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By: Chris Hodkinson

The ATV Source Team has performed a wide array of testing with different exhaust pipes to improve the performance of the Honda TRX250R. All the pipes we have tested were designed to alter the power delivery characteristics by using various tuned lengths, diameters, and cone angles.  These characteristics are used to control the release of the exhaust gasses. In testing it has been shown that proper selection of a tuned exhaust system is very important to ensure the desired performance levels. Of equal importance is the selection of the intake components. The intake components are often overlooked in the design and modification of high output engines. The intake must function well to keep up with the demands posed by the engine and in most cases the installation of an aggressively tuned aftermarket exhaust system.

Most modern ATV's utilize a reed valve type intake system. The reed valve operates on crankcase pressure to open and close the reed petals, providing the intake timing, much as a cam in a four-stroke engine would do. Reed technology initially utilized spring steel reeds.  The steel reeds provided good tension, inherit sealing properties, and long service life, but their drawbacks were numerous. Emerging from the need for better materials, fiberglass composite type reeds were utilized until today's new technology of using carbon fiber reed petals.

ESR 2000 Reed CageThe actual configuration and geometry of the reed block/cage itself has evolved as well. The majority of reed cage designs initially was and continues to be V shaped when viewed from the side profile. Moto Tassinari was the first manufacturer of aftermarket reed cages to use what is basically 2 reed cages stacked on top of each other, much like the shape of a W. The Motor Tassanari cage was the V-Force reed cage. The benefit of the W shape is that reeds need only open a very little bit to allow for the same amount of flow as compared to the more traditional V shaped reed cage.

ESR Top ViewESR, through extensive research and testing, has taken this technology a step further when they introduced their own version of the W shaped cage. The ESR 2000 Reed Cage design betters current designs by using 2 - 4 petal reed cages. In doing such with the 4 petal design, eliminates 2 reed support bridges per cage and in turn increased the overall area in which the fuel-air mixture can flow through. Simply put; more flow equals more power. An additional benefit of the ESR cage we tested is a built in spacer. The reed spacer moves the reed tips back, with the chief benefit of allowing increased flow thru the auxiliary intake ports. Another additional benefit is with the spacer inclusive of the reed cage itself.  There is one less gasket required and then one less gasket to worry about leaking!

We previously have tested and compared the V-Force Reed Cage against the Boyesen Rad Valve and in that test we choose the V-Force hands down over the Boyesen. Could ESR's new cage dethrone the V-Force as the top cage?  TRX Drag picTo answer this question we set up our timers and spent the day going back and forth between the 2 reed cages on the same quad. In 300 ft timed runs, the ESR cage consistently ran times .1-.12 seconds faster then the V-Force Cage. That may not sound like a big difference but in 300 ft runs that is 1-2 quad lengths. This a major gain for a reed cage only.

The seat of the pants feel says that the V-Force feels stronger down lower in the RPM range, but then does not perform nearly as well as compared to the ESR cage in the mid to upper end of the RPM's.

Additionally the award for quality and craftsmanship goes to the ESR cage. ESR is famous for their billet aluminum products on the 250R and this cage is no exception. You can purchase this cage in 3 colors, Anodized Red, Black, or plain unfinished aluminum. Also included in your order with this cage setup is a new rubber intake boot along with longer mounting screws which are required for proper installation.

Overall there are many benefits of the ESR cage. Our testing and evaluation has shown that this cage out performs others available by a wide margin. The added benefits of a built in spacer, the attention to detail, the craftsmanship and quality only bolster the fact that this is the best available on the market.

1510 E. Main St. Unit C
Visalia,CA 93292
Phone: 559-625-3157

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