Hybrid cam drives
I have noted in many pictures of the new hybrid gear/chain valvetrain system of the 2012 Ducati Panigale that the ratio between the two sprockets connected by the chain doesn’t look like a 2:1 ratio. Do they compensate the difference with the gears’ ratio to spread the big pulses of the power stroke of the V-twin throughout the full length of the chain, to prolong its life, considering the different nature of the V-twin to an inline four?
Sal Costabile
Ottawa, Ontario

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The Geek
831 S. Douglas St., El Segundo, CA 90245 or e-mail srmail@sorc.com

Hayabusa Rear Tire Size and Profile
I’ve read on Hayabusa sites about the benefits of XXX/55 profiles over the standard 190/50. Would it really be worth the effort to change ride height for geometry and gearing? The 190/55 profile is 16mm taller (8mm on the radius) than the 190/50 Battlax BT-016 Pro. There are those claiming that using a 180/55 has other benefits: The tire’s taller, narrower profile lays down a lot more rubber when banked over, improving traction. It’s lighter, so it accelerates and stops faster. The reduced gyroscopic effect makes the bike feel lighter and flick quicker, requiring less steering effort. It’s slightly taller, increasing your top speed slightly. And it costs less. They also go on to state that as 190/55 street compounds become more available, they offer many of the same benefits. To me the difference between comparable-compound 180 and 190 sizes is mainly tire weight. I know there have been other similar questions about this, but what are the definitive pluses and minuses in reference to fork angle and geometry, ride height, the obvious gearing difference, handling gains or losses and any possible fitment interferences?
Steve Saunders
Cleveland Heights, OH

Images and information from Dunlop's press material

Images and information from Pirelli's press material

How many miles from an FZ1?
I have owned my 2006 Yamaha FZ1 since new, and it’s been ridden in every state west of the Rockies including British Columbia, Yukon, and Alaska. It’s quick and comfortable and in short has been the best motorcycle I’ve ever owned. The odometer this past weekend clicked over the 70,000-mile mark. It still runs like new and I hope to get another year out of it, but the clock is ticking. I don’t think I’ll have the funds for a new one in that time. Since the model is essentially unchanged would I be foolish to have the engine overhauled? Who would you recommend to do it?
Larry Johnson
Phoenix, AZ

Wide Tires on Narrow Rims — again
I have read that the AMA XR1200 racers are forced to use one race tire on the rear, a 190/55 on a 5.5-inch rim. I have read your article on the cons of using a 190/50 tire on a 5.5-inch rim due to profile issues with the smaller rim, and seen your graphs that illustrate this issue. However, if this is the case on the lower profile tire how does this change on the 190/55 tire? Moreover, if it is still unstable why does the AMA require the XR1200’s to use this tire on the racetrack? Of course, now I will ask the “other” question: how will this tire work on my ‘07 Suzuki GSF1250, which also sports a 5.5-inch rim.
Mark Miller
Via SR mail

Anthony’s Suspension Woes
I have a 2009 Yamaha FZ1 with a Penske 8983 and the stock fork tweaked—read “clicked-out by my local suspension guy.” The forks are showing 6mm above the top triple clamp, the shock is 6-7mm of threaded rod out of the ride height adjuster. Yes, I know you need to know how much longer that is than stock but that’s all I have for you now. With this setup the bike seems like it still wants to run wide in the fast stuff, leaned over, knee on the deck. What would you suggest for a geometry set up? I weigh about 220 pounds with gear, and am at 35mm of sag in front with the preload cranked all the way in, 30mm rear with a 625 lb/in. spring. I know I need new springs in the front, but do I need a re-valve? A cartridge? Someone told me to junk the front end and go with an 06-08 R1 setup.
Anthony
via SR Mail

At a glance, designing and building a traction control system is easy: Monitor front and rear wheel speeds, and cut power if the rear wheel goes faster than the front. And from a safety standpoint — preventing a crash — a basic system is quite adequate. Traction control for performance, however, is a different story. Racers have long used wheelspin to help the motorcycle finish a corner, and it’s well known that tires provide more grip if they are spinning a certain amount. These contradictory goals of safety and performance have led to increasingly advanced systems, with additional sensors, feedback and signal processing aiming to provide both benefits in a single system for sportbike use. Recent patents and patent applications published by the United States Patent and Trademark Office show how various manufacturers have developed their systems for better performance as well as safety.

