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Special Motorsports Event - Honda Dakar Rally Set Up Description With Katsumi Yamazaki

PHOTO (select to view enlarged photo)

Q.Why did you choose the CRF450X as the base model for this machine?

First of all, we can't use a motocross bike to race in the Rally. Since we will be racing in the off-road category, the natural choice was the CRF450X. Q.You are entering the race on a production-based motorcycle. What are the advantages and disadvantages of this approach?

This biggest advantage is being able to quickly incorporate the experience, technologies and know-how gained from past races on a production bike. We used to race works machines, but works machines don't always mesh with production bikes. We can also offer the parts we made for this machine as parts kits for people who already ride the CRF450X and people who want to race the bike in future rallies, so that is another advantage of entering with a production bike.

The disadvantage is regulation. In particular, there are places where we can't boost power even if we want to. In terms of materials, design and dimensions, there are things you can do with works machines that you can't with production models, and that is something we are struggling with. Specific problems include narrowing the valve angle and valve spacing. Since we can't afford to remanufacture our molds, we have to make adjustments within the confines of these regulations, and that is quite difficult. Q.How exactly have you powered up the CRF450X?

Since we don't know who is riding the base model CRF450X and where they are riding it, the design parameters are extremely strict. It can run in temperatures ranging from below zero to 50 degrees, but we don't know for how long. To a degree, we can predict the speed range and mileage of motocross bikes like the CRF450R, so we boost the performance based on these factors, but we can't do this with the CRF450X. For this reason, the design of everything from the crankshaft and cylinder heads to the eco-tuned carburetor settings has fairly wide margins.

We equipped the CRF450 RALLY with PGM-FI to allow us to change the settings freely, and we expanded valve diameters as far as regulations would permit to generate more power. This is how we increased the bike's charging efficiency as well as its power. In terms of output, we are already in uncharted territory. I mean, this bike generates so much power that it would break immediately if you don't perform proper upkeep and follow a regular maintenance schedule.

But the most important requirement we are aiming for in this rally machine is overall balance. We need the bike to perform at top speed, but it can't breakdown. We also need to keep weight down. I believe it is important to strike a superior balance between these opposing factors, and I think that the machine that does this the best can win. Of course, the same logic applies to any machine. Another important factor is to make sure the machine does not overtax the rider.

Q.What other changes did you make?

Except for the gear change pedal, everything is different from the production bike (laughs). We rebuilt the frame, the engine and everything else. We used different quality materials, so most of the parts are different even though they look the same. One example is the wheels. At first glance, it looks like the production bike, but everything is different, such as the width and strength of the rims and the thickness and number of spokes . The CRF450X weighs just over 100 kg, but the CRF450 RALLY is much heavier and has a higher speed range. For this reason, the suspension springs we used have different diameters, are made of different materials and have different strengths. So, yes-we changed everything except the gear change pedal!

That being said, we have developed the bike so that, like KTM, we can offer parts kits or completed bikes to amateur riders in the future. It may be expensive, but riders with more money to spend will be able to purchase a bike with the same specs as our rally machine. That is why we have designed each part to be replaceable. My idea is to offer a cheaper base machine and optional high performance parts for riders who want high performance. For example, we could even let customers choose the PGM-FI that we are using.

Actually, we have already provided an Argentinean team entering the Dakar Rally with a commercially-available bike based on our works machine on a trial basis.

Q.Why did you use PGM-FI?

The biggest reason is the altitude difference. When you race in the Dakar Rally, you go from 0 m above sea level to almost 5,000 m at the highest point. A carburetor cannot handle that altitude difference without the proper settings, but PGM-FI can. Another factor is temperature. During the Dakar Rally, temperatures can range from minus 10 degrees to 45 degrees, for a difference of 55 degrees. PGM-FI is in a league of its own when it comes to flexibly adapting to these kinds of changes. We chose to use it for it high performance.

Q.What mechanical issues do you face in preparation for the Dakar Rally?

Since our machine was only 70% ready at the time of the Morocco Rally, our challenge is to complete the remaining 30%. We still need to work on power, durability and serviceability. At the Morocco Rally, we had some serviceability difficulties that put our mechanics under considerable stress. If we don't make improvements in this area, our mechanics and team staff will not be able to provide support during the two long weeks of the Dakar Rally. Improving serviceability at this point is extremely difficult, but it is a problem we have to solve. At the Morocco Rally, our staff worked through the night every night to make engine repairs, and we somehow managed to last one week. But it would be hard to do the same thing for two straight weeks at the Dakar Rally. So, if we solve this issue, our customers will reap all the benefits. It is a tough task, but we will have the machine ready by the Dakar Rally.

We can't just have a good machine. No matter how high it performs, if it has poor serviceability, our mechanics will get worn out. If they get tired, they will naturally be more prone to error. If an error leads to trouble, that will immediately impact how the bike runs and our end result. So, if we cannot build a machine that can race without taxing our staff, we won't be able to compete in the Rally.

If I may digress, a bike needs to be broken in after an engine overhaul. So, our mechanics work into the wee hours of the morning overhauling and rebuilding the engine, after which our staff ride it outside the paddock until morning to break it in before giving it to the rider. That's what has to be done.

I heard that even KTM, who now ranks steadily in the top spots, once burned up 21 engines during three days of testing. At the Morocco Rally, they finished their maintenance by the early evening each day.

In any case, after we decided to enter the Rally, we had very little development time, so there have been some things we wanted or needed to do that we couldn't because of time constraints. We managed to handle some of these things at the Morocco Rally with sheer manpower. Last year, Stephane Peterhansel ran into trouble and lost in the car category at the Morocco Rally, but he got his revenge in this year's Dakar Rally. I think we can learn something from his experience. The most important thing, of course, is not doing all-night repairs: it is seeing how close we can get to building a perfect machine.