Yamaha TRX
Encyclopedia
Manufactured by the Yamaha Motor Company
of Japan, the Yamaha TRX, is a motorcycle
with a 849 cc 270° parallel-twin engine. The TRX was Yamaha's first big twin sport bike
of the modern era. The TRX first appeared in Japan in 1995 and a version for Europe became available in 1996. Although the TRX was developed cheaply from the factory's 'parts bin', using FZR forks & brakes, and a modified parallel-twin engine from the Yamaha TDM850, this motorcycle performs well and has a coherent identity of its own.
V-twin, whose tubular trellis frame it echoed. However, the TRX's price was high and it sold poorly in Europe, being overshadowed by faster and more sophisticated motorcycles such as the Honda VTR1000
, Suzuki TL1000S
and Ducati 916
. In 1999 Yamaha stopped making the TRX, but the TDM, enlarged to 900 cc, remains in production.
The TRX dry sump
engine produces some 84 Nm of torque, and around 80 bhp. Uniquely, the oil tank is not remote, but is integral to the engine, sitting atop the gearbox. This design eradicates external oil lines and provides faster oil warm up. The 360° crank of the original TDM morphed into a 270° crank for both the TRX and for later TDMs.
Compared to the TDM, the TRX is lighter, lower and sportier. Its front forks
are conventional telescopics, while the rear suspension
is a rising-rate monoshock unit. Owners often replace the original disc brake
calipers with superior Yamaha "Blue-Spot" items. The heavy stock silencers
tend to choke the output; so any TRX benefits from lightweight cans. The original-equipment Michelin
Macadam tyres were of hard-compound and gave poor road adhesion. The TRX affords an excellent riding position, albeit with a rather hard rider's seat. The TRX is essentially a solo machine, so provision for a pillion
passenger is marginal: the pillion seat is hard and wafer-thin, the raised exhausts result in very high pillion footpegs, and there is no grab rail.
”, yielding a motor resembling the sound and feel of a V-twin. In a parallel-twin, a 270° crank allows both a more regular firing pattern than a 180° crank, and less vibration than a 360° crank. But unlike the 180° & 360° cranks, a 270° twin never has both pistons stationary, so crankshaft momentum is always maintained. Also, although the 270° firing interval is not as uneven as the 180° crank (parallel-twin) or 90° (V-twin), the 270° crank avoids being perfectly even; and this is said to allow better power delivery to the rear tyre by giving two fairly close power pulses followed by a "recovery gap" which supposedly helps the tyre resume full adhesion to the road. The TRX was the first production parallel-twin motorcycle to adopt a 270 ° crank, but the idea was adopted for the 2009 Triumph Thunderbird; and this 270° crank may become the norm for large parallel-twins.
(MCN) the TRX was described as "the best-kept secret in motorcycling" and a "forgotten gem" which bore comparison with the new Norton Commando
961. The review states: "The TRX It produces less power than sports 600s of the same era, but it’s much gruntier and more satisfying to use thanks to that twin cylinder character".
In a Motorcycle News readers' poll of the “Top Ten Big Twin Sports Bikes", the TRX came joint third, beaten only by the joint winners, the Ducati 916 & 748, with 90%. The TRX was rated at 88% (equal to the Ducati 996, Suzuki TL1000s & Honda SP-1). The TRX beat the Aprilia RSV1000 (86%), the Suzuki TL1000R (84%), the Honda Firestorm (82%) and the Aprilia Futura (80%). The rare MZ 1000S did not feature. MCN declared that "Although ... it's a parallel-twin and a touch on the bouncy side, the TRX is still a cracking bike. It's stable, handles neutrally and feels like a proper sports bike".
