Sunday, March 13, 2011

2008 Yamaha YZF-R1 Project Bike Part 2

2008 Yamaha YZF-R1
For Phase 2, we re-worked the suspension and added an adjustable steering damper. We also installed new brake pads and lines and finished it off with a set of sticky race tires.
Sportbike ownership is all about hopping-up your ride. In Phase 1 of our Yamaha YZF-R1 endeavor, we hit it with some affordable accessories out of Yamaha’s GYTR accessory catalog. The parts are simple to fit and after installation we were surprised by how easy it is to set your R1 apart from the stockers on the street.

In the performance department, we installed a pair of sweet sounding GYTR Carbon Fiber Mufflers and also fitted a Bazzaz Performance Z-Fi TC fuel-injection module. The Bazzaz module incorporates engine fueling adjustment on all eight fuel-injectors, a quickshifter and adjustable traction control bundled into one package. To make sure we had the grip for either the streets or the racetrack we slung on a set of Bridgestone’s versatile, multi-compound Battlax BT-016 performance street tires.

The upgrades we made increased the R1’s overall drivability and made the riding experience more engaging. However, for the next phase we wished to push the performance envelope further, especially on the racetrack.

To do this, we began by upgrading the R1’s suspension. Up front the Kayaba fork was reworked, while we opted to replace the Soqi rear shock along with the non-adjustable steering damper. In the braking department we added stainless-steel brake lines as well as more aggressive brake pads. To make sure that we’d be able to take full advantage of the changes we fitted a set of DOT-labeled roadrace tires.

Put a Fork in it
2008 Yamaha YZF-R1
On the street, the suspension modifications we made resulted in a substanitally firmer ride. Also noteable was the smoother action when the suspension compressed.

Besides a premium set of tires, arguably, the most worthwhile upgrade you can make to your motorcycle is in the suspension department. But with so many suspension tuners to choose from, it can be tricky to find the one that will work for you. We set our sights on the folks over at Traxxion Dynamics because they have perhaps the biggest asset in the black art of suspension tuning—experience. The crown jewel of their operation revolves around their proprietary Axion valve developed during the past decade on racetracks all across America. Axion valving technology trickles down to the consumer in the form of their AK-20 cartridge kit.

The drop-in kit (available for a wide range of motorcycles including nearly all-contemporary sportbikes) consists of two cartridges (one for each fork leg), springs, spacers, compression and rebound needles as well as oil. Some applications (including our Yamaha R1) include fork extenders that add 10mm of travel. The parts are designed to replace the stock internals and have been engineered to improve suspension action, road surface feel and resist bottoming effect. Another benefit is the increased level of adjustment. Lastly, the entire kit is modular, meaning it can be taken out and reinstalled on a different motorcycle if so desired.

For installation, it’s recommended that you deliver your fork to one of Traxxion’s approved service centers or to their headquarters outside of Atlanta, Georgia. For a $150 fee, a technician then disassembles the fork and installs the AK-20 kit based on information provided by the rider, including their weight, skill level, and type of use, i.e. roadracing, trackdays, street, etc. Turnaround time can vary depending upon season, but typically work can be completed in less than five business days.

Out on the street, the difference in performance compared to stock is night and day. Most notable is the smoother, more responsive movement through the fork’s entire stroke. Equally impressive is the firmer feel, especially during the initial and middle part of the suspension's stroke. Although it’s difficult to notice if you’re just cruising on the street, at an elevated pace the level of road feel delivered by the fork is considerable. In fact, it takes time for your brain to acclimate to how much feedback is delivered through the handlebars. But when you finally do, you’ll not only be able to push the motorcycle harder, but you’ll gain substantially more confidence in the motorcycle due to its increased interaction with the rider. After just one ride, you’ll never want to ride on the stock stuff again.

2008 Yamaha YZF-R1
Out on the closed-confines of the racetrack, the Traxxion fork mods and Penske Racing rear shock not only delivered an enormous amount of road feel but also allowed the R1 to be ridden much more agressively than stock.
Shocking, isn’t it?

