FORMER Australian Superbike champion Malcolm Campbell will this weekend trade the seat of his 100 horse-power back hoe for the saddle of a 130 horse-power racing Honda motorcycle when he competes in the International Challenge at Phillip Island.

The four-race series features a who's who of international and national motorcycle champions racing for teams from Australia, the UK and the rest of the world.

Campbell said that he was also entered in the newly established Period Six category - for motorcycles built between 1983 and 1990 - on the RC30 Honda with which he captured his superbike titles.

``But the International Challenge is my main focus and if the period six racing infringes on the time I need for the challenge, it will be the one to go,'' said Campbell who has previously finished second in the series.

``Although the challenge is a team race, there is also an individual winner and all the top racers will be aiming for that.

``Unfortunately for me, age (58) isn't on my side, especially compared with some of the young pups I'll be up against.

``I'm hopeful of good results, but I was at Symmons Plains last weekend and my son Scott was 1.8 seconds a lap quicker than me - that's a bit of a reality check, age-wise.

``But there are four races in the challenge and it's all about finishing each one and accumulating points for the overall win - competition at this level is so high that work on the bikes' motors is overdone to the extreme and they tend to be a little fragile.''

Northern Tasmanian historic road racers Mark Holman, Michael Dobson, Mick Damon, Peter McCormack and Hobart brothers Murray and Scott Seabrook will be among 250 riders on 340 machines to compete in the event's 44 feature and support races.

Campbell said that he was not one for organised preparation and expected to be packing his gear at 5am today for his 6am flight to the mainland.