New Aero 2016

[vosadrian]

I've hit 70kph on the EC sprint. My WRX has hit about 250kph!! I kit over 70 pretty much every afternoon I commute down Coonara (15% decline) without even pedalling!

X, there is no question that any of us will take 1-2kph if we can. The question is when it will give you any benefit. In racing sprints, I will take an extra 1-2kph. I have lost sprints by cm before, so perhaps I could have won? If in a break where I am on the front a lot, I will take it... perhaps I can hang onto the break a little longer or be a bit fresher for the last lap. If rolling turns in a larger bunch mostly out of the wind, it would probably not help much. If riding solo out of racing, I'll take it, but it will probably only get me to work 30 seconds quicker... and do I really want that!!

[skydance]

I've done 240 kph along there on a bike. It had a 1000cc motor though...

I've done 240 there on a 675 street triple naked bike.
Never though that it's possible to race a bicycle there.

[Xplora]

Apparently some would prefer to forego the extra speed... See the previous page.

To them I would say, no one is stopping you from riding a slower bike, just don't try and convince me it is not worthwhile. Some like Spartacus can use the Domane and get third in the sprint, but most of us aren't World TT champions with the pedigree and flexibility that entails to overcome the aero disadvantage of the bike. If that's you. I am happy for you. Good luck in your recovery from the back injury. But to the rest, you will only watch them ride off your wheel so many times before you regret it.

[lock_]

5-10w savings doesn't sound like a lot, probably makes a negligible difference in speed too, but there's an awful lot of effort required for me to bump my 20min power up by that much!

Looks like Specialized have an 'Aero' Allez coming out soonish. I've been meaning to build up a CAAD10 frame I have lying around, but this has me thinking...



From here.

[singlespeedscott]

5-10w savings doesn't sound like a lot, probably makes a negligible difference in speed too, but there's an awful lot of effort required for me to bump my 20min power up by that much!

Looks like Specialized have an 'Aero' Allez coming out soonish. I've been meaning to build up a CAAD10 frame I have lying around, but this has me thinking...



From here.

I would like an old steel Allez from the eigthies. In a 61cm seat tube please. And I'll still be a mid pack B-grader, if I ever raced

[lock_]

Not from the 80's, but they did do a limited re-release of the steel Allez last year.

[singlespeedscott]

Not from the 80's, but they did do a limited re-release of the steel Allez last year.

Silly sloping top tube is a nail in it's coffin

[Chris249]

I'm biased of course, but I did enjoy this 2011 wind tunnel test from the German Tour magazine, which showed that at yaw angles of less than 10 degrees, the cheap old Kestrel Talon was the most aero bike on test - quicker than the Cervelo S3, Merida Reacto Team and three other aero frames that cost up to three times as much. Even at wider angles it still ran second. The interesting thing is that the Talon frame has remained basically unchanged since 2007. Oh, and it doesn't have a sloping TT - Cervelo used to make a bit of a deal about the fact that horizontal TTs were faster so the general shift to sloping TTs does seem odd.

http://www.tour-magazin.de/services/qtr ... 7.html#/24

Of course, I'll ignore the fact that the Kestrel is about 1kg heavier, and that you can feel it move around when you're sprinting.

[vosadrian]

Is it possible that the angle the air travels over the TT gives a longer wing profile than the max 3:1 and this may have some aero benefits (in sail effect less so than drag). I find it hard to believe that a sloped tube is such a hindrance to aero when most of these latest aero bikes have it sloped. It seems they have really got into the fine detail in accumulated gains on some of these latest released frames. Surely they have assessed the horizontal TT?

[Xplora]

I am betting it is a stiffness and weight compromise. My guess is that a horizontal TT might be a bit painful. Propel users comment?

[mikesbytes]

I'd guess [ie not based on data] that the sloped tube makes little difference. However why do it when a straight tube provides better aero, but is there any data to back up that statement?

[Chris249]

I'm pretty sure that there used to be a Cervelo article about the advantages of a horizontal TT on time trial bikes, but sadly some good stuff like that has gone from their website. The horizontal TT seems logically to be more aero, although the aerodynamic gurus say that airflow is too complex to follow logic.

However, I'm wondering whether the situation could be different for road bikes because of the difference in body position. A good TTer has an almost horizontal stomach and back, and wind tunnel and CFD pics seem indicate that that the wind follows that horizontal line - it's certainly logical that it would. A roadie tends to have a more angled stomach and back, and if the air is diverted downwards a few degrees by the stomach, then it would line up with a sloping TT. So a slope makes sense for a roadie and a horizontal bar makes sense for a TT bike, perhaps?