Suzuki SV and TL Models
I have been trying for some time now to find out if I can replace my Suzuki SV1000 cams with TL1000R cams and if there is any performance to be gained by doing this. I cannot get any information from Suzuki, not even cam duration/timing figures on either model.
Mario Pin
via SRmail

Crooked Tires
I recently changed tires on my Ducati Monster 620 and noticed the old front tire has worn at an odd angle, with more wear on the left side. Does this mean there’s a problem with the tire or my bike?
April Trestick
El Segundo CA

I saw in the May issue that you are testing the Antigravity lithium-iron Battery in the Yamaha R1. I also saw, on the next page, the Shorai LFX lithium-iron Battery. I am not familiar with the qualities of the lithium-iron. However, lithium-ion batteries can and do catch fire if they get to thermal overrun. In brief, if the lithium-ion gets to about 350 degrees Fahrenheit, it will run away. Many bike batteries are housed near hot exhaust. It would not be unreasonable for a battery — given internal heat from charging, a hot day or being stuck in traffic — to reach this temperature. I was wondering if there is some characteristic of the Li-Fe battery that would prevent a thermal runaway? Saving weight is great — but not if the ride catches fire.
Tim Berridge

Making motorcycles better, safer, and more fun to ride with innovative developments has been one of the BMW Motorrad core competences for decades. As the leader in this technology, BMW Motorrad presents new solutions in quick succession that usually soon become indispensable in series motorcycles. Now a new step in development is in the offing: the semiactive suspension control system Dynamic Damping Control, in short DDC.

BMW Motorrad – competence in suspension innovations and control systems.
As early as 1986, BMW Motorrad achieved a milestone in suspension technology by launching the Paralever swingarm, an innovation that considerably improved rear suspension and the transfer of forces. In 1993, the freshly launched opposed twin “boxer” engine series was the first to be fitted as standard with a front suspension system that operated independently of the rear known as Telelever. Yet another revolutionary step in suspension technology was taken in 2005, when the Duolever offering extreme torsional rigidity for the front wheel was launched.

Bikers were also able to benefit early from pioneering innovations in drive control. In 1988, with the launch of ABS in the BMW K1, BMW Motorrad presented the first antilock brake system to be fitted as standard on motorcycles. Since 2007, the automatic stability control system ASC has been preventing the rear wheel from spinning out of control. In 2009 there followed Dynamic Traction Control (DTC) which also analyses the vehicle's inclination, a first on a series production motorcycle.

And BMW Motorrad has always been that one step ahead in suspension control systems as well. 2004 saw the advent of ESA, the electronic suspension adjustment system, which allowed the rider to adjust suspension elements at the push of a button – also a first on series production motorcycles. In 2009, the successor system ESA II went a step further and was the first to provide spring rate variation.

When setting a bike up for roadracing track work is there any rationale for scaling the bike wheel weights with the rider on, similar to what one would do with a racing car?
Rex Svoboda
Missoula MT

Bandit Butterflies
I have a Suzuki Bandit 1250. I’ve read a lot on many of the forums online where people are removing the secondary butterflies in the throttle bodies for improved performance. Why are these secondary butterflies installed on modern bikes? Is removing this system mechanically safe for the motorcycle? Can I cause myself future damage by doing it?
Peter Kwentus
St Louis, MO

At the end of each MotoGP season, Yamaha has released a technical document detailing that year's M1 and its continued development. 2010, however, was the end of an era as Valentino Rossi has now left the company and Masao Furusawa, long considered the architect of the M1, is set to retire. To mark the occasion, Furusawa presented a historical presentation at the end of the year outlining key engine and chassis features of the seven M1 models Rossi had ridden.

Mythbusters
My buddy and I were discussing tire pressures when he hit me with this information gleaned from the web of infinite truth and limited facts: Japanese sportbikes seem to have an extra 4-6 psi specified for their tires, compared to the equivalent Ducati. Why? To answer the question about higher recommended tire pressures for Japanese inline fours versus Ducati twins - inline fours heat up their tires more than a twin so a higher starting pressure is needed to prevent overheating the tires, particularly the rear tire. Years ago, superbike racers discovered that it was easier to modulate the power to prevent wheelspin on the Ducati V-twins than it was to do the same on the Japanese inline-fours. This is because there is a longer interval (in terms of both time and crankshaft rotation) between cylinders firing, which gives the rear tire a "break" - time to recover traction and match its speed to that of the motorcycle. More recently, more sophisticated traction control systems have been tried to reduce tire temperatures, improve tire life and lap times. The InterWeb is full of junk (with exception of your fine web publication), so I thought I would ask you guys to check the veracity of this information.
Darron Fuller

My track-day bike is a '99 Yamaha R6 and my street bike is a '10 Ducati Streetfighter. I don't ride on the street anywhere close to the way I ride on the track, so I end up wearing out my Streetfighter tires in the middle and I wear the R6 tires on the edges. I change/balance the tires myself and I go through at least two sets of Michelin Power Ones on my R6 per year depending upon the number of track days. What are your thoughts on putting the track-day take-offs onto the Streetfighter? I realize these Power Ones have little siping and are primarily for the track, but tires are expensive and my Streetfighter is for weekend rides and not commuting or sport touring where there is a higher chance of encountering rain.

