Introduction

I follow Austin Vince’s formula for luggage. Soft panniers to prevent injury in an accident and a lockable top box for convenience and safe storage.

However, I simply wasn’t happy with a lot of available racks, so made my own.

The design I’m showing here should apply to any motorcycle with a low exhaust.

Most of the design principles also worked on my partners MSX125 / Grom. I just don’t have enough images of the rack construction.

Related Youtube video

This video is related to this article. Linked at timestamp where I talk about the rack.

Requirements

The easiest solution is to just throw money 💸 at the problem. But even many expensive commercial racks, don’t fail at many of personal requirements.

Sadly, I’ve also seen a some DIY racks that weren’t just ugly, but also dangerous.

Safety

Crash in the outback. Spiral fracture from a fall where a sharp edge impacted the riders leg.
Crash in the outback.
Spiral fracture on tib and fib caused by sharp luggage rack shelf.

Consider that your legs are likely to fling back in a fall or just when manoeuvring through a tight gap.

Requirements:

  • No sharp edges.
    • Hard panniers are bad for that.
  • No long hard elements from sticking out.
    • Bad shelf design, caused the injury in the image on the left.

Width

Don’t turn you luggage into a parachute 🪂.

  • The ideal: Panniers fit inside the width of your handlebars / mirrors.
    • If your mirrors fit through a gap, you know the panniers will too!
    • Consider this when filtering in traffic or riding on a narrow trail.
  • Even a narrow setup will increase your wind-resistance.
    • That’s why some seasoned riders prefer a trailer that sits in their bikes slip-stream.

Shelf to prevent accidental BBQ?

On bikes with a low exhaust, panniers can sag too low and touch the muffler. I’ve burned a hole into my first set of panniers and am not alone in this. A shelf adds a mistake-proof, hard-stop which will protect the pannier from touching the exhaust.

Keep your feet / legs in mind!

  • Avoid sharp edges
  • Keep shelf well inside the bags outer edge and preferably exhaust.
  • Non exhaust side
    • Consider a folding shelf.
    • Balance exhaust with tool tube?
On CB500x
On my 500x, I used the hinges that came off the donor lounge chair.
Tool tube mounted below. Note how its location is held in place using zip-ties that will break off, acting as a mechanical fuse.

Maintenance interference

It’s best to design this after having done some work on the bike, knowing which panels have to be removed. That way, it’s easier to design the rack in such a way it won’t interfere with maintenance on the bike.

Top Box Racks: Strength

I kept the original top box racks that I bought on the CB500x and my Wave. Their initial dimensions are good, they’re good value for money and are complicated enough shapes to make for a hard time using had tools (no CNC). Initially I built my pannier racks around both (CB500x and Wave 125i) top box carriers. The idea was to have the ability to take them apart and simplify maintenance.

However, it turns out that top box are really harsh on racks, even more so if the top box rack was built to carry nothing more than a package of pasta. I.e.: On the 500x, the genuine Givi Top Box rack is only rated for 6kg, while the top box already weighs >5kg!

Bending back the Givi Top box rack as it sagged down. Note the height difference both sides.
Rack failed on my Wave 125i.
Rack on a Wave 110i that’s bent on a trip in Laos.

So, I ended up combining the racks together and re-enforcing the top box racks. Mounting the pannier rack onto the rearset drastically increases the racks strength. Next, I added a triangulation crossbeam to rear rack of the pannier rack. That spreads the forces from the rack over a wider space, reducing leverage effects as the forces move in a relatively straight line to the passenger pegs that are designed to hold the weight of a passenger.

CB500x, pannier rack crossbeam with M8 bolt that connects via a tab to the top box rack.
I simply welded tabs onto the Givi rack. For the crossbeam to fit flush, I simply “squashed” the crossbeam tube at the end in my bench-vise.

Besides making a much strong Top Box rack, this drastically reduces strain on the motorcycle’s frame as I’ve seen enough videos of bike frames that have cracked. That’s particularly true with dirt bikes.

Force flow.
DIY rack, easily strong enough to support my weight and more.

Wave Top Box Rack re-enforcement

As mentioned, top boxes are really hard on racks. On the single cylinder Wave, I encountered a few failures due to metal fatigue from engine vibrations. The “skinny” wire construction is pretty common on small bike racks. That is normally is good enough in most uses. In my case, where I do long distances with the top box over partially rough roads, the rack would crack at stressed points.

So, I added additional re-enforcements, which have now lasted me on my trip around the world.

Stress fracture despite first re-enforcement.
Adding re-enforcement around outside. I’d later add drill holes, reducing weight and acting as mounting locations for straps.
Final rack turned into single construction that attaches via 6 bolts (4 mounting locations) to the bike.

Lateral Strength

What’s stronger than one beam? 2 beams! That’s why al the racks that I’ve made, connect at the top of the Top Box rack, but also at lower position. This reduces the risk of bending the racks in the even to of a tip-over.

On the Wave, the lower cross connection is welded. Since there wasn’t any space under the fender, I went around and turned it into a license plate holder.
The main pieces on the CB500x, with the dog bone (centre) connected the rack.
Note the dog bone, just behind the fender, bolted together with 4 stainless stell bolts.

Construction Challenges

Choice of raw stock?

Flat steel is easy to work with, but is weak in the flat direction. Worse, the sharp edge that can become an injury hazard.

I’ve chosen tubular steel from scrap chairs, tables and recliners. Tubing is the most difficult to work with when welding (easy to burn huge holes in). However, not only does it look the best, it has the greatest strength to weight ratio and the round shape is the least likely to cause injuries. These were also great donors as they also had enough 90° angle sections.

I don’t have exact measurements, my guesstimate is that the tubes have a 0.5mm wall-thickness and 25mm diameter.

Hauling home a scrap table that would serve as raw stock.
On the 500x, the pannier are made of 4 angles that I welded together.
Cleaned up result (before I added cross beams to Top Box rack).

Welds

A grinder and paint, make me the welder I ain’t. I’ve welded this with limited experience using a stick welder. The thin walls of the tubing are not the easiest with to weld. The trick on these thin sections was to weld with low amps, welding one small section at a time and removing the slack after every weld. The slack is worse with these relatively cold welds, be thorough!

⚠️ Don’t forget to disconnect your battery before you weld anything that’s connected to the bike.

Rust Protection

One advantage of working in IT related fields is access to the occasional bit of e-waste. So, I managed to get hold of some “old” Tube Cable Wire Wrap. That fits neatly around the tubes of the wire, giving it much more protection from abrasion (the panniers rubbing) than plain paint could.

Final Advantages

I know these racks are a pain to make, but if they’re done well, they work amazing besides their intended use with panniers and a Top Box. Especially on the Wave, which has been my forever, every-purpose bike.

There, the many tubes and straps make it a lot easier to attach straps to the bike.

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