2009 Honda CBR600RR C-ABS Review - Motorcycle.com

Judging by the sound of crickets when I asked American Honda’s Millar Farewell, Assistant Manager of Technical Training, if this CBR system will soon be found on the aforementioned touring and sport-touring models, the reasonable assumption is indeed it will. Likely it won’t be identical, as the CBR system is optimized for sportbikes. However, in short, this newest C-ABS is simplified, smarter, faster and lighter in contrast to the existing system, so it’s likely Honda will apply a variant across other models.

Imagine a traditional brake system. When you apply the brake, fluid travels directly from the brake lever/master cylinder through brake lines to the caliper; essentially a straight shot. Hopefully you’ll come to a safe stop in the amount of time or distance you want based upon the amount of pressure you apply to the lever or pedal.

The most basic components of the typical ABS are: wheel-speed sensors, pressure control valve(s), and an electronic controller (ABS brain). With ABS, instead of fluid traveling straight from the lever/pedal to the caliper, it now first passes through a control valve, then out to the respective calipers. Under normal circumstances fluid moves uninhibited from the lever through the control valve and out to the caliper; just like a standard system but with the extra path through the control valve.

The electronic controller unit comes into the picture by monitoring wheel speed via sensors on each wheel, constantly looking for unusually rapid deceleration. The ABS brain knows, based upon parameters programmed into it, at some point in that rapid deceleration the wheel will “lock-up.”

Before this can happen, the ECU will close valves in the control valve unit, allowing pressure in the brake to drop enough in order for the wheel’s speed not to stop. At that point the brain will re-open the control valve for pressure to build again, in essence allowing another attempt at stopping.

The basic premise of ABS is that the brain plays gate-keeper between the pressure control valve unit and the brake caliper, taking its cues from wheel speed, opening and closing valves in order to decrease and increase fluid pressure. It usually does this faster than a wheel can change speed significantly, cycling at some where around 15 times per second. Often, anti-lock systems also employ a pump to assist in rebuilding pressure in the brake line(s) as well as a few other components.

There’s ABS, then there’s Honda C-ABS

Honda reminds us that traditional ABS and combined braking ABS on bikes use extra components, like a delay valve, pressure control valve, a fork-mounted secondary master cylinder and special 3-piston brake calipers. What makes this new system exceptional is that Honda was able to do away with those extra clunky bits, using a traditional caliper in the process. In the case of the ’09 CBR600RR (regardless of C-ABS option or standard brake) that traditional caliper is now essentially the same mono-block radial-mount caliper that’s on the CBR1000RR. Nice upgrade.

One of the biggest challenges to applying C-ABS in the case of the CBR models is their short wheelbase and high CoG. As you may have seen in race photos, or even experienced for yourself, hammering the front brake on a modern sportbike will have the rear wheel skyward in no time. C-ABS dramatically reduces unwanted chassis pitch from heavy braking.

In keeping with the mass-centralization philosophy of Honda sportbikes, the C-ABS components were located in places that didn’t negatively impact the bike’s handling. Despite their best efforts, one minor change, relocation of the shock reservoir to the left side rail of the subframe, was needed to accommodate placement of the rear power unit.

By now you’re probably wondering how much extra weight the C-ABS CBR600RR is carrying around. The system adds approximately 22 pounds to the honest-Indian curb weight of the non-C-ABS model’s 412 pounds. Honda did what all the other OEMs do: bought competitor’s bikes.

Forgetting ABS for a minute, let’s take a simple look at how this new system functions.

When you put the squeeze on the front brake lever or rear brake pedal, fluid from the respective lever/pedal master cylinder travels to the valve unit in which pressure sensors relay info to the ECM about how much pressure you’ve applied. The ECM then signals to the power unit. This power unit is a motorized gear-driven ball screw that operates a piston (think of it like the piston in the master cylinder) to apply brake fluid pressure. Fluid then travels out of the power unit, back through the valve unit and out to the caliper(s).

New C-ABS for Dummies: brake lever to valve unit; valve unit signals ECM; ECM signals power unit; power unit applies pressure back through valve unit and out to caliper. You stop.

If you’re starting to think about this system and realizing that your squeezing on the lever isn’t really applying pressure to the caliper, you might be wondering how, or if, you get the same feel at the lever as you would on a traditional system. Inside the valve unit is what’s called a stroke simulator. The simulator is a pair of “rubber cushions of differing density that returns increasing amounts of resistance [to the lever or pedal] as brake lever/pedal pressure is applied.” Think of it like a flight simulator for the brake lever.

So how did Honda put the sensation of traditional brake feel into two tiny pieces of rubber? Only the staff in Japan knows precisely how, but helping assess the feel required to mimic regular brakes was partially the work of Honda development riders and former racers, Jeff Tigert and Doug Toland. Both gents have countless hours of development time in Honda street motorcycles, and as Farewell said, “When you ride a CBR C-ABS, a little bit of Doug and Jeff is riding with you.” That’s quite reassuring, especially if you’ve witnessed how quickly those two racer-types can lay down lap times.

The use of the word “combined” rather than “linked” in this new system is noteworthy, and here’s why.

On the Gold Wing, for example, when applying the front brake lever, fluid pressure will actuate two outer pistons in each 3-piston front caliper. As more pressure builds, through the use of the aforementioned delay valves, secondary master cylinder, etcetera, fluid will then travel through a “proportional control valve (PCV)” to the rear caliper, activating it as well.

Similarly, when the rear brake is activated, fluid pressure will be applied through the PCV, first to the middle piston of the left front caliper, then as more pressure builds, over to the right side front caliper’s middle piston. Voila! They’re linked!

