The fastest dirt
bike of all time? Arguments go back and forth, and the new bikes are
nothing short of amazing, but as of this writing, nothing has eclipsed
the sheer top speed of the 1981 495 KTM.
Go back in time
with us for what it was like:
***
What gave us the
idea for this test was an old guy in a gas station. We had a bike in the
back of the pickup truck when we pulled in for gas. After putting five
gallons of hi-test in a can and adding some oil, we fished in our
wallets for the ransom. The conversa?tion went like this:
"Whatzat?
Some kind of race bike like a hillclimber?"
"It's
actually a motocrosser. You know, for racing off-road."
"Oh. Well,
what'llshedo?"
"The way it
sits, it'd probably top out right at 78 to 80 miles per hour."
"Hells fire!
Is that all? Shoot, my old Ford pickup truck in the back can do better
'n that, and it's got three hunnert thousand miles on it."
"Actually, a
motocross bikedoesn't need to go much faster than that. I could gear it
up more, but ..."
"Don't seem
like much of a real racer to me. Speed is speed and 78 per ain't much
speed in my book. Now back when I was a kid, I had me a Harley that'd go
so fast that..."
***
We drove off, more
than a bit embarassed.
When you think
about it, 78 does not sound like a great deal of speed. Sure, we all
know how jumps can magnify speed and you can feel like you're doing a
million on a little third-gear short straight.
This got us to
thinking. We'd heard about those Baja bikes hitting 115 or more, while
some experts have flatly stated that no production motocross dirt bike
will run over a hundred per, even with the tallest possible gearing to
be had.
Well sir, the
arrival of a 495 KTM and a genuine maniac Six Days rider appeared to us
to be the perfect combination. Rod Bush is the Service Manager of KTM,
U.S.A., and has a pretty good track record to back him up. Three golds,
a silver and a bronze. He's also the eleventh-ranked enduro rider in the
country.
We worked out the
details as we set up the new KTM. The tallest gearing possible was to be
used. A 16-tooth countershaft sprocket was delayed from Austria, so we
had to go with a 15-fang version. Internal changes were needed to make
up for this. A 20-tooth fifth gear from a 390 enduro bike was slipped
in. Primary drive was 31/79.
The gearing at the
rear was limited to 48 teeth. Not enough for what we had in mind. A
YZ250G rear wheel was found to be a virtual slip-fit, just by making
some simple spacers. This let us drop to a 44-tooth rear sprocket, which
is just about worth one more tooth on the countershaft.
To play it safe,
we also installed a gigantic 150.80 x 18 Metzeler, two-ply, nylon tire.
This massive tire is almost 29 inches tall and noticeably dwarfs a 4.50
x 18 Metz. A larger tire is much like gearing a bike up.
Rod felt that he
could get some extra rpm out of the engine by changing the timing. The
deck height was changed to 1.4mm, from a normal height of .8 to .9mm.
Intake and exhaust manifolds were carefully matched, but no porting was
done.
Carburetion was
left standard. Ron ran premium gas with a 50:1 Duralube mix. Klotz
Octane Booster was added to get rid of any possible detonation at the
high engine speeds we'd be running at.
After the bike was
thoroughly checked out and broken in, we headed out for famed El Mirage
dry lake, home of many high-speed crazies. The lake was in reasonable
condition, with a bit of mud and water at the edges. We had enough room
for our needs.
Two markers were
set up and Rod took some initial passes. We checked all three stop
watches and double-checked the distances. Our first dozen passes had us
in the 108 to 110-mph range. Rod leaned out the main jet in the 40mm
Bing carb and slipped into a set of Danaise road racing leathers and a
full coverage helmet with a shield. He also felt he could get a greater
speed with more distance available before the traps.
Because of the
limitations of the wet part of the lake, Rod had to try to get the bike
up to a high speed on a bumpy fireroad. We estimated his speed at near
90 before he got on the smooth lake bed.
It worked! On his
next pass, Rod went over 120mph! More runs and a semi lay-down position
got the speed even higher. Our best run of the day was 123.7miles per
hour! Astounding! We felt that even more speed potential was there if
we'd have more room and taller gearing.
So, what's the
point of all this?
Basically, we
wanted to deal in absolutes. The 495 KTM is representative of a new
generation of super bikes. The 490 Maico spearheaded the effort and
other manufacturers are girding their industrial loins for the battle to
come.
In a very dramatic
way, a top-speed run is the ultimate dyno. Just how much does it have?
What will she do? Make the motor try to punch a hole in the wind. Slap
enough gears on it to grunt, moan and shudder as hard as it can.
What'll she do ...
indeed.
***
Once we got all
the high-speed stuff out of our system, it was time to test the KTM as a
genuine, functional monster bike. A glance intimidates. The 495 is long
and tall. The cold, white color is broken up with just enough touches of
red and blue to make it look like a weapon, rather than a motorcycle.
It's an angular
beast. Just about the only things on the KTM that are round are the
wheels. The rest of the bike appears to have been designed by an
engineer addicted to a straight-edge ruler.
