Road Test 1978
Is progress a red herring? The Yamaha SR500E—lean, clean and crewcut—might
make you wonder. Could it be that the swift march of technology is carrying
street motorcycles into a future more fanciful than fun? Is it possible that froggy buzzers, blazing lights, digital readouts, instrument clusters, built-in
stereos, heated handgrips, rear-view mirrors with electric defrosters, and
third, fourth, fifth and sixth cylinders are subversive; or worse, some pinko
conspiracy to reduce •true-blue, Type-A-Positive American Manhood to limp
vanilla pudding? Will this single-cylinder, you-kick-it-to-life motorcycle
rescue our sport? And doesn't the SR500E belong to an era when Dick. Tracy shot
the perpetrators square between the eyes without ever reading them their
constitutional rights, when Audie Murphy blew away entire enemy regiments in
black-and-white war movies, and when Lois Lane would step into a telephone booth
with nothing more serious in mind than the Daily Planet's phone number?
Well, sorry. You square-jawed heroes who think Seventies-style motorcycling
has gotten soft without sprained ankles and brightly colored hematomas will find
little of the 1950s in Yamaha's SR500E. It's not a revival machine that
transports the aches and pains and oil leaks of 1952 forward to the threshold of
1980. On the contrary, this 500 single is a thoroughly modern motorcycle.
To say that the concept—an agile 500cc four-stroke single—is "old" misses the
point. Sometimes a good idea seems to be frozen in metal, inextricably tied to a
particular set of machines in a given time-frame. But a good idea is a really
timeless thing. And so the big-bore single-cylinder roadster has come back;
rethought, re-engineered and reconstituted in all its mechanical specifics.
Yamaha's new street bike has been developed out of the XT500 and TT500 dirt
bikes, but even here the lineage tends to be more apparent than real. The SR500E
is not a street-bike adaptation of the XT500. To be sure, TT, XT and SR all have
87 x 84mm engines, and the XT and SR units both have 9.0 to 1 compression ratios
and share basic driveline components. However, in many important respects the
SR500E engine is a creature unto itself.
The SR500E cylinder head has larger fins for better heat dissipation compared
to the XT; and while Yamaha has not changed cam timing, the inlet and exhaust
tracts have been reshaped to get better performance. Most of the work has gone
into the inlet side of the engine where the SR has a 34mm Mikuni carburetor
feeding a 47mm intake valve, compared to the XT's 32mm carb and 45mm poppet.
Further changes in the cylinder head include new valve-seat material to improve
the durability of the seat when using low-lead or non-leaded gasoline, and the
exhaust valve guide has been standardized with the intake guide.
Yamaha has not overlooked the piston. The pin-boss area of the 500's piston
has been strengthened, the overall length of the piston has been increased by
six millimeters, and Yamaha has modified the piston's oil ring. Street riders
probably use more revs over longer time periods with less maintenance than their
dirt-riding counterparts, and Yamaha has made all these modifications to guard
against excessive oil consumption.
Downstairs in the crankshaft department, Yamaha increased the flywheel
capacity by extending the diameter of the crank webs, claiming a benefit in
reduced mechanical noise. Moreover, the material in the forged and hardened
crankshaft was changed in the redesign.
Cost and appearance considerations probably led to the disappearance of the
magnesium side covers found on the dirt singles. Both the left and right side
covers on the SR500E are buffed-out aluminum. Yamaha spent their money in other
ways: The SR500E has a hoop around the clutch housing to strengthen this
component, detail changes have been made to some transmission gears to increase
their durability, and the shift pawl and drum have been modified in order to get
easier, more positive shifting. Specifically, the toothed primary pawl, instead
of being splined to the shift shaft, is integral with the shaft; now there's
nothing to loosen or slip. And the shift drum is supported on the left side by a
new needle bearing that reduces drum drag and facilitates smooth gear-changing.
