Motus Motorcycles
Sport Touring – American Style!
I recently read an article in the Wheels section on The New York Times Website about the upstart motorcycle company Motus Motorcycles new Sport-Touring bikes, the MST-01 and the MST-R. Motus Motorcycles is based in Birmingham, Ala., and was founded by Lee Conn and Brian Case in 2007. They wanted to produce a line of sport-touring bikes that leaned more towards the European and Japanese sport-touring machines rather than follow the two other “American Made” V-Twin formats. They chose do design the bike from the ground up instead.
The bikes uses a chrome-moly “trellis” frame, similar to what Ducati uses, and with a V4 engine and 6 speed transmission combo that totals less than 200 lbs, the bike weighs in at about 520 lbs. in total. The fairing, fuel tank, seat unit and front fender are all fabricated from carbon fiber. Wheels from Marchesini in Italy are forged aluminum, and sport Pilot 3 radial tires.
The 160 horsepower V4 engine is in essence, 1/2 of a Chevy Corvette V-8, and most of the design work on the engine and transmission were done by Pratt & Miller, an engineering firm that built General Motors factory Corvette race cars. I would have thought that them might use a belt final drive for minimum maintenance, but both of these bikes are chain drive.
The base model MST-01 features standard 43-millimeter Marzocchi forks and Hayes brakes, while the R model adds premium running gear such as Ohlins forks, and Brembo brakes. The both come with direct fuel injection which boosts performance, and is a first in the motorcycle industry. Lee Conn said this about the bikes,
“We designed our motorcycle from the ground up to provide all-day riding comfort with hot-rod performance.”
and a quote from the Motus Motorcycles website.
At Motus, our obsession is to build the next generation of American motorcycles for die-hard riding enthusiasts. To design the ultimate street bike – fast, lightweight and comfortable for long distance canyon carving and high performance riding, whether solo or two-up. To deliver an all new machine that combines legendary racing technology with the practical needs of serious sport riders
The MST is the destiny of everything we imagined a sport tourer could be – an authentic American-made machine with incredible responsiveness, massive torque and enough comfort and practicality to satisfy the most demanding rider.
A small fleet of prototypes is currently undergoing testing and validation, and the Motus executives are embarking on an cross-country ride with Pratt & Miller engineers to evaluate the final prototypes, visit prospective dealers and proudly show off their new take on the American motorcycle.
See the picture below for the engine specs for the Motus MST-01 motorcycle, and the video at the bottom of the page of the Motus on the race track.
I’ve seen a good number of comments with regard to Overhead Cams, (OHC) being cutting edge technology and the in-block cams being ancient and out of date. Let me update you on the history of OHC. Overhead cam engines were used as early as 1912 by Fiat and Peugeot. That’s 101 years ago. New technology? I don’t think so. It has been used and dropped and picked up again by several auto manufactures over the years for reasons of size and weight. OHC is not used in aircraft for the same reasons, meaning it is just not superior for what the intended use is.
The truth of the matter is the main advantage to using OHC is to lighten the valve train which increases potential valve speed with high RPMs. There are several penalties that come with OHC. Increased external engine dimensions, a longer cam chain or belt, and added weight. OHC cam gears are out of the question. The modern autos using the OHC engine redline at 7 or 8000 RPM and sometimes as low as 6000. Motus redlines at 8000 rpm with in-block cam so where is the advantage for having OHC? With most modern automobile engines, the OHC is a sales gimmick not a performance option. The redline is limited by the sloppy unbalanced bottom end and so the advantages that an OHC would bring to the engine are out of reach without expensive aftermarket modifications. It is just a “gee whiz” selling point. I will say one thing. It simplifies the 4 valve engineering hurdles. 4 valves, another innovation aimed at reducing valve train weight, but underutilized because of slow turning engines that they are placed in.
Sure there are the crotch rockets that rev to 10,000 and up, but who actually gets to tap that power band? The truth is the Motus is the best technology, cutting edge if you will, for it’s designed application. No OHC engine will match the Motus’ in-block cam engine for the size, weight, to power output. Also, unless you’re racing, which only a micro of a percent of the motorcycle buying public is you won’t often see the maximum hp of a Hayabusa (a different class of motorcycle). Power that is achieved above 6000 RPM is unavailable on the street. This beautiful little Motus engine beats the OHC equivalent hands down. The nearest example I can think of is the Honda ST 1300. It has a smaller displacement, the engine, is 30% taller, (raising the center of gravity), and wider. The Honda is 710 pounds compared to the 530 pounds of the Motus and the Honda is as slow as an old lady coming from the beauty parlor. The Honda has 117 hp at 8000 RPM compared to the Motus’ 161, and 185 optional HP at 7800 RPM. The Motus releases it’s massive torque numbers at 4200 RPM. Torque is that, jerk your arms out of the sockets acceleration you feel when you crank open the throttle. This is so much more useable torque because of where it is located. How much time does anyone on the street (legally) spend at 8000 RPM?
Anyway the point is the Motus enjoys the same redline as the ST without the weight and size penalties of that antiquated OHC engine so what is the technical advantage of having OHC? Gee Whiz, I don’t know. One more thing. There were complaints about the Motus’ use of chain drive. Try changing the gear ratio on your BMW, Goldwing, Honda ST, or any other driveshaft bike. You can’t. No way around it unless you own a really good machine shop. With the Motus, you change the sprocket and add or subtract some chain links. Simple and inexpensive.
Nuff said.