My BMW R1150 GSAA at Deals' Gap

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The Comms Box - Catching Waaaaay Up

Wow, it's already mid-August and I failed big time in documenting my efforts from much earlier in the year when I built the comms box for the KLX250S. I won't go into great detail on the construction steps in this posting, but following the mounting of the Pelican case to the rear rack, I

  1. Completed wiring up the radio, intercom and power distribution inside the case
  2. Completed connecting everything up wiring and wiring it to the bike
  3. Was hugely disappointed about the amount of alternator noise on the radio's transmit and receive audio(!)

Here are some pictures showing the construction efforts that went into the comms box.

Autocom and Yaesu radio mounted

Underside wiring - What you don't see

Where the wires will come out

Looks pretty clean

NMO-style antenna mount

Modified commercial PTT switch for the radio

I'd previously tamed some alternator noise on the GS by adding a 20 Amp DC Line Noise Filter from PowerWerx, so I ordered one up for this application and tried it out. It DID tame the noise on the receive audio through the intercom, but it didn't help at all on the noise that impacted the clarity of my transmit audio. So, after a brief period of head-scratching, I decided that I was simply asking too much of the little KLX250S's electrical system. I decided to go "off the grid" and go to a solar-charged, battery-only electrical system for the comms box.

Out came the DC relay that I'd use to switch electrical goodies on and off with the bike's ignition. That in itself didn't free up enough room for a battery inside the Pelican case, so I created a bracket to secure the battery to the top of the case. The battery is a 12 Volt, 5.1 Amp-Hr. sealed unit purchased from Batteries Plus

An Instapark All Black 5 Watt Mono-Crystalline Solar Panel was ordered up from Amazon. After a protection diode (1N5817) was added to the panel, a pair of aluminum brackets were fabricated to mount the panel above the battery and to the top of the case.

Simple brackets holding the solar panel and battery

Wiring details - no place to hide!

Another view of the 5 Watt solar panel

The Garmin and Yaesu head unit up front!

With everything mounted securely and wired, I'm able to say that the "off-the-grid" solution works as expected, with no electrical interference from the KLX250S. I decent sun, the solar panel extends the use of the radio, GPS and intercom well past the typical day of riding. An auxiliary power connector makes it simple to plug in for an overnight boost charge, too.


Attaching a RAM Mount to the Yaesu FTM-10SR/R "Head" Unit

One of the things I'd planned to do with the comms box project is locate the Yaesu FTM-10SR "head" unit on a RAM mount somewhere up front on the Renthal bars. The head unit provides the display and all controls for the transceiver body which will be located in the Pelican 1200.

A trip to the hardware store netted a stainless metric bolt and washers, along with a nylon bushing to take up the space inside the mounting hole on the RAM-B-272. This RAM product is described as an Aluminum Mini Motorcycle Mount Angled Base with 9mm Hole and 1 inch Ball. It's actually intended to be bolted to the bike somewhere, allowing a RAM socket "arm" to extend outward to an accessory like a GPS. In this case, I turned things around, using the 272 on the back of the head unit instead.

After the nylon bushing was sanded down to a proper length, the stainless split washer was used to tension the bolt, making for a really secure assembly.

I used a couple RAM 231 U-bolt style mounts up front on the Renthal bar, intending for my existing Garmin GPSmap 276C to be on the left and the Yaesu head unit on the right.

With the U-bolt mounts bolted in place, I test fit the Yaesu head unit and GPS holder as shown below.

Here's the RAM 231 mount and extension arm on the right

And the 231 mount on the left for the GPS

Here's the actual Yaesu FTM-10SR/R "head" unit

Once the comms box project has been completed, wiring from the back will connect the Yaesu head unit to the transceiver. Power to the GPS and audio from it will also be connected and a Push-to-Talk switch controlling the radio will also be part of the ensemble.


The "big" little comms box project is started

Time to catch up on some writing! It's a rainy day here and I've already made quite a bit of progress over the past couple weeks building up a communications box for the back of the KLX250S. This part of the overall project focuses on doing what I'd done years ago on our BMW R1150GS Adventure, but this time do it MUCH better. The idea is simple: Create a reasonably weather proof environment for a dual-band amateur radio and intercom. I already had the following items:

  • Yaesu FTM-10SR VHF/UHF Dual Band FM Transceiver
  • Autocom Pro-7-Sport Intercom
  • FZ-1 power distribution block

The Yaesu FTM-10SR is weather proof transceiver made for motorcycle use. The 10 Watt VHF/7 Watt UHF transceiver is the little brother to the FTM-10R which shares the same head unit (display and control), but has a larger body containing the circuitry capable of transmitting 50 Watts.

The three items I expected to locate inside the comms box are show below.

After some quick measurements, I settled on a Pelican 1200 case as being just the right size to contain the intercom, radio and power distribution. Although I'd purchased the Pelican 1550 cases previously from the interweb, this time I spotted a local (to Raleigh) Pelican dealer with a storefront and made a trip over to see them. US Case offers competitive pricing on Pelican products and does a wide range of customization. Highly recommended!

From the start, I planned to bolt the Pelican 1200 to the new rear rack. After deciding to orient the case's hinges towards the back of the bike, I settled on a position on the rack and used it to mark the case for drilling.

Holes were drilled and hardware procured. I used some rubber grommets as a form of vibration damping between the rack plate and the 1200.

