Communication - Rider to passenger and/or bike to bike

Part 1:

For the longest time in my life I was riding alone, and life was good. Music if anything was either played by blaring speakers in the bike or not at all. GPS was included when you bought a tank bag, you just had to 'charge' it every now and then with a new sheet of paper. Funny though these GPSs never talked to me and more than once I had one ruined because it rained and the whole **** thing fell apart. But I digress.

So for the longest time communication to the passenger was accomplished by yelling and fistbumps from the rear. The communication to other riders was a form of sophisticated sign language, which had only two drawbacks: You had to be right next to each other, and many a times those signs were misinterpreted.

Then come the late 90's and all of a sudden we had a communication system on the bike that allowed us to talk from rider to passenger and we were also able to hear the music in our helmets. We thought we were in heaven, because this was SO much better than anything we were used to. Rider to rider was still the good old sign language, and why not?

Then some of the folks had the idea, to put CB radio's on bikes, in order to be able to talk over longer distances. <sighs> Well, lets just say, I have never see a single CB installation on a motorcycle that I wanted to ride with. The reason here were among others that there are 1000's of people using the CB band, and while some folks that is good, and I can see discussing this if you are in a car, but on the bike, where I want to talk to buddy riding in the same group it is very nerving to all of a sudden hearing a Mexican CB operator blast so loud that your can
't even hear your brain rattling, much less hear your buddy talking. CB has the huge problem(among others) that there are 1000's of people using it and some of them don't give a rat's *** that you might be in dire need to talk to your friend not even 2 miles away. They blast with 1000W or more and badly aligned linear amplifiers so that they not only cover the channel you are on, but the neighboring 3 channels as well with noise. Bottom line: CB is out.

But I still want to talk to my friends I am riding with!

Well there are two viable solutions:

a two way radio (like CB) but in a different band
Bluetooth based solutions

Now, lets talk about bluetooth based solutions first. They are cheap, they are plentiful on the market, and they have a decent sound quality. Annother real advantage of bluetooth based solutions is that there are multiple manufacturers, which bring down the price.

Now lets look at the downsides of the bluetooth solutions: First and foremost: They are incompatible. Bluetooth defines a very low level communications protocol, and when it comes to talking to your phone or GPS, yes, they can all do that. More or less. But what when I want to talk to my passenger, or my riding buddy? As long as you stay within one manufacturer chances are you will be able to talk to your passenger. Beyond that we start to have problems. Remember when I said bluetooth systems are plentiful? and that there is no standard? Yeah, thats when you start to have problem, basically if you have system A and your partner has system B, your chances of that working are slim (to none) But lets for a moment assume you are your buddies all have the same system. In that case you can be right next to each other and depending on the system you can talk to each other. Well, within limits. See, bluetooth was specifically designed to be a low power, short distance communication device and protocol. The problem here is the low power. Bluetooth works with frequencies where bandwidth is plentiful, but at the same time, those frequencies are known not to propagate very well. Without going into too much technical detail the theoretical max distance of a bluetooth connection is about 3/4 miles. Well, you say, that pretty good, right? Again, please note I said the theoretical maximum distance. One tree in the way of that and your connection distance is only half as far, a cal or bus in the way and your connection distance drops even further, down to the point that if you have one big truck between you and your partner, and connection becomes a lottery.

Frankly that was something I did want. At first I believed the marketing hype and bought the systems. I still have them here to prove it. In the end they don't work as primary communication system if your goal is to reliably talk between bikes for more than 100 ft. E.g. one of you takes the wrong turn off, on the freeway. Talking to each other and communicating while the rest of the group continues with 60mph? Yeah, forget about that. Not going to happen.

So my/our stated goal was to be able to reliably talk to each other for a minimum of 2 miles. Even that is rather low. The design goal was 6 miles communication distance. And with all we have talked about before, bluetooth would not be it. And neither CB.

So how did we solve that? More about that in part 2.

