Aero Deep Dive in The Specialized Win Tunnel – Ask a Cycling a Coach 188

aerodynamics

#163

I revised the list for order and some separation between the ones that do or do not impact results.


#164

I found this list useful as a £/W guide:

Some quite surprising entries on that list, I thought.


#165

This is also worth a watch, despite the overlap.


#166

I asked Chris Yu another question on strava; what’s the aero pentaly if water bottles and cages.

Bottles + cages = 5 watts
Cages alone (no bottles) = 2.5 watts

So take off the cages if you don’t need them.


#167

I added in the post above.


#168

Tires! Rolling resistance can be substantial depending on the brand. 10-30w for two tires depending on how slow your current setup is.


#169

Likely, we should start a new thread that is “Optimization” and compile the aero and other equipment/setup options into one master resource for quick reference.

The post above (and a few others) are good starting points for the info.


#170

At this rate I’ll be cruising along at 20mph without pedaling.


#171

Those numbers are all normalized to 40kph, so ~370W of output.


#172

I get that. Since the drag force is proportional to the square of velocity those numbers just look exaggerated. You’d figure for most people cruising along at 18-20mph those savings will be probably 50% of what is shown. Even that seems a little crazy


#173

370 watts for 25 mph? We talking riding completely upright on a round tube bike on crappy pavement?


#174

Basically. Just used Bike calculator with the default values at 40kph.


#175

yeah, so 370 doing absolutely nothing to try and get out of the wind, but still ideal rolling resistance, so then with the aero savings, you can go about 40k/hr @ 300 watts (or lower)


#176

Last year’s A race for me was just that: 39.5km/h @285w. And I was maybe 50% aero. It can be done! :+1:


#177

Merckx style on a road bike? I am doing a road tri this year on a non-tt bike… BBS is saying that my target power of 275 watts will be 22 mph, but it is rolling terrain, not totally flat


#178

Merckx class I’m roughly 21.5mph at 275W on a flat course with 3 small rollers, but not very aero on a Trek Domane. I’ve seen smaller guys on bikes with better geometry do Merckx class at 23-24mph at roughly the same power on the same 10 mile course (leaderboard doesn’t tell you if they rolled Merckx or full TT).

The club Google spreadsheet for TT series doesn’t have power, but does split between Merckx and TT Nerd. The fastest guy is a duathlon international age group champion (40 something), and his fastest was 29.3mph @ 371W ave power. The “smaller guy” mentioned above did 24mph @ 284W last June in a 12mph crosswind.


#179

If I’m not mistaken you don’t sum the wattage savings from multiple improvements.

If someone smarter than me can explain this I’d be grateful…it’s an important point that needs to be understood by the consumer (all of us) but, I do not have the math/physics background to explain coherently.


#180

Road w/ clip-ons.

But a guy who did go Merckx did 340w and beat me by 1:11.


#181

If I do all these I’ll save 100 watts. Jeez. That means I should be able to ride Leadville in about 7 hours :stuck_out_tongue_winking_eye:


#182

shit happens, here is a result from one of our 2018 TTs where the fast Merckx class dude (no skin suit, no disc wheels, no deep aero wheels, no aero bars, no teardrop helmet) edged out a TT guy at roughly same power:

Time Power Speed (mph) TT Merckx
0:20:51 375 28.78 1
0:23:41 25.34 2
0:23:58 25.04 3
0:24:58 284 24.03 1
0:24:59 268 24.01 4
0:25:13 23.80 5
0:27:03 22.18 6
0:30:00 19.99 2