Thursday, April 17, 2008

Honda's new TRX700 big bore sport quad


The most notable quad missing from the recent Dirt Wheels big bore sport ATV shootout was the all new IRS-equipped TRX700XX from Honda. I guess they couldn't wait for it to show up, but it has started popping up everywhere else, including a slew of first ride tests hosted by Honda at the Dumont Dunes Off-Highway Vehicle Area in Dumont, CA.

ATV Scene has extensive coverage of the technology and their impressions from the test, including what seem to be a couple pages just on Honda's innovative Centered Chain Drive System. Off-Road.com has a basic writeup that verifies some of the Scenes conclusions, and the new ATV.com has some videos from a beginner level rider from the same test. Now for my summary...

Centered Chain Drive System

Honda has engineered a whole new approach to the traditional driveline issues with independent rear-swung models in the TRX700. The centered chain drive is only 33mm off center of the chassis, allowing for longer double wishbone a-arms and longer axle shafts. This in turn minimizes wheel camber changes and decreases extreme angles for the CV joints, resulting in both a better handling and more reliable ATV. As I said, if you really want the fully story checkout the ATV Scene article.

Largest single cylinder ATV engine Honda has produced, but...

The TRX700 is powered by a 686cc dry-sump, liquid-cooled SOHC four-valve single-cylinder four-stroke engine, which no doubt traces its origins to Honda’s Baja-dominating XR650R dirt bike. In fact, the 700XX engine is the largest diameter single-cylinder that Honda has ever mass-produced.

When put to the test, most agreed that the Honda produces its power up high leaving much to be desired in the low and mid range department. While this is not uncommon in modern (read restricted) four strokes, all of the reviewers seemed to have trouble at lower speeds both from stalling and staying in a usable power range.

"Mid range power is decent, but still lacks that hit you expect in a high performance sport quad, especially one packing this many CCs. Up high the four-valve single-cylinder four-stroke engine comes alive and pulls nicely. It’s fast, but seems a little slower than Yamaha’s Raptor 700R." - ATV Scene


Ergonomics and handling

"Moving around on the 700XX is possibly the easiest of any quad." - ATV Scene


A lot of praise for the ergos and handling overall. Interestingly, the TRX700 is shorter and narrower than even the TRX450. Where the TRX450 is 73.3 inches long and 46.3 inches wide, the 700XX is 71.5 inches long and 45.9 inches wide.

There was some disagreement on handling through high speed whoops, some quite impressed and others feeling the requirement for aftermarket help. This may be a matter of the style of riding. Another problem area could be in low speed handling, partly due to the IRS design along with some front-end pushing. Jumping, and I guess more importantly, landing the large quad on the other hand proved to be quite enjoyable.

Reliability

Honda has a reputation in this department, and the TRX700 features tough high-impact urethane skids plates and possibly the most protected rear brake and sprocket system on an ATV. Honda is offering a one-year warranty plan for the first time, which might be an indivator of their confidence level in the new design.

Conclusion
Despite Honda aiming for the TRX700 to be a “category killer”, targeting current or would be utility ATV owners who really want something more sporty, it would seem that a different niche might be carved out. Given some of the above issues combined with the easier shifting in slow speed or tight situations you would get from an automatic utility quad, seems like desert and offroad racing might be perfect for the XX, especially considering the demands on reliability in those environments.

So I guess I agree with ATV Scene once again

"In stock form we just don’t see this as a good choice for tight woods riding or perhaps GNCC racing out east. But if you’re a high performance desert racer on the west coast, with a little aftermarket help, there isn’t a better machine available."