… Handlebars — Fostering Adventure

Dual Purpose HandleBars

Adjustable width for comfort and function

Just as it was with the BMW R1200GS Adventure we owned, there were two main problems with the handlebars on the R1250GSA. The first was partly due to my own anatomy. When holding the grips, the angle of the handlebar ends didn’t sweep backwards enough and made me have to twist my wrists inwards to hold on. This caused pain to develop in my wrists in as little as a half hour of riding. By the time a few hours had gone by I was in agony, and barely able to hang on any more. I’d have to hold the handlebars with my thumbs up on top of the grips so my wrists could rotate to become straight with my lower arms. It’s not the safest way to control a large motorcycle, which is kind of a serious thing on a bike meant to be ridden for many hours every day.

You can see here how we had to turn the front wheel to get the handle bars to miss the tire. That left the front wheel of the bike poorly secured.

The second issue was just how wide the handle bars are from side to side. Normally this wouldn’t be a problem, but we wanted to carry the bike on the back of the truck. We wanted to keep the bike as close in as possible, but the width of the handle bars prevented this. When raised up in place on the lift platform, the left hand grip would hit the spare tire before the lift was all the way up into travel position. With the first bike, we turned the front wheel to swing the handle bar away from the tire, but this meant we didn’t have a really good mounting position for the front wheel, which caused us concern and stress.

Solving Two Problems at the Same Time

We downloaded a couple of photos of the bike that would help us with angles and placement.

With multiple revisions, we finally came up with the parts and dimensions needed to start machining.

The Design Phase

By designing and machining a new set of adjustable handlebars we could solve both of these rather serious problems at the same time. Although complicated to produce, the concept was rather simple. Just create a set of handlebars that can bend on the horizontal plane, on each side of the handlebar clamps. By designing our own bars we can also manipulate their geometry so that they will allow me to sit in the perfect riding position for my rather decrepit old body.

As you can imagine, the process of creating a “revolutionary” new handlebar design took a bit of work in the conceptualizing stage. It involved a lot of sitting on the bike and playing with cardboard templates to figure out where I needed the bars to sit for my best comfort. Then it was off to the computer, and my rudimentary CAD program to start drawing up the parts. Then it was printing off the parts, making more cardboard patterns, and testing them again and again. Below are images of those cardboard test pieces as we worked with them on the bike.

The Machining Phase

The two bent shapes were water jetted from 2” 6061-T6 aluminum plate.

Bar Risers & Swivel Blocks

The most difficult pieces of the bunch to make were the risers that came up from the handlebar clamps on the forks. They needed to be a complicated three dimensional shape, machined out of some rather heavy aluminum plate. Although I could have bought a block of metal from the metal store and spent hours cutting the shape by hand, this is one of those times when I took the easy way out and had someone with the right equipment cut it for me. In this case, it was done by the local water jetting shop. They use a CNC machine to cut the piece using a high pressure water jet with sand in the stream. It’s a very precise process, and all I had to do was provide the shop with a DXF file produced from my CAD program which takes only seconds to produce. Once I got the pieces from the water jetter, I then started my own, slightly more labour intensive work. You know, Old School.

With the parts back from the water jetting company, I now started to cut the parts to shape.

The excess material was cut away very carefully on a table saw with a carbide blade sharpened for aluminum.

Because of the complicated shape, this face couldn't be cleaned up on the belt sander, so I had to draw file it instead.

Once shaped and cleaned up, dye was applied to the metal so the precision layout could be done.

Holes for the swivel points also had to be laid out and drilled.

The side holes were for the clamp axle as well as the holes for material lightening, aesthetics and cross rod support.

The smaller holes I was able to drill on my little drill press, but the bigger ones had to be machined on someone else's vertical milling machine, which I could borrow.

The larger holes needed to be precision holes, so an annular cutter was used in the milling machine.

This end with the large hole will get TIG welded to the grip axle that clamps to the top of the forks.

Since it uses the same size annular cutter, the swivel blocks were machined at the same time.

These smaller holes also needed to be precision as they were where the hand grip rods would live. For these a smaller annular cutter was used.

The annular cutters come in different lengths, so we bought a long one to produce a deep hole. Then a slot drill was used to remove the centre material.

The opposite hole to the deep one was recessed to house the bolt head.

With the parts all drilled, the final shaping could be done using a combination of the table saw and disk/belt sander.

The parts are considerably lighter than when we started, and much more elegant looking.

Despite their current shape, more finishing will make them even more delightful to look at.

Clamp Rail & Handle Rods, etc.

Another machine that I no longer have since leaving working life, was a lathe. Fortunately there is a small one that I once again have access to. It’s an old machine, but it’s in fine shape and certainly good enough for this work.

The clamp rail was first, and is the backbone of the whole handlebar system. It’s the piece that gets clamped to the forks and through which all the steering force is transferred.

The part starts life as a piece of 1-1/2" diameter 6061 aluminum round bar.

The machining is relatively simply, but each end needs to by sized to fit the holes in the bar risers. We want only a few thousands of an inch clearance.

Once the outside was machined, the centre of the bar was drilled out to reduce weight.

The centre section is machined to fit the head clamps on the forks, and the ends to fit the risers. In between are two shoulders against which the risers will be pushed.

The two shoulders will ensure the risers are perpendicular to the rail, and parallel to each other.

The handle rods were a bit more involved as they had to be machined with precise dimensions on each end, and the outboard end had to have an internal thread to receive the hand guard ends.

