May 162012

Got my frame all built up. Here are the photos!

 Posted by at 3:35 pm
Apr 132010

I was in your March [2008] Steel TIG class.

I built my frame to be a time trial or pursuit track bike. I copied a lot of the geometry from a 56cm EAI Bare Knuckle that fits me well. However, I made some adjustments to move the bottom bracket back by about 35mm and up about 30mm. This is a bit counter-intuitive for some, especially those who believe your knee should never be over your toe during your pedal stroke… But, I claim that it depends on when and where you apply your power. This adjusted bottom bracket helps me open up my body to leg angle which I hope gives me a bit more muscle efficiency. Of course, I’ll have to prove this on the track…

Although the first home for this bike is the track, I wanted the option to use it in any sort of fixed gear road event. The increased bottom bracket height from the ground allows me to run slightly bigger cranks (72.5) and still be a bit aggressive on flat corners.. Some worry that this increase in height may be unstable or un-aerodynamic… we’ll see, hopefully these guys will be behind me at the end of the day…

I did discover by accident (not by design) that my special geometry will allow for full bar spins… nice… bonus…

Top Tube: 25.4mm Columbus 8-5-8
Seat Tube/ Down Tube: 28.6mm Columbus 8-5-5
Chain Stay: Kaisei
Seat Stay: Columbus
Surly Track Hooded Rear dropouts

Frame weight: 3.5lbs (un-painted)
Built Bike weight: 15.5lbs

Fork+Stem: Oval Track
Bars: Nitto
Headset: Chris King (of course)
Crank: Sugino 75 (72.5mm crank-arms)

Reynolds Track w/ Phil Wood Hubs for training (tubular)
CaneCreek Sprint 85 for race (tubular)

Paint: Rattle-Can Auto Metallic Black paint, primer, and clear-coat
+ Silver Sheet sticker stock from local hobby shop

 Posted by at 3:17 pm
Apr 132010

This is a 650c-wheeled track bike for racing on the San Diego velodrome. I built it to replace my 49 cm Bianchi Pista, which is a great first track bike, but was always a little too big for me. My design goals were to raise the bars to a more comfortable position while maintaining sufficient standover clearance, and to eliminate toe overlap.

I spent a lot of time on the finish work (which is still not quite done). I will be sending it out for paint soon, but I wanted to give it a test-ride before the end of the track season, so I laced up the wheels and built it up. There’s not much to it – Nitto bars, NOS Shimano hidden-clamp stem, Harris track hubs, Velocity rims, and Sugino 75 cranks. It turned out to be very sensitive to chain line due to the smaller distance between the bottom bracket and rear hub.

My first ride was absolutely fantastic. It rides like it was built for me – imagine that! At 60 mm trail, it holds a perfect line without being at all sluggish to steer. I’d describe the ride quality as spirited – I feel every bump and variation in traction, but without any harshness. The 650c wheels spin up faster, and I find myself racing harder because the bike is so responsive – it will go as fast as I want to go, and then some! My only complaint is that I should have left the chainstays a bit longer. My tires are a bit taller than their nominal 23mm width, so if I leave enough chain to remove the rear wheel without deflating the tire, the axle is all the way at the ends of the dropouts. If I switch to 19mm tires and take out a link, it’ll be perfect.

The bike got a lot of attention at its track debut. I kept finding myself telling people how satisfying it is to design and build your own frame. This one isn’t even done yet, and I’m already thinking about my next one, or two, or…

Thank you for a wonderful class!

 Posted by at 2:17 pm