gsteinb = cavendish
gsteinb = cavendish
Looking good, buddy. Good luck this weekend. Grab that jersey.
:) Next race in that series is June 8th. Two in July. Last one is August 15th.
Hi, I noticed the rotated brake levers when you posted the photo of you racing on the bike. Braking with your thumbs is an interesting concepts. Hard to imagine it. Not sure if I'll try it.
BTW, when we were comparing brake levers a few months ago you pointed out that your levers had a "feature" that wasn't on mine. a couple of days ago I was scouring the internet looking for write ups and photos of modified Shiv cockpits and I found this:
Racer Ex, the cockpit of the Shiv looks totally cool - nice work.
Cleave, I have to agree with you on the aero analysis of the lever turned up to reduce frontal area.
AZT; regarding that 68cm monster bike. Its a beaut for sure. But did you find it stiff enough for out of the saddle hard launching, etc.? As a builder I am curious if it was what you needed in the stiffness/strength area. When I did big and tall special builds I usually put in a lateral tube to ensure it was stiff enough. I guess if nothing else, it makes a nice place to mount water bottles and DT shifters that wasn't a mile away from the top tube...[;)
The lever position has been tested, though with a different lever set.
The "dirty" air is created by the brake levers is created regardless of position. The advantage of this position is both a reduction in frontal area, and providing a surface that allows the air to smooth and reattach.
Think of it like this:
It's a 911 Porsche drafting a 66 Chevy Nova. The Nova has to be driven through the wind either way.
There is definitely a "cool factor" with those rotated brake levers. They remind a little of leading edge devices. Except cleaner.
Ex, there is the bike without rider in the free stream, and then you put the rider on the bike in the free stream. That's the true configuration of the bike. Hands, arms, head (even with aero helmet) are much, much "dirtier" than the bike is, and no matter how small (or invisible) the bike is to the free stream, the drag coefficient of the rider is high and is NOT invisible. The total drag of the bike is with rider, not without. My thinking is that hands placed on the end of the aero bar, in the "control" position, create enough drag to more than overcome the lessening gained by rotating the levers. Or, by the tiny frontal area presented by the bull horns and head tube. You've done the testing, what have you discovered?
If it's the former that's an unoptimized position that you are in for a very small amount of time and actively steering or braking. For some TT's I might be "out there" once during the entire event. For the rest of the time those levers and base bar sit out in the airstream and aren't affected by the rider.
If it's the latter I'm not clear on what the question is.
But I will say that even a brake lever creates a significant amount of drag (try sticking your finger out of a window at 30 MPH).
When Giant did the aero-testing for development of the Propel, they built a dummy that, unlike the "DZ" dummy (molded from Dave Zabriskie) Cervelo uses, actually pedals. Cervelo's approach is of course far better than no dummy at all. One of the huge advantages of the testing Hermes and Ex are doing at the velodrome is that drag is measured for them specifically, and actually riding their bikes. That beats the tunnel approach, IMO.
The upcoming CA state TT will be quite the showdown in 50+. In addition to California speedsters like Ex, my teammate Peter will be there to see how he measures up, after a TT focus and some wind tunnel optimization over the last few weeks. Peter had a great TT for VOS, and feels he has improved quite a bit since then. We know Ex has sped up since VOS, so lookout. I was planning to be there, but decided I needed to stay in town for the last couple of weeks of my current job.
I am not an aeronautical engineer, but I would think that the hands present a fairly static kind of drag no matter what they are gripping. Every little bit helps.
I meant the extensions (I get the terms wrong, sorry). Hands, when "blunted" into a grip or fist are much cleaner than a "flat plate" palm, but are still significantly dirtier than the whole handlebar/head tube arrangement as presented to a free stream. As airflow over the hands and forearms sheds, it impinges disturbed air on the bicycle structures downstream. I tend to think that the shed air would be significantly disturbed by the time it gets to the bullhorn/basebar and brake levers that the brake levers wouldn't even present a significant increase in drag. Still, I don't know, I've not seen a wind tunnel model - just asking the fella who's done wind tunnel testing. :thumb:
Hey, try sticking your hand out of the window of a helicopter traveling at 120 knots - it will turn the aircraft!
AzT, are you coming to Long Beach for the Senior Games?
With this bar set up there's not going to be a lot of deflected air from the hand position hitting the lever or ends. Some, but not a bunch, especially when I do my stacked hands.
Ex, I may have been one of those "new pilots"!
Hermes - yeah, that's it!