IS THIS MACHINE THE NEXT GENERATION HONDA TRX450R?

On Sep 13, 2023

By the Staff at Dirt Wheels

There has been a lot of speculation about Honda bringing back the TRX450R sport quad for some time now. Here are just a few of the rumors we’ve heard over the years:

“It’s going to have EFI”
“It will have an aluminum chassis.”
“There will be a two-stroke version.”
“My buddy’s dad is a Honda service tech, and he heard it’s coming back in (insert the following year – every year since 2014)

But there is some truth to those rumors. A TRX450R was being developed that was radically different from the version discontinued in 2014. We’ve also heard that a steel-framed version similar to the 2006-2014 model, but with EFI, was being tested in more recent years. We’ve traced patent drawings and information on the aluminum model back to the fall of 2008. We also know that prototypes were developed and were being tested, but the recession that began in late 2008 eventually stalled everything. At the time, many 2009 TRX450R models were sitting in warehouses as sales plummeted along with the US economy. More rumors surfaced that those 2009 units were being rebadged each new model year after. This put an indefinite hold on the project, as pricing would be significantly higher than the previous carbureted model. The timing couldn’t have been any worse.

Here’s some of the Honda patent information we found on what might have been the next-generation Honda TRX450R.

Top View: You can already see how different the frame is from the previous 450R version. The fender profile looks familiar, and Honda retained the swingarm and straight axle design, but look at the fuel tank and radiator placement. What is going on there?

Honda appears to have taken notes from some aftermarket frame companies with the front suspension design. There’s a single lower frame rail that keeps the A-arms mounts much closer together, which would produce more wheel travel and better handling. It’s similar to the style of Roll Design’s Lobo chassis.

This is the fuel tank, and we can see an attached fuel pump, confirming the EFI rumors. You can see the filler neck of the tank at the upper right.

From this top view, you can see that the fuel tank sits below the upper frame rails. Much of the patent wording suggests Honda was focused on keeping as much weight as possible lower in the chassis. Considering a gallon of fuel weighs about seven pounds, the center of gravity and stability would significantly improve.

Patent information reads as follows –

“In a saddle-ride type four-wheel vehicle, a radiator and a fuel tank are supported on lower frames, and are arranged, side by side, so as to be distributed respectively on the right-hand side and on the left-hand side so as to overlap each other when viewed from a side. In addition, the fuel tank and the radiator are disposed at the rear of the front suspension arm and at the rear of the engine. As a result, the concentration of mass and the keeping of the mass at a lower position are achieved. Moreover, the fuel tank and the radiator are allowed to stretch outwards beyond the upper frame rails. Consequently, the fuel tank can have a larger capacity, and a ventilation path that leads to the radiator can be secured.”

Here’s a better angle of the fuel tank position low in the cradle. If you’re familiar with the existing TRX450R, that engine profile should look very familiar. The patent information doesn’t give us the fuel tank capacity, but it does state that it has a higher volume. It would be interesting to see what the aftermarket fuel tank manufacturers, like IMS and Clarke, could have developed for this design. It certainly would have favored the needs of long-distance off-road racers.

Here’s another good look at the front frame geometry. The rectangular shape is a dual radiator setup with an electric fan (circle shapes) mounted on the right radiator’s back side. We also get a good look at the single lower frame rail and the narrow distance between the right and left A-arm mounting tabs.

Additional views of the front end and left side are seen here. We also get a better view of the dropped fuel tank, which should lower the center of gravity and enhance stability and handling.

Per Honda patent info:

This top view gives us a look at the EFI throttle body (14). It’s also the first drawing that shows a split radiator design to make room for the lowered fuel tank. Honda also did this to maximize airflow through the radiators, which are designed with a higher coolant volume.

Here’s another side angle that shows the tank low in the frame. The EFI system controls, along with the battery and other electronics, are under that top cover. According to the patent information:

“Electronic equipment, such as a battery and an ECU is accommodated inside the top cover and is supported by the top of the upper frame. The rear portion of the suspension frame supports the lower part of the fuel tank. Electric equipment can be disposed at a place where the splashed water is unlikely to reach.”

Another view of the front end and split radiator design.

We can’t see exactly how you would fill the fuel tank from this angle, but that’s the cap underneath the shroud. Honda patent information states:

“According to an embodiment of the present invention, a filler mouth of the fuel tank is provided on a front fender.”

More views of the forward section of the aluminum frame and fuel tank placement. It has been suggested that Honda was considering releasing 250cc and 450cc four-stroke versions of the machine, potentially one-upping Yamaha’s Raptor 250.

A view from behind the right-side radiator shows electric fan placement and controls.

Per Honda patent text: “The fuel tank has an L-shape when viewed from above. A forward-stretching portion stretches out forward at a side of the radiator, and a fuel pump is attached to the top surface of the forward-stretching portion.”

Here, we get an overhead view of the dual radiators with the front of the fuel tank in between. Honda states in the patent information that this setup also directs more airflow over the exhaust head pipe.

Here, we get another view of the split radiator design and the front A-arm mounts. We also see the electric fan peeking from behind the right-side radiator. Per Honda patent information:

“A cooling fan is provided on the back-side surface of the radiator. Most of the cooling fan is located on the right-outer side of the upper frame.”

According to Honda patent information:

“The body frame is a frame made of aluminum material formed by integrating plural types of aluminum alloy members by welding and other appropriate methods.”

The drawings above give more details on the front independent A-arm suspension design. It’s possible and has been mentioned that Honda was testing air-charged shocks on TRX450R prototypes.

Steering components

Here, we can see electronics hidden underneath the top cover where the fuel tank is traditionally located. We can also make out the linked rear swingarm design, which appears completely different from previous production models.

From everything we’ve read and heard in interviews with industry insiders, the economy is the main hurdle that needs to be cleared to get the 450R back into production. Since 2009, the economic confidence hasn’t been good enough to convince Honda to pull the trigger and open up the assembly lines. And while our government would like for us to believe things are better than ever today, uncontrolled inflation, flat wages, and rising interest rates tell a different story. We still have faith that the Honda TRX450R will eventually return to dealer floors – just don’t expect to see it happen anytime soon.