Straight lines are nice when there are cars in the lane next to you :P. I do a number of TT's on not closed courses, ... so I prefer not to end up as roadkill. I seem to remember a certain Andy Schleck crashing with what they said were issues with a disc, turning gust of wind supposedly pick his whole bike up. Didn't turn out so well for him, perhaps he just doesn't know how to ride though.

Perhaps it would stabilize out, but I'm pretty comfy leaning into the wind... truth be told it's when it is gusty that I have real issues, but typically wind is gusty it's just a matter of magnitude.

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Jordan Oroshiba --- Roadie invading Triathlete space for knowledge access

Dude we killed that bird on St years ago. Nice red herring though.

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Brian Stover USAT LII
Accelerate3 Coaching
Insta

Andrea Schleck crashes when someone farts in the group.

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Brian Stover USAT LII
Accelerate3 Coaching
Insta

Dude, you know better than to post something like this. Wheelcover!!!

Cheap and easy.

Running IMAZ and I will not be running a disc. I'm running 808FC front and rear. Easier to change a flat if I get one and really the disc isn't much faster IMO. So I buy a Zipp disc and gain approximately 15 seconds? For what to blow my money? I'm not going to win my AG. There is no point. That is why I won't be running a disc.

Also I've used the wheelbuilder disc on my 808 and its pretty ghetto in the sense it doesn't fit very smoothly and is lumpy when it spins regardless of all the the mods I made to it.

If I were to do it over again, I wouldn't have purchased the 808 combo, but since I didn't know much about discs before that time I kind of screwed myself out of 15 seconds over an IM. Oh well

I'm with ya man. And while we are on it...screw the wetsuit. Who needs the 17 seconds it saves in an IM swim anyways? Not like I'll be first outta the water, or even second. Done with running shoes as well. They wear out too quicky and I can't afford to keep throwing money away just to put something that "LOOKS" faster on my feet. Army boots last forever, they still fit after 20 years, and it's like a 37 second difference anyway over the IM marathon. Silly triathletes.

Ah, yeah I guess I took the OP too literally. Any idea on time savings over my Stinger w/o cover?

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I tweet!

Somewhere, JackMott is laughing his ass off.

Funny guy. Other than a super small fraction of speed the disc does nothing else for me. Now wetsuit and shoes, you're retarded because that is more than just speed.

a disc cover DOES work on your old transition- I own it, and ran one the other day to see if there is clearance.

Thanks, btw- the bike is great!

http://www.zipp.com/speedshop/arizona.php

Here is Zipp's recommendation for IM Arizona.

JackMott is the only guy that thinks winning a 4 cat TT makes himself fast....and an expert in all things areo.

Classic! Need a like button for this.

Glad you are enjoying it. It is a very fast bike. Sorry about how much I had to disassemble it to get it into the box. It seems they didn't realize I'm 6ft and don't ride a 49cm bike when they gave me the frame box.

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Brian Stover USAT LII
Accelerate3 Coaching
Insta

What TT have you won? and if he won, that made him the fastest..

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I'm not the one that bragged about winning a cat 4 race....it's kind of like being the smartest kid on the short bus.

I'd love to see a WT test wth a 808 vs a disc in a frame. I'd be shocked the disk wasn't faster, but I'd also be shocked if its hugely faster. Back when discs first got popular a straight sided 30-40mm deep rims was about the next best choice.

Since then spoked aero wheels have gotten lots better and discs are still pretty much the same.

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Styrrell

Not sure where the disconnect is, but I'm quite right.

Your example is wrong. There will be no time savings, because the runs are done at the same speed after a position change. Maybe you meant keeping power constant.

Your example works in general terms (as written), when comparing required power, not resulting speed.

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Won't bother to repeat what Jamaican said above as he pretty much nailed it.

The problem is that wind tunnel tests don't tell the whole story. People often forget about rotational drag. A disc wheel takes less energy to spin than a spoked wheel. Unfortunately the wind tunnel can't measure that.

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Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook

Just curious, but what front wheel (and depth) are you running when that happens?

Personally, I'll reduce the depth of the front wheel until it's a low profile rim before I'll go away from a disc in the back.

The reason that adding surface area to the rear typically helps to stabilize a bike is that the tilting of the bike away from the wind caused by the additional surface area helps to counteract the turning into the wind caused by the torque on the front wheel (due to the surface area center being in front of the steering axis) and the "countersteering effect".

Have you ever ridden around with a deep front wheel and a shallow rear? In even light winds, the steering is very "squirrelly". Then throw a disc on the back of the bike and "Voila!", everything settles down.

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http://bikeblather.blogspot.com/

Front wheel is a really old HED 60mm, aluminum brake track tubular with no spoke holes in the tubular bed. Has a slight toroidal shaping.

I reduce the rear because I figured the effect of having a disc is smaller than that of my front wheel due to sheltering. Plus my wheel options are limited. I've got old v shaped 303s, some aluminum clinchers, have the disc and a hed cx as options from for the rear. Running the cx seems to solve my problems in wind so I just stuck with that.

For the last qustion actually I have.... The hed wheel with my aluminum clincher in the rear. I had the HED wheels as a set, but the cx had a shitty tubie so I ran my aluminum clincher in the rear for crits for about 5 weeks. It was a bit squirrelly but manageable. Never had it out in strong winds though. People always asked me why I did it and I bs'ed them with what sounded like marketing jargon "variable depth wheel technology".

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Jordan Oroshiba --- Roadie invading Triathlete space for knowledge access

If he's going the same speed in both experiments he won't save anytime, but because he has less drag he'll save energy. In other words, improving his aerodynamics means he goes the same speed when pushing fewer Watts. And since wind resistance goes up as the cubic of increased speed he should save a lot more power at 25mph as opposed to 15mph.

Nope...BUT, I am sure that it is worth the ~$100.