Service
SERVICE
PAUL DEAN
E.T. phone home
Q I have no explanation for something very unusual that happened to me more than a decade ago, and I've wondered about it ever since. I lived in Sioux Falls at the time and was on my way to the Sturgis rally on I-90 riding my 1990 H-D Electra Glide Classic. Every so often, I would glance at the gauges, and all seemed normal. At one point, the voltmeter started to act erratically and contin ued doing so for approximately 15-20 miles while in the Wall, South Dakota, area. It had never done this before, and once I was out of that area, the meter re sumed normal operation.
During the next several days in the Black Hills, I kept an eye on the gauge and saw no problems with it. But on the way back to Sioux Falls, it resumed its erratic behavior while I was again riding through the Wall area. Once past, the voltmeter went back to normal. -
[hat was the only trip to Sturgis I made with that particular bike, and I never saw the voltmeter act up again. What do you think?
John Kladstrup Quincy, Illinois
A I think you never should go there again. But if you must, make sure you're wearing aluminum underwear and a tinfoil cap with a point on top. That would prevent the aliens from suc cessfully probing your important stuff.
Seriously, I have no rational explana tion for the bizarre misbehavior of your Classic's voltmeter. If it had occurred at any other time in any other location, even once, we could write off the Wall Inci dents as pure happenstance, a crazy coin cidence, a strange echo from the Bermu da Triangle. But it didn't, so we can't.
On the other hand, Wall is not far from Ellsworth Air Force Base, which controls all air space over a range of 40 miles, including Rapid City Regional Airport. Perhaps your voltmeter was re acting to radar, microwave or some other signals emanating from Ellsworth. I do know of several instances in which rid ers of bikes equipped with radios (as well as car drivers) briefly lost radio transmission when in the vicinity of cer tain military installations; so maybe Ellsworth had something "special" go ing on at the time. Meanwhile, keep that roll of Reynolds Wrap handy.
A tender subject
Q About a year ago, I bought a Battery Tender and attached it to m~ 2006 Honda Gold Wing's battery with the metal rings on the Tender's cable. There's also a plug on the cable that allows me to easily hook up the Ten der without having to get at the battery. I recently bought a pair of heated gloves that connect to the battery with the same kinds of metal rings, but their cable has a different plug that won't mate with the Battery Tender's. Can I just connect the two metal rings on the gloves' battery wire on top of the Tender's rings? This would mean having two metal rings on each battery post so I can run two differ ent items. Would this blow cells out of the battery or maybe even damage the heated gloves or the Battery Tender? Or each time I use either item, do I have to remove the other item's rings from the battery?
Joel Prim Fort Mill, South Carolina
A You can stack as many connectors on the battery as you can get to fit without fear of damaging any part of the electrical system, including the bat tery and the accessories in question. The connectors do absolutely nothing until their respective accessories are turned on; when they are turned off or are unplugged, there is no current flowing through them, so the electrical system doesn't even know they are there.
Problems could arise, though, if you had multiple accessories connected to the battery and turned them all on at the same time. If the combined wattage of those accessories exceeded the output of the charging system, the battery would gradually go dead. And if you really overloaded the electrical system with an absurd number of accessories and turned them all on at the same time, you could possibly cause an electrical fire by over heating the bike's wiring-though it's also possible that the only damage would be a blown fuse or two. -
In your case, there is no danger of electrical problems, including blown fuses. For one thing, unless you like to keep your hands toasty while your Gold Wing's battery is charging, you would never have the Battery Tender and the heated gloves working at the same time. And even if you did, the Battery Tender would simply be putting current into the battery while the gloves were taking cur rent out. In other words, don't worry.
Groovy, baby
Q In your "Bridging the gap" answer in the February issue, you said the groo~es that piston rings fit into are called "lands." Okay, but when referring to the spiral machining inside a rifle barrel, the raised ribs that grip the bullet and impart spin to it are called "lands," and the grooves in between the lands are called, urn, "grooves." Is this just a quirk of the language or is there more to it? L
Lee Dahie Colorado Springs, Colorado
A Actually, it was more a quirk of my explanation than anything else. The ring grooves inapiston are indeed called grooves; the parallel surfaces above and below each ring are the lands. A piston effectively floats in its bore, which means the rings have to float in their grooves, between the lands, so they can maintain a consistent seal against the cylinder walls. The tops and bottoms of those grooves are called lands because they are where the rings "land" as the piston moves up and down.
