lower bottom bracket

My high BB experiment didn't work too well. That position didn't deactivate my quads enough but it sure did drain them of oxygenated blood. It's very easy for them to go anaerobic. I lowered the BB 9". It looks more aero this way, too. I haven't ridden it like this but it should feel very much like my other laidback bikes. Who knows, given there is a slight forward tilt to my position compared to my two-wheelers, I might see a little more power.

A couple of years ago I saw a picture of a British homebuilt lowracer with a laidback seat and a high bottom bracket and thought that if I ever built another race bike I would build it like that. I forgot about that idea and later built a lowracer with a relatively low BB. Lately I've been riding with an extra high BB and seat angle on my trike. While my legs, the knee area specifically, really liked this I found the position to be systemically stressful and tired of it. I laid back the seat to see how it feels with the high BB (14" over seat height) and initially, surprisingly, it feels very good and natural. I'll train with it and see how it goes. Hopefully I'll be able to activate my posterior chain more while not paying much of, if any, an aerodynamic penalty.

My goal, as of now, will be to beat BritCPower's trike record at the Putah Creek TT.

BB lift

I raised the bottom bracket about three inches. There is about a 13" seat/BB differential now. I did this to reduce the activation of the quadriceps during the push portion of the pedal stroke. This shifts the effort from my predominately fast-twitch quads to my slow-twitch glutes and hamstrings. It's also easier on the knees. Given the upright seat I'm guessing it'll be more aero too.

I had to move the idler bolt forward and down a bit to clear the chain under the seat.

Helmet mod

I Nils van der Walled my helmet to fit my tailfairing. I'm also trying out some Birk-like bars. They make me feel Euro-sexy.

seat back modification

I put a lumbar curve in the seat back. This allows me better extension to the handlebars, opens my ribcage and allows me to sit into the tailfairing. This latest version of this bike was meant to be a toy but I'm getting a real good feeling about its race potential. It puts me into a good power position and handles better than any bike I've ever had. The good handling translates into a more relaxing ride and reminds me of my trike in that regard.

tailfairing mock-up

Downsizing