When a picture of the drive side arm of the Machine Tech cranks were first shown in a British mountain bike magazine in the early 1990s they caused quite a stir. We waited and waited… but unfortunately these stunning cranks never got past the past the prototype stage.
At that time, it wasn’t clear whether the rear of the 7075 aluminium arms had simply been machined out to reduce weight or whether they were of a hollow construction. This was confirmed many years later in 2011 when a picture appeared on the socaltrailriders.org forum courtesy of member ManInAShed who paid a whopping $3200 for them. It could well be the same prototype that appeared in Mountain Bike Action, as the owner confirms they are unrideable and no others are yet known to have surfaced.
The cranks follow the same idea as those from Magic Motorcycle/Coda Magic, in that the arms are of a hollow box section construction with internal spars to provide rigidity. This is an unusual construction method for cranks and one which even Coda (Cannondale) got wrong with their Coda 900 cranks which led to a major recall – the problem being that the two parts of each arm would separate where they are bonded together.
Indications from the Machine Tech prototype are that their box section arms would also have been bonded, plus a bolt near to the spider would secure the inside plate, and tightening the pedals would also prevent the arms from separating. The design itself may well have ended up being successful, but it could simply have been the cost of manufacture which ended all hope of this product reaching the market.
The cranks were only going to be released with a 110mm/74mm BCD spider. Crank caps are shown, but it is not known if they were to be included.
Axle: JIS Square taper