How do you make a Cervelo P2 faster? This was the question I needed to answer in an attempt to save 5mins off my 50mile Time Trial PB.
I had thought I was already at the aerodynamic limit of the P2; it is (was) a popular bike among triathletes because of its slightly less aggressive (comfortable even?) geometry that is meant to make running straight off the bike easy.
However I needed to find a 5min saving somehow, so I decided to start exploiting some marginal gains. 5minutes is a lot to shave off a 50miler, so marginal gains alone probably wouldn’t be sufficient, but it would be a start.
I inspected my bike (See picture, below, before improvements) and thought of some areas that could be improved;
- The front end was too high. I rode this same set up in a 12hr TT and whilst not exactly comfortable, I felt for a 50mile TT I could go much lower. Unfortunately, with my existing stem/bars set up I was as low as I could go.
- The cables were routed externally and untidily in places. Probably not a huge source of aerodynamic drag but obviously doesn’t help, and more importantly looks rubbish.
- The bar tape was fairly bulky and unclean. Again, not exactly a parachute attached to the bike but may cost a few precious watts.
- The front brake (side arm) stuck out quit far from the silhouette of the frame.
- A Standard water bottle and cage was fitted on the downtube. The cervelo P2 has a very narrow downtube and the water bottle placed here sticks out like a sore thumb.
The picture below shows the bike after the improvements. This is what I did;
- I fitted a TriRig stem (see LINK – I bought mine from Ryan Davies who imported it but found the geometry didn’t work for him). This has zero rise, compared to my previous stem which had an 8deg rise. This would enable me to get into a much lower position.
- The TriRig stem has a centre drilling for a centre pull brake. So I fitted a campagnolo centre pull brake which fits within the profile of the cervelo frame well.
- The TriRig stem also has bottle cage mounts to mount a bottle between the arms. I had read that having a bottle between the arms is actually more aerodynamic than an empty space. I fitted a speedfill bottle in the cage so drinking in an aero position would be easier. I drilled holes in the tribar extensions to route the gear cables internally. These now exit out of the blanking plugs at the rear.
- I removed all bar tape. This looks a lot cleaner and actually feels nicer than having bar tape fitted.
- I fitted new brake and gear cables so I could get the routing as clean as possible.
The result is a much cleaner front profile, with a much more aggressive position. Even if the aerodynamic gains aren’t tangible, psychologically it feels faster. And most importantly I managed to find the 5mins I needed (although, maybe not all 5mins could be attributed to these marginal gains…).