Yamaha Motor Company
, is a Japanese motorized vehicle-producing company. Yamaha Motor is part of Yamaha Corporation and its headquarter is located in Iwata, Shizuoka. Along with expanding Yamaha Corporation into the world's biggest piano maker, then Yamaha CEO Genichi Kawakami took Yamaha into the field of motorized...
of Japan, the Yamaha TRX, is a motorcycle
Motorcycle
A motorcycle is a single-track, two-wheeled motor vehicle. Motorcycles vary considerably depending on the task for which they are designed, such as long distance travel, navigating congested urban traffic, cruising, sport and racing, or off-road conditions.Motorcycles are one of the most...
with a 849 cc 270° parallel-twin engine. The TRX was Yamaha's first big twin sport bike
Sport bike
A sport bike, also written as sportbike, is a motorcycle optimized for speed, acceleration, braking, and cornering on paved roads, typically at the expense of comfort and fuel economy in comparison to less specialized motorcycles...
of the modern era. The TRX first appeared in Japan in 1995 and a version for Europe became available in 1996. Although the TRX was developed cheaply from the factory's 'parts bin', using FZR forks & brakes, and a modified parallel-twin engine from the Yamaha TDM850, this motorcycle performs well and has a coherent identity of its own.
Design and development
The TRX was designed to exploit the 1990s craze for big twin-cylinder sportsbikes, being aimed particularly at the 900 cc Ducati SuperSportDucati SuperSport
The Ducati SuperSport and SS are names applied to a series of Pantah based air-cooled four stroke desmodromic 2-valve 90-degree V-Twin motorcycles manufactured from 1988 onwards. A limited edition SuperSport called the SuperLight was sold in 1992. The name harked back to the round case 1973 Ducati...
V-twin, whose tubular trellis frame it echoed. However, the TRX's price was high and it sold poorly in Europe, being overshadowed by faster and more sophisticated motorcycles such as the Honda VTR1000
Honda RC51
The Honda RC51, also known as the RVT1000R or VTR1000 , is a V-twin motorcycle produced by Honda from 2000 to 2006.- Mechanicals and chassis :...
, Suzuki TL1000S
Suzuki TL1000S
- General background :The Suzuki TL1000S was introduced by Suzuki in 1997 and was produced until 2001 and is frequently referred to as the TLS or Suzuki TLS. It is notable for the V-twin engine which is still used in Suzuki's modern SV1000 and V-Strom 1000 motorcycles.The TLS motor featured a 90°...
and Ducati 916
Ducati 916
The Ducati 916 is an Italian sports motorcycle manufactured by Ducati from 1994 to 1998. In contrast to Japanese inline four-cylinder competitors of the time, its V-twin engine produced less outright power, but a more even torque spread...
. In 1999 Yamaha stopped making the TRX, but the TDM, enlarged to 900 cc, remains in production.
The TRX dry sump
Dry sump
A dry sump is a lubricating motor oil management method for four-stroke and large two-stroke piston internal combustion engines that uses external pumps and a secondary external reservoir for oil, as compared to a conventional wet sump system....
engine produces some 84 Nm of torque, and around 80 bhp. Uniquely, the oil tank is not remote, but is integral to the engine, sitting atop the gearbox. This design eradicates external oil lines and provides faster oil warm up. The 360° crank of the original TDM morphed into a 270° crank for both the TRX and for later TDMs.
Compared to the TDM, the TRX is lighter, lower and sportier. Its front forks
Motorcycle fork
A motorcycle fork connects a motorcycle's front wheel and axle to its frame, typically via a pair of triple clamps. It typically incorporates the front suspension and front brake, and allows the bike to be steered via handlebars attached to the top clamp....
are conventional telescopics, while the rear suspension
Swingarm
A swingarm, or "swinging arm" is the main component of the rear suspension of most modern motorcycles and ATVs...
is a rising-rate monoshock unit. Owners often replace the original disc brake
Disc brake
The disc brake or disk brake is a device for slowing or stopping the rotation of a wheel while it is in motion.A brake disc is usually made of cast iron, but may in some cases be made of composites such as reinforced carbon–carbon or ceramic matrix composites. This is connected to the wheel and/or...
