Friday, 20 April 2012

Lighter Than Air written by Phil Cavell of Cyclefit

Thanks to Guy Pearson from Pearson Cycles for stepping up and helping with this review. My back problems are keeping me away from riding still.

Guy on a Guru

I did spend a fair amount of time on the Photon last summer and I managed to grab a short refresher this 2012 test-bike also. I value Guy's opinion greatly - I had a grudging respect for Guy for much of my racing career (he was on a different team) - we often seemed to end up in impossible breaks together and as a result contributed inordinate amounts of work to carry group of dandy free-loaders to the line. In short we are (in my case were) rouleurs not afraid to lean into the road ahead. Also like me Guy tends ride well in technical terrain where experience and smoothness keep momentum when some cannot resist the comfort of braking. We are also the same height and ten years ago resembled each other on the bike.

Guys Calves!Guy's calves give chainstays something to think about

And that's quite enough of the Guy love-in - lest we forget that nine years ago I would have happily burst my left lung to beat him in a sprint!

'An Engineer's Bike'

The design brief for the Photon was simple - build the lightest custom frame in the world ever. Sub 700 grams was the target weight. The actual frame the client receives will depend on their weight and riding style but between 650 and 750 grams is typical in our experience. This test-bike built up to 12 pounds or 5.8kg without any special effort at all.

LightweightJust 5.8kg!

To consistently achieve these unprecedented weights takes about forty man hours of precision engineering per frame. We were astonished when went to Guru in December just how labour intensive and micro-focused and controlled their carbon construction is - the whole place has the feel of a Formula 1 research lab.

Guru or Laboratory?Guru factory or NASA Lab?


Carbon But No Copy

A significant part of the Photon frame is constructed with unidirectional intermediate-modulus, high-strength carbon. This gives a good balance of strength, feel and weight to the Photon fuselage. But in key high load areas the structure is reinforced with an incredibly high-modulus carbon weave, which by nature is stiffer and lighter. To work at this level requires skill, precision and time that would simply not be economic on mass-produced frames.

40 Hours to Make a Photon!It takes 40 hours to make a Photon

Similarly Guru use a significantly higher fibre-to-resin ratio than most manufacturers so the volume occupied by resin is minimized to enhance mechanical properties provided by the carbon filaments.

The reason this is not industry standard is cost - the whole process is less forgiving and more time-intensive and therefore more expensive. This is only really possible on a handmade high-end product.


Flying The Photon

The Photon as outfitted here is exactly half the weight of my 1992 7/11 replica bike that is on display ten feet from where I am writing. Half the bloody weight! Now we are not weight obsessed here at Cyclefit but a bike this light writes its own script. Everything else is merely sub-plot because the main narrative is how different it feels to what you normally ride right?

And this is not the lightest groupset, with the trickest brakes or freaky tyres and seatpost. This is solid everyday gear with the addition of Lightweight's entry-level Ventoux wheels. What Guru has been able to do by beating the likes of Parlee and Cervelo, not by sliver but a few hundred grams is astounding. Partly in increasing the overall power to weight of the athlete but more especially in the dynamic balance between the rider and the bike. It just feels like a re-defined relationship to what most of us are used to most of the time. You have a sense of your relationship to things in life: the weight of a full kettle, closing resistance of your car-door etc. And when things interact vastly from your experience and therefore what you expect, it is a paradigm shift. It is bewildering.

Guy gets taken by surprise!The lack of bulk takes Guy by surprise

And bewildered sums up Guy's first experience.

"I did not expect that. Everything happens in a hurry - acceleration, turning, stopping. To start with the thing felt just to light to lean - surely it will fall over?"

You naturally expect so much to have been sacrificed for light weight - the first casualties being ride quality and strength. But this really is not the case. The Photon has a well attuned harmony and resonance with the road and rider. In the thousands of hours Guru spent making the Photon light they also overcame all the challenges to making it ride well and strong. Myself and Jules witnessed the destruction rig at Guru and what it can do to a bike - look at the little movie the from the Guru Factory.

The guru engineers are of the opinion that the Photon is the strongest carbon frame they have ever built.

Guy RidingThe eyes have it

We are about to equip GPM10 with Photon's as their staff bikes. Mark and his crew ride thousands of the toughest miles per year possible in all weathers. They crash a bit and throw the bikes on and off their roof-racks daily.

£4400 - Frame and fork - Full Custom


By Guy Pearson and Phil Cavell

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