The fussing with the crankshaft assembly suggests Yamaha's concern with
vibration, a traditional complaint about the big single. That concern shows
elsewhere, but not necessarily in a way the casual observer might expect. The XT
has one rubber and three solid mounts that attach the engine to the frame,
whereas the SR500E, far from being rubber-mounted all the way round, is solidly
fixed to the frame at all four points. Enormous soft-rubber bushings, like the
old Norton system, would have isolated the thumping vibrations of the 500 single
from its frame. Yamaha rejected this complicated and expensive option. Elaborate
soft-mounts or counter-rotating balancers were out of the question too; those
solutions violated the simplicity and cost-effectiveness that Yamaha wanted in
the SR500E. So the engineers did more homework on frame design and solid engine
mounting in order to hold the vibration through the frame to an acceptable
Outfitting the 500 for street duty included a new frame. The tubework may be
based on the XT500, but frame-tube diameters have been increased and key points
of the frame have been reinforced to increase rigidity. A strong and fairly
massive frame that clinches the engine tightly can carry off engine vibration
without fracturing, transmitting some of the pulsing through the suspension to
the ground. To illustrate where vibration can go, step back five feet from an
idling SR500E, watch the bike move on its suspension, and then put your hand to
the pavement—and feel the quaking.
No wonder that the rear fender, gas tank and footpegs are rubber-mounted. In
fact, even the caliper mounts for the rear disc brake have rubber bushes to
soften the vibration. The battery-box space has been made large to provide more
room so that longitudinal vibrations won't rattle the battery against nearby
Incidentally, the side cover and battery box have been designed in such a way
that both the battery and tools (under. a lockable cover) can be removed from
the left side of the bike, and the air cleaner can be pulled out from the right.
Because the under-seat items come out the sides of the motorcycle, the seat is
bolted in position. It doesn't lift up on hinges.
Compared to the XT500, the SR500E has considerably less rake (27.7 degrees
vs. almost 31 degrees) and trail (4.7 inches vs. 5.7 inches), producing a
quicker-steering bike. The front and rear suspension units more nearly resemble
the components found on the XS650 than those fitted to the XT500. Indeed, the
SR500 has no off-road capability with a front fork that travels only 6.0 inches,
whereas the XT is good for 7.8 inches. At the rear, very ordinary oil-damped
shocks provide 4.4 inches of rear-wheel travel, while the XT500's forward-cant
DeCarbon shocks allow the rear wheel 6.4 inches of movement. The SR500E also has
a slightly shorter wheelbase (56.25 inches) than the XT's 57-inch span. Not
surprising is the fact that the 383-pound SR-E packs 64 more pounds than the XT.
Some of the extra baggage has gone into the electrical system. The SR500E has
12-volt electrics charged by a multi-pole alternating-current magneto, instead
of the XT's six-volt system with a direct-current flywheel magneto. And the
breaker-points ignition fitted to the XT500 has not been carried over to the
SR-E. The roadster has a magnetically triggered CDI to fire the spark plug.
Yamaha has provided more than an energetic spark-maker in order to persuade
the SR500E into life. Obviously an electric starter would contradict the notion
of a light-and-lithe, simple-and-direct single-cylinder roadster. In addition to
the starting lever, there's plenty of gadgetry. First, one manfully gets the
kickstart lever under foot, hopefully under cover of a good boot. Of course
Yamaha figured some owners would step to the starting drill with frazzled
tennies, and so the company took pains to protect its light-footed Customers
from the uplifting and crippling effects of The Dread Single Cylinder's Recoil &
Backlash Through The Starting Lever, And Subsequent Catapult Over The Moon.
Using the compression release which lifts the exhaust valve, one cranks the
works over until a little white arc appears in a tiny window at the right
outboard side of the overhead camshaft.
Then one flicks the choke lever, provided that the engine is cold, and pushes
the white throttle-set knob, located nearby the choke lever, into its
up-position. With the ignition switched on, and with care not to crack the
twistgrip open, the rider thrusts the starting lever downward and awaits those
comforting ka-thunka/ka-thunka sounds to well up from the engine department.
