A new cycling revolution is hitting Australian streets, but a prominent road safety expert has sounded a warning about the rise of electric bikes.

Key points: Electronic bikes continue to grow in popularity

Electronic bikes continue to grow in popularity Bikes are powered by both pedalling and a small electric motor

Bikes are powered by both pedalling and a small electric motor Home-made 'Frankenstein' bikes can flout regulations

Home-made 'Frankenstein' bikes can flout regulations Regulators recognise challenge in keeping up with technology

It comes as more powerful e-bikes are released on the Australian market, capable of travelling at 80 kilometres an hour.

Road safety advocate Don Aitkin expects to see e-bike numbers rapidly increase in the coming years, along with the incidence of serious injury.

"That's serious speed — and if you hit a pedestrian at that speed, you'll do him or her great injury," Professor Aitkin said.

The bikes look like normal pedal-powered bicycles but have the assistance of a battery-powered motor on either the front or rear hub, or through the crankshaft.

They do not need to be registered, nor do their riders need to be licensed.

Under Australian road regulations, bikes sold for on-road use are limited to 250 watts and capped at 25 kilometres an hour, but the ABC has discovered it is easy to exploit loopholes in the legislation and travel much faster.

Some commuters are using bikes designed for off-road use, or heavily modifying their own cycles — and there is little current laws can do about it.

'Frankenstein bikes' a high-speed recipe for disaster

Bicycle retailer Trevor Rix says e-bikes are growing in popularity. ( ABC News: Ian Cutmore )

Retailer Trevor Rix said electric bikes were becoming a popular option for cyclists looking for a bit of battery-powered assistance uphill.

"They might feel that they're more like a motorbike, they might feel that they'll not be able to handle them, but ... when you ride them, they are fantastic, just like a normal bike," he said.

Mr Rix said most e-bikes sold in Australia cost between $3,000 and $7,000, about the cost of a trendy Italian scooter.

Simone Annis said many cyclists used kits purchased online to build their own e-bikes. ( ABC News: Ian Cutmore )

However, the internet is full of examples of e-bikes being ridden faster and dangerously in heavy traffic on Australian streets, than the legislation is designed to allow.

Online videos feature electric bikes capable of producing 1,000 watts or more, designed for off-road use, being used to keep up with cars on the open road at speeds of up to 80 kilometres an hour.

And Canberra retailer Simone Annis said some riders were making dangerous modifications using imported components to create their own 'Frankenstein' electric bikes.

"We see people all the time with bikes which are just hideous bikes, with not very nice kits on them, which they've bought over the internet," Ms Annis said.

"Obviously we wouldn't encourage that, and it could be highly dangerous riding a really, really fast bike with brakes that don't work properly and so forth."

Mr Rix agreed it was impossible to police what people did in their own home workshops.

"So you have a reasonably low-quality bike, with poor brakes and poor handling capability, with a 1,000 watt engine on it ... it could be a recipe for disaster," he said.

Regulators caught flat-footed by e-bike trend

The same governments that are urging commuters to ditch their cars in favour of bikes, are now being accused of being left behind by rapidly changing e-bike technology.

Professor Aitkin, who is chair of the NRMA-ACT Road Safety Trust, said governments needed to decide where e-bikes belong.

ACT Road Safety Minister Shane Rattenbury said it could be a challenge for law makers to keep up with technology. ( ABC News: Ian Cutmore )

"I think it is a very awkward fit. The assumption has always been for a hundred years that bicycles fitted this kind of area, and motorcycles that kind of area, and cars the big road," Professor Aitkin said.

"I think all of that is changing.

"This is a step-jump technological change, nothing like it has occurred for a hundred years in this area, and we're going to have to get used to it."

ACT Road Safety Minister and keen cyclist, Shane Rattenbury, agreed it was a political challenge.

"The technology is constantly evolving ... and government across the board is, I think, at times having to play a bit of catch-up on technology, and that is a challenge for us," he said.

"But certainly the ability for increasing speed and power is a challenge, and will present safety issues down the line if people are being reckless."

Electric bike a 'life saver'

The lycra set may sneer at what they consider e-bike 'cheaters', but many of those who ride them, swear by them.

Cyclist Carl Tallar says purchasing an e-bike helped him lose weight. ( ABC News: Ian Cutmore )

And that includes Canberra security guard, Carl Tallar, who was convinced to try an e-bike for his daily commute.

Seriously overweight, Mr Tallar purchased an electric bike three years ago to use riding to work.

He has commuted 30 kilometres a day to work since.

"I've actually lost something like 35 kilos," he said.

"I was 170 kilos when I first started, and to be honest with you I think to myself that I might not even be here if I didn't start riding.

"It's made me a lot happier person - my children have noticed."