Honda CB 125S
Honda CB 125S
Air cooled, single cylinder, OHC, 2 valve per
Bore x Stroke
56.5 x 49.5 mm
5 Speed / chain
Oil-damped telescopic forks
Road Test Cycle 1979
Long gone is the time when the major Japanese
motorcycle manufacturers were battling it out in combat on the showroom floors
and racetracks with 50cc and 100cc and 125cc motorcycles. The basic motorcycle
went from 100 to 250 to 350 to 500 to 750ccs and with each increase there was
a smaller and smaller selection of small street motorcycles.
Now, below 200cc, there is only one. The Honda
CB125. It's been around since the time when all the factories had 125 street
bikes. And it hasn't changed much over the years, though this year it has bright
red fenders that go nicely with the tasteful styling of the little bike.
There not being any competition for the CB125, it
manages to get along with the same 125cc sohc Single, five-speed transmission
and combination pressed steel and tube frame. There's no electric starting or
tachometer or turn signal canceler or disc brakes. This is a very basic
Big holes not costing any more to make than
little holes, the only way Honda could sell the CB125 for less money than Yamaha
does the SR500 is to leave off some of the features and cut costs wherever
possible. And there just aren't that many parts on a Single that can be left
off. Particularly with a sohc Single.
Of course there are no counter-rotating balancer
shafts on the 125 such as those of the large Honda Singles. Nor are they needed.
On the engine is the most basic of 22mm slide
valve carburetors and an ordinary battery and points ignition. This is all basic
stuff, stuff that's worked for years and is easy to maintain. Valve lash is set
with a screw driver and wrench. For maximum performance you shift when the
speedometer needle reaches the shift mark.
Little motorcycles naturally get stigmatized. So
do big motorcycles, but the stigma isn't so offensive. Little motorcycles lend
themselves to beginning riders because they are light and less intimidating than
bigger machines. All the controls are within the power of smaller' people, so
small folks like the son who's not fully grown and the wife who can't reach the
ground on the dual purpose bike can feel at home on the CB125.
Put in the right perspective, however, the 125
becomes fun (if not exciting) to those used to much bigger machines. When was
the last time you were engaged in a contest of speed and didn't have to worry
about getting a ticket? Heck, on the Honda 125 every stoplight is a drag race
and the competition is in Honda cars and Volkswagen busses and Buick sedans. The
CB125 will win those races, too, but mostly because people in cars don't drive
as fast as they can. Still, there's a thrill in seeing traffic fade slowly in
the rearview mirrors as the Honda is thrashed to the shift points in every gear.
At least in town the traffic fades pleasantly back. Out on an open road the
story is reversed as the Honda has all it can do keeping up with the flow of
cars doing 60.
Because the performance is so modest, the 125
tends to be ridden flat out, all the time. People who usually refrain from such
practices found themselves powershifting into second gear to pop the front wheel
in the air. Other benefits of the 125 size came when traffic backed up and the
125 rider could slip between the lanes on even narrow streets.
One place the 125 isn't fun is on a busy
interstate. In areas with rain grooves the grooves throw the little bike back
and forth, the short handlebars wiggling disconcertingly. While the bike can
reach nearly 70 mph, it can only hold 60 mph without the rider flat on the tank
and without wind. Hills or headwinds can slow the bike down to 50 where it is
uncomfortable in traffic. In California the 125 isn't even legal on freeways
because the engine is smaller than the minimum 175cc size required. (There is no
life in the slow lane in California because there's no slow lane.)
The brakes on the CB125 are worth mentioning, but
that's not something positive. It's a 10 horsepower motorcycle with five
horsepower brakes. One rider took the 125 to the bank and came back wanting to
know what was wrong with the front brake. He didn't think it had one. At both
ends of the small Honda there are tiny drum brakes, each one with 13 sq. in. of
brake area. The rear brake manages to do its job because there's lots of
leverage for a strong foot and the rear end of a motorcycle doesn't do much
stopping anyway. Up front there's a shorter lever for a hand that's not as
strong as a foot and the brake is the same size so little happens when a rider
grabs the lever.
Considering this is a beginner's motorcycle, the
brakes will only teach the rider that he can't pull the front brake too hard,
but it could also teach the rider that it's not worth pulling it at all. Before
the other factories got out of the small street bike market, Honda had a disc
brake on the front of the 125. Now that there's no competition, there's the
tiniest of drums.
