Authors: Sonny Barger
Even though frame failures are rare, you should still take some time to inspect the frame of any used bike you consider buying. Check the gussets and welds for cracks, especially in high-stress areas like around the steering head. Look for dents or severe scratches that might indicate a bike has been wrecked, and look for signs of corrosion around the battery box. Take note of flaking paint, which could also be a sign that a bike has been through a serious crash. Don’t walk away from a bike because of a little flaking in the frame’s paint, but if you do see this, keep your eyes open for other trouble signs.
Swingarms/Rear Suspensions
All modern motorcycles have some sort of swinging arm rear suspension. From the 1950s until the 1980s this consisted of a fairly standard setup, with a metal fork attached to the rear wheel, coming together in front of the wheel, and attaching to the frame at a pivot point behind the transmission. A pair of shocks, one on either side of the rear wheel, controlled the wheel’s up-and-down motion.
This status quo began to change in the mid-1970s. Yamaha used the first modern single-shock setup on its factory motocross race bike in 1973. Within a few years both Yamaha and Suzuki offered single-shock dirt bikes to the general public. At first these used triangular swingarms that placed the shock at the top of the triangle, in front of the rear tire. The shocks on these bikes rested at an angle and connected to the frame up under the gas tank. This system was soon replaced by a setup that placed the shock upright in front of the wheel. By the early 1980s all competitive dirt bikes used this latter setup.
At the same time, single-shock arrangements began to appear on street bikes. In 1980 BMW introduced the R80G/S, an 800-cc dual sport that featured a single shock, though this was mounted in the traditional position, alongside the rear wheel. Where the BMW design broke with tradition was its use of a single-sided rear swingarm, which was basically like a traditional swingarm cut in half. BMW called this system the “Monolever.”
Yamaha used a more innovative single-shock system when it introduced the Virago series in 1981. These early Yamahas used a system much like the very first single-shock dirt bikes, with a triangular swingarm and a laid-down shock that ran under the seat and connected to the frame up by the gas tank.
Over the next few years Japanese sport bikes began to feature single-shock rear suspensions, though these followed the practice of the later dirt bikes, with a vertical shock mounted in front of the rear tire. Harley even got into the alternative rear suspension business with its Softail system. Like the Virago, this system featured a triangular rear swingarm, but instead of being located under the seat, the shocks were mounted down under the engine, hidden from sight.
The main difference between the Harley system and the various systems used by the Japanese and Germans was that the Japanese and German systems were all about function. The main purpose of the Harley system was cosmetic; Harley was trying to re-create the look of the earlier hardtails (bikes without any rear suspension at all). It did this by hiding the entire rear suspension system as best it could.
Today we have a bewildering variety of rear suspension designs to pick from. Having said all this, unless you’re planning to spend a lot of time on a racetrack, you should simply make sure that any used bike you’re buying doesn’t have problems with its swingarm. Swingarms generally are extremely stout and should cause little trouble over the life of a motorcycle, but you’ll still need to check for potential problems.
First, examine the shock or shocks. Make sure they aren’t leaking fluid, or that they haven’t lost their gas charge if they are nitrogen shocks. You can check for leaks in much the same way you check the fork seals—bounce the bike up and down and then check for greasy moisture on the shaft of the shock. You should be able to tell if the shocks are properly charged and/or filled with fluid after you bounce the bike up and down. If it bounces too easily, the shock(s) will probably need work. This is not uncommon on bikes with a few miles under their belts, but like everything else, it will be expensive.
An even more expensive repair would be to replace the swingarm pivot bushings. When these get bad, they can make your rear wheel wobble while you ride down the road. As you might imagine, this can have fatal consequences on the highway and needs to be fixed immediately. Thankfully you should easily be able to determine if the swingarm bushings are bad before your bike enters a “death wobble” on the open road. The procedure for checking swingarm bushings is similar to checking the steering head bearing and is much easier to do on a bike equipped with a center stand. When the bike is on a center stand, the rear wheel is lifted up in the air so you can wiggle it back and forth to see if there is any play in the bushings. If there is a little play, that might not mean there’s a problem—on many bikes the swingarm pivot simply can be adjusted to eliminate this play—but if the swingarm clunks from side to side, you can be certain the bike will soon experience expensive and dangerous problems. Walk away from any bike with a sick swingarm while you still can.
