Custom Timetrial machine
There is a lot of talk about how 'aero' bikes are, especially for time trialling. But the simple truth is that the rider is causing most of the drag. Therefore the most important thing is to get the rider into as aerodynamic position as possible. I have been a student of time trialling for a long time - back in the UK you can (and I did!) race three or four TTs a week all season. It is often not possible to get in the best position on a stock bike - for example I have very long arms and so could never get low enough on a conventional setup. To get around this I built an integrated fork/bar/aerobar, and a frame to match with a 76 degree seatangle. This combination enables me to get my back flat whilst holding a powerful position (in 2008 the bike proved itself by taking me to second in the Oregon State TT champs in a time of 51:51 for 40km; in 2009 I went one better, taking the win with 51:13). Weight is a minor consideration compared to drag for a flat time trial, but with a weight of 16lbs the bike is light too. I custom machined both brakes in order to fit them neatly out of the wind. The aerobar extensions are aluminium and bolt on, allowing some adjustment, along with the height of the armrests.
Over the winter of 2009 I designed and built a special TT front hub which I then built up onto an Edge 1.68 rim. This replaces a Zipp 1080 on the front of the bike, with the intention to provide a similar level of aerodynamics with much easier handling of windy conditions.
Original CAD model prior to building:
(riding shots thanks to Tina Buescher: www.tinabuescher.blogspot.com)
Specifications:Frame: English custom built steel TT, integrated seatmast 1429gFork: English custom built steel TT, intergrated fork/bar 754g Aero extensions: English custom aluminium 174g Armrests/pads: Oval carbon 114g Headset: Chirs King 1" NoThreadSet 100g Seatpost: English integrated 48g Saddle: Selle Italia Flite 214g Brake Levers: Vision TT 72g Gear shifters: SRAM R2C carbon 175g Front brake: English custom single pivot pulley activated 66g Rear brake: English custom scissor action center-pull 92g Crank/BB: FSA Neo-Pro carbon, 170mm, 42-54 980g Pedals: Speedplay X2 198g Chain: KMC X-10SL 224g Front derailleur hanger: English custom bolt-on 14g Front derailleur: Shimano Ultegra 76 Rear Derailleur: SRAM Force 176 Cassette: Shimano Ultegra, 11-23 10spd 218 Front wheel: English TT hub, Sapim CX-ray x 16, Edge 1.68 rim 506g Rear wheel: Zipp Disc 980g Tyres: Vittoria/Veloflex tubulars 490g Wheel skewers: Tune Airline 18g Bar end plugs: English custom 14g Bar tape: Profile 10g Cables: Nokon 80g Computer: Cateye wireless 55g Weight: 16.0lbs |