New cycling gear shifting tech 'amazing'

A Christchurch cyclist owns hot new shifting technology that replaces mechanical levers with computers and batteries.

When John Kemp Starley created the first "safety" bicycle in 1885 it had a more steerable front wheel and a chain-driven rear wheel. Little would Starley have known where technology would take his marvellous contraption.

These days, top-level bicycle frames are made of aircraft-grade carbon fibre and lightweight aluminium, and the shifting mechanisms are integrated with brake levers. Some have small electric motors that do the pedalling.

At this month's Tour de France cycle race, which started on Sunday, professional cyclists are riding specialised hi-tech bikes designed to lessen wind resistance and shave hundredths of seconds from their times during the two individual time trials and the team time trial.

These days, cycling clothing is made of fibres that draw sweat away from a rider's body, drink-bottle holders are made of carbon fibre rather than steel, and recreational riders can now record not only their speeds and heart rates, but also how much power they are using with each pedal stroke - then download it to their computer and analyse it in detail. The humble activity of cycling has come a long way.

One of the latest hi-tech pieces of equipment from Japanese component manufacturer Shimano is the Di2, a system that replaces the traditional mechanical cable shifting set-up with a computer-controlled electronic one.

It is the latest bling of cycling gadgets - and Christchurch cyclist Kris Yee just had to have it.

Yee classes himself as a "chequebook cyclist" who has to have the latest cycling gear. When he saw the Di2 system in a cycling magazine last year he had to have it for his $27,000 carbon fibre Carrera Phibra bicycle frame.

In fact, the system is so new to the market - it only came out in March - that at time of writing, only two bikes in New Zealand had the system fitted: Yee's and a bike belonging to Avanti bicycle manufacturer Sheppard Industries in Auckland.

"I've had six bikes in nine years and do about 400km a week. My Carrera used to have Sram Red components on it, which were good, but I just had to have this new Shimano gear," Yee says.

The front and rear derailleurs each have a motor and a computer as part of their mechanism with shifting done by pressing a microswitch contained in each brake lever.

Yee says that while he was having his bike checked at John Bull Cycles in preparation for March's Le Race cycle ride he mentioned the Di2 system to a mechanic there and was told they could get the system for him - but it wouldn't be cheap.

Built on Shimano's top-of-the-line Dura Ace 7900 group set, the components for the Di2 group set cost about $7500.

The Di2 components were fitted to Yee's Carrera between Le Race and the start of Marlborough's Graperide, where he rode it for the first time.

Yee's verdict: "It's totally different (to mechanical shifters). It's amazing. You never have to worry that you're not going to get into a gear and it makes you really confident about changing gears. I would never go back to manual shifting."

Yee was impressed that the system is able to realign itself just before a shift so that every derailleur shift is perfect. The system has had one mechanical failure since it was fitted - during April's Round Brunner cycle ride, when it put itself into service mode. A small piece of bark had jammed between the cogs.

"I think the next step will be the fully automatic system, with buttons that let you select your riding style," he says.

Shimano 's New Zealand product man, Rene van Ryn, says the beauty of the Di2 system is that "there is no thinking required, no skill level required. You just ride and shift ".

Shimano tested the Di2 for about three years, he says, because the company knew that French component manufacturer Mavic had issues with its Zap electric shifting system in the 1990s. "Shimano has been testing the Di2 on pro teams for much longer than necessary, but it was to make sure the system is 100 per cent reliable," says van Ryn.

The battery for the system is predicted to last about 2000km before it needs recharging, but that depends on how many derailleur shifts a rider makes during the system's use.

"The front derailleur requires a lot more power and the motor on the front is bigger than on the back. It will start signalling you at about half way point (of the battery life) that the battery is running low," says van Ryn.

* For more info on the Di2, visit dura-ace.com

- © Fairfax NZ News