quid, it has a huge mark up on it.
And being DESIGNED or at least optimised for motorcycle helmet use, not only do you get 'slim' fitting headphones that will fit in your hat more comfortably, both the earphones and the mic will be electrically 'tuned' better for the noisy environment they are expected to work in.
MOST actually claim a nose cancelling microphone, which in truth isn't as sophisticated as the name implies, but the microphone will have been 'tuned' for sensitivity of frequencies in the vocal range, and to be less sensitive to the kinds of noise frequencies you get in the back ground, high frequency wind noise, being the main one.
There are a lot of these on the market, with different connections for different radios, and in different packaging, but there are probably only three of four different makes.
Most likely one you are likely to come across is the Oxford Bike 2 Bike PMR intercom, that contains these kind of headsets, which you can actually buy separately for about £15. They aren't at the 'high end' of the market, but they are pretty reasonable for the job, and I believe they are the same make as the ones Maplin sell in their own box for about £30. One I got For Donna, was £20 from Knights Electrocom.
IF you want bike to bike communications, THIS is where you start, with a PROPER headset.
But you still have to fit it in a hat. NOW.... mentioned the discomfort and pain of the cheapo earpieces, and the covert mic, which is more comfortable, but only really any good as an earphone. As supplied, the instructions for 'proper' motorcycle headsets, suggest sticking them inside your hat, on top of the lining..... they usually come with velcro hooks on the back of the speakers and mic, so that they will 'stick' to the material of the lining, Or you can peel the backing off the 'loop' side of the velcro and use the sticky tab to glue the pads in place.
First option: sticking to the lining with the velcro hooks..... I have NEVER got a set to stay comfortably 'in place' this way. Second option; attaching with teh sticky pads; they stay 'better' but the lining still shifts. Some people leave the headphones 'loose' on the velcro hooks, then put hat on, and push the pads up into place over thier ears, and find that acceptable.
Two things.... the first is, its a case of FINDING whatever works BEST for YOU..... second is, DON'T think that the headphones HAVE to go DIRECTLY over your ears... or that the mic has to go RIGHT in front of your mouth. I have found that having the headphones under my ears, or behind them, can be more comfortable and work as well or better. Likewise the mic can work better above your mouth or below it, or to one or other side. You need to experiment a bit to get best placement, as well as best comfort, and THEN best operation.....
However; little trick....
Photo doesn't show this to BEST effect, and unfortunately I cant strip it out to show you how it all goes together, BUT, I did this to my helmet a lot of years ago, and every helmet since.
RATHER than trying to place the mic and the speakers INSIDE the lining of the helmet, and right where you THINK they should go..... I found that most helmets you can 'wiggle' the inner padding out of with a little careful... well, wiggling!
Shown here is my Shoei, which are particularly easy to take apart; Donna's Nitro and my AGV were a bit harder, but not impossible.
THIS part on the liner, is in the LESS critical area of the chin piece, where there is actually no shock absorbing material, and the cheek pieces, which don't actually offer much shock absorbsion, as they are bearing on the soft flesh of your face, not your skull, so its NOT so critical to the crash protection...
AND if you are careful, you can sort of squash the headphones IN to the lining between the shell and the foam, JUST beneath and infront of your ears, so they are around your jaw.... this means that IN an accident they are less likely to have any adverse effect, and the speakers themselves WONT be pushed into your head.... Its all compromise and trade offs here, but I think this is a reasonable one.
SO, the headphones have been buried into the liner. Same with the mic, buried into the inside of the padding on the chin piece.... the wires neatly routed and kept in place with duck-tape! Then the chin padding re inserted into the helmet and the trim re attached to tidy it all up.
There is now NOTHING between head and helmet liner, so its as comfy as the lid was without a headset, AND the speakers and mic don't get in the way or moved about pulling the hat on or off.... And it only takes an hour or so 'fiddling' to do.....
In operation, works very well, the headphones can still be heard nice and clearly through the lining of the hat, and the microphone still picks up voice clearly... and in fact, tucked a little out of the wind, and JUST that bit further from your mouth, actually works better... or at least I have always found, on, probably half a dozen hats I've wired like this now. No guarantees, but, worth a crack, if you are struggling.