From the shift
side, the KTM engine appears normal. From the brake side, it's
positively mammoth. Fins extend out well past the cases. The unpainted
aluminum barrel and polished magnesium cases accentuate the angular
lines. If looks determined usage, the KTM49S would go around with a
machine gun mounted on the bars.
***
Sling a leg over
the 495. Or, at least, try to. With an incredible 38.7-inch saddle
height, the KTM has the distinction of being the tallest bike we've ever
tested. Riders in the five-foot nine-inch range will need a milk crate..
Once on the bike, the suspension settles a bit, making the ground barely
in reach for a five-foot eleven-inch rider.
You won't find any
sag in the saddle. In fact, it appears to be made of plywood. That
sucker is hard! It's also slippery. Sort of feels like someone put some
Armor-All on it at the factory. On the plus side, the foam never sags
and the saddle retains its shape. Long?time KTM riders say they like
the firm feel. Long-time KTM riders have also been known to howl at the
moon on occasion.
***
Fire it up, if you
will. When cold, tickle the button on the Bing carb until gas slobbers
over the cases (tsk, tsk), then, more often than not, one kick will get
things stirred up. You'll hear surprisingly little mechanical clatter
from the huge engine, even when cold. KTMs are made well and tolerances
are on the tight side. Very little noise comes out of the exhaust, too.
Especially for an open bike. Some of the "Penton" heritage
about making quiet bikes still lingers.
A new kickstarter
tucks in a lot better than previous efforts. You can start the KTM in
gear, but there's usually a hint of clutch drag that makes starting in
neutral easier. Ahhh. yes. Neutral. Catch it if you can. Hard to find
the little bugger. Impossible, with the engine running. It's easier to
locate neutral going down from second, than up from low.
When the engine is
warmed up, stuff it into gear (no graunching sound) and feed the clutch
out. The 495 will lunge forward if you're not smooth with the clutch.
You can feel the incredible power right away. Low gear, with stock
gearing, is next to useless. Second-gear starts are childs' play, and
third gear starts are reasonable.
A few trips
through the gears and some fun playing with the throttle shows you that
most of the power delivery is at midrange and up. This is not to say
that the 495 doesn't have plenty of low-end punch. It has plenty. But
we're bound to make a thumbnail comparison to the 490 Maico. The 490 has
more right off the very bottom of the rpm range, and has a thunderous
midrange, but flattens out earlier than the KTM.
The delivery of
the KTM is softer at lower revs, very strong early in the mid?range and
absolutely violent in the upper midrange to peak revs. You can still
short-shift the 495 like any good Open class bike, but if you want to
rip the socks off the bike next to you, snap open the throttle at right
around 4000 rpm and hang on for dear life.
***
You say that
motocross racing is nothing more than a short series of drag races from
Point A to Point B? Sure. And the Titanic was just stopping for ice. The
KTM belongs to an elite group of two bikes that will go from Point A to
Point B much faster than the rider is ready for. You literally aim the
front wheel in the desired direction and pull the trigger. Things happen
quickly. First-time riders will overshoot corners grossly. Unwanted
wheelies happen with regularity.
But one thing is
undeniable. The rush is there. The red-eyed, nostril-distended,
white-knuckled, puckered-butt rush is there! As you click through the
gears, the landscape whistles by at an alarming rate. By the time fifth
is engaged, you know that you're over your head. However, you'll do it
again and again. Such is the nature of super bike addiction.
***
Because there's
only one other ma?chine in the super bike class, we must compare
certain traits in the KTM to the Maico. The taller KTM does not turn as
sharply as a Maico but has greater high-speed stability. Part of this
must be attributed to the tall stature, combined with a longish
wheelbase. Take a Maico and a KTM through a sand wash in fifth gear,
side by side, and the KTM rider can relax more. The bike tracks like an
arrow. The Maico will hunt and shake a bit.
Take the same two
bikes and ride on a hard-packed track with tight turns. The Maico will
carve a line under the KTM. Once dialed in, the KTM responds well. It's
just that it takes a bit more muscle to snub it around than the big
"M."
You might say that
the KTM steers more with the rear wheel than the Maico. One must
consider the Maico as a front wheel steering bike. With the 495,
throttle and body movement are important and have more effect on
directional changes, rather than merely sawing at the bars.
***
A pair of Ohlins
shocks do the work at the rear. They're nestled in a beautiful aluminum
swingarm. Action on our test bike was beyond reproach. We were never
even tempted to mess with the preload. That's a nice feeling ... just
jump on a bike and ride it-as is. Actual travel is 12.8 inches, which is
just about the limit of current technology.
Up front, you'll
find a set of bright orange, Marzocchi, 38mm forks. We expected only
average performance from these units, but, as the commercial goes, we
were surprised! These ain't no downstream forks. Travel runs at 12.0
inches, even. We felt that the forks sagged a bit; we were tempted to
add air caps to help firm things up, but
instead we added about two ounces of oil to each leg. This firmed up the
mid and late part of the stroke, but kept things soft and smooth on the
first part. Marzocchi engineers are convinced that forks needing a heavy
air assist are flawed. Right now, most of the factory bikes are not
running air, so their thoughts are right in line.
