Overlapping pics from this year with pics of her on a Shiv (700c) (see below). It looks like 700c wheels (scaling the wheels in each pic, her torso looks to be the same length).

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ECMGN Therapy Silicon Valley:
Depression, Neurocognitive problems, Dementias (Testing and Evaluation), Trauma and PTSD, Traumatic Brain Injury (TBI)

Hey Dan, some day that 650's have more Crr that negate any aero benefits of the wheels (not the position attained), but does this statement only apply for heavier riders, meaning proportional wheel size on a smaller body at lower psi = faster ?

As for Emma Pooley, she's 153 cm, 48 kilos, built for races like Alpe d'Huez and Embrunman!

the 650c/700c discussion is very convoluted. we used to make our 650c wheels with flanges 20mm closer together, because we didn't need all that triangulation. if we had 90mm rims, and 650c wheels, the spokes were really short, so we could use narrower flanges, and THAT wheel was a whole different aero beast than a typical 650c with standard hub flange widths.

to the argument that 700c has better rolling resistance, fine. but if 700 is better for a lady who is 5'5", why isn't 800 better for a man who is 6'3". you can't have it both ways.

MTB riders understand this argument. road riders don't.

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Dan Empfield
aka Slowman

i've got my feelers out. i'm 50/50 on this. i can't tell. she's 5'5". the P4 was 650c in its 48cm size, then 700c. it had a 110mm head tube in that smallest size, then 90mm in the 51cm, 105mm in the 54cm and so forth.

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Dan Empfield
aka Slowman

here's what gerard says: " It’s a P5 but I think that’s 700c. The 650c and 700c have the same chainstay length so the 650c would have to have a lot of material behind the BB. Instead it seems about the same as on the mid-size frame on the Cervelo website."

so probably it's 700c, and i'm wrong about it being a P4. i can clearly see it's a P5, i was hallucinating.

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Dan Empfield
aka Slowman

But my point is that all the discussion on poor 650 Crr"seems" to be based on larger men. If you put a 120 lbs woman on a 650 riding at 80 psi, should be pretty good. And then you have a proportionally sized wheel which should take less watts to push through the air. As it stands a 153 cm woman of 48 kilos has to us the exact same aero watts as a 193 cm male who is 78 kilos to move the same wheel at 40 kph. The problem is that 700 wheel is a larger percent of her top line watts than the 193 cm male.

I don't know, but it looks like Amber Neben could have used a smaller bike. Although I do like the unbranded everything, continuing the proud tradition of women ditching sponsor bikes for speed concepts.

You can't ditch something you never got in the first place.

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Professional Athlete: http://jordancheyne.wordpress.com/ http://www.strava.com/athletes/145340

Coaching Services:http://www.peakformcoaching.com/

I can't answer that, but I can tell you that is a sweet paint job on the P5!

99% certain that disk is 700c. The guy she borrowed it from is 6'1".

Crr is independent of weight. The rolling resistance experienced is proportional to weight.
Also, 650c wheels have not been shown to create more aerodynamic systems. The bike needs to be proportionally taller, and the wheel needs to spin at a higher rpm for a given speed. The last testing I recall seeing (gotta go find it) showed 650c wheels to be slightly slower than their 700c counterparts.

Update: Here's some data from Zipp on 700c vs. 650c firecrests: http://www.slowtwitch.com/...ide_Report_3855.html
The 650c is slightly (1-1.5W) more aero, but that's before you add the extra rolling resistance, and taller bike tubes.
Either way it's probably pretty close. The compelling reason to go with 650c would be bike fit vs. very minor aero costs.

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ECMGN Therapy Silicon Valley:
Depression, Neurocognitive problems, Dementias (Testing and Evaluation), Trauma and PTSD, Traumatic Brain Injury (TBI)

"The 650c is slightly (1-1.5W) more aero"

as noted, however, this is with the penalty of the wider hub flange. if zipp made wheels of equal STRENGTH (narrower hub flanges, fewer spokes) then let's see the comparison.

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Dan Empfield
aka Slowman

Which is funny, because the Speed Concept does come in a smaller-wheeled XS as well...

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ZONE3 - We Last Longer

You know what's funny Dan?

The world's leading fitters are complaining that the Long And Low tri geometry is sorely missed, bike companies won't listen.

There's an increase in female triathlon participation, but small-wheeled options are dying out. People who need a pad stack under 530-540mm have very few options these days.