SO, onto The rest of the system.
VOX vs PTT
VOX is 'Voice Activated Transmission, PTT os 'Push To Talk' activated transmission.
Two Way radio's have 'simplex' operation, or are called 'transceivers'. The reception circuits receive a signal from the aerial, amplify it and output it to the ear peace or speaker. When you want to transmit, the radio is turned backwards and the signal from the microphone pumped through the same (or parts of the same receiving) circuit OUT of the aerial. They can EITHER transmit OR they can receive... they can do BOTH, but NOT at the same time...
Now, conventionally Transceivers, whether PMR446 or any other system USUALLY 'receive'. Switch them on, and that's what they do, listen to whatever frequency they are tuned into and put that signal to the earpiece. To transmit, you conventionally flick a switch or push a button, which flips the circuits and opens the microphone, and pumps the signal from that out the aerial.
THAT is 'PTT', and in MOST motorcycle headsets, you'll get a PTT switch with it, that can be quickly attached or removed from the bike via a velcro strap around the bar grip..
VOX, on the other hand, is a simple circuit that monitors the noise level on the microphone, but doesn't transmit it. It simply looks for a noise of higher than normal volume, and when it senses one, flips a relay activating the transmit circuits.
This can give you 'Hands Free' operation. Which can look useful for bike to bike comms, but, it is not without problems, and MOST people using radios regularly on a bike, opt for the better reliability of PTT.
Using VOX you say: "Testing, Testing, One-Two-Three" and what came out of the other radio is ".Ing, One-Two-Three". It Clips the first Testing and half off what you said..... This is 'VOX Lag'.... and it is bludy annoying.
Better radios have better vox circuits, and may have less lag, but it will still be there. Some of the very best radios have sophisticated filters so they only look for the frequencies of speech sound, and measure the levels in that spectrum to determine whether to turn on the transmit function, BUT, remember how it works, and now leave your living room, and get on a motorbike, with exhaust noise and wind roar, and worse wind whipping up around the chin piece of your helmet....
VOX can render the radios totally useless, as they are constantly on transmit, thinking that changes in exhaust note or wind resonance is you talking...... or they are clipping the first part of what you say into the microphone, and turning off the mic halfway through a sentence as you pause for words or sounds in your speech, particularly s's of 'sibilance' make the VOX circuit think you have stopped talking and its listening to wind noise...
VOX is a convenience, but it is FAR from perfect. again, its better on more expensive radio's but not always MUCH better. Hence why regular users so often go PTT.
This is the PTT button on Donna's headset, and its common to most of those on the market. Its neat and tidy and convenient. Its water proof, in its rubber housing and plastic mount with velcro strap to go round the twist grip.
I found it a bit 'awkward' because I have big hands and there wasn't enough room on the grip for IT an my hands... especially on Donna's bike which has heated grips and a moulded boss taking up 1/2" of grip space where the wire for the heating element comes in.
So, because of this, AND cheap-skating.... I made my own 'slim line' version!
Bit of stainless steel plate I had lying around, some plastic to give it some 'body' to grip the bar grip, two bolts to attach rubber bands to secure it, and a 50p push to make switch from Maplin...
Took an hour or so to craft.... you can make something similar however you prefer really. Clever bit is the wiring, and even THAT isn't THAT clever.
Most Radios have the headsets 'wired' for 'mic' priority, so IF the microphone is plugged in, and there is continuity through the circuit, they transmit, if there is no continuity through the mic circuit, they switch to receive, and put signal to the head phones..... so ALL you need to do, is cut one of the wires to the mic, preferably the live, rather than common earth, if the jack they are going to is common earth.... and splice in the Push to Make switch, on a length of coily wire... when the witch is pushed, makes the mic circuit, radio transmits, let the button go, circuit is broken, defaults to receive.
If you wanted, you could convert an existing button on your bikes standard switch cluster to be the PTT switch, maybe using the 'flash' button...... or you could maybe drill the switch housing and add a new button, if you wanted... thing is, there's nothing 'magic' about it, all it is is an on off switch on the mic circuit!
