Ridden: Porsche Bike RS

Take a fully carbon fibre Porsche around the 'ring they said. Enjoy performance "inspired by the company's GT road car department" they said.

Only it didn't quite work out that way. True, I was spared the schlep across Belgium. But the Porsche in question was only one manpower and for the 'ring you can substitute Richmond Park in south-west London. In cycling terms it is like the Nordschleife though, the undulating tree-lined seven-mile 'lap' plied by hordes of roadies and loved for its light traffic and smooth tarmac.

There are many astounding things about the Porsche Bike RS, from the 9kg (19lb-ish) overall weight and carbon construction to anodised trinkets from boutique component suppliers Crank Bros. In the reflected blue glow of the various aluminium accoutrements you could - almost - lose sight of the fact the RS costs, deep breath, £5,000.

Anodised goodness
That's a pretty hefty pricetag, even for the well-heeled Richmond Park MAMILs. Does the application of a Porsche badge on this bike justify it?

Well, it's a bit of a mix. First up, for Richmond Park posing it's not quite sure where it should be - on the tarmac loop or rather the gravel off-road (ish) track that surrounds it. The Bike RS is, essentially, a 29er mountain bike, one of a new breed of bigger-wheeled off-road machines (mountain bikes traditionally run 26-inch wheels) now really taking off on the UK scene after taking the States by storm. Only it has neither suspension forks nor off-road tyres.

So it's kind of a road bike. Only it isn't really. So, it's an off-road machine wearing oversized wheels, street tyres and with pretensions of mixing it with dedicated sports machines despite its apparently unsuitable foundations. It is, put simply, a Porsche Cayenne Turbo S on two wheels.

Down on power
Well it would be if the powerplant wasn't seriously down on power thanks to a bout of seasonal man flu. To be fair, even with the engine's breathing seriously constricted the Bike RS is respectably rapid.

The carbon frame, admittedly gracefully designed and built with the assistance of respected German bike brand Rotwild, has a lightweight twang to it and that distinctively hollow resonance you get on all such bikes.

On a quality carbon frame like this manufacturers can do all sorts of clever stuff to tune the stiffness to where you want it. In simplified form you want lateral rigidity for power transfer but a bit of vertical give so it doesn't shake your fillings out, the kind of tuning you simply can't achieve with conventional metal tubes no matter how exotic the material.

Tinsel and baubles
You can't fault Porsche for the build on the Bike RS either. The Crank Bros wheels, bars, stem and seatpost are all stunning pieces of kit and artfully combine carbon fibre and anodised aluminium in a way that makes impressionable wallets open wide and say "aaah!" And the 2x10 speed Shimano XTR drivetrain is beautifully made and shifts with the crisp precision of a PDK gearbox.

The big wheels and fat slick tyres take the edge off the bumps and harsher edges of the carbon frame. And it accelerates fast enough to humble at least one Richmond MAMIL. Yes, you are being overtaken by a mountain bike on slicks. Deal with it.

Billy no mates
All very impressive but the elephant in the room remains exactly who's going to spend this kind of money on a bike like this. Porsche reckons it's an 'urban bicycle' with 'ride anywhere capability' for Porsche owners living the lifestyle dream. Which urban utopia Porsche reckons is safe for leaving £5K bikes outside the corner shop or restaurant isn't entirely obvious, most city cyclists preferring slightly more modestly priced bikes for good reason. £5K would get you a lot of Boris bike miles too. And that amount of money on a 'proper' road bike would see you leaving the Bike RS for dust while a top-spec 29er mountain bike could be had for half that much.

Cyclists are an elitist, brand obsessed bunch too and in a two-wheeled context the Porsche badge has little credibility, especially at this price bracket. The Porsche brand might have stretched to a purist road bike at this price and while there's nothing wrong with the concept or build the Bike RS has been saddled with at least one too many zeroes on its pricetag to make much sense.