Service
SERVICE
PAUL DEAN
Put the pedal to the... front?
Q I am 71 years old and ride a
2008 Harley-Davidson Electra Glide Ultra Classic, and I have dropped it twice. Both times this happened, I tried to stop with the front brake while I had the front wheel turned a little, and that caused me to tip over. I had both feet down at the time, so I could not use the rear brake. Is there a way to change the brakes so that the hand-brake lever operates the rear brake and the foot pedal operates the front brake?
Harold Sandusky Porum, Oklahoma
A From a pure hardware standpoint, such a conversion could be done fairly easily. It would require making up two custom brake lines, a task that can be performed by any number of motorcycle-, automotiveor aircraftrelated businesses that specialize in hydraulic parts and repair. One line would run from the rear-brake master cylinder down near the right footboard, up the right-front frame downtube to the steering-head area, then into the junction block on the lower triple-clamp that diverts fluid pressure to both front calipers. The other line would run from the handlebar master cylinder, down the right bar upright, under the top triple-clamp, rearward atop the frame backbone under the fuel tank, down the right-rear frame downtube and back along the swingarm to the rear caliper. That sounds a bit elaborate but is actually quite simple.
What's not so clear-cut is how either brake would then perform. The diameter of the rear master cylinder's piston, the leverage ratio of the pedal, the piston size in the rear caliper and the diameter of the rear rotor were all designed to work with the amount of force generated by the typical rider's right foot and ankle. Similarly, the front master cylinder, its piston diameter and lever ratio, as well as the dimensions of not one but two large rotors and their calipers, all were engineered to work with the force applied by that same rider's right hand. If you know someone who can generate as much force with their right hand as they can with their right foot and ankle, here's a bit of friendly advice: Don't shake hands with him.
My point here is that I have never performed this type of brake-system swap and don't know anyone who has, so I can't predict the outcome with any degree of accuracy. Because of the aforementioned differences in the front versus the rear brake components, you likely won't be able to squeeze the handlebar-mounted lever hard enough to produce sufficient rear braking. Conversely, your right foot might unintentionally create enough front braking to easily lock the front wheel. That could end up with even worse consequences than those you have already suffered.
All of these problems could eventually be worked out to your satisfaction if the project were tackled by someone who understands the principles of hydraulics and has reasonable fabrication skills. Such individuals do exist; your first step, should you choose to go ahead with this idea, should be to find one of them.
Asymmetric high-miler
QI have a 2003 Suzuki DL 1000 V-Strom with 195,000 miles on it. At 150,000,1 replaced the shock with a Hyperpro 460 that's fully adjustable, including for ride height. I use Metzeler Tourance tires and have lowered the fork 13mm in the triple-clamps for quicker steering. Since installing the shock,
I've noticed that the rear tire is wearing unevenly as it approaches 9000-11,000 miles. The middle of one side of the tire is at or below the wear bars while the other side has a little more tread remaining (l-2mm). I have noticed this at the last few tire changes, and it only occurred after I installed the shock. Ride quality is good, and the tires have been balanced properly and maintained at the proper 40 psi air pressure.
I assume this wear is due to the shock settings. What are your suggestions for shock adjustment to even the tire wear?
Kith Burkingstock Newnan, Georgia
A Uneven rear tire wear has nothing to do with shock adjustment, ride height or steering geometry. None of those factors cause a motorcycle's chassis to load a rear tire unevenly. They do affect how a bike handles, but they do it symmetrically, not more on one side than the other.
You didn't mention which side had the accelerated wear, but it is quite common for tires to wear a little more rapidly on the left side than the right. This is partly due to most roads having a "crown" that angles right-hand lanes toward the right so that water runs from the middle of the road onto the shoulder during heavy rains. No matter which way you are traveling on such roads, the contact patch always is a little offset to the left side of the tire when you are riding in a straight line.