[emoji102]

Part 2

So from what we heard before, Two "solutions" are not going to work to provide reliable communication between any number of participants. Bluetooth, due to range and compatibility problems, and CB, due to overreach (I am not interested in talking to the Cuban or Venezuelan station while riding on the freeway)

So, we need different way to communicate. And in reality all we have to do is to look how other people resolved that problem. Not necessarily on the motorcycle but we can take that and adapt it our needs. One more interesting tidbit of information here is that in order to have a decent antenna you need a minimum of a quarter wavelength. What does that mean you ask? well, thats actually easy. radio waves travel at the speed of light, so about 300000 km/sec or about 186000 miles/sec, but its easier to work in km/m here. the wave length is now how far the wave travels until it goes through one full cycle.

On CB (27MHz) that is about 11m or about 36.1ft, which means a real antenna is about 9ft long. Not very practical on a bike. Just another reason that CB is not a good solution for a motorcycle.

Now luckily there are other radio bands to choose from. Here in the US we have the MURS band (~150MHz, 2m wavelength) or the FRS/GMRS band (462MHz, ~65cm wavelength)

Now there are more parameters that go into the calculation of an antenna, most notably here the so called speed factor, which for our purposes is about 0.66, so an antenna in the MURS band is about 2m/4*0.66 = .33m or just a little bit more than one foot! NOW we getting somewhere. That is an antenna we can work with, even on a bike, right? But it gets even better. The same calculation also holds true for GMRS: .65 /4 * .66 = .1m or just a little bit more than a 1/3 of a foot. Now that is a really an antenna I can work with!

So, just for antenna purposes the GMRS band wins, but there is a whole lot of other advantages: In GMRS we have 16 channels to choose from, and the maximum allowed power is 50W. Ok, we are not going to need that or even implement, that would create a slew of problem in itself, but most hand held radios (Handy Talkie, or HT for short) have 4W RF output. On MURS the legal maximum allowed power is 2W and in addition there are a number of commercial users still using the MURS band, so That makes the decision for the correct band rather easy. For bike to bike the best we can use currently is FRS/GMRS in the US, and in Europe PMR446, which works in almost the same band, just with different power limitation. Australia has UHF CB, which is again in the same band.

So, now that we have arrived at what is the "correct" or best frequency band considering that not everybody is a ham operator, now lets take a look at what the radios can offer to make it even better for the purpose that we have in mind: Reliable Bike to bike communication for at least 2-5 miles. Again talking about the situation in the US, there are two different radio "services" as the FCC calls them in the same band, and they even have some overlap in frequencies. Here is short: FRS (Family Radio Service) has 14 channels in the 462/467 MHz band. The problem with FRS is that according to the rules it is not allowed for the radios to have detachable antennas. You you have to work with the antenna that comes with the radio, and in most cases those are less than suboptimal. In addition the maximum allowable RF power is 0.5W. Which, in optimal conditions is enough to talk for 100 miles (real line of sight from peak to peak on mountains) but in real life you can assume about 1 mile, maybe 2 miles, but that is no longer reliable.

Sooo, that leaves us with GMRS (General Mobile Radio Service) (before you use that you will need to pay the FCC a license, that covers you and all your immediate family, no matter how many radios) With GMRS we have 16 channels in the 462/467 MHz band, and we can transmit with up to 50W. Most HTs give you about 4W on the antenna. NOW we are talking.

In addition, something that FRS as well as GMRS radios are allowed to do and can do is to use PL tones. PL tones are sub-audible tones, that the radios use to communicate with each other and those those allow your radios to stay silent unless they hear exactly the right tone. That means that on the same frequency, even within communication range there could be somebody else using the same frequency, as long as your PL tones are different, your radio will not start to bug and annoy you with the chatter of someone else.

Now that does NOT mean that your conversations are private. Nothing could be further from the truth. Everything you transmit on a two way radio is just the same as yelling. Just most of the time nobody is really interested in what you have to say.