This is entirely a mechanical system, and as a fail-safe, if one piece of the puzzle fails, the remaining parts of the system are still operational. Furthermore, it is independent of ABS. Because the brakes are connected hydraulically, it truly is a “linked” system.

With this new combined system, there is absolutely no mechanical link, or otherwise, between the front and rear. It is entirely up to the electronic control module to determine when more than one brake set is required. So not only does the ECM regulate pressure to each brake set, it also can “combine” front and rear brake sets based upon established parameters. Therefore, we now have the first brake-by-wire system available commercially on sportbikes.

According to Farewell, this updated C-ABS’s ECM reacts three times faster than the ECM on the VFR. The new system has to react faster by virtue of how much quicker things take place on the typical supersport machine. Additionally, thanks to the seamless anti-lock activation, the rider has no sense of its use until approximately the last few feet before stopping when a small amount of vibration, or shudder, can be felt through the chassis. And this is only because now that the bike is slowed to that point it’s possible to perceive some feedback. This occasional sensation is so minimal that it will likely go unnoticed by most riders.

Skeptical of a computer doing all the thinking for you? A fail-safe system determines that C-ABS is all or nothing. If any one point in the system self-check fails, the entire C-ABS essentially shuts down, leaving all valving open and free flowing, thereby reverting to a traditional, non-ABS brake. Also, don’t forget that this system is tailored to supersport riding and is far less intrusive than some ABS haters may think it is. Unlike some of the current ABS on BMW bikes, Honda C-ABS cannot be manually disabled.

When the system sees that you’re really crushing the brake lever in a feverish attempt to stop, it will then apply a degree of rear brake based on a predetermined pressure value from the front, regardless of ABS activation. You could do this on a conventional system, but most riders don’t have the skill necessary to match the speed and precision of the electronic system. Applying some level of rear brake will cause the rear suspension to compress, thereby helping stabilize the chassis, achieving one of the primary goals of employing C-ABS on a supersport.

When using the rear brake only, the ECM doesn’t bring the front brake into action until the rear brake is near the point of lock-up. This, says Farewell, is different than current linked systems that include the front brake much sooner. This allows a rider to use the rear brake much like a non-combined system. This could come in handy, for example, during sporty stints when the rider might use the rear for trail-braking.

Talk is cheap

In order that Honda may prove to the world just how special this new C-ABS, American motorjournalists were invited to the company’s North American R&D facility somewhere between the high-desert terrain of Mojave, CA and the middle of nowhere. Security is tighter than a crab’s tushy. After passing through the first security checkpoint, and a security escort straight to our destination, I felt like maybe I wasn’t on U.S. soil any longer…

Testing the bike would take place on what Honda calls the Winding Road course, a 4.5-mile circuit designed primarily for evaluating autos. It’s meant to simulate real world conditions. It has elevation changes, decreasing radius and banked turns, varied pavement surfaces, painted lines, and purposely placed pot holes and bumps.

So what would make an ideal testing situation for an ABS package? How about a naturally slickened surface courtesy of two days of rain? Consecutive days of rain are something of an anomaly in that region of the Mojave. The power of Honda…

After a sighting lap or two we were cut loose. Despite the potential of the new C-ABS, my hundreds of thousands of miles of riding in the wet without the benefit of ABS have thoroughly and wholly hard-wired my brain to avoid crushing the lever in such conditions. Nevertheless, Honda staffers assured us that when we were ready to abandon braking convention and discard our sense of self-preservation the new C-ABS would be waiting for us with open arms.

We weren’t there to perform the typical critique of a bike’s power and handling prowess, so going fast wasn’t my focus. However, when a corner approached or the initial ascent of a hill was spotted, I did my best to ply the front brake as recklessly as I could convince myself to. ABS aside, the CBR1000RR-like calipers provide excellent feel and very linear rotor crushing power. Anyone purchasing an ’09 CBR600RR without the optional C-ABS will nonetheless be rewarded with outstanding brakes.

My report on ABS on the road course is that it operates exactly as advertised. Absolutely no pulsing commonly experienced on many anti-lock systems was transmitted back to the lever or pedal, and only the slightest shimmy in the chassis could be felt in the last dozen or so feet before coming to a complete stop. The system is simply and wonderfully seamless. Period.

Moving over to the skid pad, one in our party had the brassy orbs to suggest purposely flooding the pad beyond what moisture had already been deposited from the sky. Foolish? Perhaps. Completely safe and manageable with the CBR’s C-ABS? Absolutely!

With more than an inch of standing water, residual mud, sand, and grit runoff, as well as painted lines, the stage was set for a spectacular crash.

Reaching speeds of around an indicated 100 mph in a very short distance followed by the hardest squeeze I dare apply resulted in nothing more than coming to a stop. A stop, I should add, that obviously required more distance than what it would have on a drier surface, but the C-ABS provided the best stop possible in that situation.

Indeed, too, it was much more apparent in this flooded environment that ABS was working, as the feeling of the rear tire slowing and then accelerating was obvious. Still, though I was conscious of this near-crash scenario, I was instilled with that cliché ever-present in moto reviews: confidence.

The best Supersport brakes?

People, this system works incredibly well. It’s a tad too early to say with impunity until we get our hands on the other players in this arena, but I’m hedging that the 2009 Honda CBR600RR C-ABS has the best brakes in class. For all my riding and braking experience, if I were in the market for a CBR600RR, I absolutely would opt for C-ABS.

MSRP for non-C-ABS models is $9,799; C-ABS models will be $10,799.

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2008 Honda CBR1000RR Review
2008 Supersport Shootout
2007 Honda CBR600RR Intro Report
Honda outlines three-year plan
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