Our Vulcan 1500 hub was laced to an 18-inch polished Sun rim. Kawasaki sells complete hubs with bearings.
Spoked wheels are popular with cruisers because of their classic style, but customizers like spoked wheels for their flexibility. The look of a stock wheel can be dramatically altered simply by changing the spokes or their pattern. Builders install oversized rims with low-profile tires or fit smaller rims with big, fat tires. The hub usually remains the same and the spokes and rims are changed. The process for attaching rims to hub is called lacing, and the steps are the same whether replacing spokes, rims, or both.
When we contacted Kennie Buchanan, owner of Sun Rims California, Inc., to see if he would like to walk us through how wheels are laced and trued, he said that our readers would better understand how the spokes interacted with the rims if they knew what went into manufacturing rims.
From the Straight and Narrow
The first step of creating a rim: the rolling machine bends the extruded aluminum bar. This is the second pass through; the left side has the final shape while the right side retains the partial curl of the initial pass. Photography by Dean Groover (www.DeanGroover.com).
Sun Rims start out as six-foot long bars of extruded 6061 aluminum. The bars already have the shape of a rim's cross-section, with the channel for the spoke nipples and the shoulder for the tire bead to seat against. The bars get cut to a rough length and are run through the rolling machine for their first bend. After the first bend, the excess aluminum is cut off the ends so that when the bar meets the rolling machine a second time, it will be as close as possible to the final diameter.
The fireworks of the rim-building process take place at the butt welder. The two open ends are clamped with 80,000 psi of pressure and moved slightly apart. Extremely high voltage is applied to the clamps on either side of the gap (We asked Buchanan how high the voltage was, and he responded that he'd have to do the math to come up with the actual number but that the voltage was high enough to badly injure or kill someone unlucky enough to get personal with it), and although the current is applied to opposite ends of the same piece of metal, the path of least resistance is across the gap between the ends. The machine starts with a pop as the electricity makes the initial jump across the gap. The sparks and smoke continue for several seconds as the arcing electricity heats the aluminum until it is molten. At this point, the butt welder slams the molten ends together, showering the floor with sparks and bits of liquid aluminum. The bulging seam glows as the rim leaves the butt welder. According to Buchanan, the weld is as strong as any other part of the rim.
The butt welder clamps the rim's open ends at 80,000 psi. High voltage arcs across the 1/16-inch gap. When the aluminum facing the gap becomes molten, the clamps thrust the ends together to fuse them.
The expander stretches the newly formed rim to a preset internal diameter while assuring that the rim is true. Although the expander is a deceptively simple-looking machine that essentially drives a cone shaped wedge down the center of a circular group of plates, it is extremely accurate and can be adjusted to expand and true rims ranging from 16 inches to 23 inches. The properly sized rims then move to the rim grinder to have the seam from the butt welder ground flat, allowing the seam to be invisible in the finished product. At this point, the polished rims get their first polish before moving on, all other rims visit the automated rim driller to be given the correct hole pattern for their specific application. Since spoked wheels vary the number of spokes from as little as 28 spokes to as many as 200 spokes, precision drilling of the spoke holes and their relative angles is paramount for true wheels. The automated drilling machine drills and countersinks up to four holes simultaneously and rotates the rim for each additional set of holes. After the holes have been drilled and deburred, the rims move on to the chromer, anodizer, or polisher.
Lacing Up
The expander expands and trues the rim by stretching it outward. The rim is ready for drilling and finishing.
While manufacturing rims is an industrial process, involving large, heavy, precision machinery, lacing rims is still an art practiced by craftsmen, though a bike owner can do it too with some patience. Truing wheels, even in the era of high technology, is largely done by eye, using only a spoke wrench and other simple tools.
Preparing the parts to be used in lacing a hub to a rim makes the job quicker and easier. Pros lay out and count--nothing would bring the job to a halt quicker than not having enough spokes or nipples--all the parts necessary for lacing a wheel. The nipples should all be lined up, standing on end, to receive a drop of thread lubricant to ease the threading process. The spokes' threads will also receive a drop of lubricant once they've been laid in the hub.
Place the hub on its side on a workbench (or wheel stand if you are lucky enough to have access to one). Our Vulcan Classic hub incorporates 48 spokes. Each flange on the hub consequently needs 24 spokes. The holes on each flange are offset and can be divided relative to their location to the outside of the wheel into an outer and inner row. Slip the spokes into the holes on the upper flange then go around the hub making sure the inner row's spokes all face the same direction and the outer row faces the opposite direction. On our Classic's rear hub, we had the inner row pointing counter-clockwise and the outer pointing clockwise. At this point, lubricate all of the spokes' threads.