calipers with superior Yamaha "Blue-Spot" items. The heavy stock silencers
Muffler
A muffler is a device for reducing the amount of noise emitted by the exhaust of an internal combustion engine. A US Patent for an Exhaust muffler for engines was granted to Milton and Marshall Reeves in 1897....
tend to choke the output; so any TRX benefits from lightweight cans. The original-equipment Michelin
Michelin
Michelin is a tyre manufacturer based in Clermont-Ferrand in the Auvergne région of France. It is one of the two largest tyre manufacturers in the world along with Bridgestone. In addition to the Michelin brand, it also owns the BFGoodrich, Kleber, Riken, Kormoran and Uniroyal tyre brands...
Macadam tyres were of hard-compound and gave poor road adhesion. The TRX affords an excellent riding position, albeit with a rather hard rider's seat. The TRX is essentially a solo machine, so provision for a pillion
Pillion
A pillion is a mostly British English term for a secondary pad, cushion, or seat behind the main seat or saddle on a horse, motorcycle, bicycle or moped...
passenger is marginal: the pillion seat is hard and wafer-thin, the raised exhausts result in very high pillion footpegs, and there is no grab rail.
The 270° crankshaft
The 270° ignition sequence in the TRX's is known as the “big-bang firing orderBig-bang firing order
A big bang engine is an unconventional motorcycle engine designed so that most of the power strokes occur simultaneously or in close succession. This is achieved by changing the ignition timing; sometimes in combination with a change in crankpin angle. The goal is to change the power delivery...
”, yielding a motor resembling the sound and feel of a V-twin. In a parallel-twin, a 270° crank allows both a more regular firing pattern than a 180° crank, and less vibration than a 360° crank. But unlike the 180° & 360° cranks, a 270° twin never has both pistons stationary, so crankshaft momentum is always maintained. Also, although the 270° firing interval is not as uneven as the 180° crank (parallel-twin) or 90° (V-twin), the 270° crank avoids being perfectly even; and this is said to allow better power delivery to the rear tyre by giving two fairly close power pulses followed by a "recovery gap" which supposedly helps the tyre resume full adhesion to the road. The TRX was the first production parallel-twin motorcycle to adopt a 270 ° crank, but the idea was adopted for the 2009 Triumph Thunderbird; and this 270° crank may become the norm for large parallel-twins.
Reception
In Motorcycle NewsMotorcycle News
MCN or Motor Cycle News is a weekly motorcycling newspaper published by Bauer Consumer Media, and based in Peterborough, United Kingdom. The title was founded by Cyril Quantrill in 1955 and bought by EMAP, before Bauer bought Emap's consumer media division in 2008...
(MCN) the TRX was described as "the best-kept secret in motorcycling" and a "forgotten gem" which bore comparison with the new Norton Commando
Norton Commando
The Norton Commando is a British motorcycle with an ohv pre-unit parallel twin engine, launched by the Norton Motorcycle company in 1967. Initially a nominal 750 cc displacement, actually , in 1973 it became an 850 cc, actually ....
961. The review states: "The TRX It produces less power than sports 600s of the same era, but it’s much gruntier and more satisfying to use thanks to that twin cylinder character".
In a Motorcycle News readers' poll of the “Top Ten Big Twin Sports Bikes", the TRX came joint third, beaten only by the joint winners, the Ducati 916 & 748, with 90%. The TRX was rated at 88% (equal to the Ducati 996, Suzuki TL1000s & Honda SP-1). The TRX beat the Aprilia RSV1000 (86%), the Suzuki TL1000R (84%), the Honda Firestorm (82%) and the Aprilia Futura (80%). The rare MZ 1000S did not feature. MCN declared that "Although ... it's a parallel-twin and a touch on the bouncy side, the TRX is still a cracking bike. It's stable, handles neutrally and feels like a proper sports bike".
External Links
- Yamaha TRX850 review at Motorcycle.com