Failing that, one again consults the old peekaboo window, gives a macho
ah-what-the-hell-l-was-only-kidding shrug, and continues to kick.
Until our test SR500E was broken in fully, and until we learned not to flood
the thing (the Mikuni has an accelerator pump), and until experience
demonstrated that the throttle-set knob should be trusted to raise the
throttle-slide the exact amount, the SR500E would either start on the first or
second kick or not at all. One Cycle staffer (not an editor) managed to kick the
Yamaha into a deeper and deeper case of moodiness until at last he was squirting
sweat and frustration from every pore in his body, and nearly a gallon of sweat
collected behind his jacket's tightly secured wrist cuff, waterlogging his right
arm all the way to the elbow. Without so much as a burp of encouragement, the
SR-E refused to push/bump start, and the hapless novice only succeeded in
leaping aboard from the left side, skidding the rear wheel, and toppling
over—bike and all—into a steaming, cursing heap.
The Yamaha never so cursed the life of the editorial staffers, and firing off
the SR500E was simple and easy—after learning what to do, and what not to do. In
fact, the neatest trick in the whole start-up routine is resetting the
start-throttle knob. The rider just rolls the twistgrip back against its
fast-idle position, thus returning the throttle-set button to its off-position.
Thereafter, the engine always drops down to its 850- 900 rpm slow-idle speed.
Everyone who rode the SR500E agreed: The motorcycle is enormous fun. Not an
awesome motorcycle, not dazzling, not brilliant—but fun. Those riders who have
grown up on electric-start twins and fours were intrigued by the single-cylinder
Yamaha because it represents a different approach to connecting Points A and B
on tarmac. The SR500E is a machine of essentials; a responsive, glove-fit
That motorcycling concept may be fun, but in the real world sometimes being
fun isn't enough. After all, steam calliopes are fun, Excalibur roadsters are
fun, fifty-year-old two-wheeled crocks are fun. But any modern single-cylinder
motorcycle must meet the hard test of reality. What can it do? How does it
perform? To make sense in a world of thousand-dollar kick-start twins from
Honda, Kawasaki, Suzuki and Yamaha, the $1500 SR500E must perform better in some
dimensions than the econo-twins. Granted, you can't buy anything like the SR-E
from another source; Yamaha has the corner on the 500cc single-cylinder roadster
market. Nevertheless, a 50 per cent premium is a lot to pay just to be
In functional terms, the SR500E starts with substantial advantages. It is a
specialty motorcycle, a fairly narrow-focus machine, and isn't subject to the
kinds of compromises that econo-twins must unavoidably make. Consider the simple
matter of seating. In order to attract a broad range of customers, the 400 twins
must offer reasonably comfortable accommodations for passengers, and this
strategy dictates fairly long, heavy, cushy seats. On the other hand, the Yamaha
SR500E is basically a monoposto device, scaled to one person.
Yamaha has capitalized on this seeming limitation. In the first place, the
distance between the seat and the rider's footpegs is great enough for real leg
room: no semi-double-back positioning.
The relationship between the pegs, bars and seat is genuinely comfortable,
and staffers—to a man—liked the riding position. Since a single-cylinder 500 is
a relatively tall and narrow motorcycle, the rider gets reasonable saddle
height, vertical roominess and a great deal of ground clearance. Because the
engine is slim, the pegs can be located inboard. and the tank is Mr. Trim.
Comfortable? You bet. There's no Fat Albert tank to splay the rider's legs out
in a frog-like stance.
