I have a 1970's Aprillia licence built CZ 350 which differs considerably in performance and component parts from the Czech built machines.
Mine does 107 MPH and is powered by a JAWA Type 631 engine fitted with Italian bearings, Italian ASSO Werk hi-compression 14.5:1 pistons and Aprillia electrics including their famous sealed beam unit.
The bike has completed 79,000 miles so far in all weathers reliably. In the 1970's Aprillia made the only Italian bikes that could run at night in the rain.
The bike weighs 291 Pounds.
Gear speeds are:
Up shift into 1st gear to 42 MPH.
Down shift into 2nd to 67 MPH.
Down shift into 3rd to 78 MPH.
Down shift into 4th to 107 MPH.
Power delivery is pure torque and not through revs, so accellertion is more than you'd expect from a similar Japanese or Italian stroker.
Brakes are TLS drums on both wheels which can easily lock both wheels even at past 70 MPH.
Handling is like being on rails, and back in the 1980's, the only bike that could give it the run for its money through twisty corners was a friend on a Benelli 2C twin.
The exhaust note sounds like movees from a lumpy V8 dargster at tickover, to a deep banshee howl when on the gas.
And then I fitted expansion chambers, port and gas flowed the engine.
Engine spec is 38 Pounds per Foot torque @ 3,800 RPM
Maximum engine power output is 30 BHP @ 6,500 RPM
Compression is 14.5:1
Clutch is by hand and foot assisted slick shift.
The clutch needs Suzuki GSX750R spring fitting as the engine will eat a set of clutch plates in 3 months otherwise (see torque output)
This then requires the rider to develop a vice like grip on the left hand. Use of the clutch is a boon with this arrangement.
Another fault is the chain tensioner, a problem on the power restricted Czech CZ 350s but a bloody pain inthe arse on the tuned up Italian built bikes. The enegine torque just rips the things apart, so the remedy is to drill the things out and fit a high tensile aircraft grade bolt. Ordinary bolts will stretch and snap within a week.
Braking is about 200% more than neccessary and locking up both wheels is possible on even Metzler tyres on a hot dry road, due to the bike's lack of weight.
Aprillia made licenced versions of the CZ 125 and 175 singles plus the 250 and 350 twins. These bike were built in Italy from 1969 onwards, along with a licence built Zundapp 50cc sports moped, in odrer to avoid the heavy import tax then in force on foreign motor vehicle imports. The bikes had to have a fair percentage of Italian produced parts.
This was the electrical system, piston, bearings but fortunately, the chrome remained the expensive thick Nickel based heavy Chrome finish that the Czechs are just so good at.
Major differences:
The ignition keys have Aprillia on them. Colours were always Brown and Cream (not a Czech used colour scheme), sealed beam headlight, totally different wiring loom.
Also engine peformance is vastly different.
I have a picture somewhere of one of a friends 250cc versions.
