CZ 125

This story is about a CZ125. It takes place in the dim and distant past, but as the CZ design hasn't changed much in the meantime, it's still relevant to more recent times and models. I may be a little astray in my recollections of the mileages covered but not of the faults - they are etched in my memory.

My CZ was of 1971 vintage, with about 18000 miles on the clock, and I found it through the time-honoured method of looking at cards in a newsagents window (shows how such study can be useful as well as entertaining!). Anyway, when I arrived at the owners address I found that it was being sold by an ex-girlfriend, or rather her husband. It was a pleasant reunion: but it didn't get the bike's price down, and when my ex suggested I came back to collect a spare helmet the husband scotched it immediately. Strange that...

My journey home was made as it was growing dark and the poor headlamp did not inspire confidence amongst the heavy Saturday evening traffic. However, I arrived home safely and in the following days I was able to take a closer look at my purchase.

The CZ design is, of course, a very basic one. When I bought mine in 1976 the current models had fully enclosed rear shocks and chains. Mine had neither but did have Posilube oiling for the two stroke single engine, which is one step up on 1987 versions. If you thought it wasn't possible for a CZ to be any cruder - I mean more basic - now you know different.

I began using the bike for commuting on a 20 mile journey. The machine would cruise OK at 40mph, but the top speed of 55mph could only be used occasionally because of intrusive vibration. Braking was adequate even from a SLS drum, later models have a better TLS front brake. It would return exactly 100mpg and use a pint of oil every 600 miles, but didn't always run cleanly. It seems to be a characteristic of CZs that if you open the throttle after a period of town riding a cloud of smoke follows you down the road for half a mile or so. At all other times, exhaust emissions were unobtrusive by two stroke standards.

The handling inspired no traumas, despite the bike being shod with a Yokohama front and Barum rear tyre - steady men, don't flinch! The Barum was replaced by an Avon SM, but little difference was apparent. I decided to fit indicators, but it was only after the third kit that the flasher unit managed to resist the CZ vibration, despite being rubber mounted.

After a few months of commuting I decided to put in for a driving test and joined the CZ-Jawa owners club (these machines get to you). I went on my first long run with these chaps and the bike kept up with the 175s and 250s, but it must have been asking too much because the following morning the bike sounded rather sick. The grinding noise coming from the bowels of the engine turned out to be a shot main bearing, which not only sounded progressively worse but wrecked two sets of contact breakers as the crankshaft was able to whip around. The specified replacement bearing was a C3 which allows greater axial movement than the unmarked type, but can only be obtained from a CZ agent. I obtained a standard type from SKF for about a third of the price and had no trouble with it for the remainder of the time I had the bike.

If you have to split the crankcases on a CZ it's worth noting that new engines have no gaskets and this tends to lead to oil leaks between the vertically split halves. I obtained a gasket from CZ and with the help of some green Hermetite it stopped most of the drip that had previously soiled my shed.

Before I fixed the bearing however, I had to take my test. The examiner's face wore a pained expression as I started up my machine which by then sounded like a mobile concrete mixer. Part way through, he stopped the test because he couldn't see the brake light come on. The trouble was caused by a brake light switch with limited movement. When adjusted to come on under gentle braking, it went off again when you stamped your foot on the brake.

That about sums up the faults I had with the CZ, apart from a transmission where I could never select first gear quietly on the first change from a cold start, despite cleaning up the burrs on the clutch plate. It's difficult to comment on tyre, chain and brake pad wear as I never had to replace a chain or brake shoe and never got through a complete tyre.

Over a year and 6000 miles, with the exception of the main bearing (which was really quite cheap to replace, anyway), it supplied cheap transport until 1 changed to something more sophisticated.

I C Kennedy