This was the second part, the practical implementation will be in part 3

I do a third. Bluetooth headset and if we get out of range, I use the headset to phone to call them. The limitation there is cell coverage, but in the tough offroad terrain I don't get further than BT range from anybody because it isn't safe. The rest of the time I'm on pavement and generally have some sort of signal...or get one soon enough.

Used autocomm for years with two way radio, no problems. Just the wires, hated them.

Along comes Sena, the 20S model advertised to save the world. It works well for phone, music, gps. Group intercomm another story. Buds and I got it when new, works ok, range is good. Now, a group of 4 or more couldn't reliably stay connected. The order of connections is important as it is some kind of daisy chain, push down stack. If the rider order is different and get disconnected, the whole group can be dropped. Automatic reconnect is ~~~ sometimes, and not everyone

Admitedly, we did buy version 1.0 Version 1.2 is out now, we'lll see.
The phone app is pretty cool though.

WoodButcher said:

I do a third. Bluetooth headset and if we get out of range, I use the headset to phone to call them. The limitation there is cell coverage, but in the tough offroad terrain I don't get further than BT range from anybody because it isn't safe. The rest of the time I'm on pavement and generally have some sort of signal...or get one soon enough.

Click to expand...

Cell phones are a very valuable tool, yet like a flat head and a phillips, while they are both screwdrivers or communication tools they have different applications. *I* would not want to use a cell phone while actively riding, due to distraction problems. in addition, and that goes towards the being a different tool, a cell phone is 99.99% a one to one communication, whereas two way radios is one to many (the whole group) without any extra steps and distractions involved.

i.e. "The road is free you can come and pass that slow guy" or similar messages for which the cell phone is utterly impractical. I have all the bluetooth test case at home, spent a lot of money and finally gave up on it. The range is just not what *we* need it to be. Not even talking about the fact that bluetooth have compatibility problems between manufacturers, and such. Again, a different tool for a different problem. Bluetooth is very good for the "last mile" connecting your helmet to your bike. Beyond that its like trying to use a flat head to open a torx, sometimes it works, but the majority of cases it has and introduces more problems than it solves.

*I* am a fan of the correct tool for the job.

SparkyBlue said:

Used autocomm for years with two way radio, no problems. Just the wires, hated them.

Along comes Sena, the 20S model advertised to save the world. It works well for phone, music, gps. Group intercomm another story. Buds and I got it when new, works ok, range is good. Now, a group of 4 or more couldn't reliably stay connected. The order of connections is important as it is some kind of daisy chain, push down stack. If the rider order is different and get disconnected, the whole group can be dropped.

Admitedly, we did buy version 1.0 Version 1.2 is out now, we'lll see.
The phone app is pretty cool though.

Click to expand...

The wires: that is what bluetooth is good in replacing. And other than that you are making my point, that bluetooth is not the right tool for bike to bike. I don't know about you but when I am on the bike I don't want to be a rolling test lab on how can make bluetooth work. I just want to talk to the folks in my group. Reliably and without fiddling with technology.

apleschu said:

The wires: that is what bluetooth is good in replacing. And other than that you are making my point, that bluetooth is not the right tool for bike to bike. I don't know about you but when I am on the bike I don't want to be a rolling test lab on how can make bluetooth work. I just want to talk to the folks in my group. Reliably and without fiddling with technology.

Click to expand...

Roger that, we spent WAY too much time trying to stay connected.... 'can you hear me now?'

I picked up a couple of really cheap Baofeng Ham radios and I'm working on getting the wife her Ham license. Seems to be the cheapest way to get longer-distance coverage.

cheez said:

I picked up a couple of really cheap Baofeng Ham radios and I'm working on getting the wife her Ham license. Seems to be the cheapest way to get longer-distance coverage.

Click to expand...

I have some of them myself. The only problem with baofeng radios is that they are not waterproof. And programming them via the front keypad, while possible is worse than anything minor pain in the rear. In addition, the goal here is to let everyone in the group participate and having a ham license is a rather steep entry problem.

