The Honda TRX250R is a sports ATV manufactured by Honda between 1986 and 1989. It combines lightweight frame and good handling, with a two-step liquid-cooled engine and a close-ratio six-speed transmission. Although only produced four years, the "250R", as it was known, was the top choice for ATV racers until the rise of factory involvement and the use of four-stroke engines at the start of ATV sports in 2003.
Video Honda TRX250R
Specifications
Maps Honda TRX250R
Generation
TRX250R was introduced for the 1986 model to answer the Suzuki LT250R, which was released the previous year. Honda borrowed many parts from 3 wheel ATC250R to Fourtrax design, including engine and rear suspension. Although mechanically similar, Honda turned off the engine for use in Fourtrax, through reduced compression and less aggressive porting, to ensure that quad additional weight would not affect engine reliability.
The model year of 1987, now no tricycle due to the CPSC ban, saw the engine receiving a five millimeter long connecting rod, accompanied by a five-millimeter wrist-mounted piston pin. In addition, the cylinder is altered to include a bridged intake. Most of the 1987 Fourtrax chassis remains the same.
The 1988 model brought the most dramatic changes to the TRX250R. The engine compression ratio is raised to generate more power, making it almost equivalent to the Kawasaki-powered Tecate-4. It was the chassis, however, that received the greatest attention, spilling 25 pounds more than the previous year's model. In addition, a shorter aluminum swing arm is added, but the frame is extended in such a way that the overall wheelbase is slightly larger. This shifts the heavy bias backward, curing Fourtrax's "loop out" problem. Aesthetically, Fourtrax headlamps were moved from the handlebars to mounts mounted to the hood. It's also the only year that will be available with red fenders.
For 1989, TRX250R received some changes. The most prominent is the use of needle pads in the clutch pressure plate, for a smoother action. These needle pads are the necessary upgrades for the 1988 TRX250R, as well [3]. The color returned to white for the final year.
Rise of after-sale market
Though largely in stock in the early years, when the production rule started only about six TRX250R components had to be purchased from Honda [3]. According to Allen Knowles of CT Racing, "More aftermarket parts are made for 250R than other ATVs." [3] "Sixty percent of my business is based on R, compared to the next highest Banshee, at fifteen percent.With only Banshee, I will starve" Wayne Hinson of Hinson Racing said. [3]
Initially, the items that were subjected to the most abuses of the race were the first to be re-created. Originally made of cast aluminum, the clutch basket was found to be weak when power increased or experienced racing conditions. The first aftermarket clutch bucket was a piece of steel machine that Gary Denton campaigned for in 1989. Wayne Hinson, who later invented the worldwide clutch component manufacturer Hinson Racing, designed the clutch basket and then converted it into an aluminum billet in 1991. ]
Ordinary trends that begin on Fourtrax that will not carry over to four strokes are the use of aftermarket frames. Stock frames in most of the mass produced quads are made of mild steel and, although suitable for recreational use, will rapidly develop cracks while running. Without the new quads after the 1989 model, a stronger replacement frame for racing was soon needed. The first aftermarket frame for 250R is made by dirt track motorcycle chassis builder, C & amp; J in 1991 for CT Racing. [3] This frame is a direct replacement for the original stock suspension geometry. The first modified geometry frames were introduced by JP Racing moments later. [3] This design carries a front suspension mount in an inch on each side, enabling the use of longer suspension arms in competition, which increases wheel travel and improves ride quality. In 2003, a myriad of aftermarket frames can be obtained from various manufacturers in both stock and modified geometry, made of steel and aluminum. Lone Star Racing produces a titanium frame, but the AMA rules prevent its use in competition.
Although Honda initially concerned with the reliability and detuned of the original 250cc motor, with the release of the Pro-X (pro-cross) and head cylinder in 1994, the 250R displacement can be upgraded well into the 300cc range by changing the cylinder only. In addition, these and other aftermarket cylinders offer advanced port layouts for more tuning options. With modifications to the transmission case, later aftermarket cylinders and crankshafts allow engine displacement to reach 500cc. The latest version of the Pro-X cylinder, as well as the others, also adds an exhaust-operated powervalve, the remaining feature of the 250R but is used almost universally by its competitors, as well as the Two-Stroke motocross motors since the mid-eighties.
Despite the massive increase in displacements and strengths possible, the TRX250R transmission does have its limits, and gear strength becomes a problem. To allow for larger engines, a joint venture between Baldwin Motorsports and Timken Bearing, in the 90s, resulted in a more robust set of aftermarket fixtures. This gear allows more than 330cc engine to be reliable. TRX250R is the only quad where the product is created.
Honda's Reason Behind Stop TRX250r
Driving reasons Honda chose to use a larger four-step displacement engine than the traditional two steps as part of their re-engagement in the ATV competition can be learned from the following quote taken from world.honda.com:
"To achieve cleaner emissions and higher fuel economy targets announced for motorcycles in 1999, Honda began as early as 1997 to take steps to stop the use of a 2-step engine by the end of fiscal year 2002. This is only a 2-engine - structured steps have been adopted primarily in small motorcycles because of their superior output.Our goal is to replace them with the more environmentally friendly 4-stroke engine technology.î But in fact in recent years there has been a steady increase in TRX250r's popularity with some aftermarket companies are still making components for quad. There is also a push to make TRX250r legal for racing in some Pro classes against 4 strokes.
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Named "ATV of the Century" by "4-Wheel ATV Action" [9]
External links
- Honda Web site
References
1. Ed Scott; Randy Stephens, editor. (1990), Clymer Honda TRX250R/Fourtrax 250R & amp; ATC250R 1985 - 1989 Layanan * Perbaikan * Pemeliharaan , Penerbitan Intertec, ISBN 0-89287-540-2 CS1 maint: Banyak nama: daftar pengarang (tautan) CS1 maint: Teks tambahan: daftar penulis (tautan)
2. Lanphier, Bill (Maret-April 2006), "Long Live the R!", Olahraga Pasir , 12 (2): 64-67, 114, 10961941
3.
4. Beckman, Phil (November 1987), "Hello and Goodbye", ATVSports , 8 (11): 32-33, 0196-5549
5. Beckman, Phil (Juli 1986), "Terlalu Dekat untuk Kenyamanan", 3Wheeling , 7 (7) : 36-39, 0196-5549
6. Kirsten, Dean (Mei 1986), "Melacak Elusive Fourtrax", 3Wheeling , 7 (5) : 34-35, 105, 0196-5549
7. Beckman, Phil (Februari 1987), "Kejuaraan Lintas Negara", 3Wheeling , 8 (2): 36-38, 0196-5549
8. "Honda All New TRX250R", Dirtwheels , 25 (6): 190-192, 194, 198, 202, 206, Juni 2005, 1060-4804
9. "Survey Pembaca: Honda Fourtrax TRX250R", Aksi ATV 4-Roda , 16 (11): 42, November 1999, 1098 -0423
10. "Penembakan Legendaris!", Aksi ATV 4 Roda , 17 (9): 56-61, September 2000
11. "Ultimate High Performance Shootout", Aksi ATV 4-Roda , 17 (1): 16-22, 24, 26, Januari 2000
12. "Specifications", Honda's Service Manual; Honda Motor CO., LTD. Office of Service Publication : 1-3, September 1988
13. "world.honda.com", world.honda.com , 2006
Source of the article : Wikipedia