The Fort Knox of Radiator Guards!

There’s no denying the benefits of liquid cooled engines. By controlling an engine’s range of normal operating temperatures, engine designers and manufacturers are able to employ tighter clearances and lighter materials to improve an engine’s power, reliability, and expected life span. That’s the good part. The down side is that liquid cooling adds to the cost of the engine due to higher manufacturing costs, more complexity, and a number of extra parts such as water pumps, thermostats, radiators, radiator caps, hoses, clamps, etc. To those of us who maintain our own motorcycles, liquid cooling also means more complexity, more maintenance, and more parts to fail. We sure put up with a lot in the name of performance, don’t we?

Among the more critical parts involved in liquid cooling are the radiators, which transfer the heat from the liquid to the air, returning cooled liquid to the engine to help keep the head and cylinder operating within its designed temperature range. When used on liquid cooled dirt bikes, radiators not only add weight high at the fuel tank level, they’re almost always made of light weight aluminum, and they’re never inexpensive! Aluminum is a great material for radiators, since it’s light, easy to form, and conducts heat so quickly. That light weight comes at a cost, though, since aluminum is also soft, easy to bend, and easily damaged. To tell you the truth, when liquid cooling first began showing up on factory-special motocross bikes, I assumed it would remain a factory-bike-only advantage. I didn’t think it would ever trickle down to consumer use showroom bikes, because the radiators are too delicate to withstand the abuses and crashes of the typical off-road rider. Other notable predictions of mine included Observed Trials becoming a huge sport in the U.S., and that Bill Clinton had about the same chance of being re-elected to a second term as President, as I did in becoming the first rider over 50 years old to win a National Enduro Championship! I don’t guess well... I guess.

Dirt bike radiators have become far more popular and far sturdier and damage resistant, than I ever dreamed possible. I’m sure there have been cases of radiator failures other than crash damage, but I’m not personally aware of any. So if you never fall, crash, or run into anything, you may as well quit reading this right now, and go tell someone else your lies. The rest of us worry about the cost of replacements (at $150 and up, there goes the money for the new tires, sprockets, and chain!), the loss of considerable riding time (that day, and until the repairs are made), and perhaps even how we’re going to get our steaming, overheating bike out of the woods the day we destroy a radiator!

Today’s best solution to this problem is to add extra protection. It only stands to reason that the more frequently we crash, the more protection we need, so I was considering adding steel cage frames around my radiators. Now wait a minute! Don’t laugh! Some of you guys needs need two frames per radiator! I’ve seen your medical x-rays!
I’ve already reviewed the Works Connection Radiator Braces for the CRF250R/X , which I still think may help prevent radiator damage from frontal impacts. They fit well, they’re easy to install, they come with all the necessary hardware, and their $70 cost is far less than the radiators they protect. But are they enough? Remember, they’re “radiator braces”, not “radiator guards”, and braces running from the outside edge of each radiator back to the frame will simply act like a hinge when the bike encounters a side impact, as in a simple fall-over. In fact, most cases of dirt bike radiator damage I’ve seen resulted from a side impact, when something crushed the radiator toward the bike’s frame. Such radiator braces offer very little protection against side-impacts.

But now, for just $15 more, you can get wrap-around protection for those delicate, high-dollar heat shredders! For just $75 a pair, Flatland Racing offers the best and most thorough radiator protection I’ve seen for any dirt bike. Each guard for the CRF250R/X forms a triangulated, hardened aluminum barrier around the radiator. That’s right, I said around the radiator. These guards don’t even touch the radiators themselves, so the radiators remain free to squirm around on the vibration insulating mounts designed and intended by Honda. The Flatland guards have hefty braces on the rear, but they also have a full width, full height shield up front. This shield serves us in two ways that radiator braces do not. First, they protect against frontal attack. Before a tree branch or a thrown rock can reach and poke a hole in the radiator, it first has to penetrate a perforated sheet of 1/8" hardened aluminum! And anything carrying enough energy to do that is likely to rip the radiator right off the bike anyway, and maybe the rider’s leg behind it! But no, let’s not go there!

Secondly, in a side-impact, such as a simple sideways fall onto a rock, log, Suzuki, or other trail trash, before the impact can crunch the radiator, it will first have to crush the triangulated structure of the guard surrounding it! And it’s strong!

Wait? Do I hear a swelling chorus of curious voices asking, “How strong is it?”?

