chiggy

I've got my first race ever on a bike coming up (a no-draft duathlon actually). The bike leg is only 20k. I'll be near the front and would like to win, so I'm looking to find some free time.

I don't have any real cycling/tri gear other than some shorts. I usually just wear a running singlet. If it's worth it I may go looking for something more form fitting. This is just for fun though so I'm not going to go spend much money. Really i'd do shirtless if I could, since it's free, just don't wanna be that guy.

mprelaw

For Tony Martin, probably a lot. For you? Not so much.

Lots of people believe that a ponytail cost Laurent Fignon a yellow jersey, when the Tour ended with a short ITT. He lost to LeMond by 8 seconds, going into it with a lead of over 50 seconds.

Don't worry about being that guy. If doing this bare chested will make you feel faster, go for it. I assume you can take your shirt off without causing snickers, right?

69chevy

At that distance, short of a full TT setup with skinsuit, you won't notice any gains.

I have a friend who does Triathlons in a speedo. Swim, run, bike, all in a banana hammock.

You'd look overdressed next to him riding shirtless.

RChung

Depending on how loose your clothing is, possibly .05 m^2 on up. For a 20k ride that could mean in the ballpark of 2 minutes, give or take. A well-fitting cycling jersey will be better than a running singlet, which would be pretty close to a parachute.

mprelaw

Mario never worried about being "that guy".

But then again, he's Mario. YMMV.

wphamilton

For sure it makes a difference. Even a "club fit" jersey opposed to something skin tight makes a bigger difference than people would think. Flapping shorts also.

Since you say you're being cheap on this, maybe you could get an inexpensive compression shirt?

caloso

It makes a difference. Shirtless will be more aero than a flapping shirt. Biggest bang for the buck is aero bars. Do you have those?

milkbaby

Events that are sanctioned by a sport governing body might not allow shirtless participants, I think it's against USA Triathlon rules. If it's not sanctioned or no rule against it, then go for it... Winning trumps all haters. I'd rather win shirtless than come in second.

Over 20k, any amount of time you save, which is probably measurable in seconds not minutes, will probably be negated by the time it takes to change in transition. Even if you think it will only take seconds to change, consider the fact that you might be sweaty and something else could go wrong that will steal time, e.g. your watch catches on the sleeve or your sunglasses go flying when trying to switch your shirt. I would consider a tight tri singlet/suit. See below:

banerjek

I'm curious how you know you'll be at the front if this is your first race and you haven't already figured out on your own how gear affects your performance...

FrozenK

The most often quoted figure is on the order of 1 second per kilometer for a tight-fitting jersey vs a loose fit, t-shirt type of jersey. So at most you are looking at about 20 seconds.

I'd buy an Under Armour compression sleeveless shirt for $20 and call it good.

caloso

Biggest Bang For Your Buck In Time Trial Equipment | CyclingTips

K.Katso

TT racer here. I'll be the first to admit that I don't know jack about Tri/Duathlon, but I know aero and it works. A skinsuit is definitely an advantage over a floppy jersey and shorts, and a TT helmet is better than a regular vented road bike helmet. Shoe covers also help. The one thing that is really important though, is to look at your position on the bike. Get as low and narrow as you can. Your body is the biggest source of aerodynamic drag. If you're not already riding a TT/Tri bike, then you should spend some time optimizing your position and tucking in cables and other parts and removing any crap that you don't need (i.e. water bottle for a 20km TT ). Get a clip-on aero bar if you're on a road bike and tuck everything you can out of the wind. That's a cheap upgrade.

greenlight149

Biggest Bang For Your Buck In Time Trial Equipment | CyclingTips

this gives you an idea of which upgrade saves you the most time, and which ones are the most cost effective. (clothing and position make the biggest difference)

smarkinson

Check the rules if you want to go shirtless. It appears there is no specific rule against shirtless but it can vary from event to event. Nobody wants to see a sweaty, chubby, topless middle aged guy in a triathlon bike or run leg.

The big triathlon races (ie those run by WTC and ITU ) do have rules about shirts but you're probably not in that league.

69chevy

These recommendations are good ones, but I assumed (I may be very wrong) since the OP doesn't own any cycling gear, he wasn't a very serious cyclist.

If he rides 15 mph on this duathlon, none of these things will save him much time.

Especially if he is on a road bike that sits him upright which a lot of riders seem to ride.

RChung

Try measuring the difference in CdA rather than just quoting a figure. I've measured the difference between a loose fit T-shirt and a tight fitting jersey. On me in a "Merckx-type" race (that is, regular road bike with non-aero helmet) the difference was more than .04 m^2, or the difference between 0.30 m^2 and 0.34 m^2. Running singlets can be tight or loose but a loose running singlet could be worse than a loose fit T-shirt. The biggest issue even with tight running singlets is that the neck scoop tends to be large. Notice that tri-tops tend to fit closely around the neck so that when you bend over the bars you're not scooping up air.

A 1 sec/km difference in speed is roughly equivalent to a difference of 0.01 m^2 in CdA when riding at 40km/h in calm wind conditions. If you ride slower than 40 km/h, the time difference will be greater than 1 sec/km.

I think 2 minutes over 20 km is the right ballpark. Whether the OP thinks 2 minutes is large or small I have no way of knowing. I do know a little about measuring aero drag.

asgelle

mmmmm data.

Heathpack 

The understatement of the year.

(Y'all should listen to @RChung. He knows of what he speaks.)

Heathpack 

Haha, I haven't purchased a skin suit yet. I better get moving.

Hey, @RChung, the new TT bike + wheels with no aero helmet (having trouble finding one that fits) and no skinsuit bought me 2:20 off my 20k time. And I rode the 20k on the TT bike too conservatively. It probably could have been 2:40-2:45 pretty easily. I'm totally hooked.

BillyD

Good. Don't be that guy. Have some class.

RChung

Nice improvement. A good fit on a good TT bike can make a pretty big difference. Congratulations.

FrozenK

Thanks for sharing your knowledge. Really appreciate that you are willing to share the results of your testing. And I didn't think about the neck opening, but it makes perfect sense. I'll make sure I zip up my jersey when I'm racing.

chiggy

Wow, up to 2min in only 20k! More than I expected. Love the data too rchung, it appeals to my engineer side. I would assume a lot less for me since I'm slow, won't be using a skin suit etc. etc. Still, 30 seconds could easily make the difference.

I do have aero bars, probably pretty poor position though. I know aero makes a difference, but don't have the experience to know how much and never had a reason to care until now.

@banerjek It's my first duathlon and first race that includes a bike, but not my first race. I'll be the best runner by a large margin and I cross train enough on the bike to have an idea what I'm (not) capable of. The plan is to dust everyone on the run, get sucked up and spit out the back on the bike, then catch up and nip them at the line on the last run.

RChung

I don't know how long the run vs. bike legs are in your du but in triathlons the bike legs are often roughly 4x longer than the run legs. One way to think about this is that a 1 sec/km difference on the bike saves you about as much off your finish time as a pace difference of 4 sec/km; a 2.5 sec/km difference on the bike saves you about as much as a 10 sec/km pace difference on the run. If you run a lot you probably know your run pace. Think about how much effort it'd take you to run 1:40 faster for a 10k.

Don't wear floppy clothing on the bike.

kini62

Go get yourself a cheap compression shirt. No need for an expensive bike jersey. Even a rash guard shirt would work.