Honda CBR1000RR Traction Control and Chassis Upgrades | Literbike Mods

Part Two in a series of modifications to our Honda CBR1000RR test bike

The Hotbodies Racing bodywork took some time and effort to install and prepare for paint, but the work paid off: John Reeves’ CBR looks fantastic with this retro paint job that recalls the HRC Interceptors from the early ‘80s.
The aluminum oil filler cap is made by Sato and is predrilled for safety wire. The Akrapovic exhaust canister is titanium-wrapped and has a carbon endcap and carbon mounting bracket.
The Sato rearsets offer plenty of adjustability and their knurled pegs are plenty grippy. Shifting can be changed from street to race simply by moving the lower attachment point of the shift shaft. Note Sato engine cover on this side as well.
The Akrapovic header system has the company’s typically fine craftsmanship, and snakes around the sump with plenty of clearance. Note the Sato engine cover made from aluminum with a replaceable nylon pad. The Hotbodies bodywork required some trimming to clear the exhaust.
The traction control map shows a level of sensitivity from 1 to 10 in each cell of the rpm/throttle position array, a level of cut at each throttle position and a level of trim for each gear.
The CBR spent some of its time on Continental’s ContiRaceAttack Comp tires, the company’s DOT race tire that has a continuous compound that changes over the surface of the tire, rather than being split into two or three distinct compounds. Note that the Comp tire differs from the Street version, and is available in three compounds.
We also used Bridgestone slicks for some of our testing. As we’ve noticed in previous tests using traction control, the rear tires showed a very favorable wear rate even after a day at punishing Willow Springs.
This screen shot of data from a lap of Willow Springs shows speed (black) and when the Bazzaz traction control is active (blue). Adding in rpm and throttle position allows the TC to be fine tuned for a specific track or even rider.

In part one of our Literbike Mods series (July 10) we featured John Reeves' 08 Honda CBR1000RR and the Bazzaz Z-Fi system, which we installed and set up for use. The purpose of the project was to experiment with the Bazzaz system and its traction control module, which is almost infinitely adjustable, to find more speed at the track. Much of our experience with traction control in the past has shown that it results in slower rather than faster lap times, and it is obviously not the magic go-fast aid that many riders wish for. Since that first installment, we've added some chassis modifications to the CBR, attended several track days, and made good progress with the traction control.

Since John planned to attend track days regularly, we gathered up some appropriate modifications for the CBR with that in mind. Many riders feel that the stock steering damper, which adjusts electronically based on road speed, is too stiff even for the race track. We ordered up a GPR Stabilizer V4 Sport unit, which mounts in place of the stock damper and offers a wide range of 20 adjustment clicks. The $495 stabilizer is available in five colors, installed quickly and easily, and provides damping from barely any to more than enough for even the roughest track.

We sent the CBR’s forks and shock off to RG3 suspension to be freshened up and modified to better suit track use. The $479 service involves revalving the stock components, installing springs matched to the rider’s weight and ability, and refilling everything with Maxima fluids. This is a cost-effective alternative to a replacement shock and fork cartridges, and the improvement was noticeable immediately after bolting the components back on the bike. The suspension is now noticeably stiffer, but more compliant over rough pavement. While we were impressed with the RG3 upgrade especially considering the price it’s worth noting that keeping the stock shock limits setup options as there is no way to adjust the Honda’s rear ride height. With most bikes you can use shims in the top mount to change ride height, but not with the Honda’s Unit Pro-Link setup.

While the suspension was out being serviced, we bolted up a set of Sato Racing’s beautifully made rearsets and the company’s engine slider kit. The $595 rearsets, offered in black, gold or silver, are adjustable to 12 positions and work with either street- or race-pattern shifting. The footpegs are deeply knurled for extra grip and the pedals mount with bearings to make shifting (and braking) effortless and sure. The $199 Sato engine covers mount over the stock covers, making installation a snap and adding some security for the engine. The sliders have replaceable nylon sliders on anodized aluminum mounts, are nicely machined and look plenty sturdy should the CBR end up on its side.