The SR500E gives the rider something more than a well-scaled platform; once
underway, he discovers that there's usable power. Usable power isn't the stuff
that comes blazing out of some little twin at 7500 to 10,000 rpm. Rather, the
Yamaha 500 pulls decisively from 3000 rpm; there's enough authority on tap at
3500 rpm to make gear-changing strictly optional. This kind of power won't
establish new quarter-mile records for 500s, and the SR-E feels strained and
out-of-breath above 75 mph. But with the Yamaha's deep-rpm power a rider is able
to get into a natural cadence and rhythm with a winding road that rolls on mile
after mile with 45 to 75 mph corners. Since he doesn't have to tap-dance the
shift lever all the time, the rider is left free to concentrate on his line
through the next corner—or the trees and flowers if he's so inclined.
The SR-E lets you take a good crack at corners. The narrow motorcycle almost
seems to make any road about two feet wider than normal. And assuming you
approach a corner too hot, the SR-E can brake with vengeance, right to the limit
of your confidence in the front tire or its adhesion, whichever occurs first.
The hydraulics, front and rear, are first-rate; some riders may skid the rear
end but an oversensitive rear disc won't be the cause of the problem.
The nimble Yamaha responds quickly to rider inputs, but its quick responses
seem more a function of its light weight and mass placement (relatively high),
rather than the result of steering geometry. While the SR500E can be dialed into
corners quickly, its basic slow-steering geometry (and chassis rigidity) keep
the motorcycle feeling rock-steady through corners. High-technology twins and
fours, both 400s and 550s, must—thanks to their weight—get quick input-response
via chassis geometry, and this can leave those motorcycles feeling less than
perfectly stable through rough 75-mph corners. By comparison, the Yamaha single
has an almost Ducati-like quality in its through-the-twisties stability.
While the suspension is compliant, the SR-E doesn't have the velour
ride-softness that characterizes bikes like the XS11. The single feels bucky and
harsh on the concrete slabbing of freeways. Whipped through bumpy corners, the
stiffish rear springs will allow the SR500E to skitter its rear end a little
toward the outside of the corner as the rear tire momentarily loses contact with
the pavement. Handlebar waggle, dead-reardamper floatiness, and suspension
wallowing are all happily absent. And that's what you'd expect, given the
Yamaha's weight (383 pounds) and its modest horsepower output.
Because the SR-E has a great deal of ground clearance, we suspect that the
SR-E's Bridgestone tires, patterned after the old Dunlop Gold Seal rubber, set
the bike's outer boundary for corner-carving. The tread design looks dated, but
within the parameters of street riding we can't quarrel with performance of the
No matter where or how you ride the SR500E, you'll discover that the seat
will begin to burn a hole in your backside within 150 miles. Were it not for the
excellent riding position, the SR-E would probably become wearisome inside of 75
miles. For a specialty motorcycle that works best on a Sunday afternoon's ride,
a comfort-to-misery point at 150 miles is acceptable. In no case is it possible
to ride the motorcycle 175 miles non-stop. Generally, the bike went on its
reserve gasoline supply at 135 to 140 miles, returning about 53 mpg. The only
gasoline-station hassle was the SR500E's leaky filler cap.
Vibration-fatigue, you might think, far more than burning buttocks would
signal an end to a day's riding. Not true. Of course the bike vibrates; the
rider feels it through the seat, bars and pegs. But the vibes do not lullaby
your extremities to sleep or numb your reflexes. Big-single vibrations are
low-frequency, high-amplitude quakings that aren't nearly so insidious as the
electric-drill machinations of high-output two-strokes. Unlike vintage 500
singles, the Yamaha does not spray loose nuts and bolts and shed parts at 60
mph. Only one license-plate fastener escaped during the test period.
By design the SR-E is not Everyman's Motorcycle. Prospective owners should
test-ride this motorcycle to verify that they can start it, ignore its
vibration, enjoy its agility, accept its modest output, and revel in its
handling, braking and usable power. If you can use the SR-E, then you'll
understand that it's a $1500 motorcycle.
And don't let anybody tell you the SR500E is just a funky revival of
England's Grand Old Gold Star. Funky, yes; fun, certainly; repli-revival, no
way. The SR500E is a modern five-star remake of a timeless idea
Source Cycle 1978