Dean V

You find the fit that works for you.
You find a frame that enables you to get that fit.
Doesn't matter what "label" it has.
I can get the same fit on "endurance" and "race" frames.
It is just the difference of a few stem spacers and a different stem length.

RoadLight

Hi Kontact,

I can understand why you think that and it's why pro teams who are forced to use such bike models from their sponsors will often resort to using handle bar stems with negative angles to compensate. Plus, let's remember that pro cyclists typically size down on their frames as I explained previously.

The reason I didn't raise the issue of head tube height in my post is because it is a more complicated issue than most realize. The head tube height, by itself, can be deceiving for those aero frames with (1) integrated handle bar systems that lower the handle bar stem part-way into the head tube and (2) reduce the height of the fork's crown. Both of these features are intended to reduce drag. We need to look at the frame, handle bar stem, handle bar and fork as a system. A better way to compare them would be to measure the height of the handle bar above the front wheel axle. If all you consider is the head tube height, you'll misunderstand the geometry.

Raria has it right -- a "race geometry" is primarily about aerodynamics. And I would add: "within a peloton." That's what the pro road teams and their mechanics tell us and I believe them.

Does this mean that every bike manufacturer will do the same things to a bike intended for traditional road racing vs endurance road racing? Of course not. There is huge variety in their approaches and their veracity. Some of them are clueless and make mistakes with their nomenclature. Therefore, I think a better understanding of this issue will come from the pro bike fitters (with a proven record of success) who configure both types of bikes.

Kind regards, RoadLight

Kontact 

The newer integrated bikes have tall head tubes to blend with their stems, but that doesn't explain the Cervelo R5 and similar non-aero racing bikes with tall head tubes that were used extensively by pros.

But really, you pretty much ignored my post: There is nothing about racing bike geometry that prevents any owner from sitting in the same position as an endurance bike.


Moreover, racing bike geometry is old - you'll find the same fit and angles on TdF bikes from the late '70s. It is geometry that allows you to ride comfortably on the tops or hoods all day and then move to the drops for an aero breakaway. And then do that for another 3 weeks. Don't confuse that with a time trial bike.

raria

That may be true for your racing bike and endurance bike but not for mine (or most peoples I suspect).

I have a CAAD12 and a Fuji touring (I know its not an endurance bike per se but it is quite similar).

For the Fuji the Stack and Reach is 601 and 377
For the CAAD12 the stack and reach is 551 and 387

So that's a 5cm difference in stack which would take a lot of spacers and one of those 20+ degree stems to fix.

As for reach, one can't just plunk down a shorter stem on a bike like the CAAD12 to shorten the reach for a more upright ride. The bike already quite twitchy/receptive and shortening the stem would only make it worse.

Dean V

Trek Domane stack and reach of 561 and 371. That would be doable depending on how long a stem you use on the CAAD. That Fuji you listed seems like an extreme example.

raria

The stack to reach ratio for most endurance bikes is around 1.5x, the Fuji is there

For a racy bike it's around 1.4. The CAAD is there.

Kontact 

I wasn't suggesting a rule that works on every bike - I was pointing out that a very large number of racing bikes do not force the rider to bend low - at all. The stack of your CAAD12 is lowish in today's road bike market, but not low by the standards of '90s road and touring bikes. It is the way the bike was designed, and if that design isn't appropriate to your fit, you shouldn't buy one. For many riders the lowish stack of a CAAD12 or traditional level TT bikes isn't a yoga pose but a fairly normal way to sit on a bike. If I were to buy a Cervelo R5 I'd have the 17° stem slammed on a 51 to get the rather small amount of seat to bar drop I like.

Many current road bikes come with enough frame stack and steerer length to put the handlebars above the saddle. Which is great if you need that, but not really the traditional way anyone has sat on a road bike.

This Pinarello is just as "low" as a CAAD12. Does the rider looked bent over, cramped or uncomfortable, despite 2cm of spacers and probably 8cm of drop from saddle to stem?




And shorter stems don't make steering "twitchy"; the CAAD12's steering angles and trail aren't any faster than most any other bike. The wheelbase isn't even all that short.



People should start getting in the habit of discussing geometry with numbers rather than adjectives, because the adjectives some of you are using have little to do with the numbers.

Dean V

Fuji is 1.59
Domane is 1.51
As I said, Fuji is an extreme example.

raria

If the Fuji is an extreme example then so is Jamis's endurance bike, Cannondale Synapse, Flight and about 5 of the Merida bikes have stacks of 595mm+.

See Slowtwitch.com Stack & Reach Database:

Kontact 

595 for what size? Hard to make generalities with a single size.

raria

Sorry, I should have mentioned, always size 56 (or M/L).