And THAT really, is about it for the 'Show & Tell' stuff, for a while. Lets get back to the FAQ, of recommends for Bike to Bike radio comms.....
To recap, so far I have said START with a decent, and bike specific headset, because they are better optimised for the job, tend to be a LOT more comfortable, and work far better, and usually have these Push To Talk switches, making comms a lot more reliable, without VOX lag, clipping or sensitivity problems.
CAREFUL headset fitting, then helps get the best you can out of the headset, and permanently fitting inside the liner can really help make them most comfortable, easiest and least hassle to take on and off, AND give better sound and transmission, with least distortion or back ground noise....
So... so far we are off to a good start, but we haven't talked about real HARDWARE yet, or actual radios.....
OK... so two common 'recommends, that pop up, without all my explanatory waffle! The FIRST is Autocom, the second is Oxford Bike2Bike mike.
First of all, OXFORD Bike2Bike. These sell for roughly £50 a user set, and comprise of a dedicated helmet headset and a PMR446 'Walkie Talkie Radio'. As an 'all you need in a box' starter solution, its a PRETTY good place to start, especially if you can find a set discounted to about £30 on e-bay. Buy two, and you have a pair of PMR's and a pair of proper motorcycle helmet headsets, for about £60 - £100, which is what many people are prepared to pay.
The headsets, are available individually for about £15, so they are the 'cheaper' dedicated m/c headsets, but they seem 'OK' ish. The Radio likewise, is a 'not bad' radio, I believe made for Oxford by Alan. (Oxford are a marketing company, not a manufacturer)
Reports on how 'good' they are vary, from 'rubbish' to 'excellent'. I suspect a LOT of that is down to expectation, more to the fitment of the headset, but MOST down to the limitations of the PMR446 radio system they work on.
These radios, are from a reputable maker, but they are low end radios, and as such not LIKELY to offer the best performance, though for the money, they probably do well. So, lets look at the other end of the scale, and the other mush vaunted system, the Autocom.
First thing about 'THE Autocom' is that it is neither a radio, nor a headset.... the Autocom 'system' is based around a 'multi device interface'..... its a box of tricks..... that lets you plug multiple 'audio devices' into it, and switch between them. Its a very CLEVER box of tricks, but then for prices starting from over £150 it bludy well ought to be!
One shown, is the Duo, which for around £200 comes with two high end headsets, and on its own, powered of the bikes battery, offers rider to pillion communication.... but you can plug in, or 'connect' any manner of audio devices through it, say an Ipod or MP3 player for tunes, or a Sat Nav, so you can hear the voice directions, or a mobile phone, or I don't know what else.... AND it will give priority to signals from different devices and either turn off or turn down the volume on them to play one over another....
So, say you are riding along, listening to Meat-Loaf, and your pillion wants to tell you to slow down, it will turn down the music so you can hear them, or it will turn off both so you get a turn instruction from your Sat-Nav.... all really 'cool' stuff.
Main thing here is to make it offer bike to bike comms, you need to plug it into a radio.... and Autocom recommend a couple of radios to plug in, both from Kenwood, and both, like the Autocom, high end, (EXPENSIVE... no EFFOFF expensive) PMR446 sets, from Kenwood, the cheaper of which being a £150 a hand set radio!
So, the autocom is NOT a cheap Bike to Bike comms system, its a bludy expensive one, and its NOT even that, its simply a fancy interface FOR a PMR446 Radio....
AND as far as PMR446 Radio goes, how well it works has very LITTLE to do with the Autocom, its all down to the PRM446 radio plugged into it, and you could do the same job, simply buying the high end PMR446 that autocom recommend and a high end headset to plug straight into it WITHOUT the £150+ of autocom box....
So, lets look at PMR446, 'Licenec Exempt' radio. Because THIS seems to be what we are REALLY talking about, after headsets.
