Fixed Time Trial Bikes

^Amen. Note to self: must rebuild TT bike and tape ears down, aero head supplied naturally, talent less so.....

It's about priorities and proportional gains innit. If your tuck is shit, fix that first because a shit tuck destroys more aero than a helmet can fix. In the same way, assuming your tuck is ok, not having an aero helmet and shoe covers destroys more aero than a frame can fix.

Assuming the guy in the picture has heart & lungs and an ok tuck, the next step for him would be shoe covers and an aero helmet, *not *an aero frame. If he does not have heart & lungs and his tuck is shit, his bike is already overspecced.

It's probably true that many people who haven't been to a wind tunnel or done extensive field testing are getting no more benefit from long-tailed helmets than they would get from shaving their heads

Assuming this is true (which I like to do with your statements), it's still foolish to engage in competitive cycling without a helmet. An aero helmet* is going to be considerably more aero than a normal road helmet, with or without windtunnel tuning.

*Not necessarily the pointy type but also the smooth round ones.

it's still foolish to engage in competitive cycling without a helmet

Time Trialling is a road ride plus timekeepers, it doesn't really have any relationship to the kind of competitive cycling where your argument might be valid.

An aero helmet* is going to be considerably more aero than a normal road helmet

Might be true, but is it more aero than a shiny dome? The testing I've seen suggests not, and that only a properly selected and fitted pointy hat can beat a shaved head. If you have a shock of lustrous wavy locks, you're probably better off squashing them under a styrofoam bowl.

What does Tuck have to do with it?

http://1.bp.blogspot.com/_nYmWjp9KBI0/S7k5bmxz36I/AAAAAAAACao/evxsphGMTk4/s1600/PhilROSE1984robinOfSherwood.jpg

It's probably true that many people who haven't been to a wind tunnel or done extensive field testing are getting no more benefit from long-tailed helmets than they would get from shaving their heads

I thought field testing was only important for cyclo-cross and grasstrack?

What does Tuck have to do with it?

He is demonstrating an advanced variant on the shaved head approach, using a strip of hair as an aerodynamic trip to delay boundary layer separation.

....and I swear he was off at number 19 on the last TT I rode.

To summarise: twist your body into the right(ish) aero shape, shave your head (unless you're me) and nowt else matters very much.

blue touch-paper lit

Aren't people starting to wonder whether shoecovers actually save any time? Increase in A vs (alleged) decrease in D.

wrong tread ?

http://www.google.fr/imgres?imgurl=http://www.fixedwheel.co.uk/keithmurray.jpg&imgrefurl=http://www.fixedwheel.co.uk/fixedwheel%2520records.htm&usg=__ODJX3U-IvnCjMOwpQFPQK9OWTk0=&h=245&w=250&sz=20&hl=fr&start=3&sig2=eUvzRhkdNbRosC5rAHvk_g&zoom=1&tbnid=xSIhVBJoUc6m0M:&tbnh=109&tbnw=111&ei=rkHHUcv3LPDa0QXb9IGQBA&prev=/search%3Fq%3DChris%2BBoardman%2B%28%2BNorth%2BWirral%2BVelo-Kodak%2B%29%2Bshattered%2Bhis%2Bown%2B25%2Bmile%2Bcompetition%2Brecord%2Bon%2B110%2522%2Bfixed.%2BRiding%2Bon%2Ba%2Brevised%2Bversion%2Bof%2Bthe%2BH25/13%26um%3D1%26client%3Dfirefox-a%26sa%3DN%26rls%3Dorg.mozilla:fr:official%26hl%3Dfr%26tbm%3Disch&um=1&itbs=1&sa=X&ved=0CDAQrQMwAg

That is a comically large helmet.

Just thought I'd pop mine in here, not rode any TT fixed yet but would love to have a bash :-)

1 Attachment

That is a comically large helmet.

Obligatory that's what she said comment.

It's probably true that many people who haven't been to a wind tunnel or done extensive field testing are getting no more benefit from long-tailed helmets than they would get from shaving their heads

Regardless of how it tests, I'll stick to the sperm hat. At least you don't have to walk around looking like a skinhead the rest of the time.

Aren't people starting to wonder whether shoecovers actually save any time? Increase in A vs (alleged) decrease in D.

I'm pretty sure according to Alex Simmons testing for one of his rider's attempts at the Masters Hour record, they are faster.

This must have been posted previously?
Link

Aren't people starting to wonder whether shoecovers actually save any time? Increase in A vs (alleged) decrease in D.

stupid question time, what is A and D? Drag?

Area and Drag

Overshoes increase the frontal area - you're adding material to your shoe but they should decrease drag by making the whole unit slippery.

Maybe I lied.. looking at a forum post Alex Simmons says:
"Using lycra booties over shoes is not always more aerodynamic than not wearing them. One should do their aero testing..."

So wearin all that 'speed gear' is fo kicks?

So wearin all that 'speed gear' is fo kicks?

No.

Well if I lose the speed socks, sperm hat, shave my heed and legs and go out in my underpants I would be just as fast?*

*Thats what I understood.

surely the amount of area added by an overshoes which is 1mm thick is completely negligible?

It always 'depends' but I always wear a helmet and aero helmets ARE faster than normal road helmets so there's that one answered. Shaved legs might be faster and they look better so there's that one answered. Overshoes might be better - they might not, the difference isn't going to be much. I wear them although I couldn't adjust my shoes yesterday so my foot went numb which has more of a negative effect than the positive aero benefits I may have received. I believe skinsuit materials have tested faster than skin and they offer some compression so probably faster. You also don't break any indecent exposure laws.