Aerodynamics / Aerodynamic Cost / Aero parts

For roll down tests the simplest thing is just to start on a hill at 0mph and coast down noting the max speed. Add more magnets to get better resolution but pay particular attention to road surface, even marking chalk arrows to hit like a SNES game would be a good idea as Crr changes could affect changes in CdA

@StevePeel as you're on a fixed TT bike, will you be unclipping from the pedals on the downhill? Even if you're a good spinner, you could still be slowing yourself slightly, affecting results by differing amounts each time.

Thinking I would fit a freewheel

Fuck...

Thanks Xavier. I was thinking that the aerodynamics would barely come into play at low speeds, that's why I was going to start at speed but I'll certainly take your advice.

He was going to fit a freewheel.

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It's worth mentioning that doing that on a single speed bike will be exceptionally tedious and your boredom threshold will give out before you get enough data if you're trying to test a zillion things.

As with all testing protocols, the first time you do one ONLY TEST ONE CHANGE. Don't rock up with a load of kit expecting to be able to test it all, just first verify that your protocol works otherwise you could have wasted an afternoon/morning/whatever.

Gotcha with the one thing at a time, not sure why single speed makes a difference, I'm just rolling down a hill to a stop aren't I?

I just mean if you have one gear whether it's fixed or single speed it'll be a git to get back up the hill again every time

Ah ok, it'll be a good bit of hill training too :)

I don't know how quickly air pressure changes

Rapid changes in pressure are accompanied by wind, so you'd never do any aerolabbing at times when the pressure was changing by more than 0.5mb/h. Taking a random* summer's day from here I got a total range of 1.03mb between 0800 and 1100 on July 15^th last year, and 0.69mb between 1800 and 2100 the previous evening.

*Randomness not guaranteed - I picked the nicest looking period in the first half of July.

Can you do them with track number pockets on the back/sides? Or would it affect the seam on the back?

They would cover a bit of the seam but doable - email NoPinz and they'll advise you.

For anyone watching the Revolution series on Eurosport over the weekend Lydia Gurley was riding for AeroCoach and had a TripSuit on during all the women's races.

@xavierdisley I know you love the Ventus, but have you ever measured them against USE R1s? I've just spotted the R1s have a Shiv shim, which I take to mean they might fit on my bike's normal 'aero' stem.

Those new TriRig bars are taking too long to appear...

I'm not entirely convinced by the R1s - the pods are quite big. Also they're a sod to adjust quickly for extension length etc

But more importantly, I'm an idiot and forgot I have hydraulic brakes which kind of rules out those funky brake pods anyway. Thanks for continuing to answer my ill thought out questions :)

Looks like I carry on waiting for the new TriRig bars.

On the subject of bars, am I right in thinking Ventus have been discontinued?

Anyone know what 3T have up their slev(less)?

What's the next best option for the budget concious toaster, assuming I'm not interested in the various flavours of Chinese carbon upcycled by the likes of ADR?

Tulas.

I don't think 3T will release another UCI illegal bar now all of the high end tri (and TT) bikes have integrated bars.

I don't think 3T will release another UCI illegal bar now all of the high end tri (and TT) bikes have integrated bars.

That explains it...

How climby climby would it need to be before a disc would lose its advantage to a 404?

I was thinking of hitting up some sporting courses on the road bike for shits and gigs and I'm wondering if I should go with disc (prob. wheel covers on G3) or my 404s.

Go disc. Unless it's a hillclimb, aero>weight.

Very. Why not TT bike though? Go full roadie or full TT.

Because they're just going to be training rides where I ride out race and ride home and I'm likely to be on a road bike with clipons for TransAm so makes more sense to do more miles on that.

I'm guessing none of the courses are technical enough that the acceleration argument comes into play either?

No course than I can think of would be. Can't remember any hairpins on TT courses...