Kontact 

Okay. Does that mean that all the Endurance bikes sold with notably lower stack than the Fuji's aren't Endurance bikes?

dddd

I wouldn't be so dismissive of the effect of stem length on the bike's handling, and how that correlates to any specific headtube angle.

Those are critical variables that need to stay within ranges that are compatible with each other.

And this also illustrates how the features that make an endurance bike frame specific to it's intended use (hopefully in accurate agreement with it's performance as marketed) can appear invisible to any over-simplified view of bike fit and geometry that fails to recognize how one dimension or angle's range affects another.

A clue can often be found in the length of stem that the manufacturer specifies for a given size of frame, and how it correlates to headtube angle can lead to conclusions that are in agreement with observations from the field.

Different riders will have different preferences for steering quickness and different makers will perhaps have their own preference, so hard numbers are hard to nail down, and so comparisons of specs and comparisons from the field will provide the last word for any given rider. But it's normal for makers to bias the range of values for reach and headtube angle such that the largest number of riders will fit within ranges that work well with each other.

And there is more to race vs. endurance geometry in terms of how closely that a rider can safely draft the rider in front of them. That alone is one more reason for race bikes to favor a steeper headtube angle that shortens the front-center wheelbase component while favoring a longer stem to realize optimal steering behavior and while moving the rider closer yet into a lead rider's draft.

Likewise with the headtube height, where the makers in each case are trying to use a dimension that will accommodate the greatest percentage of the bike's intended riders without running out of spacers to remove or having to stack them more than a couple inches high, all while keeping the bike's aesthetic appeal intact.

Kontact 

I think you have some rather strong ideas about stems and handling because your bikes have screwed up weight distributions. Stem length is going to seem more critical when the real wheel loading is under 50%.


Generally, bike manufactures spec'd 110mm stems on most sizes because that was the middle of the standard 90-130 stem range. Bikes only come in so many sizes, and frames are like belts - they come with multiple holes in them to fine tune the fit. If a bike comes with a 110mm stem, it would be insane if the bike was unrideable with a 95mm stem.

These days 100mm stems are more common, but mainly because everyone's hands are glued to the hoods, and the hoods have gotten longer.

Dean V

Riding a bicycle isn't very demanding on handling. I have ridden many different bikes with different geometries and stem lengths from 70 to 140mm.
They feel and handle a little differently but after a short time of getting familiar with them I have never had a problem getting them to go straight and around corners how I want.
Look at all the shorter people that are forced to ride short stems to get their fit. Do they have trouble controlling their bikes?
Likewise with those that end up with extra long stems.
As "Kontact" said, only when weight distribution starts getting too far from the norm is there likely to be issues. eg. Forward TT type position on a regular road frame.

dddd

The small frames usually have slack headtube angles that are actually best suited to short stems.

Try putting a short stem on a road bike whose steering head angle is on the steep side and see what happens, you sure won't want to ride it in any endurance event!

Or put even a 120 stem on some road bikes like the Orbea Orca with a 72.5-degree headtube angle, and it's no longer any good for sprinting or even for attacking steep hills with the rider of course off of the saddle.

A bike maker just can't afford to ignore such details when assigning a stated purpose to the bikes they offer.
Case in point, even long before the term Endurance Bike was a thing, the E. Merckx "Century" bike had very specific and documented changes made to it's geometry that simply shortened the frame's reach while retaining the same steep headtube angle, which gave the rider the option to either use a longer stem for slower steering, or to utilize a more rearward saddle position with the same stem. Both options thus retained the same distance from saddle to handlebar. Or, the rider could split the difference in saddle and bar positions to achieve both effects but to lesser degrees, and even shorten the saddle-to-bars distance by some fraction of the total 1cm change in frame reach in whatever proportion that they chose. Note here we are talking a change of 1cm, and while no headtube angle change was made at all in this case, the rider could now adjust several factors which affect multiple fit/handling parameters toward a more rearward position and/or slower steering.
And this was over 25 years ago.
As one who is relatively long in the leg, I can sure appreciate that a shorter-reach frame was designed seemingly for me, and which fortunately retained the quite-steep headtube angle that the original Corsa was known for.
And it's not a bad bike for longer rides even with the steep headtube angle, at least not now that I have a decently-long 110 stem on it that I finally changed just last week.


As for what Kontact said about weight distribution, it sure wasn't the case with the Orca, whose slack headtube angle if anything balances out the forward weight transfer of a 120 stem by extending the front-center about a centimeter vs. say a 73.5-degree headtube angle on many other popular road racing bikes, yet those bikes handle fine out of the saddle with a 120 stem and the Orca does not.
Never underestimate the effect on handling of a 1cm change in stem length, it is quite real. True, it also affects weight transfer, but as a much smaller percentage of how much that it affects the offset of the rider's hands from the steering axis!

dddd

I'm not sure what you're saying there, what did anybody say about a bike being unridable with a 95mm stem???
And under what conditions are you referring. We're talking road/endurance bikes here, what makes a good road vs. endurance bike.

