[quote=halbritt]Aerodynamics matter as much in sprint as in a TT, you’ve only got X watts and a slight aero advantage might get you a top speed of 45.7 rather than 45.6mph. In a sprint, a couple of inches at the line can make a big difference.
Aero tubes mean very little in terms of top speed or TT performance. Position is really everything, which is why aero bars are so useful. An old ass bike with 32 spoke, low-profile wheels, round tubes, and aero bars is going to be faster in a TT than modern aero-tubed bike, with aero wheels, and road drops.[/quote]
Aerodynamics definitely matter, but more in terms of rider position than bike aeroD. You’d see greater advantages with weight. (I was referring to the rapid back and forth movement of a road sprint). Example, I’d rather run a 1000g wheelset than a discwheel in a road sprint, because the weight would be better than the aero.
WHY AREN’T MY PICS OR VIDS SHOWING UP! They all show up fine on my comp?
Link: http://www.youtube.com/watch?v=MOGGyPdQJqQ
Also, aerodynamics on a TT bike in terms of the bike are huge. But they AREN"T as huge as your own positioning. I think the rule was if you could take 2cm off of your hips, you’d basically be improving your aeroD the same as a disc wheel?
Nice video of what happens when the boundary layer disconnects from the airfoil. I don’t think that’s going to be a big issue for bike frame tubing.
Then how are you fathoming that frame aerodynamics work? In your previous post you’re talking about aerdynamics in a sprint could make the difference between a win and a loss. If such narrow margins are there, an aero frame (or non aero frame) could mean the difference.
Anytime you have airflow over an airfoil (like a bike frame) and you shift the relative wind (like in a sprint) you’re going to increase your aerodynamic profile. If you could actually deform the frame (which you can’t) you’d be ok, but since you can’t you’re lateral drag increases exponentially. This has to be overcome with power. Simple as that.
I know you know this stuff?
Again, I’m referring to the back and forth motion of a sprinter in a road race.
If the aero tubes provide any kind of reduction in CdA then your statement must be true. My point, poorly made, was that in a sprint, aerodynamics make a big difference, but that aero tubes actually has little effect on CdA during a sprint. So, I agree that the forces you’re describing exist, I just believe that they’re so small, they make very little difference.
Fuck it, get me Mark Cavendish, his bike, and some lasers. I’m gon’ do some CFD.
As you and others have said, position is everything. Thus my earlier point about putting aero bars on a vintage bike being better than having drop bars on an aero bike for a flat TT.
ummmm maybe watch where you ride bro
or are u kidding bout the 5 flats
coz that shit is ridiculous
i haven’t had a flat in like 6 months
…aaaaaaaaand now you’re getting a flat.
We don’t talk about flats, remember?
actually my road bike has little tread left but
i haven’t swapped out the tire coz it a tubular
and i don’t have a good tire to glue on
just my other worn out spare
i should buy a new tire and put it on before the worn out one flats so i can use it as a spare
then i’ll have two shitty spares
[quote=stiffytruck]ummmm maybe watch where you ride bro
or are u kidding bout the 5 flats
coz that shit is ridiculous
i haven’t had a flat in like 6 months[/quote]
That’s rad, bro. I don’t get flats when I ride to the liquor store and back, either. But when I’m on a 100mi+ solo ride through the neighboring redneck infested county where the main hobby is throwing beer bottles out the window, shit happens.
Tru. I don’t get flats in Asia as often because people don’t chuck glass bottles out on the road for no reason as much as they did in Chicago.
[quote=surfcat][quote=stiffytruck]ummmm maybe watch where you ride bro
or are u kidding bout the 5 flats
coz that shit is ridiculous
i haven’t had a flat in like 6 months[/quote]
That’s rad, bro. I don’t get flats when I ride to the liquor store and back, either. But when I’m on a 100mi+ solo ride through the neighboring redneck infested county where the main hobby is throwing beer bottles out the window, shit happens.[/quote]
haha. sweet burn on bonertruck.
also.
maybe you should scrub your tires when you ride through shit.
most of my flats happened in a place in carlsbad I called little mexico.
LOL I really don’t ride through shit, I dodge and weave like crazy. But it’s really hard to dodge them all, sometimes. My worst experience to date was on a 200k brevet on Jan. 2nd, with Grand Bois tires. There were 100yard+ stretches of broken glass. And other sections with miles of funky pointed seed things. Pasela Tourguards have changed my flat-changing life for the better 
IKNOWRITE??
But they work really nice for me… not as nice as the Grand Bois, but less flats so better. I have bad flat karma, so I have to be flexible in this area. So far, the Pasela TGs have not let me down in wet, dry, whatever. So, sticking with them for the time being. But I do understand and appreciate that many others have better luck with other tires. I loved the GB but it just wasn’t working for me.
actually i rode a 28mm conti gran prix 4 season on the davidson all last year.
its’ like a nice gatorskin, higher tpi i think.
so in something like 2500 or 3500 or maybe even more miles of commuting and weekend rides i only got one flat. the rear.
the hole was in the inner part of the tube so maybe there was a tool mark or something (got wheel used) on the inside of the rim that rubbed a spot in the tube or something coz i never found any debris that punctured the tire.
maybe those miles don’t count coz it there was only one ride that was over 100 miles, it did consist of maybe 40-50 miles on two lane country roads in the hill country with a shoulder about a foot wide…this is texas though. not sure if we have any bottle throwin rednecks out here. lulz.
the way back in was maybe 30-40 miles of rough and annoying as fuck country roads with no stripes and fucking cattle guards that we had no choice but to ride over. those fucking suck at 18-20 mph. doubt there are rednecks out there either.
You need to rock this steez:
tire scrapers
[quote=surfcat]IKNOWRITE??
But they work really nice for me… not as nice as the Grand Bois, but less flats so better. I have bad flat karma, so I have to be flexible in this area. So far, the Pasela TGs have not let me down in wet, dry, whatever. So, sticking with them for the time being. But I do understand and appreciate that many others have better luck with other tires. I loved the GB but it just wasn’t working for me.[/quote]
lose the GB.
seriously, the conti gp 4 season seems to be an ok riding and quite tough tire.
but 28mm is the largest size and that really only measures about 27mm at 110psi.
I’ve got about 1500 miles on my set of GP 4 seasons thus far. No flats. There’s glass and stuff around, but I try to avoid it. I imagine I’ll start getting flats on the rear soon as the tread is starting to be worn. IIRC, Steve runs 32s, in which case, there’s not much else with flat protection that rides fast. For 28s (or nearly 28s as the case may be) I’ve found Gatorskins to be quite good for commuting through the shitty streets of Oakland. I’d regularly pull my wheels and use a pair of industrial tweezers to remove the embedded glass and other bits about once a week when I was running them.
That said, this topic (tyres) has been done to death.
