Coup D'etat (Monster Bobber)
Project By: Stuart Baker (firstname.lastname@example.org)
I've had an idea for a SuperSport swing-armed Monster framed chopper in my head for about 6 years now. I did some initial sketches years ago and lost them in my move to the LA area. Suffice to say, the final version you see here is vastly different than my sketches were.
I had originally envisioned a more radical chopper styled motorcycle with the following equipment:
The frame which eventually became the Coup D'etat was from an engine donor that a friend had purchased on the internet. He wanted the engine and wiring... and sold me the frame for a song. The rear half had been run over by a car in an accident (rider was OK), and was badly twisted up but the front half survived quite well. So, I cut the rear stub off (sort of an 'ultimate tail-chop' if you will) and hung the front stub in the rafters of the shop until I could sort out the rest of the build in my head.
- Rear brake only
- Ape-hanger handlebars
- Jockey-shift w/hand clutch
- '60s era Moon-Eyes 3.5 gallon fuel tank
- Stromberg '97' carburetion
- Wild green paint
The engine in the bike is a '98 M900 which was also from a wrecked bike. This mill has the 'W' heads (750 cams and valves) so it's less desirable for all-out performance. The smaller valve train actually suits this bike just fine as torque is the order of the day.
Rear suspension duties are handled by a 2000 SuperSport steel swing-arm from a wrecked bike and the same adjustable Sachs shock too. The upper frame of the swing-arm was cut off during the lowering of the seat and a trellis style support was built up on the left side of the arm. The rear wheel is off of an '88 Honda Shadow VLX from a local salvage yard. I was looking for a wheel w/a 17mm axle so as to avoid changing bearings out and making spacers. It looked a bit fat on the bike initially... but it did have a 160 tire on it.
The front-end is off of an '88 Suzuki Savage (from the same salvage yard). I took the entire front-end to make certain I would only have to adapt one thing...the steering head bearings. I wanted a front-end with a simple lower fork leg, big spoked wheel, single disc brake, and a nice set of triples. The Suzuki delivered on all counts. I had to have a spacer lathed up for the upper bearing, and ended up using a Kawasaki lower steering bearing with a custom machined outer race. After adapting the bearings, it all bolted right in w/o any issues other than the steering stops were different.
As the progress started, it was clear that the bike wanted to become something different. More Bonneville, less boulevard. More flat-track, less drag-strip. More low and lean, less tall and boisterous. So I took the front fork springs out of the sliders and rolled it outside for a look-see. At that moment, low and lean was the order of the build. The mini-Apes went into the dumpster and a pair of drag-bars were donated by my friend Dave M. The rear shock was repositioned from the standard SuperSport location to a lower point on the left side of the bike to allow for the rear seat to position itself directly behind the vertical head. Originally the build was to be powered by a 750 engine so the frame tubing above the vertical head was positioned as such. Somewhere along the way, I thought about what makes a true hot-rod bike. A big engine. I test fit the 900 engine several times before realizing that it was too tall as it sat. So, out came the grinder. I ground the frame a bit, and the head a lot. It's a snug fit, but you may be able to squeeze a piece of paper between the head and the frame.
After deciding on the lowering, I had to decide on the finishing. Primer black? Gold? Red? How was it all going to turn out? As always, the project evolved into what it wanted. Primer (looking) black and red w/chrome & polished bits. The color scheme for the bike was lifted out of the folder of dream cars in my head. A black primered '32 Ford coupe w/red wheels.
Some people comment on how the exposed vertical head could lead one to becoming sterile. While the exposed head does get hot and radiate heat, it's only bad when you're stopped at a long traffic light in the summer time. I have got off the bike and stood next to it before and will likely do it again. When riding though, the majority of the heat is expelled through the cooling fins of the cylinder barrel and not through the upper portion of the cylinder head. It's not all bad though... it makes for a great butt-warmer on cold mornings. No, I'm not kidding.
The 1.7 gallon tank is a mystery. As an ebay purchase, the previous owner didn't know what bike it came off of. I didn't think much of it as I was only building one bobber. 'Why would I need to know?', I thought. How short-sighted of me. Now that requests for this bike have begun to roll in I find myself wondering what it came from. Oh well, it could likely be duplicated in aluminum for less expensive than finding an old tank and reworking it.