Base line here is the Oxford Bike 2 Bike, which I have said at £50 retail, a user set, radio and headset, is a pretty cost effective start. PMR446 radios, start in price at around £10 a pair, in bubble packs in Aldi/Netto/Liddle 'offers', and go up through mid range radios in the £50 to £100 a hand set range, to really high end sets pushing £200 a pop, like those recommended by Autocom.
With PMR446 you REALLY get what you pay for... or probably better to say, you DON'T get whet you DON'T pay for!
PMR446 'Licence Exempt' is a quite sophisticated radio standard, exploiting regulations for 'radio transmission devices' in a frequency allocation, reserved fro consumer products, where devices do not need an operators licence to use them.
The frequency range allocated is very high in the radio spectrum, and intended for short range transmission, hence it is also strictly limited to a VERY small transmitter power.
It is INTENDED for such 'stuff' as alarm remote key fobs, garage door openers, radio controlled toys, and 'that kind of thing'... and these days, the number of 'wireless' devices that use 'licence exempt' frequencies is huge, everything from baby monitors to wireless keyboards or wireless headphones.... probably even wireless kettles! EVERYTHING seems to be going 'wireless' these days!
Anyway, first of all, it was presumed, when it was conceived and the frequency allocation 'blocked' for consumer products, that required or 'acceptable' range would be small.... I mean you don't want to turn your car alarm on from three miles away or open your garage door before you get to the end of your drive, or have your wireless keyboard in a different street to your computer, do you?
So, the regulations that permit 'walkie talkies' on these frequencies don't REALLY encourage it. If you wanted half decent radio voice transmission, over a decent range, you'd select a much lower frequency allocation, where you get a much more robust signal, that ISN'T destroyed by obstructions so easily, and ask for a higher transmitter power you you could bang out a beefier signal, that would get through or around obstructions a lot more reliably..... You would NOT try and work within the limitations of the very high 446MHz frequency range or a mere 1/4 watt transmitter power....... No, you'd ask for at LEAST 4w of transmitter power and a much lower frequency allocation, maybe around 26/27MHz.... Actually no, you'd ask for something more like 30 or 40W of transmitter power, down in the MW frequency, something like 1MHz.... but you wouldn't get it.... you'd get 4w transmitter power and 26Mhz.... because they blocked THAT out years ago and gave it away as 'Licence Free' or CB Radio, which was DESIGNED for the job of transmitting voice over more reasonable ranges, reliably..... and I will come to this later, because it is by FAR the more superior 'system' than PMR446..... but it is little used, because, first until a couple of years ago it wasn't entirely 'free' there was a one off, licence registration fee, and secondly, people still associate it with the Dukes of Hazard Wannabees in beaten up old Ford Carpri's with big whip aerials with confederate flags painted on the roof!
So.... PMR446 EXISTS to exploit a loophole in legislation, and utilise this 'free' bit of the airwaves, TRYING to make the best of a less than ideal, short range radio frequency and incredibly small transmitter power.....
At BEST, PMR446, has a useful range of PERHAPS 10Km or 8miles, in IDEAL conditions, which basically means a clear line of sight between the radio aerials, and good quality radios operating at near bang on maximum permissible transmitter limit, and sending a VERY clear signal to VERY sensitive receiver circuits..... because if you don't have the power to shout very loud, you have to talk VERY clearly, and listen very carefully.... and THAT is how PMR446 eeks out the limitations of the system, permitted in 'Licence Exempt' frequencies.
BUT, you only get that clear speech and careful listening from higher quality, more expensive radio sets, where they are made with the best quality components and assembled, balanced and tuned to a very high degree of accuracy.
'Cheap' PMR sets REALLY just cant have that good a quality components or circuits, especially when they are trying to boast the 'features' like higher end PMR's of LCD display, PLL Tuning, and selectable channels, multiple call tones and whatever else, for the same price as a pair of 'matched frequency' single channel, Toy Radios, like Action Man walkie talkies.....
So, your £10 a pair bubble wrapped PMR's are likely to be pretty much useless for bike to bike comms, and a waste of time trying to plug them into dedicated motorcycle headsets that probably cost at LEAST three times as much as the radio...... even if they work, they are not going to offer very good range or reception..... line of sight, and THEN not over a great range. You might be lucky to get more than a few hundred metres out of them practically.... fine for your kids on the beach, NOT for rider to rider comms on motorbikes.