We were looking at getting a TT bike for my girlfriend, who stands a proud 5"1 tall. When Giant announced the Avow, we were honestly excited - Ultegra Di2 at the right price-point, modern aerodynamics, and very low front-end - but when we tried to order one, Giant responded with:
What kind of ridiculousness is that? So much noise about their "dedication to women's fit and geometry", about the lengths they went to produce a bike with a small wheel - and then it's not even available.

When Quintana Roo announced the PR6, I remember very clearly that a small-wheeled Size 45 (IE, frame stack 450mm) was announced - but that option seems to have disappeared.

Funnily enough, when checking possible pad stack combinations, it seems like the Felt IA1x is the lowest option remaining.

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ZONE3 - We Last Longer

I built a P3 45 with Pad Y of 485 a couple of weeks ago. 530-540 is for tall people (as far as some of my clients are concerned).
However, I totally agree with what you wrote - would be nice if the fit options were increasing with Tri bikes rather than shrinking.

True, the P-series are another option (though their local pricing is not competitive here).

Too bad about Giant, since it really ticks all the boxes for us. Oh well, together with the phantom aluminium Propel, they really have a knack for announcing desirable bikes and then not delivering...

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ZONE3 - We Last Longer

You really think the concept of a 650c front wheel and a 700c back wheel is desirable?

Sounds really strange/impractical to me...

I'm neutral towards towards the wheel issue, and the rest of the bike is pretty much everything I'd want in a modern tri bike - so yes, I consider this bike desirable. In the context of a tri bike in our household, it's possibly even a better solution than 650c front and back: Compatibility with existing parts is a big plus, since we have a disc wheel, Powertap training wheel, trainer wheels and the trainer itself all set up for 700c wheels. None of which are big obstacles (well, sourcing a clincher 650c disc wheel might be) but it makes life easier to at least keep all drive wheels the same spec.

In terms of carrying spare tubes, that's not an issue either - you can stretch a 650c tube onto a 700c rim and fold a 700c tube into a 650c rim. I've done this often, also with 29er and 26er MTBs. If the bike's integrated storage can hold two tubes, we'll just mount one of each - if not, a single tube and patchkit will do.

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ZONE3 - We Last Longer

Fair enough.

FWIW, though, the 'integrated storage' on the Avow is basically nonexistent. The bento box on top has the capacity for maybe two skratch packets or two Gus, plus your 3 port junction. It is pretty disappointing. So yeah, a 650c tube stuffed between the saddle rails or a saddle bag would be the only real option.

i don't see any reason to go 650/700. dual 650 makes more sense. but it's arguing between 2 options that aren't going to see daylight.

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Dan Empfield
aka Slowman

You only need taller head tubes for taller riders. There is a height below which you don't need taller head tubes on 650's! As Dan said, build the 650 wheels with hub flanges for 650, not 700 and put them on a small riders riding lower psi (since they don't run the risk of a pinch flat) on a proportionally small bike and we're golden.

All the talk is skewed by the requirements of the average size male participant.

I outlined why I don't mind the 650/700 hybrid (or rather, how I rationalized it over a dual-650 bike, which I agree makes more sense to begin with). Regardless, it's just mind-boggling that company after company fails to deliver a bike that caters to the shorter end of the population. That's without considering the sub-5-foot females, who might not even get a proper fit on a 650c bike.

The MTB industry has it right for a change. Some companies offer 27.5 and 29er options across the whole range, some do 27.5 on the small wheels and 29ers on the medium and larger sizes - everyone can fit something without crazy compromises.

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ZONE3 - We Last Longer

700c.

I've fit both Carmen and Amber. Amber has a unique set up in that she's limited from her ToC injuries. Her new position was the result of 3 days of fitting and aero testing (1 day in the tunnel, 1 on the velodrome). Interestingly, we tried many things with her, but she's a great example of you just don't know for sure until you test. Before her testing, I would have put some serious money down that certain things would have been far more aero on her, but she's "bizarro" girl when it comes to aero. For example, and referring back to the Giro Aerohead thread, she's the one athlete who that helmet was not fastest on.

She is, however, using one thing (I say "thing" because, for fun, I don't want to give away yet what it is), that could be one of the best aero deals in all of cycling. Bang for your buck, it's tough to beat. Anyone care to guess?

Both ladies are true pros, and I hope both punched their ticket to Rio.

