This bike was shown at Bespoked 2014 where it won the Steve Worland award for "Most innovative design" for the use of conductive paint (essentially powdered silver in varnish) to form the power and signalling circuits for the Di2 groupset.http://talbotframeworks.co.uk/wp-content/uploads/2014/04/innovative1.jpg
I mention this because it was something we did purely for the fun of it, because we had the idea and thought it would be cool- and for no other reason.
With that said, one of the nicest things about the show was the validation that yes, other people thought it was fun as well.
On to the bike!
This bike is called the Dalsnibba after a mountain in Norway- a mountain that has an annual duathlon run on it's slopes.
I'll be racing this bike (or the second version of it- more on that later) in the duathlon this June.
That had some input on the overall design- we wanted the frame to be very stiff around the BB-Chainstay area for power transfer (what little of that I have I don't want to squander), and also to steer very precisely for the descent- again, I need all the help I can get there as last year I was shaking so hard that I could barely hold the bars.
To that end we used a 38mm Columbus Spirit downtube, with at one end a Paragon Machineworks 44 headtube and at the other a Paragon Machine Works PF30 bottom bracket.
The fork chosen was an ENVE tapered steerer unit, again stiffness was a key consideration.
We used a Columbus MAX bi-axially ovalised top tube, in the reverse orientation than is normally seen.
The thinking behind this was to ensure that the joints to the 44 headtube at one end and the 28.6 seat tube at the other were allowed for in the orientation of the tube, and provide nice large contact areas for the fillets.
We also thought it looked cool.
The seat tube we chose was Reynolds 853, swaged from 28.6mm at the top to 31,8mm at the BB, in order to keep the frame stiff around the BB cluster but to allow some flexibility nearer the seat cluster.
Chainstays and seatstays were a mixture of Columbus Zona and Life, and a wishbone was chosen for the seat stay.
This connected the two 14mm seat stays to the 16mm wishbone, the idea being to take advantage of steels ability to flex without work hardening and becoming brittle.
As an old man I liked the idea of comfort, without sacrificing stiffness.
The dropouts were Paragon Machine Works, and I think that concludes the tubing choice and design- it was all mitred on the Talbot End-Mill, and then fillet brazed by Matt on the Anvil Journeyman jig in his workshop in Crystal Palace.
Once the frame was finished it went to Mario Vaz who primed it, painted it brilliant white, then painted the blue sections on the top tube, seat tube and seat stays.
The frame then came back to us, where we bonded on flexible terminal pads just behind the head tube, and on the seat tube and DS-chain stay.
The bare circular patch of metal you can see is because we used the frame itself as one of the circuits- it is the negative.
I'd spoke to a friend who is a very talented painter about the circuits- without letting on that that was what I had in mind, he'd recommended going to a Pin Striper, so we found one in Croyden, a lovely guy called Neil, who we took the frame too in order to have the circuits painted on.
We then used the services of the "masked engineer" to solder on the (remnants of) the Di2 wiring harness.
He did a very neat job- which because we ran out of time had to be left visible:
The plan was to pot these joints in epoxy, then wrap then in vinyl dressing tape, and then clearcoat the whole frame.
That we didn't have time to do that was a blessing in disguise at Bespoked as people could see what we were talking about.
Although it did look distinctly "prototype", which is fair enough as that is what it was.
As it stands the bike weighs in at 7.2kg, with HED Stinger 4's and an electronic groupset from 2009.
I'm happy with that- we could hit the UCI minimum with a change of wheels and a modern group.
More here: http://talbotframeworks.co.uk/bikes/dalsnibba/