mrblue

I often read in reviews, and hear people talking, about a bike in terms of geometry. A road bike has either an endurance or a race geometry,or so it seems.

What does that mean? I know that with endurance bikes the riding position is typically more upright, but what are the other differences one should be looking at, in regards to these two different descriptions of geometry?

Also, just because a bike has an "endurance" geometry does that mean it lacks something and would not make a good race bike? What about the opposite, if a bike has "race" geometry, does that mean it would be a poor endurance bike?

What is the deal with sloping top tubes? Why are they not horizontal? What about compact geometry? Is that more exclusive to endurance bikes or race bikes?

Thanks.

brianmcg123

Generally an endurance geometry will have a longer headtube, longer chain stays and more tire clearance for 28-32mm tires.

All this is dependant on the manufacture.

Obviously you could take an endurance frame and run 25mm tires and slam the stem and it would feel just like a pure race frame.

Kontact 

It is a fairly meaningless claim. Some "endurance" bikes have race geometry, but more headtube and some sort of softer ride. Some race bikes have the same, or even "relaxed" steering geometry.

Generally, "endurance" is a term used to contrast one bike model from another within a brand. It won't steer you to any strict set of features.

Many "race" bikes make fantastic bikes for very long distance riding. Tour de France length riding.

Voodoo76

I look at this as the next evolutionary step post the introduction of compact frames in less sizes. It's more about stack/reach and the rider fitting than purely about the handling characteristics of the bike. The rest is marketing to the type of rider who's fit is typically going to work on a given frame. I'm going to call the taller/shorter front end "endurance" and a lower/longer front end "race", and outfit them accordingly.

On the plus side this trend offers more fit options in really good frames. Thus reducing the frequency of the obnoxious pile of spacers (and it's companion the esthetically putrid upside down stem), and the just as ridiculous "Pro" look of a frame 2 sizes too small with an 18" long seat post & a slammed 140mm stem.

FlashBazbo

I will agree to a great extent with the other responders. Bike fit is very personal. And suitability for "race" vs. "endurance" is extremely dependent upon the type of road, surface, event style, and topography. I have seen circumstances where a bike manufacturer labels a bike as "endurance" when its geometry is very much the same as everybody's "race" geometry. The distinctions are silly.


When I was a Specialized S-Works guy, I road raced an S-Works Roubaix ("endurance"). I felt faster on it -- especially on chipseal roads. But I did long endurance races (over 100 miles) and gran fondos on an S-Works Tarmac ("race"). For me, they just worked better in those (contra to Specialized's marketing) roles.


Today, I ride and race everything but criteriums -- road races, gran fondos, sprint races, etc. For everything except time trials, I ride a BMC SLR01 ("race"). I find its geometry faster, better handling, and more comfortable for me no matter the event. A 200 mile "endurance" event? I'm on my "race geometry" SLR01. By choice.

spectastic

the longer head tubes on endurance bikes mean more upright geometry, which is more comfortable for longer rides. longer wheel base on endurance bikes mean more stable, less twitchy steering.

on a race bike, lower head tube means you can get lower and get in a more aero position. the shorter wheel base mean you can handle the bike more spontaneously in a corner, escape a nasty situation, or catch people off guard when you go on an attack.

however, there has been a shift towards longer head tubes, which yield stiffer frames, so the race geometry bikes have been looking a lot like endurance bikes, and endurance bikes have been looking a lot like street cruisers. it's not uncommon nowadays for racers to go a size or two smaller in frame, in order to get low enough, and use a longer stem to get them to their ideal reach.

about compact geometry, smaller triangles generally mean stiffer frame. also, with the seat stays lower, the cross section of the bike is also smaller, making it more aero. it's generally a race oriented design that applies to endurance and race frames alike. but the traditional horizontal top tube would be more comfortable, I think, due to the higher compliance from longer tubes.

raria

Surprised by the answers here.

I thought it was simply that with a racing geometry bike you were put in a very aero position bike (i.e. flat back). That's certainly what my CAAD12 does. Endurance Geo put you more upright very unaero position.

I can't agree that aero positions are comfortable for centuries.

beermode

You aren't in the drops all the time.

raria

Of course, but the hoods on my CAAD12 are still pretty aero compared to an endurance bike geo. My core strength is decent but still, riding a century in such an aero position is beyond my capabilities.

Kontact 

That's you CAAD12. But if you had a very racy Cervelo RCA or Specialized Tarmac you'd have a very tall head tube.

Arguably, Cannondales are some of the lowest stack modern "racing" bikes available right now.

raria

Ah I see. So then why is a Cervelo RCA racy? If it sits you more upright then its kind of hard to ride fast not only due to aerodynamics but also from a powerful pedal stroke perspective.

Kontact 

Because removing spacers and 17° stems allow you to put the bars low, even on a frame with a tall head tube.