KA5PLE


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Nice write -up. Anyone know what implications are of operating a GMRS radio on a bike without a license?

ceddec said:

Nice write -up. Anyone know what implications are of operating a GMRS radio on a bike without a license?

Click to expand...

If you get caught there are stiff fines. The license is not hard to obtain, costs $90 is valid for 5 years and covers your whole immediate family. IMHO not worth the risk.


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Since there is a fair amount of interest in this area, I will be posting the two remaining parts faster than anticipated. Here is part 3:

Part 3

Electrical: When installing any kind of sound equipment on your bike you are facing always the same problems. Basically the electrical systems of none of the bikes I know of has been prepared to deal with sound equipment and it is always up to you to make sure you don't have ****** sound quality. Of the problems the most pronounced ones are generally alternator whine and spark interferences. If you have those there are usually a number of ways you can go and they depend how much power you need. For the purpose here all the equipment we install aka communication and music equipment is generally rather low on power usage.

Usually the approach that most people take is to work with a network of inductivities (coils) and capacitors. And while that approach can have success many times it does not because the electrical system is SO dirty.

Another problem you will be facing, especially when connecting multiple sound components together is the possibilities of creating ground loops. Generally ground loops happen if you connect a piece of equipment to ground (chassis) on multiple points. Ground loops are a rather nasty problem, but relatively easy to fix (In most cases)

In the following example we are going to use three pieces of sound equipment, but the principles can easily be expanded to more than the three. Also as a requirement we ask that the whole system is operated by the bikes power.

So we have:
A central sound distributor (J&M, Autocom, ...)
A Cell phone for music and GPS service
A Two way GMRS radio


Like I said all of them connected to or operated by the bike's electrical system. It is easy to see where the ground loops come in: Each of the devices is connected to power and hence to ground. And that is for power only. But since we also have to get the sound signal to and from the devices. and that usually consists of a signal line and -- you guessed it: Ground! And Ooops now we have a second path to ground. the very typical form of a ground loop.

Ok, so how can we eliminate that? Well, there are multiple ways, but basically all of them depend on the fact that SOMEHOW you have to break the ground connection somewhere, either on the power supply or on the signal line. Believe it or not, in most cases it is easier to break the ground connection on the power line, and its just because the approach is the same, every time.

So, we need some piece of electronic wizardry that allows power to be transferred and yet isolates us from the bike's electrical system. In doing so we get rid of a whole slew of problems at the same time: No alternator whine, no spark interference and most importantly no ground loops. The easiest way is to buy the needed number of DC-DC converters. If you do go out and look for them, make SURE you get isolating DC-DC converters. Lately folks on ebay and elsewhere sell simple regulators also under the term of DC-DC converter, but a simple regulator does not isolate and will put you therefore back to square one. Here is a link to one such DC-DC converter. http://www.cui.com/product/power/dc-dc-converters/isolated/chassis-mount/pyb20-u-series I specifically like those because they come in 10W, 15W and 20W versions and as you can see are easily mounted anywhere on the bike as well as being fully enclosed and waterproof.

What these guys do is to make it appear that each of your electrical devices run on battery, they isolate power as well as ground from the bike, while providing about 10-20W of power. Thus the connections to "ground" on the signal lines are now no longer connections to ground but a star wired "ground" and there are no loops.

The disadvantage is that these are rather expensive (~$60 for the 20W version)

Putting it all together in part 4

Part 4

putting it all together.

Since I had put off writing part 4 I got several PMs and emails to finish the saga, and I have to admit I was just lazy. But I have finally sat down on my butt and done it.

One thing that I have to stress again here is that the setup I am about to draw in front of your virtual eye is specifically designed to work. making sure that no element has a function is should not have and putting a high value on reliable function.