The rim driller makes up to four holes simultaneously then rotates the rim to drill the next set. Special bits drill and countersink at the same time to ensure that the nipples line up with the spokes.
Lay the rim over the hub. If the hub that the rim will be laced to is heavily offset, use pieces of wood to raise the rim so that its center line is on approximately the same plane as the midpoint between the flanges on the hub. Starting with the outer row of spokes, take one spoke and rotate it until it lines up with a hole at the very tip of the spoke. If the spoke could line up with one of two or three holes, take a pen and insert it into the hole in the rim. Since the holes have been drilled at an angle, only one of the hole angles will cause the pen to line up with the spoke in question. Slip the nipple through this hole and loosely thread the nipple onto the end of the spoke. Do not tighten the nipple more than a couple turns. Slack will be required to maneuver the other spokes into position. Count four holes clockwise on the rim, and the next outer spoke (clockwise) should line up with this hole. Thread the nipple and continue with the outer row. The inner row will lace in the same manner.
Start lacing a wheel by placing the hub on a stand or bench. Next, thread the spokes into the top flange's inner row of spoke holes followed by the outer spokes. Make sure everything lines up neatly.
One way to be certain that the spokes are going to the correct hole is to count the number of spokes it crosses. On the Classic, the spokes will only cross once; other wheels may have several crosses. Turn the wheel over and thread the spokes in as with the other flange. Starting with the outer row, lace the wheel following the same steps as with the previous side. Once all the spokes have been threaded to nipples, the nipples will need to be tightened on all the spokes so that each nipple just barely covers the threads. Before doing so, go around the rim and place a drop of oil (regular 30 weight will work fine) under the head of each nipple. Next, choose a group of four spokes (two from the upper flange and two from the lower) and run the nipples up on these spokes until they cover the threads--and no further. Find the four spokes directly on the opposite side of the wheel from the first group of four and tighten them similarly. After those four are run up on the threads, go to the center of the hub and choose a group of four spokes 90 degrees from the first two sets and repeat the process. Then run up the rest of the remaining nipples onto their spokes. The loose-laced wheel is now ready for truing.
True Stories
Starting with the outer spokes, thread the spokes to the rim, making certain that each spoke's angle matches that of the hole in the rim. Then loosely screw the nipples on to the spokes.
Truing spoked wheels is really just a process of averaging out errors. No wheel needs to be absolutely perfect, and trying to make a wheel that way with a dial gauge will only lead to undue stress. Remember the wheel isn't what contacts the road, and the tire will cancel out small wheel errors while bringing its own set of small errors to the game. With this in mind, good wheelwrights will simply use a surface gauge to check visually for a wheel's bumps and wiggles and then, using a spoke wrench, make the rim run as round as possible.
Place the wheel on a truing stand or take an axle and clamp it in a vice so that the wheel will be horizontal (the axle is vertical) when placed on it. Go around the wheel with a spoke wrench and put a little tension on each spoke. Next, put the surface gauge in position and give the wheel a spin. The loose-laced wheel will wiggle in one of three ways: It will roll from side to side, it will have either a hump or dip, or once the other problems are addressed, the entire rim may sit either too high or low, relative to the hub. Since side-to-side motion (which is an up-and-down motion if the wheel is positioned horizontally on the axle) is the easiest to remedy, start by finding the center point of the twist. Spokes will pull the rim sideways when they are tightened so tighten the spokes that would pull in the opposite direction as the twist. For example, if the rim is high in one section (assuming it's on the stand horizontally), tighten the spokes on the bottom side of the rim. Do just the opposite for low sections. Only turn the nipples in the center of the high point one or two of the flat sides and nipples at the outside of the imperfection one or no flats, depending on the severity of the side-to-side roll. Several small adjustments may be necessary to fix the problem.
Once the spokes on the top flange have been loosely installed, flip the wheel and, starting with the outer row, slip spokes through the hub and into the rim. Repeat with the inner row.
If the rim has a hump (a place where it rises away from the axle) in one section, tighten the spokes at the center of the hump on both the top and bottom of the rim. Dips usually occur when the spokes in a section are too tight, and loosening the top and bottom spokes slightly, should improve things.