For THAT job, you need to be looking up the price range, and realistically at sets in the £30+ a hand set bracket.... which means that the Oxfords, including a £15 headset for under £50 are probably only JUST in the quality range that is likely to work.
And at THAT price, you are only JUST getting over the threshold of the cost going into the product to give it the features that make it look like a 'proper' PMR446 and starting to make it work like one..... to actually start seeing the benefits of the better circuitry and sensitivity and getting close to useful reliable ranges, you need to be looking at the £50+ a hand set price bracket.
Add £20 for a headset, and you are talking maybe £75 for a half 'decent' PMR446 system (For ONE rider).... and probably short changing yourself, becouse only £20 further up the price range you start getting into the higher end hand sets that really CAN deliver, names like Cobra, Midland, and Motorola, rather than Binatone or Realistic.....
Probably the best 'rated' PMR446 on the market at the moment is the Intek MT50-50 multistandard PMR446, which retails for about £70 a hand set, and is rated as being able to compete with high end sets twice its price for performance, and is much loved by (illegal) radio modders, because it is a multi standard radio, and can be re programmed to use other non PMR446 compliant frequencies and even higher transmitter power.... but I don't endorse such antics, its illegal...... (Regs say that PMR446 units must be factory 'sealed' and using one that is 'unsealed' is an offence.. you have been warned)
IF you want to base a system on PMR446, though this is the sort of conclusion you come to, IF you actually want it to 'do the job'; reliably and well.
A pair of radios with free 'button' earpiece/mics and VOX activation, all for £50... yes, its cheap, and it can work, just about, but you WILL quickly find the limitations and problems I have described and deem it a 'waste of money' and give them to some kids to play with.....
The £50 a unit Oxfords, twice the price, are more likely to be 'useful' and a better starting point, but like a £50 pair, I suspect that many find their limitations and short comings irritating, and would either quickly abandon them, or keep the headsets and upgrade to 'better' PMR radios.
As a System to base bike to bike comms on, it really has very little going for it, as said, if you were starting from scratch for a radio coms system, it is NOT where you would begin, it only exists to exploit a loop hole, and its only real merit is availability..... loads of PMR446 radios available, and compatibility with the number of people that already use PMR446, because if you walk into Argos or look in the magazines that's ALL they are offered....
If you want to turn up to group rides, and talk to other attendees, chances are IF they have radio's they will have PMR446's, and if YOU have PMR446, you can talk to them...... And THAT is its only real merit.
If you want much more reliable, more robust, bike to bike comms, between two users, and you are both going to kit up to talk to each other, and don't mine (or actually prefer!) being on a different system to every one else... then you ought to consider 'Licence Free' CB radio.
Alluded to this earlier; its NOT what you would ask for if you had a clean sheet of paper and wanted really good mobile radio..... but its what the government gave us for the job, and these days, there's no licence or registration fee, and you can buy a CB Set as easily as a PMR, and have sixteen times the transmitter power, on a much more robust frequency allocation... using more versatile hardware.
Starting point is the same, the headset, but you plug it into a CB radio, instead of a PMR.... I have PMR and CB, and the headsets will, with adaptors lug into either system of radio.
Just to give you an idea, here are a few of my radios. Far left is 'The Brick'. This is an 'old' 40UK Channel 'Eurosonic' Hand Held CB. Next to it, broken down to show how it comes apart is the Midland Alan 42 Multi, 80Ch Hand Held CB, which is a lot more compact. Between their aerials is a £2 coin for scale. Then next is an Uniden PMR446, and next to that, just for scale and comparison, my Nokia mobile.