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Jim Manton / ERO Sports

My guess: pedals. Specifically Speedplay aero.

I'll say the Velotoze shoe covers.

Ding, ding, ding. Velotoze - $18, practically disposable (which is good 'cause they're easy to rip), and they've tested faster than anything else out there over and over again.

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Jim Manton / ERO Sports

You need a taller frame (or a raised seatpost and steerer spacers) regardless. Assuming the BB height remains constant, you need to get the extra height missing from the wheels somewhere. The exception on the spacers would be someone who is using a negative stem on their 700c bike.

I'd opine that 700c wheels aren't sized to the average male participant, they are sized based on a traditional standard. Plenty of big guys used 650c wheels back in the day (Dave Scott, 6'1" was a big advocate). It takes a relatively large advantage to get folks to switch to a new standard, and 650c just didn't seem to offer it.

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ECMGN Therapy Silicon Valley:
Depression, Neurocognitive problems, Dementias (Testing and Evaluation), Trauma and PTSD, Traumatic Brain Injury (TBI)

I fail to see how if you are 5 feet to 5'6" why you need a taller head tube with 650's....you just end up with a proportional head tube to the rider and to the wheels. That's all.

As for switching to a "new standard" Dan can chime in, but in the 90's in Kona in terms of wheel size it had gotten to the point where things were dead even

I wish I could find some pics of my Daccordi time trial bike that I used when I first attempted some triathlons in the early 90s. It atracted attention, but was a bear to ride with a 650/700 setup.

I seem to recall Greg Lemond did quite well at the Tour De France in 1989 on a TT bike with a 26" front/700c rear disc wheel, setting the record for the fastest time trial in Tour history, until last year when Rohan Dennis broke the record. The main reason the setup fell out of favor was because the UCI banned 'funny bikes' and the use of dissimilar wheel sizes, mainly in response to Graeme Obree twice breaking the world hour record on such 'unconventional' equipment.


I wish I still had my 'team issue' Tommasini time trial bike I had in the late 80's.

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¯\_(ツ)_/¯

First, I am willing to bet a head tube is much more aero than a wheel (no need to have a bad leading edge since it is not also a tire, also it does not need a trailing edge that is sometimes a leading edge, greater depth, etc,

Second, this is for people that can not fit on 700c bikes. That 700c has a frame that is too large to begin with, so the 650c with a smaller frame is exactly what you want. You do not need to make up for the smaller wheels, that is the point.

That is the key point.


Looking at Amber (below), she still has pad risers on her 700c bike. If the bike had 650c wheels, the extra stack would have to manifest somewhere (taller headtube, more spacers, etc.). I agree her fit doesn't look ideal, but from Jim's comments she's tested it quite a bit and it works for her.

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ECMGN Therapy Silicon Valley:
Depression, Neurocognitive problems, Dementias (Testing and Evaluation), Trauma and PTSD, Traumatic Brain Injury (TBI)

2X national time trial champ and she has to borrow a disc? Geez, it's rough out there.

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ECMGN Therapy Silicon Valley:
Depression, Neurocognitive problems, Dementias (Testing and Evaluation), Trauma and PTSD, Traumatic Brain Injury (TBI)

Why should the BB height remain constant? If we look at it from the point of view that a rider who needs 650c wheels to start with will automatically be using smaller cranks e.g. max of 165mm, then the BB can be lower (looking at it from a pedal strike point of view), so the rider will sit lower and won't need that extra head tube or spacers. I.e. is the reason for the longer head tube/extra spacers because of the higher BB in the first place - manufacturers having to accommodate the average 170-175 crank length? And obviously, the lower the rider can sit relative to the ground, in absolute terms, then surely the more aero?

BB height does not need to remain constant. It's independent of wheel size.
A company could offer its XS frame with a lower BB and 165s regardless of wheel size.

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ECMGN Therapy Silicon Valley:
Depression, Neurocognitive problems, Dementias (Testing and Evaluation), Trauma and PTSD, Traumatic Brain Injury (TBI)

Indeed, but that's not my point. My point is, is the reason why smaller riders are testing the same on 700c frames as 650c, because the 650c size isn't optimised for them? i.e. it is designed to accommodate the same size cranks as people will use on 700c frames? Hence, the same overall BB height (from the ground) and hence, the same absolute height? If BB height on 650c frames was designed around the fact that riders who need small frames will use 160-165 cranks, then surely the rider would have a lower absolute position, and how can that not test faster???