To finish things off, we replaced the stock bodywork with a set of Hotbodies race bodywork and a Hotbodies windscreen. The $805 race bodywork, fashioned after the HRC kit used by the Ten Kate World Superbike team, includes an upper, lower, tailsection and tank cover. Elsewhere in this issue, we have a very positive review of a set of Hotbodies bodywork for a Kawasaki ZX-6R (see SR Tested), but the CBR bodywork required a full day of work to fit and prepare for painting and even a couple of additional brackets to be made. A call to the company revealed that the HRC kit for the 1000 will definitely need trimming to fit any exhaust, as the WSB team requires an ultra-tight fit for maximum cooling effect. As well, the company upgraded its process last year to include a better primer base for painting; our set was made previously to the upgrade. We also installed a $70 Hotbodies dual radius windscreen, that is one-inch taller than stock with a more pointed shape for better aerodynamics.

We touched on the Akrapovic exhaust in part one, but we’ll recap here: The $2226 Evolution system is a 4-into-2-into-1 race exhaust made from almost all titanium. Scaling in at just 11.5 pounds, less than half the weight of the stocker, the pipe was a bit finicky and required a test-fit on the workbench to see how it all went together before the actual installation. Still, fit and finish is excellent and up to the company’s usual standards. The final modification we made was to tap into the Bazzaz Z-Fi system and access an output signal that shows when the traction control is active. We fed that into John’s data acquisition system, which also monitors speed, rpm and throttle position, and planned to use the combination of data to better dial in the traction control.

We started at a Buttonwillow track day hosted by The Track Club, using Continental ContiRaceAttack tires. We know from previous experience that the Contis offer excellent grip and neutral steering, and John agreed after riding the CBR, although he noted that stability was an issue. Continental is definitely closing in on the major players with its race tires, and is now offering trackside support at races and track days to match. We sourced our set of medium-compound ContiRaceAttacks through Superbike Tires, the west-coast distributor.

We also attended a Motoyard track day at Willow Springs with a set of Bridgestone slicks in YCX (the middle of three) compounds. John was quite impressed with the Bridgestones, comparing them favorably to the Continentals and even to other DOT race tires he later tried on the CBRas you’d expect from slicks. Still, the Bridgestones offered incredible traction and exceptional stability at high-speed Willow, and seemed well suited to the CBR. Part of the explanation is that the Bridgestones are physically bigger tires and give the bike more favorable geometry.

The CBR is loads of fun to ride in its current state, and steady work over a few track days resulted in the accompanying traction control map. We worked on the premise that less is better, turning the sensitivity and cut down where TC is not needed but the system showed it to be active. For example, at combinations of high rpm and with the throttle significantly open, it’s a safe bet that the rider is on a straight and less TC is needed. But small throttle openings represent a cornering situation, where more TC is needed. We also found that less TC was required in the higher gears, and in the map shown here turned it almost completely off in first gear as there are no first-gear turnsin a race situation, that would allow for the best launch off the starting line. We seem to be heading in the right direction; at the last track day, John and our man Bradley both rode the bike, turning their fastest lap times with more overall TC dialed in than less.

With this project coming to a successful close, we’ll have to turn our attention to something else. Not to worry, though; John Reeves is an adventurous guy, and we’re sure another literbike will be along for us to experiment with before too long.

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While peak torque is down slightly from stock and the modified CBR makes a bit less power near the original peak, the modified bike carries on for almost six more horsepower than stock. Some of that is due to the Akrapovic exhaust, and some due to the Bazzaz Performance Z-Bomb, which removes the CBR's top-end restriction by tricking the ECU into thinking the throttle is not fully opened.

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RESOURCES
Akrapovic
www.akrapovic.com

Bazzaz Performance
(909) 597-8300
www.bazzaz.net

Bridgestone
(800) 543-7522
www.motorcycle-karttires.com

Superbike Tires (Continental)
(408) 881-3274
www.superbiketires.net

GPR Stabilizer
(619) 661-0101
www.gprstabilizer.com

Hotbodies Racing
(858) 486-3838
www.hotbodiesracing.com

Motoyard
(800) 830-2815
www.motoyard.com

RG3 Suspension
(714) 630-0786
www.rg3suspension.com

Sato Racing
(831) 899-1822
www.satoracing.com

The Track Club
(408) 723-2099
www.thetrackclub.com