The Erosonic 'Brick's a bit err big, and it takes ten AA batteries, and isn't the most elegant radio you can buy, but it does the job. And you can buy them in working order on e-bay, second hand for about £20-£30. I actually bought that one, for about that price nearly ten years ago, to give CB 'a go' for car to car comms on green laning expeditions in Land Rovers... proving its worth, and the limitations of a hand held, inside a metal box, I later got a proper car mounted 'mobile rig' for the Rangie. But, for bike to bike, I pulled this out of the glove box, and making up my own adaptor set and Push to talk set, to connect it to the speakers and mic in my helmets, that were originally there for a rider to pillion intercom, its CHEAP bike to bike comms..... OK its cumbersome, but for £25, and some old bits of wire and a switch? This is better than high end PMR quality coms for LESS than 'cheap' PMR prices......
The Midland 42 Multi, was bought second hand to 'partner' the Eurocom, for bike to bike comms. Its a far 'nicer' radio, and has a lot more features.... most of them unused, and a lot more chanels. Its also a Multi standard Radio, like the Intek PMR, and can be easily reprogrammed to use frequency allocations for other countries... not that I can think of many reasons I would want to, but still.
Brand new, these radios can be bought, with warranty and accessories, for 'about' £120, which is competitive with higher midrange, lower high end PMR sets. Second hand, mine was virtually unused, and I paid £65 for it, though more typically they go for around £75.
The 'Cheapest' brand new Hand Held CB on the UK Market is the Maycom AH27, which I believe is made by the same company, Midland Alan, and is a 'cut down' version of the Midland 42, and takes the same battery cases and accessories, but doesn't boast the same features. Its retail is about £100, but if you shop about you can get them for perhaps £80. Curiously they seem to fetch near their new price second hand on e-bay, so don't expect to snaffle a half price bargain, they seem to fetch about £70ish. If you want 'cheap' second hand hand held CB, best bet is the bargain priced Eurosonic.
These 'modern' CB Hand Helds are very compact. They are modular in design, and usually come with two battery boxes, one for 1.5v alkaline batteries, another for 1.2v rechargeable batteries of your preferred type and capacity, with integral charging circuit and socket (for which you get a wall charger) Or you can remove the battery compartment, and attach the 'battery eliminator' to run off a car cigarette lighter socket.
Idea here is that so equipped the unit is about the size of a conventional 'mobile' CB microphone' and can be hung in a car, and powered by its power cord, while plugged into an external vehicle aerial via the same adaptor, for more optimum range and reception, courtesy of longer aerial.
The short 'Rubber duck' aerial, is a limiting factor to Hand Held CB performance, but with sixteen times the transmitter power, and on more robust transmission frequency, it is still far better than the incredibly restricted performance of a PMR446 set and its very short integral aerial!
For bike to bike comms, there is then the potential to run a hand held CB off the bikes 12v power supply, and if you were keen to use a longer external 'car' type aerial....
And I do have ideas along those lines. However, the benefits for bike to bike comms are probably not huge. In the Range Rover, between cars I regularly achieve useful comms over ranges of a couple of miles or more, even without line of sight between aerials. With the Hand Helds in pockets, on the bikes, I have not yet been in a situation where I have actually LOST comms over the range they offer, 'as is'... and they have normally been in the 'low' power saver mode, limiting transmitter power to 1W, four times the power and twice the effective range of a 1/4w PMR.... they work pretty good up to a mile or so.... if I need more than that, can always flick them to high to double the range again... and if THAT isn't enough..... well, probably time to stop and use the mobile phone ANYWAY!
If I was going to permanently wire CB to the bike, I'd probably NOT use the more expensive Hand Held CB Sets anyway, but much cheaper, car type mobile CB sets, making up an adaptor to wire the headset and PTT switch to the mobile Mic and external speaker sockets.... Mobile CB rigs start at around £45 for a basic set, to which you'd need to add maybe £15 for an aerial and £5 for an aerial lead... rather than starting with a £90 Hand Held and then spending more money on adaptors and aerial and leads.....
Anyway; that's the story. If you want 'Decent' bike to bike comms, start with a proper head set, and spend time getting it to fit nicely and work well in your helmet.