On a related side note, I've never understood why fitters never seem to mention BB height when talking about fit, as again, if you have two bikes that can be fit the same, yet one has a lower overall BB height, then surely that would create a lower overall position, and hence, be more aero? Am I missing something?

 . . national TT Champ and two wheel sponsors! :)

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Steve Fleck @stevefleck | Blog

"if you have two bikes that can be fit the same, yet one has a lower overall BB height, then surely that would create a lower overall position, and hence, be more aero? Am I missing something?"

the original P3 had a BB drop of 60mm, and i believe the speed concept has 80mm. these are 2 very obvious departures from the norm. i don't know that one of these is demonstrably better than the other. i hear what you're saying, but i've learned not to trust intuition overmuch when it comes to how a bicycle (mis)behaves in testing.

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Dan Empfield
aka Slowman

Thanks for chiming in.

Yes, for a given frame size (not wheel size.)

Good designers understand that smaller frames are for smaller riders, who often use shorter cranks, so the BB can be lower than on bigger frame sizes (and sometimes is). Regardless of wheel size.

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Damon Rinard
Engineering Manager,
CSG Road Engineering Department
Cannondale & GT Bicycles
(ex-Cervelo, ex-Trek, ex-Velomax, ex-Kestrel)

Other factors are much more important...in the end, you're just moving the big blob up and down with barely any change to the exposed area of the frame. Also, the lower the BB, the shorter the head tube needs to be for a given stack height.

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http://bikeblather.blogspot.com/

You clearly haven't read the Pinkbike comments section recently...


But seriously. There's a huge faction who hate 29ers, and who hate 27.5, and who hate the new wider "mid-fat" tires, because they're all an industry conspiracy to kill the 26" wheel and force everybody into the newest "standard" which itself will be obsolete in two years.

It's hardly far from settled that tall guys should use 29ers and everybody under 5'9 should be on something else. It doesn't even break down between XC and DH. And don't even get me started on the Boost 148mm hub standard.

my next bike is a 27.5 plus bike. just because they make a new wheel, that's not going to force anybody to buy the bike. you have a bike available that you can buy, but nobody's forcing you.

there's a lot of choice in MTB and that's a good thing as far as i can tell. we have less and less choice in triathlon bikes.

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Dan Empfield
aka Slowman

Oh, I'm in total agreement with you about choice. There are a couple main problems though:

• Compatibility: My old 26" wheeled bike is not compatible with any more current standard. It uses quick releases (virtually dead) and 135mm rear axle spacing (virtually dead). Want plus-size tires? Gotta buy a new frame and fork with Boost spacing, plus wide rims. Then you have to convert your drivetrain to the correct chainline. Then if you put normal size tires on, your BB height is screwed.
• Consumer choice: The availability of quality replacement parts is next to zero. Everybody says 26" isn't dead, but I have to settle for Nashbar leftovers -- and even then, the disc brake rotors are different, so I can't just use my old ones.
• Evidence: Limited testing shows that 29ers are faster for many real-world applications. But nobody has proven that they are faster for tall people, or only scalable down to a certain frame size, or that rollover benefits outweigh the perception of different handling traits. And people who think that 26 "just feels more playful" are never going to be convinced by science.

This is why everybody should just buy more bikes.

Proabably way off topic, but why did the MTB gang go to 650B instead of 650C when they wanted a tweener wheel size?

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Advanced Aero TopTube Storage for Road, Gravel, & Tri...ZeroSlip & Direct-mount, made in the USA.
DarkSpeedWorks.com.....Reviews.....Insta.....Facebook
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the MTB folks never were onto 650c. in 1987 i started farting around with bikes, and specifically 650, and when i ordered and got my first rims they were 559 bead diameter. the 571 bead was used very sparingly, by funny bikes mainly. MTB in 26" has always been 559m, from the get-go.

now, 27.5", i don't even know what that bead diameter is.

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Dan Empfield
aka Slowman

Supposedly, it is 584mm. Which is just 1% more than 650C.

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Advanced Aero TopTube Storage for Road, Gravel, & Tri...ZeroSlip & Direct-mount, made in the USA.
DarkSpeedWorks.com.....Reviews.....Insta.....Facebook
--

And only 12.5mm (< 1/2") larger on the radius (the "working" dimension in regards to wheel performance) than a 26" wheel :-/

The adoption of 650B in MTBs was (IMHO) only because after the bike industry realized that maybe not EVERYTHING was desirable to switch to 700C, they couldn't go all the way back to 26" because that would basically be admitting a mistake.