To determine if the entire rim is too high on one side or the other, the distance between the edge of the rim and the hub needs to be measured on both sides. Place a straightedge across the top of the hub or the rim, whichever is higher (the Classic's hub was higher in our case) and measure the distance from the edge of the hub (or if it is not symetrical, the flange) to the edge of the rim. Flip the wheel in the stand and repeat the process. If the difference between the sides is 1/16 of an inch or greater, the entire wheel needs to be adjusted. Slightly tighten all the spokes on the side with the greatest gap and slightly loosen the spokes on the side with the least gap. Now go back to measure the differences. Once the difference is less than 1/16 of an inch, double-check to make sure the wheel is true. Some minor adjustments may be necessary.
Hoop Dreams
After all spokes have been positioned and started in the nipples, tighten up all the nipples until they just cover the spokes' threads. A power ratchet speeds this up.
Our representative wheels for this article were a set of Vulcan 1500 Classic hubs. Jon Sprenger, an R&D guy at Cobra, slipped our hubs in with a batch of Cobra's parts to get chromed. When the hubs returned, he painted all of the rough cast sections of the hubs, like inside the hub where the cush drive will reside, glossy black for a nice custom look, since those sections don't readily accept chrome.
For our custom rims Buchanan suggested 18-inch (instead of the stock 16-inch) rims with low-profile tires. A quick call to Avon Tires revealed that we should be able to fit these new hoops under the stock fenders if we used an Avon 150/70VB18 AM23 ($195) tire on the rear 4.0 x 18 rim. The front 3.5 x 18 rim required a trick from the Harley customizing world. We will install an Avon 130/70VB18 AM23 ($165), which is a rear tire, and then flip it so it rotates backwards from the way it would as a rear tire. This will enable the tire to direct the braking loads (which travel from the opposite direction from the drive loads on a rear tire) into its carcass as intended.
In the looks department, we chose Sun Rims' bright, buff polished aluminum rims laced to the hub with stainless steel rippled spokes from Buchanan.s. The front rim cost $254 and the rear $277. These prices included hand drilling for our custom-sized wheels. The polished stainless steel ripple spokes add $354 to the cost, and lacing and truing labor were $84 each. The result was two unique-looking wheels that we can't wait to see on our Vulcan Classic.
THE TRUE PATH: WIRE-WHEEL MAINTENANCE
Spinning the wheel next to a surface gauge (the pointer at bottom left) tells where the rim is out of true as it moves relative to the gauge. Tightening spokes on the opposite side of the rim lessens outward shape. When the spinning rim no longer moves up and down or in and out, the wheel is true.
Every bike with wire-spoke wheels, be they aftermarket or original equipment, will need some wheel maintenance sooner or later. We asked Gary DuPape of Wheel Works what knowledge he's gained in his 20 years in the business which he can pass on to riders who want to keep their spoked wheels round and true.
According to DuPape, riders should clean their wheels regularly. That's the best way to prevent big problems. While cleaning, grab groups of four spokes and squeeze them. If done enough times you will develop a feel for the spokes' tension and notice when they start to loosen. Also, broken spokes or small cracks in rims will be noticed before they lead to other problems. A broken spoke should not be replaced individually and forgotten. It could be a sign of a problem. Consider buying a new set (How about those fancy ones you've been eyeing?) and have the wheel completely trued.
Every time the tires are changed, the wheel should be checked for trueness on a truing stand with the tire removed. While properly trued wheels shouldn't suffer from spoke "settling" after the wheel has been laced, new wheels should be checked after their first 500 miles or so. If a loose spoke is found, tighten it up snugly but not so tight as to influence the shape of the rim.
Eventually, spoked wheels will need to be retrued. Spokes are subjected to constantly varying stresses, and they stretch over time, causing looseness. DuPape says that only through regular spoke observation and maintenance can riders stay on the true path of motorcycling.
A selection of popular spoke styles, from top to bottom, are: twisted, round body, diamond blade, and ripple. The different styles of spokes are available in a variety of finishes, ranging from lustrous chrome to stainless steel to carbon steel.
RESOURCES
Avon Tires
P.O. Box 336
Edmonds, WA 98020
(800)624-7470
(206)771-2115
www.avonmotorcycle.com
Buchanan's 805 W. Eighth St.
Azusa, CA 91702
(626)969-4655
www.buchananspokes.com
Sun Rims California, Inc.
943 S. Raymond Ave.
Pasadena, CA 91105
(626)441-6829
Wheel Works
12787 Nutwood
Garden Grove, CA 92640
(714)530-6681
www.wheel-works.com
Related Articles
How to Run Tubeless Tires on Wire-Spoke Wheels
Custom Cruiser Tire Buyer's Guide
Roadside Tire Repair
Billet Wheel Buyer's Guide>Tire Tech & Tips
For more articles on how to maintain and modify your motorcycle, see the Tech section of MotorcycleCruiser.com.