The handle rods were made from 1-1/4" diameter 6061 aluminum.

The main grip section of the rod was machined to the standard 7/8" diameter which is common on most motorcycle handlebars.

Here's a nice before and after picture of the handle rod.

When the bolt is screwed in from the left side of the pivot clamp it pulls the shoulder of the handle rod against the opposite side of the pivot camp and tightens it around the pivot.

The last few pieces that needed turning on the lathe were the pivot locking caps and the pivot shafts themselves. The caps were more than just a cosmetic top to the pivot point as they provided downward clamping force to assist the pivot clamp in holding the handle rods from moving during use. The pivot shafts were short stubs of round bar that were machined to fit the holes in the top of the bar risers and interface with the pivot clamp/handle rods. Unfortunately, for some reason I didn’t get any photos of them being machined.

The pivot caps were machined for some 1/2" aluminum plate from which I cut a couple of hole saw blanks.

They were then stacked on a centre bolt for the machining process. This was to move the part further away from the chuck jaws.

When one cap was finished the two pieces were flipped around so the second one could be done.

The pivots themselves were also machined from 6061 aluminum rod. They would eventually be welded into the bar risers from underneath.

The pivot rods were indexed and had alignment pins in them that engaged with the pivot caps.

Both the screws that threaded into the pivot rods and those that threaded into the handle rods were the same size as the head clamp screws. One wrench to fit all of them.

Here is the assembly all put together before any welding was done to tie them all together.

This shows the indexing pins protruding from the ends of the pivot shafts. They index to the pivot caps so only the pivot clamp rotates when the handle rods are moved.

The final cleanup

Before all the components could be welded together, we had to finish dressing up all the parts. Since this was done both with the sanding machine as well as the bench router, it had to be done before the welding process.

All of the edges had to be radiused with the small router bit to eliminate sharp corners and enhance the finished look.

The radius had to terminate before it wrapped around the end of the riser to allow enough material width for welding around the hole.

Here one part is finished and one not. Certain areas could not be routed because of the geometry. These had to be hand filed instead.

On the left riser end you can see where the router bit could not reach, and it is still a sharp corner. The right end is after it has been filed.

This shows how nice it is when all the edges can be reached with the router, and they all blend together.

On the bottom riser you can see where the router jumped a bit and left an imperfect radius. This had to be blended in by hand using a file and emery paper.

I used the cut off piece of the riser to use as a clamping jig so as to hold the unparalleled sides of the riser in the vice for sanding.

The pivot clamps were easy to radius because of their simple shape.

Once all filed and sanded, the assembly was ready for welding.

The handle rods were also re-sanded so their grit pattern would match the pivot clamps and the risers.

Tying all the pieces together

The last thing to do before sending all the pieces out to be black anodized was to TIG weld all the permanently fixed joints.

The pivot shaft was indexed and held from rotating prior to welding by a centre punch mark that tied it to the bar riser.

Once tacked, the assembly was manipulated and held in various positions for welding by the drill press vice.

The only welds needed to hold the bar risers to the head clamp tube was the ones on the outside ends. Filet welds on the inside would distort the assembly unnecessarily.

The top joint from the pivot stub to the bar riser, and the inside joint from the head tube to the riser were left un-welded and crisp looking.

All finished and ready for black anodizing.

Before we sent all the components out to be anodized we did one last test fit on the bike to ensure that everything worked according to our design. To prevent from marring any of the nicely sanded surfaces everything was covered in masking tape. Happily, everything worked perfectly.

Final Finish and Assembly

Once we confirmed all the parts were made right, all the tape was removed and each component was then wrapped up carefully in paper towel to protect them until the anodizer was ready to start coating them. Once we got them back it was just a matter of carefully assembling them on the bike.

We always lay out the parts and photograph them before taking them for finishing. It confirms the parts and gives the anodizer a record of what we should get back.

All wrapped up and ready to go.

Confirming what we got back. A few pieces aren't seen here as they go elsewhere on the bike.

First job, get the old handlebars back off the bike. We did some riding while waiting the weeks for the parts.

The last view of the old handlebars. They'll be safely stored for later when and if needed.

First part on the bike was the riser assembly.

Then the handle rod/clamp assemblies get installed.

All finished with all the hardware installed back on the bars.

The only tricky thing was that the lines to the handle bars had to be relocated from inside the forks to outside.

This relocation was needed to gain extra length in the lines to accommodate the higher position of the handlebars.

All ready for Riding

With everything assembled and adjusted for the perfect riding position, the bike is all ready for our riding pleasure. And what a pleasure it now is. No more wrist pain whatsoever, and now the left handlebar side can swing in easily to miss the tire when lifted up into place on the lift platform. It was a lot of work to be sure, but certainly well worth it.

A wide view of the new handlebars.

The black anodizing marries in with the bike colour scheme perfectly.

Despite how beefy the pivot joints are, they don't look oversize in the grand scheme of things.

We also added new larger, unbreakable mirrors.

We got new bolts from the BMW dealer to match the head clamp bolts. They gave them to us for free. Nice.

The top cap indexing marks can be seen here, and allows us to ensure the two sides are identical when doing adjustments.

The bar adjustment lets us have them almost straight across or folded completely in parallel to the bike length.

The rerouted cables lie nicely outside the bar risers.

Even with the swept back adjustment, there is plenty of tank clearance.

We dressed the weld on the end of the head clamp joint, but the one under the pivot point was left alone since it can't easily be seen.