After a quick check that everything fit, it was time to bolt and rear rack plate back onto the KLX250S and then bolt up the 1200 on top. This proved a bit challenging due to the limited space between the rear rack place and the plastic fender underneath. My fingers didn't fit well in there to position the washer and nut on each bolt! With a little help from Elizabeth I was able to make this work and was happy that bolting and unbolting was not going to be a common activity once everything was assembled. Pictures below show the empty 1200 bolted in place.


Below is a picture of the working space inside the case. The real fun was about to begin!

I wanted the radio, intercom and power distribution to all be mounted solidly inside the box, so a sheet of 6mm thick expanded PVC from Budget Robotics was selected. This easy to use material can be drilled, cut and sanded without much trouble.

After some measuring and experimenting with a paper template, I used a router table to "mill" the sheet to size. A table saw would have worked, too, but I don't have one. Here's the base after sizing and drilling for mounting on stand-offs inside the 1200.

I'll cover the mounting of the radio and intercom, along with all the wiring in a future post to break things up a bit. Besides, my coffee cup is empty and it's time to top it off again.


KLX250S with bags spotted in the sunlight

By popular demand, here are some photos of the bike captured outside the garage. You should be able to get a better idea how the bike looks with the bags on it from these.

I've started working on the communications box that will mount to the rear rack and am on a hunt for certain small bits and pieces now to finish it up. I hope to make some progress this weekend.


KLX250S Adventure Make-over - Phase 4

Phase 4 began on Saturday afternoon with me in the garage as the wind howled outside. The Happy Trails SU Side Racks were looking a little bare and it was finally time to mount a set of Pelican 1550 cases sourced from Nalpak Group on them. Along with the LED tail light assembly detailed in a previous posting, I'd picked up the Happy Trails SU Puck Kit for 3/4" tubing (P/N HTPMK750-A), as seen below.

I was favorable impressed with the ruggedness of the aluminum "pucks". Hardware was included for tool less mounting/unmounting using the big plastic knobs - 2 per side. In addition, extra bolts for wrench-required mounting/unmounting were also included.

To make sure I mounted the bags in the same location on both sides, I planned to use one of the ridges on the bottom of the Pelican case as a guide rest for the tubular rack. With this in mind, I knew from trial fitting that I'd have to remove some of the plastic from the ridge opposite the guide ridge due to the width of the SU Rack. I tackled this modification on both bags using a Dremel Tool earlier in the week, as shown in the photos below.

Knowing that I needed to make sure the bags were in exactly the same location on both sides of the bike, I decided to create a template when planning the left side that I could flip it over to use as the template for the right side.

I removed the left side SU Rack and positioned it where I wanted it to be on top of the template and Pelican case. Following the instructions from Happy Trails, I then positioned the 4 "pucks" in place to maximize stability at the bottom (no forward or backward movement allowed) and to allow rotation at the top for case removal.

Upon doing this, I realized that more plastic was going to need to be removed in order to allow the puck in the lower right to mount flat to the case.

The Dremel came out again, making short work out of the additional plastic removal. Then with the rack and pucks back in place, I used the insert from a ballpoint pen to roughly mark through the bolt hole of each puck. This worked out pretty well in practice, but probably has some of you cringing.

Small pilot holes were drilled through the paper template and left side case. I then used a step drill to work my way up to a clean 5/16 inch hole for each.

A keen eye will notice that the step drill got away from me on one of the holes. Oh crap. In reality, this mistake didn't cause any harm, but I was much more careful when drilling the remaining holes.

With holes drilled and deburred, I test fit all the hardware to make sure everything was secure. Yes!

With everything looking good and feeling very solid, I flipped the template over, traced the main lines through and taped it to the side of the right side case. I used the right side rack and pucks to check everything out. With just minor variations in rack dimensions, I only had to adjust the location of one hole before drilling. No mistakes this time!

Before I mounted everything back on the bike, I took a moment to weigh everything.

  • Left side Pelican 1550, mounting hardware and SU rack:  13.1 lbs.
  • Right side Pelican 1550, mounting hardware and SU rack:  13.2 lbs.
  • Happy Trails SU Rack "Bumper": 1.7 lbs.

That's a total of 28 extra pounds on the back of the bike, before I pack anything in. I might have to check that preload adjustment on the rear shock after all.

With the weighing done, the bags were removed from their respective racks and I commenced re-bolting the SU Racks back onto the KLX250S. I'm getting to be pretty good at doing this now and I managed to complete the process in about 15 minutes. The trick to making it a little easier is to start with the middle bolt on each side, followed by the shorter, front bolt and finally the hefty rear bolt. None should be tightened much until you are satisfied that the bolts are threading in properly. Stripped threads in the frame = much badness.

With everything in place and tightened up, I then bolted on the rear bumper using the 4 temporary (actually undersized) bolts, washers and nuts I'd used initially. I did end up asking Bob at Happy Trails about the missing hardware and he kindly arranged to send it to me! I'm not sure how it got missed in the first place, but it's the customer service that matters in this case. Thanks Bob!

A few minutes later I had the bags in place and the mounting hardware tightened. I'm really pleased with the results and managed a short, brisk ride this morning to get the feel of riding a (much) widened KLX250S. I actually couldn't seem to tell the difference, but I bet I would in a stiff cross-wind.

Anjoy the photos below of the finished work! I'm now starting to think about electronics.