In my February response, I stated that having too little ring end gap could result in damage to the ring lands, and I then explained that the lands are the grooves the rings fit into. In that context, I see the grooves and lands as virtually one and the same, since the top land forms the upper limit of the groove and the lower land forms the bottom. In retrospect, I can see how that description could be a bit misleading, but it was not my inten tion to confuse anyone.
Jingle bells
Q I have a 1994 Kawasaki ZX-9R that is in excellent shape consid ering it has 51,000 miles on the odom eter. It usually runs like a charm but just recently began making a really disturbing noise down in the clutch case. It's kind of a jingling, rattling noise that is worst at idle in neutral. That sound mostly quiets down once the bike is moving, but then it makes a heavier, lower-pitched noise when I let the clutch out after a gearshift, especially if I am not very smooth when upshifting or downshifting. I pulled off the clutch cover and everything in there looked okay. I once had a Honda that made a clutch noise because the tabs on the clutch plates got hammered down enough to rattle around in the clutch basket, but the plates and basket on my ZX looked almost like new. Any idea what might be making all the racket?
Kevin Hiliman Posted on America Online
A It sounds-literally-like some or all of the damper springs on the back side of the outer clutch hub are broken. The outer hub-or basket, as you call it-attaches to the primary drive's big driven gear via six coil springs that allow the two components to rotate a few degrees in either direction relative to each another. The springs serve as a shock-absorbing medium that helps cushion some of the abrupt forces that can result not only from clumsy shifts but also from normal gearchanges and onloff throttle applica tions. When the springs break, the hub is then able to shift back-and-forth with little or no resistance. That movement, combined with the rattling of the loose or broken springs, causes the noises you are hearing. The outer clutch hub and primary gear are manufactured as an assembly and are not designed to be taken apart, so the only reasonable solution is a new hub.
Tuning under pressure
Q I just bought a 2009 Honda CBR1000RR and I'm looking to modify the exhaust by installing a slip-on rather than a full system. After reviewing the available slip-ons, I see that on al most all of them, the mid-pipe has sort of an "S" shape before reaching the silenc er; the only system that doesn't do that is the Two Brothers slip-on. I'm not a scien tist, but don't you think that a straight > pipe with a free flow would definitely im prove horsepower compared to a pipe that makes several turns before exiting. Your thoughts on this would be greatly appreciated.
Pepe Martinez Posted on www.cycleworld.com
A There is much more to exhaust system design than simply giving the pipes the straightest possible shapes. You are presuming that bends in a pipe create back-pressure, and that back-pres sure is a bad thing, but that's not so; backpressure is a vital part of exhaust tuning. Engines that only have to make good pow er over a very narrow rpm range-for topspeed runs at Bonneville, for example, or turning flat-out laps around Daytona In ternational Speedway's 2'/2-mile tn-ovalcan benefit from a near absence of back pressure; but for an engine to have a broad, usable powerband, it needs back pressure.
But not just any kind of back-pressure. Bike manufacturers and the better after market exhaust companies work long and hard to determine the ideal lengths, diam eters and volumes of all parts of their sys tems to produce the best power for the ap plication. For streetbikes, that means having the widest possible powerband combined with competitive top-end power while also meeting the prevailing emis sions and sound regulations. Doing all that requires carefully tailored back-pressure. This explains why so many streetbikes now have computer-controlled powervalves in their exhaust systems that close to provide more back-pressure for excel lent low-end and midrange performance and open to allow less back-pressure for optimum peak power.
So in the end, the level of performance that can be gained with an exhaust sys tem that has curved pipes far outweighs what can be extracted with perfectly straight pipes if the bent pipes provide the proper tuning.
What the fork?
Q What are the advantages and disadvantages of inverted forks? The !~verted type is now con~imon on supersport models, but I am surprised that some bikes-including the new Yamaha VMax-do not have them. Take the Kawa saki Ninja 650R (standard fork) vs. the Versys (inverted fork): Granted, the Versys is kind of a dual-sport, but these two essentially have the same drivetrain. Is it price? Rigidity? Weight distribution?
