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Unread 05-24-2016, 10:17 PM
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Smithers Smithers is offline
Join Date: Feb 2004
Location: San Luis Obispo, CA
Posts: 3,238
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Here is another shot of the rim. It's a product made in Norway and they are pretty proud of their work even putting a neat Made In Norway sticker on them. Too bad they turned out to be prone to cracking and are known to fail early. I'll keep using the classic style rims until they give out.

Here is the interesting stock 1992 KTM 540 DXC rear hub and sprocket. The sprocket has a very large inner diameter which is unique to the late 80's and early 90's KTMs. When removed the sprocket is a very peculiar shape that isn't nearly as thick as a standard sprocket. Did they do this to make the hub larger and stronger? It's laughable that they put an aluminum sprocket on the rear of such a powerful bike. Just the fact that the original rear ALUMINUM sprocket is still on this bike means that this bike has very little time on it. I was lucky enough to locate a brand new aftermarket aluminum sprocket on Ebay for pretty cheap. I would have bought a steel sprocket but the one I did see for sale was more money.

I have since adapted a newer KTM rear wheel to this bike without much trouble at all. I am having fun keeping the original stock rear wheel on this bike for now but I have a feeling that the Norway made rim will crack close enough to make me retire the wheel before I wear down the aluminum sprockets. When this setup is retired I will be running a newer KTM rear wheel which has endless sprocket options. Finding the "thin ring" original sprockets is a pain in the butt on Ebay and the options are very limited. They ARe on Ebay but the sellers don't put what style the sprockets are in the listing description. This means that you can't type in a search term in order to list the unique "thin ring" sprockets. You have to actually sift through the pictures looking for a sprocket picture that looks like the older sprockets.

Here is another reason I will be retiring this rear wheel once I use up the aluminum sprockets or they crack enough for me to lose confidence in them: the rear brake disk is a really bad design. This sucker has the disc bolts paired together instead of evenly spaced around the disk. What is going on here?? And the inner part of the brake disk should fall in a groove machined in the outer edge of the hub that it is bolted to. The disk actually is bolted along side the hub. This instead of coming to contact on a typical shoulder groove that is machined into the hub's outer diameter mounting surface. This is a very non-traditional way to mount the disk which puts a whole lot of sheer force on the mounting bolts. I don't intend to over stress the bolts to failure but this design is not a self-centering design where the disk rides in the groove of the hub (and the bolts just hold it in place). No, with this design all the force is applied from the brake rotor to the bolts as they try to hold the disk along side the hub. Not cool.

Last edited by Smithers; 05-24-2016 at 10:30 PM.
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