Sunday, October 24, 2010

another new project

I'm addicted, I guess.  Better than crack and only slightly less expensive.  Embarking on another 'mono project -- this time, for the street.  Plan on using the DRZ/KLX engine again, as I have a bare engine for mockup purposes, and a few spares and extra hardware that I can use... as well as experience with the engine. 
As for the frame, I am starting with a Muz Skorpion frame that I got off of ebay.  The Muz was normally powered by a Yamaha 660 single, so the smaller DRZ will fit in with no problem.  I also got a subframe for the engine, but its about 10 lbs heavier than need be -- for a passenger, as well as to accomodate luggage and two exhaust pipes.  No thanks.  The angle grinder and cutting wheel will get some use.
I also found a DRZ rear swingarm for $14 -- this is the S version, so I want to find an SM for the final version -- a bit shorter, with proper streetbike axle blocks.
As for how the back end will be suspended, I'm thinking of going retro with twin rear shocks, or perhaps a single offset rear shock a la Norton rotary racer or ducati sport classic.
Allegedly a R6 front end bolts on fairly easily... I have acquired a set of 99-02 front forks (the RSU version), and a front wheel with twin discs for only $19 (the forks and triples were just over $100).
As for what the final "look" of the bike will be, I'm not 100% sure on that -- while a complete idea should be in place prior to the welding bottles being opened up, there are some mechanical things I need to develop or create, that I want to put into practice on this bike.

The first involves the oil tank.  I need a minimum of 2 L of oil for the dry sump engine.  What I would like to do is "hide" it, by incorporating it into the frame.  The DRZ400 dirtbike did this with a rectangular downtube on the stock chassis.

You can see engine mounting tabs just aft of the steering head.  The idea would be to use a 2.5" OD tube (with some jiggry-pokery to get the right volume) to mount to the front engine mount on the frame.  One would bolt to the other, and then the proper fittings would allow the hollow front engine mount tube to act as a oil tank as well.  The rad would mount to that, and etc, etc.  Of course, before I do any of that, I need to mount the forks in place, and create a "rolling chassis" -- need to get the angle of the dangle of the rear swingarm, and finally determine how long the front engine mount will be.  You can see some old 2.5" tubing in place for mock-up purposes already.
When dad delivered the frame and parts this past weekend, we also drilled out the frame engine/swingarm mount hole to 17mm -- even had a nice bolt at the right length hand I can use.  As you can see in the pic, a few spacers need to be made to center the swingarm (and ergo, the engine) in the frame.  I've got some nice aluminum alloy material to start with.

This can hopefully be an ongoing project to play with over the next few years... I'll keep everyone posted with updates as they come in.

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