I embarked on some maintenance and repairs of my KTM recently, and came to the conclusion that this whole internet thing, you know, blogs, and forums, and email, and websites and all, it’s really something. I would have been lost without the online community on KTM TALK, a forum for KTM owners and enthusiasts.

The basic issue: when you replace worn out sprockets on motorcycles, you generally need to replace both the back and the front. If both get worn to to the point where they start to resemble shark’s teeth, instead of symmetrical triangular profile, then you probably need to replace the chain as well. On high-end racing bicycles, road and mountain, you usually replace the chain frequently enough to avoid wear on the front chainrings and rear sprockets clusters. A new Campagnolo front chainring on my road bike costs more to replace than both front and rear sprockets on my KTM motorcycle. Go figure. The lighter the part, the more you pay. Chains, on the other hand are cheaper, and you can make cool hippie bracelets out of old ones, which is nice if you are a hippie. Go figure!

Back to the motorcycle: Both front and rear sprockets looked like shark’s teeth, so it was time to do the job. I used an online parts finder at KTM Cycle Hutt to open up a schematic of my bike and order the part online. This is the same system the local chumpshow uses to find and order parts. The parts showed up in a few days, free shipping, and I was excited to rip into this project. The problem is, the front sprocket I ordered didn’t resemble the worn one that was on my bike. That’s when I consulted the community on KTM TALK. Ask a question, get an answer. It turns out there is a thing called a “dampened front sprocket” with a massive rubber bushing that sandwiches the metal sprocket. These are only put on new bikes as a sound dampener to ever so slightly reduce the operating noise inherent in these Austrian-made gas-powered rattlers. They also do not appear on the KTM online parts diagrams. The replacement sprockets do not come with the rubber, because, once the bike makes it into the good old U.S.A., why does KTM care if it’s a little noisier? Point is, if I didn’t have KTM TALK, I’d still be scratching my head wondering what to do about these two rubber pieces that look like cross-sections of a hockey puck. I’ve had great luck finding answers on ADV Rider as well, and it seems like the good resources there also cross over to KTM TALK. Just a heads up, y’all. The world wide intraweb thing is pretty cool.

After 8,000 miles, the 640 Adventure was ready for new sprockets and chain. The teeth on the rear sprocket look like shark fins, ditto on the front, and after what happened to Darth on the last few miles of Loop the Lake (had to leave the Blue Angel on the side of the road and ride bitch with Stanton), I decided it was time for some preventative maintenance. I bought all my parts online from KTM Cycle Hutt, located in North Dakota, after a bad experience with the KTM dealer out in Draper. After counsel from Bart, I realized I needed to do the chain too, so I called Cycle Hutt to try to squeeze the chain on my order, but it had already gone out. The sprockets showed up before the weekend, but the chain didn’t, so this project will have to wait a few days. Stay tuned for a report. Instead, I decided to install new turn signals, taken off of Darth’s KTM 450 EXC-R. These are the stock “pointy” ones he took off after adding tiny micro LED turn signals. That was before he crashed while trying to ride wheelies. He probably wants these back now. This job required taking off the front mask, clipping some wires, and getting jiggy with the soldering iron, but after putting it all back together, they work just fine and the whole setup looks pretty slick.

 
Lights on.

 
Lights off.