1975 ISDT Rokon

This ISDT Rokon belongs to and was ridden Dave Mungenast.  I haven't got any real details on the history of this bike.  I think it was ridden by Dave in the 1975 ISDT, but I don't have any confirmation.  I will try to find out more about the history of this bike and add the information as it becomes available.

Special thanks to Becky Gaines of Classic Motorcycles LLC for letting me borrow her digital camera to take these pictures.  Becky also told me there is a good chance this bike will be on display at the Swap Meet section at Vintage Motorcycles Days at Mid-Ohio on July 7, 8 and 9, 2000.

I took pictures of things I found interesting, I hope you find them interesting too.  To see a full screen view of each picture just click on it.  The first picture (1) shows the rear end of the bike with the enduro bag and extra belt.  The second picture (2) shows the crash bars that help protect the aluminum torque converter cover.  From the circle welded on the front clutch section of the cover I am wondering if this bike or at least the cover was used with a Comet clutch, when I modified my cover for the Comet clutch I ended up with a hole about the same size and place.  The third picture (3) shows the cylinder and head, if you look closely there are hole drilled through the fins and something is threaded through the holes, I'm thinking sound deadening.

Moving toward the back of the bike (4) we see the RTII looking exhaust, Koni dampers and aluminum carrier for the rear disk.  I also found the brake stay are to very interesting, it aluminum with a 'I' beam like cross section very cool.  All the way to the back (5) you can see another view of the belt and tool bag.  Turning the corner to right side of the machine (6) you can see the forward mounted dampers, like the MX versions.  Another interesting feature of this bike is the right hand mounting of the side stand.  I wondered why it was equipped with the stand on the right side, it seems this would be awkward to pull on the starter with the bike leaned to the right.  After think about this for a while my guess is there was no room in the traditional spot on the right side due to the exhaust.

Moving forward (7) there a couple items of interest, below the front sprocket and to the rear of the master cylinder you can see a hole in the bottom plate of the frame, no doubt to let some of the junk that tends to accumulate back there out.  Sticking up in front of the master cylinder is an enduro wrench held in place by a rubber band.  If you look closely you can see the 9/16" open end wrench that is used on the chain adjusters.  The next picture (9)show how much metal was remover from above the recoil starter, much more than the MX models.  Next (10) the skid bars that protect the RTII type low exhaust can be seen.

The next picture (11) is the right side of the bike, followed (12) by the left side.  This bike has the 1975 style gas tank, shaped like the earlier fiberglass, but made of plastic.  I find this next picture (13) to be of special interest, especially the steering head.  The steering head is gusseted on top of the top tube, but not nearly as much as the frame on my Cobra, which was built in September of 1974.  I find it very interesting that a 1975 ISDT frame would have less gusseting in this area than a Cobra frame.  Does anyone have any insight into this?  I'm wondering if this frame wasn't built earlier and updated with a forward mounted shock swing arm.

In this picture (14) you can see the aluminum carrier for the front disk and the 8" travel front forks like those later RTII.  Next is another picture (15) of the crash bars from the right side.  This picture (16) is another enduro wrench.  The large socket is a 15/16" for the rear axle.  The small socket is a 13mm.

(17) Route sheet holder and speedo mounting. (18) Top on the gas tank.  (19) Yes another view of the spare drive belt, but the white section in this view has Rokon and the Rokon part number printed on it.

Picture (21), what appears to be a pop rivet used as a rim lock in the cast wheels.  And last (22), show how the enduro bag is mounted, also note the spare set of foot pegs mounted to the support bar.

If you have any comment or more information please e-mail me at 340mx@home.com

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Tom Kean's 75 Rokon Side Hack

Ron, I've been checking your site since I acquired this RT 340 sidehack rig last fall. It was allegedly fabricated by a mad brit in the '70s, and has been sitting out on a high western desert for about the past 10 years.  It wasn't badly rusted when I got it, but it took a lot of heatin' and beatin' to get it apart.  When I sanded off the orange-brown weathered plastic tank to see what was down there, a glance from the fresh plastic to my old John Deere suggested the color scheme.  The frame build quality is high:  tubes carefully bent and bird mouthed, front and hack swingarms have silent bush pivots - all joints brazed!  The hack wheel rides on a huge ball race.  The aluminum body work was so nicely done that I just hammered it out best I could, wire wheeled it, light sanded, masked it off and painted it.  The motor was good after minor repairs and clean up, as were the speed reducer and drive pulleys.  Jim Hosking was a big help supplying the little bits, and always gave full credit, no questions asked, for returned stuff that didn't work out. This is my first Rokon, and it is a trip. It's a real screamer, in that it always gets the monkeys screaming.  Great brakes (sidecar brake is operated by the monkey) allow interesting cornering techniques, usually requiring good teamwork.  Power braking the front wheel through turns allows the back to get spinning and kicking out, releasing the brake into the straight makes you feel like you're riding a sling shot.   Motor # is 7487650, frame # is RT 340 1386.  Any info you have is welcome, add this to the registry if you like.  Tom Kean, Somerset Ky tkean@gateway.net

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