What's more, because we ride and drive on the right side of the road in this country, the radius in any given comer or curve is longer when rounding it to the left than it is when going right. Thus, we tend to go faster around lefthand corners than we do around rights, because the lefts allow us to do so more easily and offer longer sight lines around the curves. Tires therefore wear a little more quickly on the left than the right for that reason, as well.
What's odd about your bike's symptoms, though, is that they didn't materialize until more than 150,000 miles clicked on the odometer. Unless you just failed to notice uneven wear during previous tire changes, there must be something bent or misaligned on the bike's chassis. With the equivalent of nearly 8 trips around the world under its belt, the V-Strom could have a misaligned steering head, a slightly twisted swingarm, a bent axle or some other misshapen component that is causing the rear wheel to tilt slightly to the left when the bike is being ridden straight.
You should be able to track down this problem fairly easily with a level, preferably a digital type. With the bike on its wheels, prop it in a vertical position and locate a perfectly straight steel rod that is at least six inches longer than the swingarm pivot bolt. Slide the rod through the hollow pivot bolt, put the level on the exposed part of the rod and adjust the bike's attitude until it is perfectly level. Now withdraw the rod, place it across the legs of the swingarm, as close to the sprocket and brake rotor as possible, and use the level to see if the arm is twisted. If the arm is okay, use this same basic technique to check every other surface that is supposed to be perfectly horizontal or vertical, such as the rear wheel, the front wheel (with it aimed directly at the rear wheel), the sides of the steering head, etc. If something is misaligned enough to cause uneven rear tire wear, this procedure should eventually track it down.
ConAligner
Q I read with great interest your description of the ProAligner rear-wheel adjusting tool in the March issue's Serice. I, too, have used lasers and string to perform rear-wheel alignments and have had some success with each. My 1977 Harley-Davidson Electra-Glide is perfectly balanced rolling down the highway with no pull to either side.
You said that the first step in the procedure for using the ProAligner was to sight down the right side of the motorcycle and make sure the front wheel was aligned. Now, help me out here: If I could align the front wheel by sight, why would I need a $30 tool to align the rear wheel? The tool makes sense, but as I read the article, I thought of the oldfashioned wooden, fold-up carpenter's ruler. I think this would work as well and can be found for pennies at any flea market if not already in your toolbox out in the garage. Tony Phillips
Kure Beach, North Carolina
A When you align the front wheel with the rear, that is just a first step; remember that the rear wheel may be out of line, which could very well be why you are performing the task in the first place. But before you can align the rear wheel with the front wheel, you have to ensure that the front is aimed at the rear as accurately as possible. So, when you sight down the sidewalls of the front tire and compare the measurement on the left with the measurement on the right, you merely are using only the front edges of the rear tire as reference points rather than all four front and rear edges. Even if the rear tire were a few degrees out of alignment, you can still use its front edges to make that first measurement. Then you adjust the rear wheel and take the measurements again until you get even spacing on both sides.
In the article, I acknowledged that someone could come up with a similar tool on their own but that the time and effort to do so might not be worthwhile. I considered the idea of using a carpenter's ruler, but the numbers on those are so much smaller than the ones on the ProAligner that they're almost impossible to read with any degree of accuracy when the ruler is positioned at the rear tire and the viewer is a couple of feet ahead of the front. If you can accurately read the ruler's numbers under those circumstances, your eyes are far better than mine.
No-purpose dual-purpose
QMy 2005 Kawasaki KLR650 with only about 2800 miles on it has a problem. It starts fine, but under power, it cuts out and hesitates. It never stalls or backfires but acts more like it's running out of gas, then suddenly takes off normally, only to repeat that scenario over and over again. So far, I've removed, cleaned and Sea Foamed the gas tank, inspected the fuel filter, and removed and cleaned the carburetor, but to no avail. I also installed a new battery and used my experience as a licensed master electrician to check the ignition coil, exciter coil, CDI unit, diode unit, sparkplug wire and plug cap. They all fall within the specifications listed in the shop manual, but the problem remains. Do you have any idea what the culprit might be that is giving me fits and causing me to lie awake at night?
