Motorcycle Forum / General / Sportbikes / June 2005

I have an FZR-1000. It's like three or four generations older than the
R1...

I will never buy another motorcycle without at least thoroughly reading
a repair manual. Even if I say, "Oh, bullshit, what a pile of steaming
dog crap!", at least a $20 manual is cheaper than getting into a $1000
repair bill on a motorbike that's worth $2K or $3K at most...

I didn't read the repair manual on the Yamaha until after I'd bought
it. It seems that Yamaha is some kind of think tank for avant garde
motorbikes. They are the cutting edge of motorcycle technology, but it
seems that their engineers are working in committee environments, with
the engine farmed out to one department and the chassis to another
department and it seems that the engine power department designs a
basic powerplant and some engine accessory department has to figure out
how add an electric starter, alternator and cooling system. The whole
contraption turns out to be some sort of Japanese
Ducati! I don't mean it's a 90-degree Vee-twin with a rabid following
of rich
motorcycle collectors, I mean that it's a contraption of odd pieces
attached to a chassis...

The thing that pisses me off most about the FZR-1000 and YZF-1000
Thunder Ace is
the location of the starter clutch. Now, I had enough problems with
starter clutches on my Suzuki GT and GS series. The
Frankenstein-designed starter clutch is a ramp-and-roller centrifugal
clutch. It automatically engages the starter anytime the engine isn't
running. The whiz-ching! sound you hear when you turn off the key is
the rollers dropping onto the collar that's on the idler gear. That big
idler gear has to sit motionless while the crankshaft is spinning
inside of it at 10K to 11K RPM. Sometimes the bushing or needle bearing
inside the idler gear wears out from lack of lubrication and the idler
gear tilts and engages the rollers of the starter clutch. Or the
rollers stick because the owner hasn't changed the oil in a long time.
If, for whatever reason, the starter clutch engages the starter while
the engine is running at
several thousand RPM, the 10 to 1 reduction gearing will try to turn
the starter at 10 times engine speed. This destroys the starter of
course, and maybe it locks up the rear wheel, spitting the rider off...

And what does all this have to do with the FZR-1000 and the YZF-1000
Thunder Ace? Well, unlike intelligently-designed engines that use the
Frankenstein clutch, the mad men at Yamaha designed the starter clutch
to be *buried* inside the engine! It's the very last thing you get to
when you strip a FZR or Thunder Ace motor apart. I reckon that it would
cost $1K to fix that little problem...

At least the Frankenstein starter clutch on the TL-1000S in bolted to
the back of the alternator rotor, right there under the side cover...

And, of course, I seem to be the only person in all of Usenet's
motorcycle NG's that has ever had starter clutch problems. I dunno,
maybe the other riders didn't survive the mysterious crash that
resulted when their Frankenstein clutch seized up.

Clue: If the Frankenstein clutch is loose on the back of the alternator
rotor, it makes a hellacious clatter that doesn't go away when you pull
in the clutch lever...

I suppose that many riders are quite happy with their CBR-900RR's. It
was a 600cc-sized machine that was intended to be a 750cc machine but
Honda went on to make a 900 out of it, and there wasn't even a class it
could run in, except maybe endurance racing and open displacement club
events...

The 900RR doesn't fit me, but that's not it's fault. The short fat gas
tank goes where my pot belly rightfully should fit, and the seat is a
little too high for my vestigial legs...

My main objection to the 900RR's engine was the fact that the cylinder
was part of the crankcase. Even if you could pull the head off, you
can't get to the piston rings without splitting the crankcases. My
practical minded friend who
hadn't taken a four-stroke motor apart for about 17 years said, "Well,
how often do you have to re-ring an engine anyway?" I had to admit that
I hadn't re-ringed an engine in ten years anyway...

And, there are people riding the same 900RR for over 100K miles. I saw
a 93 with that many miles on it. The bodywork looked like one of those
beater econoboxes you see running around town, with mismatched
bodywork, but it was still running. Low-tension piston rings don't seem
to wear out...

What sportriders hated about the 900RR was the 16-inch front wheel.
They had to be *brave* to trust it to the limits. 16-inch front tires
wash out suddenly, without warning. Sometimes the 16-incher would hook
up again, sometimes not...

The cure for the 16-inch wheel was to install a 17-inch wheel from one
of the CBR-600's. CBR riders hoped that Honda would eventually get the
message about 17-inch wheels, but they went through several model
changes without actually doing that.

The early 900RR chassis was too stiff. The engineers at Honda thought
that a chassis should be very stiff and they were wrong about that. The
stiff chassis.  made the stiff suspension behave worse, the tires
couldn't grip the road as well as they should when running over small
pavement irregularities...

And, when leaned over to high lean angles, the stiff chassis would
allow the rear wheel's kicking motion as it ran over small bumps to
cause the front forks to waggle back and forth...

Honda's engineers realized that they needed *less stiffness* in the
rear of the chassis, where the swing arm bolts to, and the amount of
stiffness should increase as closer to the steering head...

They de-stiffened the chassis in 1997, claiming that the result was a
better chssis for sport riding on the streets. They still didn't add
the much-desired 17 inch wheel though. I don't think that happened
until the CBR-929RR...