As opposed to modifying the stock Soqi shock, we opted to replace it with Penske Racing Shocks 8987-series Triple Adjustable shock absorber. The Penske piece features an aluminum body and has a very high-quality look and feel. Each shock is built to order with a steel spring matched to your riding weight ensuring that the shock will be tailored just for you. Before it leaves the factory, it’s tested on the company’s dyno ensuring proper functionality. The results are included in a graphic format, which illustrate its damping ability.

Similar to the stock Soqi piece, the Penske features adjustable spring preload, separate high/low-speed compression and rebound damping. But that’s where the similarities end. With the Penske you get the ability to a adjust ride height (+/-12mm), allowing you to compensate for different tire sizes and profiles. The range of spring preload and clicker adjustment is also substantially wider and also more precise, providing 30/18 clicks of high/low-speed compression and 34-clicks of rebound damping adjustability. Lastly, the shock is rebuildable and its internal settings can be modified based on your needs.

Before you hit the streets, Penske recommends you set the shock’s sag for optimum performance (see sidebar). With preload set at the recommended racetrack setting, cruising down the street reveals a substantially firmer ride, which for some will border on being too firm. However, simply remove a full turn or two of preload via the supplied tool and everyday comfort is restored.

But posing around the street isn’t what Penske’s shock is designed to do. At a speedy street pace or on the racetrack, you can’t help but notice the vastly improved action, rear-end feel and subsequent increase in control afforded by the shock. With the stocker we’d routinely run out of adjustment limiting how quick we could lap. Another problem was the inability to deal with excessive tire wear. Fortunately, with the Penske, no matter which racetrack we ride at, there’s always plenty of adjustment to get our lap times down while compensating for tire wear.
2008 Yamaha YZF-R1
We replaced the R1's non-adjustable steering damper with GPR's 20-way adjustable V4 Road Stabilizer.

Fine tuning the shock’s preload and either compression adjustment clickers is especially simple. On the other hand, accessing the rebound adjustment knob located on the bottom of the shock body is tight and can be really difficult to adjust when the bike is hot due to the close proximity of the exhaust pipe. Nonetheless, if you’re serious about riding you’ll appreciate the advantages of Penske’s shock.

Steering Clear

In most conditions, the stock steering damper does a great job of smoothing out headshake. But the subsequent increase in velocity afforded by our track-spec suspension combined with more aggressive turning Bridgestone race tires (more on that later) means we’re pushing the performance envelope of some of the stock components, like said steering damper. And that’s where the GPR V4 Road Stabilizer comes in.

As opposed to the non-adjustable linear damper, GPR’s is a multi-way adjustable rotary damper. Inside, it features only four moving parts. An impeller pushes fluid through a port based on handlebar movement. A Barrel-style adjustment knob on top of the damper opens or closes the port making it easier or more difficult to move the handlebars from side-to-side. The entire unit is tiny, measuring only 3-inches square and weighing right around two pounds. It’s constructed from billet aluminum and GPR stands by its product offering a lifetime warranty on the unit and a 90-day warranty on the seal. And if the seal ever does fail, just send it back to GPR and they’ll replace it for a $25 service fee.

Galfer brake lines come in a kit ready to install.
Galfer USA's DOT-approved stainless-steel braided brake line kit is designed as a direct replacement to the stock rubber brake lines. With a set of metric tools and Mityvac's vaccuum-assist brake bleeder tool installation can be done by the home mechanic.
Brake it Up

In stock form the R1’s front brakes have always left something to be desired. Although they are more than capable of getting you stopped, when used aggressively, they lack the outright power and feel one expects based on the size of the components (six-piston Sumitomo calipers and 310mm rotors). We attempted to solve the problem by fitting Galfer braided-steel brake lines and Ferodo SinterGrip brake pads.

The Galfer brake lines come as a direct replacement kit (front and rear). The brake hoses come preassembled and are already cut to the correct lengths. New copper crush washers and banjo bolts are also included. The hoses are constructed out of Teflon with a stainless-steel outerbraid and are designed to provide less hose expansion and resistance to high-temperatures, thus increasing overall brake feel and performance. Detailed instructions come with the kit and with the right tools, including Mityvac’s brake bleeder tool, installation can be accomplished in your own garage.