The electrics and wiring on the bike needed to have an old feel to them. To accomplish this, I hid as much of the wiring and electronics as possible and dressed up those that couldn't be hidden. The battery sits on the swing-arm covering up the main power relay and the starter solenoid. A special bracket below the engine holds the voltage regulator and the charging fuse. The fuse-box and ignition system are located on a special bracket in the tunnel of the fuel tank. Lastly the horn takes up residence on a bracket off of the front of the engine down by the starter. It's a good thing the bike's a bob-job... 'cuz if it had more electronics... I'd have to wear a back-pack.
To add to the old feel of the bike, I chose wiring from a tractor restoration supply house. It's modern wire, but with the old cloth covering over it. A lot of people comment on how different and cool it is. Personally, it was just one of those touches that needed to be done. A 1952 Ford Ranch Wagon ignition switch was purchased and wired into the loom. The 'ON' circuit powers the ignition and lighting, while the 'START' position turns on the starter. A YTZ7S battery was fitted because of its small size which opened another can of worms as the reserve capacity is limited by its size. So, during carb tuning... there was a lot of battery charging.
Construction took 4 months initially, and another 3 months after it's debut. I did push some customer projects to the side to accomplish this. Originally, the frame was powdercoated gold to imitate the Ducati frame color. But, during the few months after it's debut, I opted to change the frame color to black. It needs to come apart one more time to powder coat the frame in black (currently the frame only has paint on it).
Ride and final impressions.
The bike rides great and performs almost all tasks quite well. The bike's a touch short on stopping power, but a larger caliper is being looked into as on option to solve that woe. The foot rests are a bit too low, but then again...so is the rest of the bike. The 140 rear tire is a bit too narrow for drag-race style starts or wet-weather starts, but for most duty...it's sufficient to hold the high-torque 900 in check. It's not your average Ducati, but it does get the same amount of looks from people....just a different crowd of people is all!
Custom Ducati Specialists
I would like to thank the following businesses/individuals for their help with this project:
Dave M. & Richard R. / West Coast Cylinder Heads, Reseda CA
Jim G. / Granger's Classic Auto Body, Reseda CA
Cycle Stop, Los Angeles CA
Pyramid Powdercoating, Sunland CA
Derek / Distinctive Metal Polishing, Chatsworth CA
Lee / Lee W. Pedersen Tractor Restoration Supply, NY
(Ducati M900 Monster)
- 1999 Ducati Monster frame w/serious tail-chop and the neck raked out to 36'.
- 1998 Ducati Monster 900 engine (est. 60 hp)
- H-D wrinkle black paint and exposed fins
- Polished side covers, belt covers, cam-end covers, and valve access covers
- 2000 Ducati SuperSport swing-arm flipped upside-down (to lower the rear 1/2") and the upper support removed
- 2000 Ducati SuperSport rear shock w/travel limited to 1" of throw, 2" travel at the wheel, spring powder coated 'Red Baron Red' w/1.5 coils cut out of it
- 1988 Honda Shadow VLX rear wheel, hoop powder coated 'Red Baron Red' w/polished hub, and stainless spokes and nipples
- 1988 Suzuki Savage front-end complete w/fork sliders cut 2" to lower the front
- 1988 Suzuki Savage front wheel, hoop powder coated 'Red Baron Red' w/polished hub, and stainless spokes and nipples
- Tires: Continental Blitz. Rear: 140/90/15 Front:100/90/19
- Exhaust: Home-built duals w/fender washer baffles and VW beetle tips all wrapped up in header wrap
- Intake: 2x Mikuni 34mm round-slide carbs on custom manifolds w/custom velocity stacks
- Unknown 1.7 gallon fuel tank painted Benelli dark-grey w/red pin striping
- Universal aluminum rear H-D fender painted Benelli dark-grey w/red pin striping
- Vespa / universal scooter kill switch and horn button
- Universal headlight w/HI beam switch drilled into the top of the bucket
- (Now w/Loris Capirossi's signature!)
- Marsh Instruments pressure gauge screwed into right side engine cover to monitor oil pressure
- 1954 GMC tail-light on custom bracket off of swing-arm