The Final Drive
This is also the time to check the final drive system. As mentioned in chapter 1, there are three common types of final drive systems: chains, shafts, and belts. Belts are the best system, in my opinion, and require little maintenance, but they can fail with age and wear. For this reason, check the condition of the rubber to ensure it’s not cracked or coming apart. Most important, make certain the belt has all of its teeth. If teeth are missing from the belt, it is just about to fail.
A damaged belt is not a huge problem on some belt-drive bikes, but, on others, it could get expensive. Generally speaking, if the belt runs inside the frame as it passes over the swingarm pivot between the front and rear pulleys, as it does on Harley-Davidson touring bikes and Softail models, the frame will have to come apart to replace the belt. This is a huge job and is much more expensive than changing belts on models that have the belt running outside the frame, such as Harley’s Dyna and Sportster models. If the belt has any damage or noticeable wear, check with a local shop to see how much they charge for replacing belts on that model. If you decide to buy the bike, reflect the cost of belt replacement in your offer.
I prefer belts over shafts because belts don’t alter the handling characteristics of a bike the way shafts do, even though shafts require less maintenance than belts. When you have a shaft-driven bike up on a center stand (most bikes with shaft drives have center stands), you can check the oil level in the rear drive unit by opening a screw-in plug that rests on the upper part of the ring and pinion housing and looking inside to see that the oil is at the proper level. Once you’ve determined that it is, put the bike in gear (with the engine off, of course), grab the rear wheel, and jerk it back and forth. If you feel a loud, loose “clunk” inside the rear drive housing, the bike may be about to experience a very expensive drive-shaft failure.
Chains are the most common types of rear-drive systems, and they also wear out the fastest. In the 1970s and early 1980s a few manufacturers like Harley-Davidson and Yamaha used chain-drive systems that ran the chain in an enclosed oil bath. These enclosed chains lasted virtually forever, but the cases that held the oil were heavy and prone to leaking. They eventually proved to be a technological dead end and by the mid-1980s all motorcycle companies had abandoned the idea and gone back to open chains and sprockets, or in Harley’s case, belts.
You’d be lucky to get twenty thousand miles from a chain and a set of sprockets. If you’re like me, that won’t get you through one riding season. Add to that the fact that the chain final drive is the most maintenance-intensive system on a modern motorcycle, and you can see why I don’t care for them. You’ll need to adjust your chain at least every week, perhaps every other day if you’re a serious rider.
Be prepared to get dirty when checking the condition of the chain. Although there are some good chain lubricants that don’t leave a greasy buildup or attract too much road grime, even the cleanest chain on a bike that is regularly ridden will be somewhat greasy and dirty. This is where the clean rag you brought along will come in handy.
First check the tension on the chain to make certain the chain isn’t so loose that it will cause problems when riding. If the bike is well maintained, then the slack should be within the manufacturer’s tolerance, usually meaning the chain should have enough free play to move up and down an inch or two. An overly tight chain might be evidence of a well-meaning but ill-informed seller. A slightly loose chain may only mean the bike gets ridden a lot, but in my mind, a chain that is sloppy is a red flag indicating its owner neglects basic maintenance. If the chain is too loose to ride safely, have the owner adjust it before going out on a test ride.
When the chain tension has been set to the proper level, roll the rear wheel to turn the chain and check it at various spots. If the tension varies from location to location, the chain may have tight spots, indicating that it is on its last legs.
The condition of the sprockets will also tell you how long you can expect the chain to last. Since the wheel only turns one direction under power (no chain-driven motorcycles have reverse gears), the teeth of the sprockets only wear on one side. Because of this, they develop a distinct cupping appearance as they wear out—one side of each tooth appears worn and the other appears almost new.
