Gruber Assist electrifies just about any bicycle
By Darren Quick
May 5, 2009
May 5, 2009 There’s a few reasons why cycling has remained a popular form of transport for over a century. It’s cheap, keeps you fit, is environmentally friendly and it’s fun - usually. Unfortunately it can get a little less fun when you hit a steep hill or have neglected your fitness for a while. This is where electric assist devices such as the Gruber Assist can come in handy. They still let you do most of the work, but help to make the job that little bit easier. Whereas electric bikes such as the E+, the eneloop and the Gocycle electric bikes require the purchase of a complete bike to get some electric assistance, the Gruber Assist can be retrofitted to practically any bicycle provided it has a seat tube with an inner diameter of 31.6mm.
The Gruber Assist auxiliary drive consists of a 22cm cylindrical unit that houses the motor, gears and freewheel and an electronic control unit that serves as the brains of the drive. Both the drive and the electronic control unit are hidden from view – the drive is inside the seat tube cavity and the control unit is built in to the supplied seat post. This means the only way someone will be able to tell that your sudden burst of speed was provided by the drive is by the electric whine of the system as you cruise by. That is assuming no one notices the small button placed on the end of the handlebars, used to control the system, or the saddlebag containing the rechargeable battery, used to power the system.
Although the auxiliary drive is permanently connected, the system employs a freewheel when not in use to ensure the device doesn’t generate any additional friction. The NiMH battery weighs 900g and fits into a conventional saddlebag. It provides you with motor-assisted cycling from 45 minutes to 1.5 hours, depending on how hard you pedal, while an optional 1kg lithium-ion Mangan battery provides assistance for longer.
Gruber is not only aiming the Gruber Assist at those who want some extra help getting from A to B, but also serious sportspeople who want to maintain a constant pulse rate regardless of the terrain they are riding on. That's just as well since casual weekend riders are likely to baulk at the £1649 (about USD$2,473) price tag.