Malt Owens Chagrin Falls, Ohio
A Inverted forks were originally used on motocross bikes to give the front end a greater degree of rigidity. Pre viously, telescopic forks had their smaller tubes, the "stanchions," at the top, with the larger-diameter "sliders" at the bottom. An ongoing increase in suspension travel during the late 1 970s and early 1 980s be gan allowing MX bikes to traverse rough terrain faster and faster, and the resulting long, long fork tubes presented suspen sion designers with a daunting challenge: preventing side-to-side fork flex as well as bent forks caused by Knievel-length jump landings. They tried all sorts of preventive measures-fatter stanchions, beefier triple clamps, triple-clamps with more than the usual one or two pinch bolts per side, spacing the bottom triple-clamp farther from the upper one-with limited success.
But then someone got the bright idea of essentially turning the fork upside-down, putting the larger-diameter tubes at the top. This provided so much more clamp ing area for the triple-clamps that flex and bending no longer were significant issues. Inverted forks soon found their way onto sportbikes, which had evolved into streetgoing roadracers that could generate sufficient cornering and braking forces to) make conventional forks flex and twist.
Inverted forks did present a fundamen tal disadvantage in that positioning the skinnier tubes at the bottom provided a smaller oil reservoir compared to conven tional forks. Suspension manufacturers gradually overcame this drawback with different damper designs and alternative methods of circulating the fork oil.
As to why some bikes have inverted forks and others do not, that's a question for which there is no consistent answeralthough neither drivetrains nor weight distribution have anything to do with it. Sometimes it's purely a cost issue on a model that is price-sensitive. Sometimes it's just a matter of need; no sense bolting a high-performance fork on a low-per formance bike when a less-expensive conventional fork is way more than adequate for the task. And sometimes it's a cosmetic consideration on a bike with classic or traditional styling.
That explains much of the reason the new VMax has a conventional fork. The designers wanted to preserve as much of the original Max's appearance as was rea sonably possible, so they decided against an inverted fork; they did, however, equip the bike with an exceptionally rugged conventional one.
Slick shifters
Q Overall, transmissions on modern bikes seem to shift much better than those on bikes from the 197(Js and before. I am not comparing high-mile age bikes to new ones. My 2005 BMW R1200 shifts better than any new airhead I ever rode. Six-speed H-D gearboxes are way better than their predecessors. My Honda 954 (other than its neutral-to-first shift) was much slicker-shifting than the Honda 550 I owned 30 years earlier. Obviously, some aspect of transmission design has changed. What was it? D~k Ok~k~n
VVLL~L vva~ iij. Bob Sheehan Nederland, Colorado
A Jeez, Bob, what hasn't changed in the last 30 or 40 years? Bikes are exponentially faster, lighter, betterhandling and braking, and they now rival cars for durability. Wouldn't it be peculiar if transmissions had not also reached a higher level of sophistication? Engineers have continually used the tools at their disposal-breakthroughs in metallurgy, the precision of computer-controlled manufac turing, advances in the field of lubrication, improvements in shift-mechanism designto evolve transmissions that perform just as impressively as all of a motorcycle's other components. There still are a few gearboxes that balk every once in a while, but they are few and far between.
Got a mechanical or technical problem with your beloved ride? Can't seem to find workable solutions in your area? Or are you eager to learn about a certain aspect of motorcycle de sign and technology? Maybe we can help. If you think we can, either: 1) Mail a written in quiry, along with your full name, address and phone number, to Cycle World Service, 1499 Monrovia Ave., Newport Beach, CA 92663; 2) fax it to Paul Dean at 949/631-0651; 3) e mail it to CW1 Dean@aol.com; or 4) log onto www.cycleworld.com, click on the "Contact Us" button, select "CW Service" and enter your question. Don't write a 10-page essay, but if you're looking for help in solving a prob lem, do include enough information to permit a reasonable diagnosis. And please understand that due to the enormous volume of inquiries we receive, we cannot guarantee a reply to every question.
