Installing Crash Protection Bungs on your Motorcycle

Most of the riders in Thailand are buying for the first time a big bike. Now, novice riders being what they are, most new riders got a reasonable chance of dropping the motorcycle on the tarmac (not that we'd want something like that to happen), so it's a good idea to get some solid nylon crash bungs for your new motorcycle. Crash bungs are a smart move, and they're fairly easy to fit too.

Like most DIY jobs, from painting the house or repairing the washing machine, preparation is key. In the case of crash protectors, the very first step is to read the instructions. Our crash protection bungs come with simple but fairly clear instructions, but it still took a couple of scans to clarify the job so we fully understood it. Lay out all the parts, and make sure you know which part goes where.

Get a ruler so you can check which bolt is the 'M10x100' and which is the 'M10x110', and arrange the parts out in order for each side. In our crash protection kit, there's a short mushroom and a long mushroom, as well as a small spacer, and two different-sized bolts. Getting them in the right order is a simple way of making the job go right from the start.

Survey the scene, and prepare the motorcycle. A good wash is worthwhile before hand, to keep you clean if nothing else. Get it on a paddock stand (it's worth cable-tieing the swingarm to the stand as extra security while you're working) and see if there are any fairing panels that have to come off.
If there are any large engine-mount bolts to loosen, it may be worth loosening thee off before you put the motorcycle onto the paddock stand, so you're not heaving at super-tight, possibly seized bolts on a wobbly stand.

The offside mushroom is easy, so do this one first. Remove the engine-mount bolt with a suitable bit. Assemble the mushroom, bolt and washer, put a touch of grease on the threads (or, if the bolt you removed had thread lock on it, then use that), and hand-tighten the bolt with a socket and extension bar.

Our instructions recommend tightening until you feel resistance, then adding a quarter-turn, but it also warns against exceeding 40Nm of torque. The best plan is to use your trusty torque wrench and dial in the correct setting to avoid mishap.

Now the scary bit: taking a drill and sanding bit to your pristine, fairing panels isn't for the fainthearted, but a bit of care and patience helps no end. First up, re-read the instructions and make sure you have the right bits. Using a bit of tape over the area gives you a better surface for marking the part to cut, as well as preventing your cutting tool from slipping on the first cut. So put a big square of tape over the area then offer up the mushroom and mark round it with a pen. For some jobs, it would be better to remove the panel altogether, but on our motorcycle, it seemed easier to do in-situ, so we could instantly see where we had to cut.

With your hole market out, it's time to cut. Remember, it's easy to take more material away than to add it again, so be conservative with your markings. Using a small 1.5mm drill bit, drill a series of holes around the shape to be cut, and then pop it out. A craft knife can help here, but just drilling close enough so the holes touch also works.

Next, using a Dremel, AEG Multitool or similar tool, with a small sanding bit, gently smooth out the hole, keeping inside your markings, and regularly offering the mushroom up to check where you need to shave more material away. Our hole was complicated by the fact it was situated at a point where the panel curved in, so the hole was more of an ellipse than a circle. Go gently, and keep checking until the hole is big enough for the crash protection bung to sit in place, lined up with the mounting bolt.

Remove the engine-mounting bolt, then assemble the new bolt, spacer and mushroom, add a dab or grease to the threads, and torque the bolt up to the recommended 40Nm torque.
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