The clutch is also marginal. It can't be held in
until the signal changes because it warms up and begins to grab. When the engine
is revved up before taking off the clutch can object with peculiar noises. Even
during gentle riding the clutch level moves a long way, slowly taking hold,
before it all-of-a-sudden grabs. Beginning riders deserve better.
Starting the 125 is simple, but not as easy as
other small motorcycles have been. The lever is short and needs more pressure
than a small two-stroke needs to kick it over. Once moved, the Honda starts
within a couple of kicks, hot or cold. When cold, however, the choke must remain
on for a few minutes or the cycle will die, but when riding the bike the choke
has to be turned off so the engine will rev. Cold running could certainly be
improved. Once when the Honda was kicked over it backfired and refused to start.
The frustrated rider gave up and took an easy-starting Yamaha SR500 home for the
night, discovering the next morning that the backfire had blown the plastic top
off the 125's carburetor, taking the slide with it. The plastic carb top had
simply broken in two. Another excessively cheap part.
Suspension? Yes, there is some. Again, it's what
you'd put on if you couldn't sell the bike for as much as you'd like. Travel is
4.5 in. front and 2.6 in. rear, with springs stiff enough to keep a normal size
person from bottoming the shocks but still able to absorb the shock from big
holes. Rear spring preload is adjustable, the only adjustment on the suspension.
Considering the spindly forks and tiny shocks, the suspension works better than
Handling is a matter of trust. How much does the
rider trust the 18 in. Bridgestone in front and the 17 in. Nitto in back?
Scraping the pegs on the 125 would be a matter of bravery, not skill. Honda
makes a 125 roadracer, hut this isn't it. The 47 in. wheelbase and 200 plus
pounds of motorcycle make for a flighty sort of motorcycle, one that will turn
instantly at the slightest provocation and the quickness increases as speed
The CB125 is economy transportation.
It did 78 mpg on the CR' test loop, the best
result since we began doing repeatable miles-per-gallon tests. And the loop is a
hit unfair to small engines, as they are working hard on the highway portions
that allow superbikes to cruise with throttles barely cracked. In intended
service, for example running errands, short hops to school and store, the 125
would he even better. (A minority comment here, from those who recall that the
old 500 Twins, as in Triumph, used to return almost as many miles per gallon. A
mild, slow-turning large engine can be as efficient as a small, high-revving
engine.) But overall, the CB125 is our mpg champ to date.
One reason it's so tough to build a good small
motorcycle is the amount of safety equipment required on a street bike. The
reflectors and two brake light switches and signal lights and the emission
certification cost as much on a small bike as on a large bike and the required
equipment becomes a greater part of the motorcycle's cost.
There's a curious blend of features and lack of
features on the 125. There's a helmet lock and tool box hanging below the seat
on the right side. A grab strap runs across the seat. Two pods contain the
speedometer/odometer in the lefthand pod and warning lights for turn signals,
high beam and neutral in the righthand pod. There is no oil pressure warning
light or sight gauge for checking oil level. No trip meter. The 35 watt
headlight only seems to work on well lighted streets. It would be appropriate on
a moped, perhaps. Yet there's a locking cover over the gas tank filler that
surely requires more parts and more cost than a simple locking cap that would
also be easier to use.
When Honda came up with the revised XL 125 a
couple of years ago, it would have seemed natural to stick the improved 125cc
engine in the CB at the same time. After all, the CDI, six-speed transmission
and better carburetor cost little extra and one engine could have cut production
costs. Instead, Honda changes the CB125 by adding rectangular turn signals and
redesigned clutch and brake levers and hand lever dust covers and new fuel tank
striping and sidecover emblems and improved seat styling.
All those changes make for a more attractive
motorcycle and Honda is betting that the inexperienced rider who will buy the
CB125 is more interested in the better styling than he or she would have been in
improved brakes and clutch or better tires. Honda, as usual, is probably right.
Fortunately, there's also the XL125 and the
almost-identical but more powerful XL185 that cost little more than the CB 125
and provide much greater performance. With a suggested retail price of $928 the
CB125 is the cheapest pure street motorcycle available. It's also the best
under-200cc street bike because it's the only under200cc street bike.
Source Cycle 1979