Frankly, I don’t know, but I was curious too, so I decided to go a little nuts and test it. I fastened it to a board on my ATV lift, using the board as the third side of the triangulated design in much the same way the motorcycle frame acts when the guard is bolted in place on the bike. Then I used the ATV lift to raise the motorcycle, putting the bike’s entire weight on just one of the radiator guards. It took some fiddling, but I got the bike so precisely balanced, all it took to keep the bike from toppling forward was a roll of paper towels at the front tire, Checkout the photo and you’ll see how little pressure is on the roll of towels. Note too that the radiator guard is not sagging, bowing, or bending. This not only shows the resistance of hardened aluminum, it demonstrates the strength principles of a triangulated structure. Or, to put it another way... it’s damn strong! And it’s just the protection a clumsy rider like me needs... protection against a lost day of riding... protection against having to ask someone else to ruin their day of riding by taking the time to tow me out... protection against lost riding time while waiting for parts and repairs... and protection against lightening my wallet to pay for the repairs!

Installing the guards was very easy, by just following the instructions. Only the side shrouds, the white plastic louvers, and four radiator bolts need removing. The three bolt holes in each radiator guard line up perfectly with the frame. It couldn’t be easier.

Reinstalling the shrouds, however, wasn’t so easy. First, the tough plastic inner ribs on each shroud have to be trimmed, and this is easier said than done. It takes a sharp knife or razor, and a lot of “being careful” to prevent cutting yourself. Never cut toward yourself, and always support the piece being cut on a soft pad, piece of carpet, or something similar. This provides a better, non-slip surface for the piece being cut, and it gives a softer surface for your hand to slam into when the knife slips or cut through more quickly than expected. Be careful when cutting such tough plastic, and when using sharp tools!

It took several trail and error fittings, but once the shrouds were trimmed to fit, I reinstalled them on the bike and discovered that the front lower shroud bolt doesn’t fit very well on either side. No, let me change that to say, “it doesn’t fit well period”! It was so difficult, in fact, to get the bolt threads started, I finally gave up and decided not to use that bolt! All it does is secure the front lower corner of the shroud. If I was worried about it not being fastened, it would be much easier to use a strong zip-tie to secure it than to get that damn bolt started!

So, once the other three shroud bolts were tightened in place, and the decision made to skip the troublesome one, I was done! Installing the radiator guards themselves took less than 30 minutes, but I spent more time than that trimming the inner shroud ribs alone. I’d suggest allowing about an hour for the whole job.

Although probably not necessary, I took a tip from Rick Ramsey, and cut, hacked, and trimmed the stock white plastic louvers to fit in front of the radiator guards (see photos). This took another 20 minutes. A lot of the bike-side of each louver was trimmed away to provide turning clearance for the top fork clamp and the rear portion of the front fender. Then I fastened each lover in place on the radiator guard using a nylon zip-tire at each corner.

I measured the distance between the forward-most tips of the shrouds before I removed them, and got 17-1/2". I measured them again after installing the Flatland Racing Radiator Guards, and got 18-5/8", so the guards spread out the shrouds by about 1/2" on each side. Since this is in the same area as the handlebars anyway, I see no problem with this.

So, that’s it. The Flatland Racing Radiator Guards for the 2004/5 CRF250R/X install easily and solidly, with perfect placement and alignment of the bolt holes. Trimming and replacing the stock Honda air shrouds was tedious, difficult, and requires great care to prevent self-injury, and one shroud bolt becomes so poorly aligned, I finally decided to leave it off! None of this alters my opinion, however, that these Flatland Racing products are the finest and strongest radiator guards I’ve ever seen for a liquid-cooled dirt bike. I was so impressed with their strength and triangulated design, I felt compelled to prove it to anyone reading this review, by supporting the entire bike on just one guard, which neither bent or bowed as it held the bike’s weight (approximately 255 lbs. at the time) with ease.

My thanks to Rick Ramsey and Mark Pettitt for convincing me that we needed to review the Flatland Racing Radiator Guards. They were right!

Note: Flatland Racing also offers other products for Honda CRF’s, to include a $24 wheel spacer (#21-11) to replace the stock CRF250X odometer drive unit, a nice thing to have for those of us who dumped the stock odometer in favor of a Trail Tech computer.

CRF's Only Review by Gordon Banks, January 2005
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