BTW, why is it called 27.5" when the diameter is only 25mm (less than 1") larger than a 26" wheel? Shouldn't it be a 27"?

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http://bikeblather.blogspot.com/

Thanks. I assumed good designers would, but so far I hadn't found any examples of lower BB heights for smaller frame sizes. And taking one example (it's hard trying to find companies that list full spec builds), Felt with their IA, I note that the BB height (drop 72) is the same across all sizes, yet they spec a complete build for the smallest size with 165 cranks, and the largest size 175

• Crankset:
  Rotor Flow Aero w/ Power 48cm = 165mm 51cm = 170mm 54 - 56cm = 172.5mm 58cm = 175mm
  

...maybe SuperDave will chime in on why they didn't lower the BB in relative terms across the range, to get the rider lower.

As a highly contented CAAD 9 rider, still looking forward to hearing the fruits of your work with Cannondale!

Thanks for writing. I'm not just talking about how the lower BB would affect the the frame, but also, the absolute height of the rider from the ground, which would be reduced. If frontal area is height/width, then surely being lower in absolute terms, equates to a lower frontal area???

For instance, if we took a guy who rides 150 cranks - there was a recent thread on this - then if we custom built him a frame with a super low BB to take advantage of the short cranks (with the reduced amount of clearance required for pedal strike) then he would get quite a significantly lower absolute position, and hence, frontal area. Surely, that would be quite significant??? Or am I still missing something?

"then he would get quite a significantly lower absolute position, and hence, frontal area. Surely, that would be quite significant??? Or am I still missing something?"

yes. you're missing the test. we're having a discussion now on which side of the bike presents better to the wind in a yaw. the result is completely (to me) unintuitive. bikes do not always behave as you suspect they would.

as to 650c wheel bikes, the reason you don't lower the BB as you suggest is because the point (my point) in making 650c bikes was to fit and handle properly. i believe my BB drop in my women's specific bikes was 45mm or so. i started building these in 1988, and it's an absolute crime that the bike industry has allowed these bikes to fall out of favor. with all the discussion of women's proper and equal treatment in sport we've had over recent years, this is one that these equality and access movements have not been nuanced enough to understand.

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Dan Empfield
aka Slowman

It's not mind boggling though, because we're talking about a small minority of the market that would require significant investment to properly serve, fair or not. The world's leading fitters may be lamenting the demise of long and low, but the other 95% of fitters who don't know what they are doing are perfectly fine fitting/recommending bikes that are far too tall for that small minority. I went on a rant about this a while back in the 'why are women's bikes more expensive' thread.

You must be Dutch if you think 5"1 is a small minority of the market. Or, just a blind male.

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ZONE3 - We Last Longer

You must not have read the link.

Actually, no.

Take a look at a frontal picture of a cyclist. The overwhelming majority of the frontal area is the rider. The bike makes up a small fraction. Moving the "blob" that consists of the rider up and down (keeping the body position constant relative to the BB) doesn't change the contribution of the rider to the frontal area one iota.

All you end up doing is exposing or covering a very small portion of a very small contributor to the total frontal area, especially for the BB differences being talked about here. So, it basically doesn't make an appreciable difference in this case.

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http://bikeblather.blogspot.com/

I did. You really do sound like an MBA textbook cliche.

More and more women cycle. Women's pro cycling is on the rise. Companies market for women, advertise for women, and yet - if you're a 5"1 female which is the global average, you'd be hard-pressed to find a tri bike that fits. Regardless of price or gender-designation, because there is no "male SKU" to substitute. A business manager who chooses to ignore a quarter of the potential customers is doing a pretty bad job - and sponsorship and other up-front investments in male cycling are still way, way larger. I wager you've never discussed sponsorship costs with a male pro team, have you?

I don't care if it's labeled male, female or orc. I want to buy a bike that allows a 5"1 person, who needs a pad stack in the 490-530mm region, to ride a position as optimized as a 5"9 person could achieve.

Of course, all this started when I asked how come a bike company announces a frame size, prides itself on that frame size (just see how much of the Liv Avow material refers to that small front wheel), and then doesn't let national distributors order that size.

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ZONE3 - We Last Longer

I think it's because they don't care about serving the <5% of the market who KNOW they need a stack that low. The worlds best fitters may know, you may know, but it's still a sliver of a sliver who are actually butt hurt about this.