It does sort of sound like you are perhaps throwing that out as a presumed "quote" that nobody actually said.
Not a good way to support an argument.


Easiest way to verify the longer reach and steeper seattube angle of a 2018 Tarmac vs. a 2018 Roubaix is to go to Specialized's website and see for yourself. The Roubaix also uses longer chainstays, to add to it's stability, and has a 611mm stack vs. the Tarmac's 565mm stack. These are exactly the sort of expected changes that I've been talking about, all real numbers and all for the same 56cm frame size.
The Specialized site was even the very first one that I checked, and Bingo.
As you've said, the bikes can have same toptube lengths, and these ones do, but all of the other differences still result in the endurance bike having (published) taller stack, slower steering and shorter reach.
You can slice and dice the numbers with how tall of a rider goes on which bike and how the rider might adjust everything, the rider gets to decide all that, but the effect is the same, and even greater in this case than the differences I already explained between the Merckx Century and the Corsa.

Kontact 

You said:

And I replied about those "critical ranges" and just how critical they are. Bicycle stems aren't there to dictate handling, they are there to fine tune fit after the most appropriate frame size has been chosen. If you need 60cm or 160cm stem, you probably aren't on the most appropriate frame size.



I'm not sure what the rest of you post has to do with anything I've been saying. Many "race" bikes are tall and can be made to fit just like many endurance bikes. Endurance bikes are primarily about steering and ride, not a different type of fit.

raria

I think that's where people will disagree with you.

All the endurance bikes put me upright and the ''proper" race bikes put me in a flat back position.

ROLObikes website puts it nicely

". As the ratio decreases, the reach increases relative to the stack so the rider becomes increasingly stretched out on the bike: the position is increasingly aggressive and aerodynamic. Conversely, as the ratio increases, the bike becomes more relaxed and the rider’s position is more upright."

As I've mentioned before and put a link in an earlier post in, the ratio of stack to reach varies from close to 1.6 for endurance bikes to close to 1.4 for race bikes.

dddd

Again you are doing the very same thing here, using the suggestion of exaggeration "60cm or 160cm" to support the argument that you made before, but have curiously abandoned.

This is looking like an obvious habit of yours at this point!

So, getting back to the topic of this thread, "Endurance vs. Race Geometry".

You said: " Endurance bikes are primarily about steering and ride, not a different type of fit"

I have to disagree that the fit is not a big part of what an endurance bike enables, hence the generally much taller headtubes on Endurance bikes vs. race bikes, not to mention the reduced seattube angle of the Roubaix (vs. Tarmac) or the Century (vs. Corsa).
Again, the rider will sit a bit further back to achieve balance over the bb, because of their reduced average level of pedaling effort/torque.

Kontact 

Again, I would ask you to consult actual geometry charts instead of making blanket statements.

Are the following not pro racing bikes?

S-Works Roubaix McClaren - 1.6
Madone 9.9 - 1.54
Cervelo RCA - 1.5

Kontact 

Please refer to what you are arguing about directly. I don't know what "the argument you made before" is.


And I'll stick to what I said about the difference. If a Roubaix is as tall as any Endurance bike, the argument that race bikes are low is deeply flawed.

And the Roubaix and Tarmac both have 73.5° seat tube angles in size 56, so I am once again going to have to ask people to refer to geometry charts instead of making (incorrect) generalizations.

Maelochs

Okay .... when you feel that spiralling motion .......

dddd

You must have been looking at the 2018 head tube angle? I see 74-degrees for the Tarmac Seattube angle, in addition to the 14mm longer reach and the 46mm lower stack as compared to the 2018 Roubaix (both in S-Works 56cm sizes).


It's right here if you scroll down to the geometry. S-Works Tarmac: https://www.specialized.com/us/en/me...=239625-129090


...and the S-Works Roubaix: https://www.specialized.com/us/en/s-...=240099-134017


I think that it's always going to be most useful comparing bikes from the same maker, as different brands from the same maker can have a different take on what size rider fits on what sizes of bikes that they offer. Case in point, LeMond and Trek once used the identical OCLV frame labeled a full 3cm different (LeMond wanted the buyer on a bigger frame).

Kontact 

It is 2018 and I went to Specialized website and looked at the bikes you mentioned. But if you want to talk about past models:

73.5° and 74° are both steep seat tube angles, so any argument about "more relaxed" position is way off base when you are comparing steep and steeper. "Relaxed" for medium sized bikes is when the STA is less than 73°. These angles are just relative - there is a very concrete relationship between STA and expected set back, and those angles are NOT going to create the extra set back of a relaxed, more upright position bicycle. They are both "aggressive", steep STAs.

Trek and Lemond weren't "the same maker" any more than Giant is "the same" as the Trek's they made.