[mikesbytes]

Suppose another way to put the question is what benefit(s) does a sloping top tube give?

[Duck!]

The sloping top tube improves rear end stiffness by shortening the seat stays - for a given cross section, longer tubes have more flex. Stiffer frame = more consistent aero performance as the tail isn't wagging. If the transition from head tube to top tube is nice & smooth to direct airflow around it, there would unlikely be a particularly huge increase in drag due to the slightly increased frontal area - which remember is in the lee of the head tube anyway.

[cerb]

^ this.

Sloping top tube has little to do with aerodynamics and is all about stiffness of the rear end imo.

However, I think the stiffness increase improves power transfer and therefore makes a faster/smoother/better bike. I doubt 1-2mm rear stay movement, perpendicular to the direction of travel and behind the riders legs, would have much effect on drag...!

[toolonglegs]

Sloping top tube probably has more to do with making it possible to just produce 3 or 4 frame size choices than anything else.

[singlespeedscott]

Sloping top tube probably has more to do with making it possible to just produce 3 or 4 frame size choices than anything else.

Bingo and that's why Giant did it back in the late 90's.

Why you would want a stiff top tube is beyond me. Stiffness is not everything. You want it around the bottom bracket, chainstays and downtube but anywhere else it's going to produce a bike that's to uncomfortable and doesn't perform when your tired and cant churn out max wattage.

[g-boaf]

New Venge -damn!

Looked at a matte black one with shiny black logos on it tonight. Extremely nice.

[tk38]

I'm an occasional follower of the pros and mostly watch for the bike porn. I'm a bit of a fan of the speshy stuff, but I can't seem to see too many new venges around. If anything I still see plenty of old venges around.
Café mates are poking fun that it's a bit of a flop.

[vosadrian]

I'm an occasional follower of the pros and mostly watch for the bike porn. I'm a bit of a fan of the speshy stuff, but I can't seem to see too many new venges around. If anything I still see plenty of old venges around.
Café mates are poking fun that it's a bit of a flop.

I have an old Venge. The new Venge is still very new. I think even if you wanted one you would be hard pressed to get one through the supply chain, so that may be one reason. But I think the other reason is that the new Venge is a different bike that is far more "specialized" pardon the pun. The old Venge was basically a race bike like the Tarmac with aero shaping on the frame and regular componentry. It did everything a normal good race bike did, and compromised a bit of weight and comfort for some aero. It was happy at a crit, going up a climb and doing a century ride, and if something went wrong 50k from home, it could be fixed like any other bike. The new Venge needs to be bought specifically to your size and adjustment later is difficult/costly. It uses non standard components which will be more difficult to fix should something go wrong. It is no compromise for fast and probably not as comfortable for a century ride.

I would love a new Venge in my stable for racing and certain training rides that can get pretty quick, but I would not give up my old Venge which I would use on the weekend centuries and anything at more relaxed pace or requiring me to be able to fix things on the road miles from home. I think Specialized have made a great bike, but I wonder if they should have left something like the old Venge in the lineup for those wanting something that is aero but more versatile. I guess a Tarmac with Aero wheels is pretty close.

[g-boaf]

The new Venge is very rare and very, very expensive. I've heard prices in the AUD$16K range for a couple of them.

It's almost a superbike (the term for exotic modern TT bikes) with normal road-bike bars on it, if you could call them 'normal' because they are anything but normal.

Yeah it is a beautiful bit of engineering and design, but would I prefer it over the Giant I already have? Probably not.

[Xplora]

You just won't see many of the very latest aero bikes because they are all priced extremely high. Trek is a bit better at 10k but seriously, that's ridiculous. If I get a lump sum within 6 months, maybe that's doable. But cripes, big bikkies and IMPOSSIBLE for shops to keep on the floor. 52 and a 56, 20k of bike!

[tk38]

I meant for pro's. The money isn't a problem for them. For example Sagan seems to always race on his tarmac.
I've actually seen more on the road than on TV. Total rush has sold a few and they go out for Saturday shop rides.

[Xplora]

It's a bike for a particular purpose. The Tarmac is a bloody good bike on it's own and they could easily tweak the carbon layup for Sagan. It's a credit to the Tarmac, rather than the criticism of the Venge. You would ALWAYS take the general purpose bike over the Aero bike if the difference was minor for your style.

[BigDog]

First of all how long has the Propels current shape been out for and does anyone have any idea if they would be releasing a newly designed Propel next year?

Reason being is that I want to buy one, BUT I don't want to go and spend 9K and then a year later Giant release a brand new Propel