Sunday, November 2, 2008

Swingarm silliness

My plan for mating the rear swingarm to the frame and engine was to bore out the Aprilia Pegaso bearing sleeves to match the 15 mm od of the shaft I was going to use. I have since learning that trying to bore out a small diameter, tempered steel sleeve is pretty much impossible. One option was to use a smaller Pegaso swingarm pivot, but I wasn't too keen on that -- it would mean some significant modifications to the frame. I decided to go with another option. Knocking out the torrington bearings in the swingarm, and getting bronze bushings machined to the right specs. A bit low-tech, but worked fine for decades on TZ250s, and 350s. Considering this is going to be a fun street-trackbike in the end, good enough for me. The swingarm and shaft are currently at Atom-Jet where they will work their magic on the CNC machines. I'll choke at the price in the end, but a necessary evil -- and still cheaper than buying my own lathe.
In the meantime, I've been compiling a information and picture resource of interesting singles and parts to suit. Again, all asthetic at this point:




This is the DRZ400-based CCM CR40 cafe racer. Alloy tank, twin shocks, spoked wheels. A neat, retro-looking machine. I'd love to get my hands on an exhaust system... would suit my purposes just fine.




This is a CR&S Vun (one) -- powered by a Pegaso/Bombardier/BMW/Rotax 650 single. Lovely bike. Google it if you want to see the website. If you have a spare $20,000 or so lying around, you could get them to build you one. Customizable down to EVERY last detail. Some neet videos on the site as well.



Airtech sells this BMW Rennsport fairing. Originally for a late 50s and 60s BMW R50. Gustaffson sells a windscreen for it for another $100. I REALLY like the shape of this, and it should be nice and narrow for my project. The issue is the HUGE 8" headlight cutout. I could see if they can build me one with the headlight cutout filled in, or I could do some work on it myself, maybe using a smaller pair of lights or the leftover 5.5" one from the Ducati.


I'm also partial to this seat, actually from a Bimota. The built-in fender extension will double nicely as a place to mount a licence plate, and a small rectangular (LED?) tailight will fit just underneath the ductail. I could get a proper seat made, after moulding a base "pan" from this, and benefit from a real cushion for my butt -- rather than a slab of foam. Perhaps it can even curl down over the side of the seat like a real seat pad. Dimensions seem right (supersize the image to see), but this will be something I would have to get in my hands first, prior to building the rear subframe.

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