How to turn an MZ into a race bike:
They’re clunky, low-tech and have been objects of ridicule for years – but turning an old MZ ETZ251 into a race bike is remarkably easy.
First, get yourself a bike. A relatively new five-year-old model will cost you just £1500, and anything older than that can be had for pocket money.
Next, remove everything that isn’t needed. Lights, speedo, rev counter (though some people keep this), plastics and anything else that can be dumped is. Saving weight is the key. A good MZ racer is just 100kg (220lb), nearly 50kg (110lb) lighter than the road bike.
The engine can be tuned and ported and the piston changed. Usually a Suzuki 250 trail bike piston is used, which boosts power from 21bhp to a staggering 30bhp. The oil pump is junked and the bike is run on pre-mix to save weight. A closed loop ignition system from a go-kart means you can lose the battery.
The whole exhaust is moved from the right to the left side of the bike for ground clearance. Some changes are allowed to the end can, though its diameter has to remain the same.
The carb is bored as big as it will go and re-jetted. A quick-action quarter-turn twistgrip from a motocross bike makes response quicker. Clip-ons replace the commuter bars.
The forks have to remain the same, but are usually revalved, and the shock can be replaced. The tank has to be kept, but most racers add a second fuel tap to get more fuel into the carb.
Brakes can be changed, but most racers run standard calipers with race pads, steel lines and drilled discs. If you have the cash, wheels can be changed, and some opt for 17in TZR125RR wheels which can run slicks. Poorer racers use MZ wheels and super-sticky Dunlop race tyres.
Before you go racing you need an Auto Cycle Union (ACU) race licence. Call: 01788-566416 for an application form. Before you send it back with your £27 membership fee, there are a couple of other things you need to do. First, get a sight test at your local optician for around £20 and enclose the result. Then you need proof you’ve joined a race club. This can be either a membership card or a signature from an authorised official. I joined the British Motorcycle Race Club (BMCRC), which organises MZ race meets, for £30. I sent them my ACU form as well as my membership application and they signed it and sent it on. Sorted.
If it’s your first time racing you’ll also need a novice orange jacket. The ACU will supply you with a jacket for £5 – just add it on to your application fee.
Obviously, the ACU gets loads of applications near the start of the season, so get this done as soon as possible. Every year loads of racers miss the first few races as their licences are still being processed.
MANY MZ riders change their wheels for 17in ones and run slicks, but those who can’t afford to do that stick with the 18in MZ rims and use Dunlop KR825 tyres. These are
race-only and stick like nothing else, especially on a bike that weighs just 100kg (220lb). There is a rear fitment, but the KR825 front can be used on the back, which helps the bike turn in faster. One set of tyres will probably last a season and cost around £160. They can be bought direct from Dunlop on: 0121-306-3553.