Every once in a
while, we'd hit a square-edged bump and a shudder would send a message
to our wrists. Over normal ruts, bumps and whoops, the Zokes worked
well. Using a set of 43mm Yamaha forks as a "10" we'd have to
rate the Marzocchis as a solid eight-plus. Some flex was experienced
when the front end was dancing over rain ruts, but nothing alarming.
Count on them
sacking out after a while. Some will do it after four to five hours of
operation; others after 20 or so hours. Don't bother replacing them with
another set of Marzocchi springs. Investigate some Yamaha springs with a
similar rate. We'll check into this and try to get some part numbers to
you in the near future.
***
Clutch pull is on
the stiff side. A Terry cable will help a bit. Clutch adjustment is
critical. Sufficient free-play is essential to the plates staying alive.
Brakes are
excellent at both ends. Both drums and shoes are arced in at the
factory. While not as powerful as Japanese brakes, the KTM stoppers are
more predictable and easier to use.
Wheels are primo;
Sun rims; good hubs; reasonable spokes. Keep an eye on the spokes during
the first 10 hours of riding, then forget about them, except for regular
maintenance.
Metzeler tires
come stock on the KTM. Ours had a nylon, 21, two-ply up front and a
rayon four-ply at the rear. Both are superb tires, with the nylon tires
being a bit lighter.
By the way, we ran
Metzelers for the high-specd run, with 28 psi in each wheel. The
Metzeler folks told us that they've run a knobby at 130mph on a test
drum for 20 minutes with a 760-pound load before they had a knob chunk
off. Impressive,
We didn't care for
the brake cable guide and installed a Pro Clamp up front for safety.
All plastic is
well-made, with the number plate/rear fender combo being particularly
nice. No sense in covering up shocks and things with side plates.
A 40mm Bing carb
with a Powerjet is stock on the 495. While ours worked reasonably well,
it was still far too sensitive to temperature changes to leave us happy.
Jet a big Bing right in the morning, and by eleven o'clock, it's
blubbering down low and detonating at midrange. No thanks. We'd prefer
to see something else more sophisticated on the KTM-like a brick with a
hole drilled in it. Oh yes. We plan to try a Mikuni on the big 495 in
the very near future. Keep posted on that.
The stock tank is
2.8 gallons, with an optional 2.2 and 3.5 gallon tank available. This
means you can have some serious range on your KTM, should you need it. A
KTM gas cap will fit on a Maico tank. Oddly, a Maico cap will often
require a set of channel locks to get it off. Same with the KTM. Hmmm.
New cases on the
495 shave about 10 pounds off of last year's engine. It's a tidy lower
end, well protected by the frame rails, with nothing hanging out to
catch a stray rock.
Bars are a bit
high and take some getting used to. There are two sets of risers under
the bar clamps. This strikes us as a weak setup, but we never tweaked
it, in spite of a few simple low sides.
Shifting proved to
be smooth, almost effortless. Just slap at the folding tip and ignore
the throttle. Very much improved over the performance of the 420 KTM.
A large muffler
hangs off the rear of the pipe, stabilized by a bar attached to the
frame. There must be a better way to mount this unit. The pipe itself
could use better mounting brackets. It's hung the same way the 250 is,
and we experienced cracks on the hangers after a period of time with the
smaller bike. We can expect no less on the killer bike.
A
sensibly-designed and well-tucked in kickstand is mounted on the
aluminum swingarm. Normally, we yank them off most bikes. We left ours
on the KTM.
A well-protected
air filter is housed in a large, easy-to-reach box. The saddle must be
removed to gain access.
***
Hey, you only live
once. But some folks keep asking us the unavoidable question: 490 or
495? Which way to go?
If it were us,
we'd have one of each in the garage, because both of them are so far
ahead of the rest of the scampering big bike field. But, here's the
bottom line. If you just want to race motocross and the occasional GP,
then the Maico is probably the bike for you. If you like to use your big
bike for motocross, enduros and cross- country, then the KTM is the big
bike to buy.
With little more
than a skidplate and a speedo, the KTM is enduro and trail-ready. The
Maico still owns the corners, but the KTM is more stable at warp speeds.
In a drag race, through the gears, both bikes come out dead even. They
cost the same and both machines have enough steam to scare you silly.
Which one you end up with just might depend on how much you can
brow-beat your local dealer.
Is that all there
is, my friend?
Have we just
written off all of the rest of the Open Class bikes in one fell swoop?
Is a 420, or a 465 just not in the hunt?
Well now, they
are... against each other. But folks, we're talking super bike here.
Every other Open bike around is putting out around 41 to 42 horsepower
to the rear wheel. Both the Maico and the KTM are putting out right
around 50. They, effectively, are in their own class.
Wouldn't it be
great to get all of the Open Class bikes made and then take them all out
to El Mirage dry lake on the same day and see who comes out on top? We
plan to do just that. Not right this minute, but soon. Or just hang
around El Mirage every day for the next few months.
Right now, the
magic number is 123.75 miles per hour. Who can beat or even match that
number? For now, the 495 is standing tall, in more ways than one.
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