James Loughead, Ph.D., is an Assistant Professor of Neuropsychology at the University of Pennsylvania. He also knows how the mind of a motorcyclist works: his company Hammarhead Industries has attracted an extraordinary amount of attention over the past year. His Jack Pine bike was one of the all-time hits on Bike EXIF, and this is the follow-up. James tells the story far better than I can, so here it is, in his own words.
“The Solo X (read cross) project began when the Ural sT was posted on Bike EXIF in May 2010. When I saw the images of that bike, I immediately fired off an email to Ural to see if we could get an sT to customize. The sT was attractive because it’s an elemental motorcycle, but this also made the build a bit of a challenge. There was not any plastic to strip off—Urals are apparently made of metal.
“I got to know the Ural sT providing support for our Pier 18 video. The Ural is perfect for ratting around in the dirt, and then shooting through traffic to grab that much needed Hoagie. The bike is low and long, but not big. It felt much smaller than the R100 I rode in the early 90s. The suspension was dialed in well, and the build quality was excellent. It seemed crazy but I felt the bike need to be prepped for off road.
“Even though the sT is very basic, I stripped the bike further. The instrument cluster was removed and a new headlight selected—one that could swallow all the electrics. The correct handlebars were found hanging in the shop and these were fitted out with basic switchgear and internally wired. The bars are capped with Oberon bar-end LED turn signals. The ignition switch is relocated under the seat, and the speedo mounted to the transmission. The steel fenders were replaced with alloy units that were re-arched to fit the 18-inch wheels. A simple LED taillight is all there is out back, as the bar end signals are visible from the rear.
“Much of what was needed to protect the bike off-road was available from Raceway Services. They provided crash bars, skid plate and the awesome high pipes. Jim Petitti at Raceway also advised me to install a Power Arc, which is the only engine modification we made. The head temps are considerably lower with this system, and there is less delta in temp between cylinders.
The high pipe introduced a new problem on the bike; the high exit made the airbox intakes seem poorly placed—particularly for a spirited stream crossing. While thinking about the exhaust, I had looked at some fantastic images of 1940s R75s and early Ural M72s. Once the high pipes were a go, I went back to the R75 for inspiration regarding the intakes. To replicate the tank-mounted air box of the BMW R75 rig, I cut the bottom out of the Ural tank; a pass-through air box was formed in the tank that could accommodate two conical K&N filters. We fabricated and tested 1¾” intake tubes before the tank was modified, so these were fitted. The exhaust and intakes required a slight re-jet of the stock carbs but otherwise no changes were needed. When the winter weather breaks, my first outing with the bike will be a deep stream crossing at a farm just outside Philly. I’m looking forward to getting drenched.”
[Images by Ryan Miller and Enrique Oliva.]
Concept: James Hammarhead
Assembly: Hammarhead Industries
Base: 2010 Ural sT
Power: 745cc Twin
Output (hp): 40 @ 5600
Torque (ft-lbs): 38 @ 4500 rpm
Length: 2160 mm (85.0 in)
Wheelbase: 1490 mm (58.7 in)
Seat height: 760 mm (30 in)
Ground clearance: 170 mm (7 in)
Dry weight: 192 Kg (425 lbs) Build Time: 90 days
Carburetion: Keihin L22 AA
Air filter: Modified K&N
Exhaust: Raceway Services
Ignition: Power Arc Optic Ignition
Suspension & Brakes
Front: 40mm Marzocchi telescopic
Rear: Twin Sachs Shocks w/Progressive Springs
Front brake: Single 295 mm full floating disc, 4-piston Brembo
Rear brake: Single 245 mm disc, 2-piston Brembo
Wheels: 2.5 X 18 Alloy
Front Tire: Duro HF-308, 3.5×18″
Rear Tire: Duro HF-308, 4.0×18″
Bars: no name flat bars
Fenders: no name alloy
Skid plate: Raceway Services
Engine guard: Raceway Services
Speedo: Koso with custom cable
Switch gear: Emgo
Turn signals: Oberon Performance
Taillight: Street Magic