We have talked about two way radios earlier and that in my opinion anything with less than 2 watt RF is not really sufficient. So, that now brings us to the dreaded radio selection. Its not as hard as it may seem, but at the same time, even though the requirements are rather simple, when you go out on the market you'll see that there are precious few radios that fit a simple set of rules. So here goes.

a) The radio needs to be water and dust proof. Please make no mistake and take somebodies word for it. Do yourself a favor and read up precisely which IP(x) class you need. By spending some money (doing it wrong) I came to the conclusion IP65 is in my opinion the minimum IP 66 or 67 would be better. A definition of what the code mean can be found: IP Code - Wikipedia, the free encyclopedia

b) The radio should be able to cover the GMRS band (doh!)

c) if possible (good luck!) there should be a mounting solution for the bike.

d) I would like to be able to power the radio from the bike's electrical systems.

Given those 4 rather simple requirements the number of radios on the market that fill all 4, is simply 0. There is none. Heck, its hard to find radios that are IP65 or better. Now to make a long story short, the radio I came up to solve most of my problems is a radio that is usually not associated with the GMRS band, but which can be pressed into service in that band. Depending on how someone reads the law that could be perfectly fine or just ever so slightly outside. Now, I have never heard of anyone ever in the history of GMRS getting fined because they were using a good radio which would be able to be certified according to part 95 technical specifications, but is not part 95 approved. If that would be the case many hundreds of GMRS users with GM300s in their cars would be in deep trouble. So anyway, the radio I came up with is the Yaesu FT277 with the MARS/CAP modification in order to allow it to receive and transmit in the GMRS band. The FT277 is dustproof and submersible, it can be powered from the bike, the only problem it has is that it does not have bike mounting hardware. Look at pics for I solved that. I may have to change that as time goes on, for now that works perfectly and holds the radio 100% stable.

We also talked about the preference of external antennas. Even though the antenna that comes with the FT277 is of decent quality I opted to replaced it since I can do better than a HT mounted antenna. Again look at the pics.

The phone is mounted to the bike via a X-grip from RAM mounts. and again, that is a solution that holds our phones very stable for many thousands of miles already. Even though it may not look like much, for a phone it works. Both the phone, as well as the two way radio are hard wired to a auto com logic unit. and I have a PTT switch mounted on the left side of the handle bars. A short word to the PTT switches: autocom's PTT switches are ****! there is just no better way of putting it. the push button requires so much pressure it is basically worthless. At the same time, the auto com unit can trigger the PTT automatically via box, and that is what we are opting for most of the time. Then all that is needed is to make a bit of a noise to open the box, then the carrier on the two way radio goes up and we can talk. no pushing buttons, always keeping your eyes on the road. I would strongly recommend, when you select your communication unit to make sure it has a box setting. its just much safer.

As explained in earlier parts of this series, in order to avoid nasty ground loops each element has its own DC-DC-converter. so I am basically running a 20W DC-DC converter for the radio, a 10W for the autocom unit under the seat and another 15W for the phone. This way the sound quality is crystal clear, there is no alternator whine, no (very, very little) ignition or spark interference.

Now to the pics and some explanations, since a few pics explain things so much better:

How the phone is mounted, front and back





Now a few of the radio and the PTT button.





And the antenna in the rear. AS you can see it really is only a few inches tall and is a full 1/4 wave antenna



And this is how it looks from the riders perspective



One last thing: I have been in contact with a few folks stating they wanted to keep the bluetooth helmets, because they like the "no cable" setup. I can understand that, and I can appreciate it. I can see it working *IF* you make sure that your helmet only has one audio source it needs to talk to, so basically if your communications unit has a bluetooth module that lets the communications audio switch talk to the everything else and do the switching (after all thats what it was designed to do) and your helmet bluetooth only has to talk to the audio switch. If you ask the helmet bluetooth unit to switch between sources, I am almost certain you will experience problems sometimes. and on the motorcycle that is one distraction i do not need or want.

And of course as always, if you have questions, feel free to ask.