Also, marketing. Giant touts "women's specific geometry" as an advertising principle, not as a fit principle. They fail to mention that the geometry is the same as the men's on the rest of the line...

Last I checked, the Avow comes in a different range of sizes than the Trinity which caters to smaller women. Their marketing blurbs are all about the extremes they went and how they realized the XXS needs a 650c front wheel. The Liv Envie has a different geometry than the Propel, too, as do the other Liv bikes and their Giant counterparts.

You know what? You're wrong. It doesn't matter whether you're a die-hard bike nerd who aero-tests his equipment, or a complete beginner. If you can't swing a leg over the top tube without impaling yourself on it, you won't buy that bike. Same if you can't reach the handlebars comfortably. You're getting hung up on that one long-and-low comment, but I'm talking about those who need short-and-low. You know, women. Just on my team, we have four girls who haven't bought a TT bike because they can't find that fits, and a few who bought a bike too big for them because "it's still better than none".

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ZONE3 - We Last Longer

Emotional much?

No, quite calm. Nice job assuming, though.

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ZONE3 - We Last Longer

The Cervelo P series 45 doesn't work for them? The Trek Speed Concept XXS is also really small but unfortunately Trek now only offers that in the pricey 9.5 model. My wife is 5'0" and bought a first generation Speed Concept 7 and it fits her just as well as her custom Seven, it has a very short reach..

I wasn't at Cannondale when the new SuperSix EVO was designed, but check out row K, BB drop:

It varies with frame size, in step with expected crank length.

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Damon Rinard
Engineering Manager,
CSG Road Engineering Department
Cannondale & GT Bicycles
(ex-Cervelo, ex-Trek, ex-Velomax, ex-Kestrel)

Yeah, my mum has the old SC 7 and it's a great fit for her - if we could locate another one it could be a match. Cervelo would be an option but right now the local distribution switched hands to a shop I'd rather not rely on.

That being said, I've found that Orbea and Canyon (again, like Felt, two brands with no local presence...) manage to make super-low 700c bikes with a pretty short reach, too. Worth a look.

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ZONE3 - We Last Longer

With regard to the pressure of 80psi...I don't know anyone that can ride 80psi on 650's and not pinch flat, even some of my 115 lb friends.

I don't know exactly what it is but I can ride 85-90 psig all day long on my 700C road bike with no issues but I'll flat on my 650 bike. That is my experience using the Pro4 race and Conti 4000SII tires

Not everyone that rides 650 wheels use 160-165 cranks. I know the trend is going that way though, personally I dislike anything shorter than 170 (yes, I spent a considerable amount of time on them) and have thought of going longer.

There is no need to drop the BB 5mm. People that need that small of bike (smaller than 48cm) don't punch a very big hole in the air anyway. I would rather have the pedal clearance above the ground.

What did you use on the front end of the P3?

I'm at a pad stack of 500 right now and don't need to go lower but my P2 is capable of it, I was just curious of the front end components you used.

FSA Sl-K -20 stem - the design means it's lower than a standard stem with -20 angle would be
Vision clip on bars
Slamthatstem cover doesn't fit the headtube diameter perfectly, but you well know that every little counts in getting low

Can you influence Cannondale to make a real 650C road racing bike?

Thanks, I'm on the Vision clip on bars as well but am using a PD Prosvet basebar so I could take out the last 12.5mm spacers from under the pads and use the teeny tiny ones.

I haven't needed to go as far as using a slamthatstem cover yet, I did on my old P2. I have a COBB spacer on another bike that looks to be a better fit although it's 2 or 3 mm taller and that may not be an option.

I'm going to look for that stem, I'm currently using a Performance bike adjustable. It's OK but I'd like to get away from it.

jaretj

Any idea how low one can ride on a tubular 650?

I'm 158lbs and ride 90 psi without any problems. I'll try lower in the next few weeks to see what happens.

Thanks for posting. Yes, my CAAD 9 does exhibit the same BB difference, but the problem for me, and where this stems from, is that my saddle height (I have a 48 cm) is not determined by optimal fit, but by the necessitude (certainly in my opinion) of being able to touch the ground with at least even the tip of my toes. Sure, it's not a problem when racing, but for general riding, I don't consider it safe. (I have short lower legs and a long torso.) So despite the added advantage (in terms of lowering the saddle height in absolute terms) of riding midfoot, my saddle height is still a fraction lower that what it would be if the bike had a lower BB. So please, lower them a fraction further on the small sizes ;-)

In reference to JaretJ's comment, it is not all about pedal clearance.