The Ferodo pads we installed are a direct replacement to the OE pieces and are designed for use primarily on the street. They feature a full-metal compound that not only increases stopping power but also offers increased pad life and less rotor wear. The pads are a snap to install, plus the bed-in process is as simple as making a few hard stops followed by an immediate standstill cool-down.

To our surprise, on the road the upgraded set-up didn’t offer any more power than stock. However, they do offer more feel, especially when you aggressively pull back on the brake lever. Additionally, that dreaded “wooden” feel that plagued the stock set-up disappeared giving us more confidence during corner entry.

Get Your Rubber Right
The Bridgestone BT-003 DOT-labeled road race tire sports a new tread pattern designed for enhanced performance.
Bridgestone's BT-003 tire replaces the BT-002 DOT-labeled roadracing tire.

Last time we used Bridgestone’s Battlax BT-016 high-performance street tire it surprised us with its performance both on the street and track. However, this time around we wished to try something designed specifically for closed-course use, thus we tried Bridgestone’s all-new BT-003 DOT-labeled roadrace tire.

The new generation race tire replaces the tried-and-true BT-002 model. It comes in three unique compounds: Type 2 (hard), for maximum resistance to wear on abrasive pavement or for use if track surface temperatures exceed approximately 110 degrees Fahrenheit. Type 3 (medium), for less-abrasive circuits and mild track surface temperatures. And Type 4 (medium-soft) for use during cool weather and/or bumpy pavement conditions.

Visually, the BT-003 sports a new tread pattern engineered to work in unison with the tire’s carcass construction for improved overall handling and resistance to chatter. Both the Type 2 and 3 tires make use of an almost identical profile, while the Type 4 utilizes a unique construction that alters the tire’s shape giving it a slightly flatter surface at the tire’s center. Inside, a modified carcass permits the tire to flex more, thereby increasing tire warm-up times, as well as providing superior bump absorption.

To see how the tires worked, we tested them while blasting at upwards of 140-mph on the ultra high-speeds of Willow International Raceway’s 2.5-mile road course as well as the bumpy surface of Willow’s tighter 1.3-mile Streets course.

Yamaha R1 Project Bike Contributors
Lofting the front wheel under power becomes difficult with TC on its maximum setting.

Like the outgoing BT-002 tire, the new Double-Zero-Threes heat to operating temperature fast, even without tire warmers (perfect for a trackday). Both turn-in and stability have always been a hallmark of Bridgestone’s racing tire, so we weren’t surprised by its continued nimble handling attributes and ease of tire-to-bike set-up. We were surprised, however, by how different the medium-soft Type 4 compound front tire is. Lapping around the Streets the tire has the ability to mask pavement irregularities and less than optimum fork set-up, while offering up an absurd amount of grip. They even offer above average tire life as compared to other soft front racing tires. While the rear tire lacked the same amount of grip, like the front, it offered an elevated level of feel so when it did spin, you wouldn’t be surprised.

With its slightly more triangulated profile, lapping around the big track proved that the harder Type 2 tire actually steered quicker than the Type 4 tire. While warm-up times were longer (we didn’t use tire warmers), the grip felt similar and we were surprised just how long the tires lasted—especially the rear, considering how warm it was (track temperature roughly 90-degrees Fahrenheit).

The Final Word

All said and done, we dropped $6,183.03 on our R1. Some might wonder why we doled out all that cash with only a marginal increase in engine performance. However, for the majority of street and trackday motorcyclists (myself included) a modern liter bike’s 150-some horsepower is more than enough to get the blood pumping. Plus, even in stock form, as a whole, the most high-performance component within the motorcycle is the engine. Therefore, it only makes sense to spend the cash on other pieces, such as suspension, brakes and tires, which have the ability to achieve the largest gains in terms of feel, control and comfort. And that’s just what we did with our R1.

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