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    • xorius

      Heyo. I wanted to put together how I built a very fast TT bike over time with a relatively low budget. I started racing time trials around 2014, and liked it so much I decided to put together a dedicated bike instead of using clip ons with my road bike.

      I think in general there are two big advantages:

      1. The most important aspect is is positioning, you can get a position that is both really aero and powerful with a dedicated setup.

      2. Weight is a nonfactor so you can organize the bike to be purely Aero.

      The bike we will be talking about is this Cervelo P2. Feel free to ask questions as we go along, everything here has a story and a purpose :)

    • xorius

      The bike itself was about $2000 out of the store, it was on sale from the previous year. They had just updated the P2 to 11 speed. Ended up being much cheaper to get the old model with 10 speed and have the bike shop swap 11 speed onto it ;).

      It came stock with profile design bars, some TT saddle I replaced immediately, and all 105 except the fsa brake calipers (will get into that later)

      The wheels were stock, but I already had the flo wheels you see for the road bike. The bike shop kept the training wheels to save me some $.

      I love the wheels, extremely good Aerodynamics and a reasonable price, these 60 mm wheels are 900 new. Go for Aluminum, way cheaper. The Flo guys have really dialed in the Aerodynamics; the only compromise is weight, which doesn’t really matter for TT and triathlon.

    • xorius

      On the subject of wheels, tire choice is pretty important. I run tubed tires instead of tubeless or tubular because they are just easier to deal with.

      For time trial, there are a couple of things you are looking for, rolling resistance and aerodynamics. Typically these days, wheel manufacturers are designing for a specific tire to maximize aero. This way they can make sure that the tire isn’t wider than the wheel and nothing is poking out and hitting the wind.

      Conti 4000 s2 have been a popular tire for a while. 700x23 is recommended for the Flo fleet of wheels (and I recently learned for Envy as well.)

      I have also run supersonics (no puncture protection) for reduced rolling resistance, but I don’t want to ride them around daily or for longer than a 25k TT.

      Speaking of which, don’t run gatorskins! They have such a huge penalty to rolling resistance that you could change 3 flat tires in an iron man and still be faster!

    • xorius

      Since I’m running tubes, I gotto mention that I prefer latex. They are really good bang for buck speed wise, as you could save 2-3 watts per wheel over a butyl race tube. They are slightly more expensive, about $15 per tube.

      I run vittorias because they have removable cores. You need that to accomodate different wheel sizes, since deep dish wheels can be all different.

      I find that latex tubes cause less flats, and are easier too get in and out when changing a flat anyway.

      Note: This may look a little strange that these are 25/28 tubes instead of 23 like the tires, but because of the wider rims (24.5mm) on the wheels, the system actually holds more volume, so these fit nicely.

    • xorius

      In case you were wondering how removable cores work.

      On the left is a zip valve extender, and on the right is a core removed.

      The idea is that you take out the core, put the extender in its place, and then put the core into the extender. Just don’t toss out at tube with an extender, thats a sad day since they are about $15 on their own :(.

      There is another kind of extension that just screws in on top of the core, but I really don’t like them. The reason why is that you have to release the twist on the valve like you are going to pump it up, and then fit the extension. If you mess it up, you could have to change a tire. Thats a bad day if you are pumping up before your race :/

    • xorius

      Here you can see that the tire is basically flush with the rim from the front. No bulge in the tire, important for aerodynamics.

    • xorius

      Disc covers! When you are on a budget, who needs a dedicated disc? These are about $100 and are custom built for whatever wheel you are running.

      These are about the difference in cost between a 60 mm wheel (which you can use for other things) and a dedicated disc wheel.

      The only downside is that if you do want to reclaim your wheel for normal riding, it can be kind of annoying to take the cassette on and off.

      These will save a decent chunk of time in a TT and I’d put them in the high bang for buck category.

    • xorius

      Brakes! This TriRig Omega X brake is supposedly the most aero brake out there, so I figured it was worth a go. The FSA Gossamer brake looks a bit like a tangled mess from an aerodynamics perspective, so the clean lines here felt like a really nice upgrade.

      I have only replaced the front brake, because it is a better value; the wind does come from the front after all. It is almost $200 so it is on that borderline of definitely worth it for the front, maybe not for the back.

      That being said, my next purchase for this bike will probsbly be a rear omega x :P

    • xorius

      Here is what the FSA gossamer brake looks like in the rear for camparison. Definitely a lot more bits dangling in the wind.

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