Thanks for explaining. Sure, the frontal area of the big blob wouldn't change, but I'll take your word that the reduction in the frontal area of the thing under the blob (from being shorter, in terms of absolute height of the bike) would be insignificant.

There is one more question I have, if you could get the rider lower to the ground in absolute terms, would there not be a benefit from the reduction in wind speed from being lower? Or again, would that be insignificant?

I am confused, so you want to be able to put a foot on the ground, while still sitting on the saddle?

In still air, no difference, since the apparent wind gradient is basically zero in the vertical direction. With any ambient wind, there would be a small effect since there is a non-zero velocity gradient in the air flowing across the ground (i.e. zero at the ground surface and then increasing quickly)...but again, the differences in height of the "blob" we are talking about are not enough to make an appreciable difference due to this effect. So, in theory there is a difference...but in practice, it will be basically immeasurably small.

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http://bikeblather.blogspot.com/

I think Tubulars are a different animal than clinchers when it comes to pinch flats, those are the kind of flats that are most common to me.

Now it's been several years since I raced on tubulars. Back then I was on TUFO, then Conti Competitions then Vittoria Corsas.

I thought the Corsa was narrow for 90 psig but I was on the high inflation pressure train back then and rode them at about 120psig.

If I was riding tubulars now I think I'd be nearer 100 psig, most tires feel fairly soft to me at that pressure and that is just under what I ride on clinchers, (I'm about 142lbs)

Hi jaretj,

No, but I personally think that would be really cool, and could present the case for consideration. I'd be interested to see your preferred geometry, and a guess as to the number of riders who might buy such a bike.

Cheers,
Damon

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Damon Rinard
Engineering Manager,
CSG Road Engineering Department
Cannondale & GT Bicycles
(ex-Cervelo, ex-Trek, ex-Velomax, ex-Kestrel)

My personal issue is that I have short legs and gorilla length arms. I need a low saddle to get the right knee angle and the corresponding low bar height to get the right hip angle. Now I'm not exceedingly low, it's just I'm 64" have the arm-span and body length of someone that is 67".

The problem I have with the 700C road bike is that when I get the bars in the position I like, (I've done it on my Felt F5) the bottom of the handlebars are below the top of the front tire and I don't think that is legal for ITU draft legal racing (I don't seem to be able to get an answer from anyone about that). I'm using the shortest drop bar I can find (Bontrager Race VR-S), I've thought about bending the bottom of the drops up slightly since I only need about 3/4"

Now if I could find a 700C bike with a higher bottom bracket that would work great, it would be similar to putting blocks on my pedals like when I was young.

As for the guess as to the number of riders who may buy such a bike, I know it'd be small but Cannondale could paint it pink and put flowers on it to market it to small Asian women and I'd still ride it.

My measurements for my Cannondale CAAD5 XS (44) are in my profile. I really like that bike but it's really short front to back. The Trek 2200 I have in there fits great but the frame is 16 years old.

I understand. Roger Hammond told me the same thing, the UCI does require the bars not be lower than the tire. But he was worried about his knuckles rubbing other riders' rear tires!

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Damon Rinard
Engineering Manager,
CSG Road Engineering Department
Cannondale & GT Bicycles
(ex-Cervelo, ex-Trek, ex-Velomax, ex-Kestrel)

[quote jaretj
I'm going to look for that stem, I'm currently using a Performance bike adjustable. It's OK but I'd like to get away from it.[/quote]
This rider had a single bolt adjustable on her P4. It creaked and flexed - was never the ideal solution.
The FSA is quite pricey and the clamp on the bar is 50mm wide so can be a limiter on aerobar width. But it is a solid and useful bit of kit. I've got one too - to compensate for high stack bars on my 56

With the Vision clip ons you get a 5mm drop in Pad Stack for every step outwards in pad width. So it can be useful to go with narrow hands to get the right pad width on a wide setting.

Thanks again, I saw they were a bit pricey.

jaretj

Have you tested these against the Smart Areo shoe covers?

Once again, thanks for taking the time to explain.

Front wheel power "requirement" is more aero and less rolling resistance than rear wheel. So the optimum size for each should be not the same.