An RCA is racy because it is light and stiff with good handling geometry.

The head tube is not the bike.

raria

Ah I see. Thank you.

So it seems light, stiff, good handling geometry bikes (and what-ever floats your boat) with tall head tubes are quite versatile. You can set them up to right upright and also to be more aero? Is that correct?

I have been seeing quite a few newer bikes with very tall head tubes.

So what are the downsides to a tall head tube besides some extra weight?

Kontact 

The primary downside is that you will have some people that wish to be lower and can't. But this is the identical situation as someone who wants to sit upright and can't raise the stem further.

The old level top tube standard of head tube height is probably too low on average given the usual 40mm spacer maximum for the majority of road riders. However, I suspect that the height of many high end bike's head tubes has a lot to do with the average age of people who can afford $10,000 bikes.

Racing Dan

Imo a lot has to do with ppl not wanting to ride dorky looking bikes with a lot of spacers and stems pointing up rather than down. Hence many bikes now have tall head tubes and even drop bars that rises above the stem and a stem that points down and look cool.

https://cdn-cyclingtips.pressidium.c...Diverge-39.jpg

In reality, Im betting most middle aged men could ride a CAAD12 just fine with a higher stem, a compact bar and other slight modifications.

Kontact 

They could, but once you have all 40mm of spacers in and a 14cm 17° stem flipped over to give you enough height and reach it starts to look a bit comical.

Of note, Cervelo recently decreased the headtube height on the R5 by 1cm while leaving the otherwise similar R3 at full height.


It's all about being able to offer a bike that fits the most number of people who would buy that model.

jpescatore

I drive an All Wheel Drive Subaru Outback, which I think of as a station wagon. Nearly identical looking cars are now sold as Crossover SUVs. I'm sure there is some car industry definition and I could probably modify my station wagon to fit the definition of Crossover SUV but I just needed a car to carry stuff that would be capable of handling well on snowy and wet roads.

I drove a few and bought the one I liked - didn't really matter what it was called. That's pretty much what I've done over the years with bikes! With so many choices, not much need to modify one bike to look like another bike called something different.

So, after 20 years of riding a Trek 520 touring bike (called that because it had loads of braze-ons and came with a rear rack standard) I realized I wasn't doing much loaded touring anymore - mostly long local rides (apparently now called sportives or Gran Fondos)with the occasional credit card touring type multi-day ride (now called bikepacking.) I decided I wanted a lighter bike with a more upright position but keeping the ability to run 32mm tires and ride on crushed limestone/gravel rail trails as part of the mix. Rode a bunch of bikes, ended up with a Trek Domane - turns out I can call it an endurance bike, who knew?

raria

I thought the frameset of the Cervelo RCA was $10K. All the other parts are extra :-)

12strings

The latest Domane is being also marketed as a gravel bike.

jpescatore

Uh oh - does that mean I should not be using my Domane on those crushed limestone rail trails??

memebag

I rode 1 century on a more upright frame, then 4 centuries on a CAAD12. The CAAD12 was more comfortable for me. I don't have it super slammed or anything, but I'm definitely more aero on the CAAD12.

My guess is that my core was strong enough to start with when I bought the CAAD12, but that bike has kept it strong, or maybe made it stronger, so I feel comfortable with a flat back for 100 miles.

raria

Wow that's great. What fraction of the time were you in the drops vs on the hoods?

memebag

It depends on if I was in a pace line, solo or pulling. When pulling I'm mostly in the drops, but I'm only pulling a small fraction of the time. Drafting I'm on the hoods. Solo, it's a toss up.

Sojodave

I had a Ridley Fenix which is their endurance frame. I spent the whole time trying to get it more aero. When you sit more upright, you fight the wind, and your body acts like a barn door. My new bike is more aero and I am faster on my Strava segments and I am more comfortable. If you get a racing frame, work on your flexibility and your core. It makes a big difference.

athrowawaynic

I think it really comes down to chainstay length.

If race vs. endurance is relative, then the main differentiating factor is probably acceleration vs. comfort.

I feel like so much of the fit and rider position can be replicated between the two frames.

But the geometry differs so that your center of gravity relative to the rear axle differs.

E.g., there's this local KOM I've been after. It's a short sprint that starts with a slight downhill, shielded by trees, which then opens up onto a straight stretch of road with no wind cover at all. I've been trying it on both of my bikes (one a 24lb. retroroadie, and the other a 20lb. modern gravel bike). All of the rider/saddle/bar positions are fairly close--I feel I shift around a lot from one ride to the next, so any differences get lost in the noise. I've run the same tires at the same pressures. But I cannot, for the life of me, get as good a performance out of the lighter, more modern bike. It feels like the issue is that the modern bike with the longer stays just cannot spin up as fast, so that when I come out of the chute onto the wide open stretch, I'm just not carrying enough speed.