With the production of the MZ motorcycle, the East Germans, back in the days when Germany was divided, made a machine that could run on terrible fuel, was tough and reliable and was a triumph of function over form. They're generally reckoned to be horrendously ugly and offer the motorcyclist an extremely budget-conscious ride, earning him or her the lowest possible status in the world of biking. The chassis is terribly heavy, with very cheap suspension and the two-stroke engine smokes terribly and steadfastly refuses to rev to more than about 5,000rpm. An average road 250cc MZ makes about 12bhp and barely tops 65mph - downhill and with a following wind.
A few years ago, some bright spark decided it would be very cool to strip the chassis, tune the engine and start a race series for these bikes...
Why Race MZ Motorcycles?
MZ racing rules allow for very few modifications to the bike, compared to other race series, in order to make this the cheapest possible route into racing. The bike can be purchased, prepared and the engine tuned, for under £1,500. Compare this to around £5,000 to £7,000 for a Super Sports 600 race bike. MZ racing is no less competitive than any other series and has developed a strong following of dedicated racers. The British MZ Racing Club travels around England to compete with Bemsee at Club level. If you want to race, but are short of cash, this is the way to go.
Bike Preparation 1 - the Chassis
The first thing to do is to totally dismantle the bike. The frame and chassis have all sorts of extra bits and pieces on them that can be cut off or discarded, such as:
Centre-stand and a huge chunk of metal that holds it in place.
Loads of little fixing and locating lugs.
The air-box and air-cleaner.
All of the electrical system, including the battery.
Two-stroke oil tank.
Rear mudguard assembly.
Rear exhaust mountings.
And this is by no means an exhaustive list.
The foam on the seat is very heavy. Although you have to use the original seat base, you can remove almost all of the foam, going as far as your buttocks will allow. Most people leave a little hump on the back as a rest so you don't slide too far back along the seat when crouched over the bike. The forks are lowered through the yokes, and some people have them shortened. The rear shocks can be changed1 but you can't adapt the suspension to use a mono-shock arrangement, or move the mounting points. The wheels and brakes can be exchanged for units from other bikes - Yamaha's TZR125 being the most popular donor here - to save weight. Clip-on handlebars are fitted below the top yoke, to allow a more sporty seating position and to save more weight. The hefty footrests are removed and rear sets fitted. The general rule is 'save weight to gain speed' and it's a remarkably effective way of boosting the top speed and acceleration of these reluctant machines.
Bike Preparation 2 - the Engine
The engine can then be removed and sent for tuning. There are a fair number of people doing tuning for MZ engines and you don't have to have the whole thing done by one tuner. The top end can be done by one person and the bottom end (particularly the clutch and gearbox work) can be done by another. Modification to the gearbox - the third gear selector forks - is essential to produce a reliable gearbox that will function properly under race conditions. To prevent money being a substantial factor in competition, this is the only gearbox modification allowed.
The oil pump and feed pipes are removed. Virtually all racing two-stroke engines run on pre-mixed fuel and recommended is Castrol A747, a superb oil. Many riders also remove the rev-counter and so the mechanical rev-counter drive can be removed from the side of the engine. There's quite a lot of work done in the tuning and most tuners work in different ways. The piston is changed to a Suzuki one, as this is lighter and stronger, helping the engine to rev higher and sustain those higher revs for longer. The basics include polishing the cylinder head and grinding this head to the barrel thus removing the need for a head gasket, altering and increasing fuel/oil mixture flow, adding ports to the head and piston and some serious black magic.
The standard exhaust breaks ACU rules as it sticks out beyond the back of the bike. Most tuners offer an alternative of some sort, based on the original but with altered internals. Expansion chambers are not allowed. The carb doesn't allow for enough of a fuel flow and so is widened and the internals polished. There are various other bits and pieces to do, mainly to save weight, but this is the main stuff.
Get out There...
To race in the UK you need an ACU licence. You also need to be a member of a recognised racing club and for MZ racing that's Bemsee - the British Motor Cycle Racing Club. At the time of writing the licence will cost £22 this year and first timers - the 'novices' - will also have to get their eyesight tested. Bemsee membership is another £15. Novices have to wear a 'wally2 bib' - an orange vest that shows other racers that they're new to the sport. After completing ten races at at least four different race tracks (with only one race from each race meeting counting), the bib can be discarded.
At each race meeting your bike has to be passed by the 'scrutineers', who check to see if it's a safe machine to ride. They also check your leather one-piece (two-piece leather suits are not allowed), gloves, boots and helmet to make sure they are safe and undamaged.
What's it Like?
Exceptional. If you want an adrenalin rush like you've never had before, this is the sport for you. But be warned, motorcycle racing is horribly addictive and will take over your life.
It's not for everyone. Many have gone out, had one go and said, 'this isn't for me'. Fair enough - there's no shame in not liking something. But you're not likely to meet a racer who just regards racing as a pastime. If you do take it up, you won't be able to do it half-heartedly...
A well-tuned MZ is capable of over 100mph and accelerates hard. Good ground clearance and low weight combine to create a machine that has a high corner speed. Getting and keeping this corner speed is one of the main parts of MZ racing. Larger and bigger-engined bikes often get in the way on the twisty parts of the track. All in all, a surprisingly nimble and fast race bike can be made from an old East German monstrosity.