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

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

Street vs. Race Tires…Again

Ask the Geek
Got a question? The Geek
831 S. Douglas St., El Segundo, CA 90245 or e-mail srmail@sorc.com

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

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

This year marks the end of the two-stroke era in grand prix roadracing, as the 125cc class transitioned to Moto3, using four-stroke, 250cc machines. Ironically, as Moto2 uses a production-based Honda engine and MotoGP is likewise threatened to be an all-CRT class using production engines in the future, Moto3 may be the only class using prototype engines going forward. Alternatively, the MotoGP rules may end up being similar to those for Moto3 — prototype engines but commercially available and with strict controls and a claiming rule.

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

It’s been 20 years since Öhlins first experimented with semi-active suspension on Yamaha Grand Prix bikes, but the technology is finally making it to production. Öhlins introduced its Mechatronics (mechanics and electronics) system late last year for the BMW R 1200 GS, and recently released an aftermarket TTX shock for the Kawasaki ZX-10R using the technology. At the same time, BMW has gone a step beyond its Electronic Suspension Adjustment (ESA), and released information about a new Dynamic Damping Control (DDC) system. Both Mechatronics and DDC operate on the same basic premise: changing suspension action in real-time to better suit conditions, based on data collected from various sensors.

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

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

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

Got a question?
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