New-Bike Break-In
I purchased a new Kawasaki Z1000 on Saturday and am in the process of breaking in the engine. My owner's manual says to keep rpm below 4000 for the first 500 miles, and below 6000 for the next 500 miles. I have two questions. First, I am curious to know why modern motorcycle engines require a break-in period, while modern car engines do not. Is there something different about the manufacturing processes or materials used in car engines? Or are car engines broken in at the factory? Second, I am curious whether Kawasaki's break-in guidelines are too conservative. Many sources on the internet recommend a much more aggressive break-in procedure; they claim that if a new engine is driven too timidly, the rings will not seat well and compression will be lower than optimal. What is your opinion on the optimal break-in procedure for a typical street rider?
Vic Anand
Lansing, NY

Materials 101
Please explain the differences between 7075-T6 aluminum alloy, 6061-T6 billet aluminum, 2024-T3 billet aluminum, titanium, and Inconel alloy 625. What is the advantage of one over another in a given application, such as rear sprockets?
B. David Bland
Germantown, MD

I recently purchased a 2008 ZX-14. I had no problems getting the shock set up but when it came to adjusting the fork I was completely puzzled by the results I was getting. By running the adjusters through the extremes of adjustment my useable range of sag was between 42mm and 56mm. Typically, I set sag to 30mm front and rear. I have set sag on the numerous sportbikes I have owned over the past 26 years and have never encountered anything like this. I searched the Internet and the only real information I found was on Race Tech's site. The info leads me to believe I have encountered what's known as "top-out" springs. I have read the Race Tech tip "Sport Bike Relaxed Preload" but it is still unclear to me how I go about setting up fork sag properly on this bike. Race Tech says the bike has a long top-out spring and "this requires 20mm relaxed preload minimum". Does this mean I just deduct 20mm from my calculations to get the correct sag? I am not sure how to go about setting the fork sag on this particular bike, could you enlighten me?
Dan Forest
Goffstown, NH

Ducati brakes
I have a 2005 Ducati 800 Supersport track-only bike. The previous owner was a very experienced racer and installed an aftermarket Brembo 19x18 radial master cylinder. It is ferocious. It brakes with amazing violence and I love it, except that there is very little lever travel from no brakes to full brakes. That provides little feel for me and I was looking for something with similar power, but more lever travel. One shop recommended the 19x20 Brembo while another thought the 16x18 Brembo was the way to go. Could you offer your thoughts and explain how all this works?
Mark Roberts
Tecumseh, MI

VFR1200F Intrigue
When Honda tells us that having the rear cylinders' conrods on the inside of the two forward ones on the new VFR1200F, I can only swallow one of their explanations: That it eliminates the small rocking couple from staggering the rods on the same sides. But this part about "making the rear cylinder bank narrower" has me scratching my head. Unless the center crank journal has to be wider than on an inline-4, wouldn't the cylinder bank's width be determined by the minimum wall thickness between the bores? Am I right or does the center journal actually need to be wider than I think?
John Gregory
Fairview OR

Fork Oil Height And Scooter Brakes
If I do not want to increase front preload, but do want to reduce the chance of bottoming the fork, I can increase the level of fork oil. Is there a safe limit of air gap at the top of a fork with springs in and at full compression? I have a Honda with linked brakes. It's getting time to replace all the brake lines with stainless steel hoses. The front caliper is a Nissin 3-piston sliding unit, with the center piston actuated in tandem with the rear single-piston caliper (it's a NSS250 Reflex). If I would run two lines from the front brake master to the normal front connection and the center piston connection, all front braking would come from one master cylinder. I would then run a single line to the rear. The reason for doing this would be to increase front braking, simplify the plumbing, reduce the cost of converting to braided steel, make the scooter more consistent in braking operation with the two other motorcycles I ride (none with linked brakes). My concerns are if the front brake cylinder will require much more travel to feed three pistons instead of two, or if the braided lines will offset this somewhat. The rear brake feels weak, so I don't think running it by itself off the original dual circuit will make it too powerful.
Tom Mix
LaCrosse, WI

Sticky Floats
I have a 1992 CBR600 F2 that I bought last summer. It was abused: trashed fairings, stretched chain and worn out sprockets. After I finally got the fairing and chain problem fixed it sat most of the winter. I live in Washington State so the winters are pretty much not a big issue, except this year we hit record lows in the single digits and my bike sat weathering it all. We finally got a break in the weather and when I went to start it up I had fuel just dumping out of the number one and two carburetor breather hose. I never really dealt with multi carb rebuilds so I am hesitant and don't have the money for a shop/dealer. Any ideas?
Michael Renshaw
Centralia WA