Project KTM 390 Adventure – Skid Plate
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One of the reasons I bought a Duke 390 and not a big ass adventure motorcycle was to be able to go trail riding. I didn’t think I would be able to ride a large and heavy adventure motorcycle off road without throwing it down every hundred meters or so. I had already removed Ratchet’s bottom plastic fairing and exposed the crank case. So I needed to protect it with a skid plate that would prevent stones from kicking up and hitting the engine or ramming the crank case onto the top of a large rock when riding a trail.
The person I use for things like these is a metal wizard called Babu Chari from Mapusa. He has built all sorts of stuff for my Enfield in the past. I usually sit with him the entire day and we figure things out as the day progresses and the metal takes shape.
First we cut a piece of cardboard to roughly the shape that we wanted to skid plate to be.
The original plastic fairing was bolted onto the crack case using three brackets and we decided to use them to anchor the metal skid plate. We marked the holes and gave the card board a tentative shape.
Then we took a thick metal sheet and use the cardboard as a stencil to cut it to shape.
Next we drilled holes for the bolts that would fasten the skid plate to the brackets.
Then Babu proceeded to beat the crap out of the sheet metal to bend it.
It is important that the skid plate is well rounded towards the front of the motorcycle. If it has sharp edges and you ram it into a rock, you may rip the bolts out and probably crack open the crank case in the bargain, thereby defeating the purpose of the skid plate. A well rounded skid plate ensures that the belly of the motorcycle scrapes the rock and skids over it. Hence the name skid plate.
We then proceeded to fit the skid plate and found that the stand was coming in the way. Somehow we missed that interference with the cardboard as it was flexible. We had to cut out a portion of the skid plate. We also added spacers for the holes. Babu thought spacers would be a good idea. I didn’t have a strong opinion either way.
Ultimately he realized that the spacers were causing more problems then they were solving and he ground them off to a couple of mm tall.
After trial fitting the skid plate it became obvious to me that while we had created a functional part, it looked a little weird as it was protruding under the engine in some places. So I marked areas that we needed to trim off and Babu got to work with his grinder.
Out of the three brackets that held the plastic fairing to the crank case the first one was bolted using two bolts that were coaxial clasping the crank case from either side. This meant that if the belly of the motorcycle hit a rock at a decent speed the bracket would swing like a pendulum and really not offer any resistance. That could be disastrous to the crank case. This was a red flag to me and I instructed Babu to ditch the bracket and instead add two strips perpendicular to the surface of the skid plate and bolt them into the crank case. The result was this.
We filled up the holes that had created in the plate while we were experimenting, ground the edges to a smooth finish and the skid plate was ready for use.
I paid Babu Rs 1,200 for material, labor and having to put up with me and I was off to ride Ratchet on a combination of good and bad roads to check for rattling. There was none. I’ll be sending the slid plate to be powder coated tomorrow.