Aerodynamics / Aerodynamic Cost / Aero parts

Possibly, I just found his first sub 20:00 ride details on the TTForum.

Him and Mark Jones <18:45 off <320w, CdAs 0.176m^2 and 0.170m^2 respectively.

320W, C_dA 0.176m²

ftfy. About the only good feature of the new forum software is support for HTML tags, including <sub> and<sup>

How much of an effect is the width of a rear tyre likely to have especially if the wheel is a disc?

Just wondering if the extra volume afforded by a 25 is going to be a significant penalty on my flo disc, given that I'll be racing on bumpy uk road and reportedly shocking roads in Italy...

Flo is wide isn't it? Can't have thought there'll be much in it, especially given how well your frame will shield the wheel. Might as well, especially if you'll be on rough roads.

Generally Italian roads are okay. Whereabouts are you racing?

@umop3pisdn Yes Flo is 24.4 at the brake track, is the 25 likely to make a material difference?

@andyp Racing in Rimini, friends who ride that area every year say the roads have taken a bit of a nose dive in the last couple of years as the local government seems to have stopped repairing them, I don't know if this means the occasional big hole or just a rough surface...

The 20mm drop at the front end of the bike doesn't seem to have limited power at all, and if anything feels more comfortable, apart from slightly feeling like I now need to hold on to the aerobars, but that may be a factor that the two test rides I've done were in long sleeves so there isn't as much friction on the elbow pads - I did the main bit of the h10/2 course this morning and nice to see lots of PBs on strava despite not giving it everything and wearing a normal jersey and road helmet, my pre season aim of 22:xx seems like it may be easier than I thought!

Doubt it. Aero gains from 23mm probably lost to rolling resistance, and vice versa. But I'm not an expert.

Not aero enough...... https://www.lfgss.com/conversations/266821/#comment12244609 .....gotta make more aero.

I thought aero gains from the REAR tyre/wheel transitions are not worth worrying about. Aero gains for any rear wheel aren't huge. So a fat, quick tyre is the way to go.

^ AFAIK #notanexpert etc, etc.

Oh my...

http://road.cc/content/news/149414-introducing-spoke-fins-swivelling-fairings-your-spokes

The guy from HED was saying that you want a far narrower tyre than your rim width onthe front. But that on the back rolling resistance and traction are king.

Something like that.

That was regarding modern aero road bikes that shield the rear.

If you mean your Felt tri weapon. Its definitely true.

Oh, yay, now you can make your bike ugly and be able to hear it rattling from over a mile away...

Transition innit

Yeah. Personally i dont feel the need for a big front. So im running a 22mm tub on a 28mm wide rim, with a 25mm brake track. Pretty sure the most aero solution would be an even smaller tub.

I have a 25mm on the rear. With both tubs at 95psi its pretty comfy. Plus the 25mm fills my frames rear wheel cut out neatly. Which looks faster.

Ive totally gone off the idea of going over 100 psi. The bike bounces far less around corners at lower psi. So theres a safety aspect too.

Out of curiosity....

What is the rough aero penalty of a dropbar vs a base bar?

My Felt AR1 will have very close to the geometry of the A1 tri bike, when I flip the seatpost around. So I should be able to get into in a prime aero position. The bike cant be far off being as aero as a low end TT bike. But I'll have a pair of Enve SES road bars With Extensions, instead of TT bars. These do have a neat looking clamp, all cabling is hidden, and will eventually be fed out of the back of the stem. Plus I have a tririg front brake, so that cable isnt out in the Wind as such.

I've really thought about this, and its definitely the most practical set-up. In terms of the sort of events I'll be entering.

2 Attachments

Bike only it's anything between 12-20w depending on what you're going from/to:

http://www.tririg.com/galleries.php?id=2014_08_TriRig_Alpha_Wind_Tunnel_White_Paper&num=9

Obviously with the ENVE bars/clips it will be less of a jump than standard round tube bars with clips that sit high, and some of that difference will be reduced when you stick a rider on.

You have to win a prize for THE most penis-looking bars ever. Please tell me they're not photoshopped?

Feck, thats actually a notible amount.

They are absolutely Cock bars.

My childish side wanted to go With red end covers and pink tape.

But they do actually work brilliantly though.

Bullet tri bar end plugs are done, came out at just under 7g a piece

DIY dildo bars

Ooh, are these in production or just one off's for thine self?

I made a small batch, there are a few available for sale.