You then have the choice between PMR446 radio's or CB Radio. PMR446 is more widely available and more commonly used, and the better bet if you want 'compatibility' to talk to other riders. If you want better, more reliable and longer range communications, between a smaller or more select group of riders, maybe you and a riding buddy, CB is far more robust, versatile, and reliable, and offers a lot more usefulness.
If you want 'Cheap' bike to bike comms.... well, Cheap PMR is tempting, but the PMR's I have were £45 a hand set, when I got them seven or eight years ago, they are far from 'cheap' PMR and they are only barely 'useful'. Best bet for 'Cheap' PMR with some chance of doing the job is the £50 a user set, Oxfords, if only because you wont have to buy a proper headset on top of that... if you can find them discounted on E-bay, might even get them as cheap as a Maplin headset on its own! But don't expect TOO much from them. By price alone, they are only JUST into the quality range where they stand some chance of being useable, rather than 'useful'.
But at that kind of money, second hand CB and a bit of improvisation, make do, DIY and make your own... you could have a system that offers the sort of usefulness of far more expensive PMR based systems.. and to all extents and purposes, as good as more expensive CB systems!
And actually... well, the headset and PTT I have MADE, basically from bits of old scrap, actually works BETTER on either radio, then the proprietary headset we bought Donna.... I don't have a big PTT switch in the way pushing my little finger off the end of the grip to start with! while the 'in lining' speakers and mic, are far more comfy and work much better than Donna's set, attached inside the lining as per instructions.....
And, Autocom? Well, everyone says its 'the best'.... BUT, its NOT a bike to bike radio. Very clever system, but its bike to bike comms are only ever going to be as good as the radio you plug into it.
Couple of 'googlies' to end on; there are possibly a few alternative systems.
The first I'll mention is the 'Helmet PMR'... a novelty, its a PMR radio that attached to the outside of your helmet with sticky tape and velcro, and has hard wired earpiece and microphone to slip in the helmet... Its popped up a couple of times.. and basically.... its neither decent headset nor decent PMR.....
Second is the 'Blue Tooth' rider to pillion, or bike to bike intercom. Uses Blue Tooth digital transmission system, between rider and pillion, I believe its reasonable, but the blue tooth system, is like 'Licence Exempt' radio designed for very short range wireless communication. The claimed range, even in ideal conditions, 'bike 2 bike' is really only a couple of hundred meters.
Lastly, mobile telephones. With hands free operation on many models, and increasingly common 'friends' tariffs that allow up to an hour long 'free' call between declared numbers.... in areas of good reception, such a tariff could be exploited to give very good range and reception, compared to broadcast radio.... but only between two people.
And there ARE other radio systems; marine radio, aviation radio, amateur radio and 'taxi' radio, to name a few, that work on more useful frequencies and allow higher transmitter powers, but their use is governed by paid for licences and are not 'freely' available to the general public.
And ILLEGAL radio. I alluded to the fact that you can get easily modified PMR Radios. Or buy PMR Radios with higher transmitter power and or which are programmed to alternative frequencies for different regional regulations. You CAN get hold of commercial radios, Taxi radios, which have a frequency allocation over lapping that of PMR446 being a common one, or 'old' Ham radios that can have almost any power or any frequency ranges.... of you can modify CB radio to have higher power output... all things are possible...... its a question of legality.
Of the more common illegal radio; high power foreign zone PMR is probably the more common. Often pop on ebay "4w PMR" Direct from China, or as sold in Australia where that's the power limit they have.......
Two things.... first, if you pick a PMR that works on alternative frequencies to UK PMR, you are buying all the short comings of a PMR by way of inconvenient frequency allocation, without the convenience of compatibility with other UK PMR users, AND using them you are breaking the law..... second, It's been reported, that radios shipped to the UK mail order, whether from within the Euro Zone or outside, are often intercepted and impounded by HM Customs & Excise, who write to the delivery address advising them that equipment will not be released without a valid user licence being provided.... if the equipment does not conform to a licensable UK radio spec, and or you don't have a valid licence, you MAY never see your radio.. or the money you paid for it.......
So... there you go.... probably a LOT more about PMR446 and CB radio than you even thought any one could be arsed to tell you... but I did anyway!