Darryl S. Burkhardt
Bear Lake, Michigan
A My guess is that either the vent in your KLR's gas cap or the ignition cut-out switch on the sidestand is malfunctioning. The cap has a one-way valve that allows air to enter the tank to displace fuel as it is consumed but does not permit gasoline vapors to exit. If the valve is stuck closed, the flow of fuel into the carburetor will be impaired enough to cause the engine to stumble and possibly stall. But if the valve is only partially clogged, the engine will still get enough fuel to continue running but will hesitate and run erratically. The easiest way to determine if this is the problem is to ride with the gas cap open. If the engine then runs normally, you'll either have to disassemble the filler cap and rectify the problem with the valve or replace the entire cap. If that proves not to be the problem, check the electrical switch located at the pivot for the sidestand. It's a safety device wired into the ignition circuit that shuts off the engine when the transmission is in gear and the clutch is disengaged with the stand deployed. On KLR650S of that era, the contacts in the switches seem to get dirty or corrode fairly easily, creating enough resistance in the circuit to make the engine stutter and stumble. The solution is to either replace the switch or remove it altogether and connect its two wires to complete the circuit.
Torque monster
I really enjoyed the "Horsepower" story you wrote in last year's May issue. At the time, I thought it taught me a lot about horsepower and torque that I never knew. But I just became confused again after reading an Internet story about a big Caterpillar diesel truck engine that makes 2050 footpounds of torque but only 625 hp. How can that possibly be? I know nothing about diesel trucks, but I would think an engine that produces that much torque would make a huge amount of horsepower. You've probably answered questions like this a thousand times, but could you please do it one more time and help me understand how an engine could make so much torque but so little horsepower by comparison? Craig Mclnerny
Santa Clara, California
AI think you may have forgotten what arguably is the most important piece of information in that article, which is that the relationship between torque and horsepower is a matter of simple math. Torque is an actual twisting force an engine produces, but horsepower is just a mathematical calculation of the amount of work the engine can do. To calculate horsepower at any given rpm, you multiply the torque the engine produces at that engine speed, multiply it by that same rpm and then divide by the constant of 5252. If an engine makes 100 ft.-lb. at, say 4000 rpm, you multiply 100 by 4000 and get 40,000. You then divide 40,000 by 5252 to get 76.16 hp.
Let's now take that Caterpillar engine and calculate its horsepower. I looked up the specs for that engine and found that it makes its peak torque of 2050 ft.-lb. at just 1200 rpm. If we do the math (2050 x 1200 5252), we see that
the engine makes 468.4 hp at that rpm.
It makes 625 peak horsepower at 1700 rpm, however, so we find the torque output at that engine speed with another simple formula, which is to multiply the horsepower at those revs by 5252 and divide by the rpm. If we again do the math (625 x 5252 1700), we get 1930
ft.-lb. of torque when the engine is making its peak hp at 1700 rpm.
So, Craig, here is perhaps the missing link in your understanding of all this: Because horsepower is a calculation derived by multiplying torque by rpm and then dividing by 5252, the only possible way an engine can have a peak horsepower number that is bigger than its peak torque number is if the torque peak arrives above 5252 rpm. If the torque peak is below 5252 rpm, it will be divided by 5252 in the calculation, resulting in a smaller horsepower number than the torque number. It's that simple. I hope this clears up your misunderstanding about these two related but entirely different terms.
Injection or infection?
QI have a question about fuelinjected motorcycles. Over the past several years, I've noticed that more and more bikes are using fuel injection instead of carburetors. I know that all cars have had fuel injection for quite a long time, but they are.. .cars. I originally became fascinated by motorcycles many years ago because of their simplicity compared to cars, but bikes have now gotten so much more complex over time, and it seems to me that fuel injection and all of its related hardware and electronics have just turned motorcycles into two-wheel automobiles.