Sprockets usually wear out at almost identical rates as chains, requiring the chain and both sprockets to be replaced at the same time. Since wear is much easier to see on the sprockets than on the chain itself, you can expect that the chain will have about as much life left in it as do the sprockets. If the owner claims to have replaced the chain but not the sprockets, ignore anything the person says after that because he or she is either a liar or a fool.
If the bike lacks a center stand, the process of checking the suspension and chassis gets a lot trickier. Here’s where taking the bike to a mechanic can be worthwhile, because any worthy mechanic will have a lift he or she can use to hoist the bike up for these types of examinations. Barring access to a secure lift, your next best bet is to use a good stand, like those built by the company Pit Bull. Quality stands will support either wheel (if you have two, you can support both ends at once), but unlike a lift designed specifically for motorcycles, which connect to a bike at the center of the frame, stands lift a bike at its wheels. This loads the suspension with the weight of the motorcycle, making it much more difficult to check for problems with the swingarm bushings or steering head bearing.
Brakes
The brakes on any motorcycle you’ll consider buying are perhaps the single most important items when it comes to saving your bacon out on the highway. There are two kinds of brakes: disc brakes and drum brakes. Disc brakes slow your motorcycle by squeezing pistons inside calipers, which are attached to your frame or fork so that they don’t rotate with the wheel. These pistons push pads against a disc that’s connected to the wheel so that it rotates with the wheel. The pressure of the pistons slows and gradually stops the wheel’s rotation.
Drum brakes work by expanding the brake shoes—stationary, horseshoe-shaped devices—against the inner surface of a rotating wheel hub. As mentioned earlier, you’ll only run across drum brakes on extremely low-end motorcycles, usually the smallest cruisers from the Japanese manufacturers, which often still feature drum brakes in the back. The majority of quality motorcycles you’ll be considering will have discs at either end.
Finding a bike you like with a drum rear brake shouldn’t cause you to exclude that bike automatically. Disc brakes are unquestionably better, but drum brakes can be at least adequate, provided a motorcycle isn’t too heavy. Make certain they work smoothly and stop the bike without shuddering.
If there is a problem with the rear drum brake, this means the shoes are worn. Often these can be adjusted. There will be a lever coming out of the wheel hub that activates the shoes inside. Where the lever connects to the brake cable leading to the brake pedal on the right side of the engine, there should be an adjustable rod connecting the cable to the lever. This rod will have a spring on it to keep tension between the rod and the lever. You’ll find an adjustable nut at the end of the rod. If the nut is at the beginning of its travel and there is a lot of room to tighten it down before it reaches the end of its travel, chances are the brake shoes still have some usable life in them. If the nut has been adjusted down toward the end of its travel, most likely the brake shoes will need to be replaced soon.
Replacing the brake shoes is a relatively inexpensive process, and one you can easily do yourself, even if you’re not mechanically inclined. The hardest part of replacing the shoes is getting the wheel off the bike. If you can do that, the brake cover should just pop off. Yet even simple tasks require your full attention to detail. Always remember that the life you are putting on the line will be your own. As you start taking the wheel apart, take careful notes, outlining where everything goes, so you can put it all back together correctly when you are finished. Leave off one cotter key or leave one bolt loose, and you might find that your wheel falls off when you stab at the brake pedal. If you have any doubts whatsoever about your ability to fix your own brakes, leave the job to a professional.
If you find a bike with a drum brake in front, it will either be too old or too small for you to seriously consider buying. Any bike worth purchasing will have at least one disc brake up front, and likely two. The process for checking disc brakes is quite a bit different than it is for drum brakes.
The first thing you need to check is the condition of the fluid. This will be in a reservoir on the handlebar, right up by the front brake lever. Some BMWs from the 1970s placed the reservoir under the tank, and custom bike builders often place reservoirs in the oddest places you can imagine. But if you’re following my advice, you’re not going to be looking at antiques or hand-built customs, so any bike you should be looking at will have the front brake reservoir on the right handlebar.