By the CN Staff
There
are
probably
as many
approaches to building a lightweight
competition machine -as there are
companies that build them. There do
seem to be some general categories into
which most 125 racers fall: the souped
up trailbike with the ligh ts stripped off
(a number of Oriental giants seem to go
this route); the screamer engine bolted
into the lighweight frame and hope it
holds together until the race is over;
then there is another, less frequent
approach. This category of building
lightweight competition machines seems
to be based on taking a competitive big
bike frame, running gear and suspension
and then putting a 125 class motor in it.
Everything is beefed for more stress and
horsepower and there's no way that
machine is going to break.
The last approach is the one CZ took
with their entry into the lightweight
market.
The
small
Che·Zed
is
extravagantly overbu'ilt. It has exactly
the same frame, wheels and running gear
as the 250. Even the lower end is the
same. Only the barrel, head and piston
are changed. The carb is a 28mm Jikov
which is also stock on the 250.
This particular configuration makes
the 125 CZ one of the most reliable,
bullet-proof and otherwise unbreakable
lightweights you can buy. It also means
that the smaller piston has the same
weight of crank, rod, flywheels, etc. to
get moving as does the 250 every time
you dump the pre-mix to it. It takes a
lot of revs to get the CZ moving at a
respectable speed and you have to keep
it wicked to continue that way or that
big (relatively) lower end mass starts to
drag the R's back down.
Once underway, be prepared for a
revelation. The weight of the 125
machine is perfe.ct f6r the new
standardized CZ frame and suspension.
This machine has a severe case of good
handling. The low CG, long wheelbase
and supemeat Barums let you get so far
over in comers it's scary. VItti! you do it
a few times, then it's fun. You can drive
the CZ into a comer as fast as you're
willing to go and just lean it over, make
the turn and go. Don't let the revs drop
and go like stink. Arriba! Arriba!
(Hmm, that's not quite righ t for a
Czechoslovakian bike, but that's the
feeling.) The suspension never tops or
bottoms (the new CZ shocks seem to
have better dampening than the old
models that came on the redtank CZs),
probably because it too, was designed
for the 2505 and 380s. It probably
wouldn't hurt a thing to change the
front 2.75 to a 3.00 X 21, the front end
wouldn't bury as much in a loose sand
or dust comer.
The engine always seems to run
spot-on. There was a strong CN
prejudice toward the dual-coil, dual-plug
setup, it's kind of like having
one-twelfth of a Ferrari. The motor is
simple, reliable and hard to break.
Shifting is excellent with the classic CZ
long
throw
and
positive
gear
engagement. It's almost a cliche by this
point, but the snick up through the
gears, clutch optional, is almost perfect.
As a matter of fact, the CZ distributors
are seriously considering guaranteeing
all CZ transmissions for the life of the
machine.
CZ already has a first in that the
distributor offers a 30-
"5
....
~
w
Z
W
..J
C,)
>
C,)
.125
....
(whichever comes first) warranty on all
new CZs. It's the only warranty we
know of on a competition motocross
machine, and it's a whole lot better than
nothing since any factory errors should
become
obvious
by
that
time.
(American Jawa must believe this review
about the CZ being reliable, etc.)
Anyhow, we doubt if you'll ever have to
change that steel plate clutch.
The brakes, encased in the conical
magnesium hubs that are standard on all
CZ models this year, are very good.
They are progressive and positive. Good
enough to set you on your ear if you get
ham-handed. There still isn't a rear
brake return. As generations of CZ
owners have done, get the old inner
tube strip and wind it from adjuster to
brake rod, with another sec.tion from
lever to frame. It seems awesomely
strange that CZ hasn't seen fit to have a
rear brake return incorporated into their
MXers after so many years; the same
with Maico front brakes. Curious, these
Central Europeans.
While on tf:1e subject of things we
don't like, we'll throw in the steel rims.
They tend to be malleable; that means
they pick up dings. Bu t they don't pick
up mud, which probably means that the
rims are just about right for the wet,
muddy courses of Czechoslovakia. The
adobe and rocks of California courses,
and desert, are a different proposition.
The seat is great, and the air cleaner is
super waterproofed in the still air box
under the seat. It's really hard to kill the
motor by moisture. They also finally
started putting folding pegs on the
bikes, thereby destroying a major
To negotiate bumps and ripples get on the pegs and really gas it. You'll get there.
,,
California industry based on building
folding foot pegs for CZs. The new pegs
are OK, but not the best ever seen.
There is only one major problem with
the 125 CZ. No low end. Our test bike
had a trick pipe that forced the horses
into the high rpm range, and we figured
that pipe must account for it. We rode
another 125 CZ with the stock pipe and
three still wasn't enough low end to let
you come 'blasting out of a comer after
letting the revs drop from their usual
high-singing state. A clutch of possible
explanations came OUt of the sage CN
staffers:
I) "It's all attributable to the 250
lower end. Lt's just too much weigh t for
the little piston to push when it's at rest
or barely moving."
2) "The 125 needs a fewer-toothed
countershaft sprocket for motocross."
3) "It needs a reed valve."
4) "It's undercarbureted and the
engine is starving ou t. "
5) "Lt's too heavy."
6) "What do you mean no lower end?
I let it down to eigh t grand and it never
bogged once." (That from the resident
road racer.)
The handling compensates, in the
opinion of most riders, for any lack of
low end, since the confidence inspired
lets even the novice keep it singing. It is
suggested to dealers to sell it for $975,
which is in the ballpark with most of
the high performance 125 racers, and
you have the distinct advantage that
you'll probably never have to replace
anything. One of the staffers had a CZ
that went Over a year, without having
anything major done to it and it still
wen t faster than he did. The innards just
don't seem to break, and the frame is
built like a tank. CZs are built to last.
'
The CZ is a momentum racer. The
longer you ride it, the faster you get.
The faster you get, the better it handles.
It
also
gets
more
stable
and'
confidence-inspiring at higher speeds.
You gotta stay on the pipe.
-.