I can tune and troubleshoot carburetors with my eyes closed, but I feel like I am legitimately blind any time I try to diagnose an engine problem on a fuelinjected bike. I'm no master mechanic, but I have friends who are, and even they frequently complain about the difficulty of dealing with fuel injection. Is this switch away from carburetors out of any real necessity or is it driven mostly by some other factor on the part of the bike manufacturers? Spencer R. Sykes Submitted via www.cycleworld.com
A Make no mistake, Spencer: It definitely is out of necessity. Ever-tightening emissions regulations have left bike manufacturers with little choice but to switch to EFI. Actually, given no other alternatives, they most likely could somehow engineer their motorcycles to meet current emissions requirements with carburetors, but no one would be happy with the performance caused by the resultant ultra-lean fuel mixtures. Sluggish throttle response, herky-jerky cruising, lower horsepower levels and higher operating temperatures would be the norm. EFI, on the other hand, can control fuel metering much more precisely because it regulates the mixture based on a much wider range of parameters than a carburetor can equal; and that—at least with the vast majority of motorcycles— allows the manufacturers to provide smooth, glitch-free performance and impressive levels of power while also meeting current emissions standards.
Smaller bikes and scooters still can get away with using carburetors because the total volume of exhaust gases they emit during the emissions certification process—which is fundamentally the same for all motorcycles, regardless of size—is so small. A few mid-size bikes that have been around for a while also can squeak by with carbs, but the throttle response and warm-up characteristics of those machines often are not as desirable as they are on very similar bikes that are fuel-injected.
Break-in or just break?
Ql'm no expert mechanic, but I have come up with my own method of breaking-in tires. I drop the tire pressures to as low as 30 psi on new tires for approximately 200 miles and even lower for a shorter stint. I believe this generates more heat and puts a greater contact patch on the pavement without creating unruly handling.
This also allows the rider to scrub the tire farther away from center with out having to lean the bike over as much as would be necessary with the tires inflated to the usual 33-36 psi. What are your thoughts? Mike Vulpis
New York, New York
A Without knowing what you ride, how you ride and where you ride, I can't make a very accurate assessment of your "break-in" technique. But despite that absence of information, I— and the people I have consulted at several tire companies—strongly believe you are making a big mistake.
To begin with, unless you install new tires and then immediately begin riding at continuous speeds of around 120 mph or higher, tires do not need to be broken in. When people use that term, they are referring to the need to scrub off the slippery mold release that is on the surface of many brands of new tires; and even on new tires that come out of the mold with no form of release, it's wise to gradually scuff all of the tread anyway just to be sure it will provide the optimum grip.
So, running new tires at exceptionally low pressures not only is unnecessary, it can lead to problems that include accelerated tread wear, excess heat, reduced handling capabilities and, in the worst case, possible catastrophic tire failure.
Low pressures cause a tire to flex more dramatically and over more of its carcass than usual, and that generates excessive heat. Once a tire's temperature exceeds a certain point, any additional heat, combined with excessive flexing, is potentially damaging. It can cause delamination between the carcass plies and the rubber that holds them together, especially if the bike is ridden for any period at relatively high speeds. Moreover, when the pressures are too low, the tread "squirms" as it rolls over the road surface, causing a higher rate of wear than would occur if the tire
were properly inflated. And while the overall area of the contact patch might be slightly larger on an underinflated tire, the pressure the patch is putting on the road is inconsistent across that area, and the sidewalls are not as well supported, either. This obviously reduces a tire's handling capabilities as well as its straight-line stability. Plus, when an underinflated tire hits a pothole or an abrupt pavement transition, the possibility of damaging the carcass—and the wheel rim, as well—is greatly increased.
In the end, there is absolutely nothing positive that can come from riding on new tires that are underinflated, but there sure is a lot of negative. □
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 design and technology? Maybe we can help.
If you think we can, either: 1) Mail a written inquiry, 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 949/6310651; 3) e-mail it to CW1Dean@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 10page essay, but if you're looking for help in solving a problem, 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.
