grolby

Ugh, I hope not. I finally sucked it up and switched over to wide rims (needed to rebuild a bunch of wheels anyway) despite not being convinced that there was any real benefit. But I guess the eventual switch to disc brakes will render it all moot .

RJM

Rivendell has sloping downtubes on several bikes.

Just saying.

tekhna

I know! It's hilarious. If people don't like sloping top tubes for aesthetic reasons, don't buy them. But it's absurd to say they're a mountain bike import that serves no purpose.

I love compact geometry because I'm very tall with relatively short legs. Compact geometry makes for a better bike fit than traditional geometry ever could.

grolby

The best part of that is they call it "expanded geometry," and insist that it is "completely different from compact geometry." It's not, of course, they just start from a higher headtube height.

RJM

I think the higher headtube height combined with a longer top tube is the difference and they are calling attention to that difference with the different nomenclature. I think Grant's "Just Ride" book had a chapter on the "expanded geometry" but don't remember it all that well. I do know that my Sam Hillborne has quite a long top tube.

My Roadeo has a 2 degree downslope where the Sam has a 6 degree downslope.

Dave Mayer

It is a sub-optimal design. it results in a heavier overall frame because of the extra material that has to be added to the seat cluster to support the extra leverage of the longer seatpost.

For a more upright riding position, you don't need a sloping top tube. Most efficient approach is a a stem with more rise. Or a frame with an extended top tube.

elcruxio

But it also makes both of the triangles smaller, requiring less material to be used (shorter tubes) hence overall lighter frame. Which one of us is right in this?
Longer exposed seatpost also allows for a better ride since there's more to bend and absorb road bumps. This works especially well with carbon and basalt posts
Also, shorter tubes and smaller triangles make a stiffer frame.

So uhh, even if the frame is a bit heavier (which I really don't think it is...) the pro's still outweigh (see what I did there ) the cons

Dave Mayer

Look at pro-level road bikes. No sloping top tubes. These are bikes that are subject to pro-level stresses, and are under extreme weight to strength constraints. Every gram counts.

The bigger manufacturers have the finite element models that allow frame stress modeling. They have analyzed every possible geometry tweak to the traditional diamond-shaped bike frame. The conclusion is that the horizontal top tube is optimum.

But for marketing purposes, the sloping top tube is better. It allows:

• Baby boomers a more upright position to accomodate aching joints and to allow extra room for their gut
• An easier sell to newly converted MTB riders - for no other reason than MTB bikes have sloping top tubes

RJM

Really? Come on now......

elcruxio

You actually have this a bit backwards...

Pro level frames are custom made for the riders. But where you think they are purposefully made for a horizontal top tube, the bikes are actually made with the original length seat tube and a shorter head tube. This has in fact nothing to do with top tubes.

Taller riders usually don't ride bike which have a lot of slope since their head tubes are so ridiculously short. No mere mortal can ride those frames. Or they can, depends how flexible you are. But for example some frames Mark Cavendish has ridden have quite a bit of slope. Tom boonen has had Specialized frames which had a bit of slope. However the pinarello dogma Bradley wiggins rode didn't have a slope, but that could also be attributed to Pinarello being very Italian and also very traditional in their geometry.

svtmike

Someone is really out of touch.

Vincenzo Nibali's bike. I'm pretty sure he's a pro, and I'm pretty sure that's a sloping top tube on a compact geometry frame. There are plenty of other examples. I'd expect the vast majority of the pros are riding compact geometry these days.

tekhna

Pretty sure Jan Ullrich was a pro 10 years ago when he was riding this pink machine.



That's seriously out of touch. Wonder when the first compact frameset entered the pro peleton. Mid 90s?

tekhna

Or maybe Pantani in '98? Pretty sure he was on a compact Bianchi.

Lazyass

In 1975, JC Penney hired 12 college students to ride their bikes from NYC to San Francisco. They were promoting their new disc brake equipped bikes OEM'd from Huffy Manufacturing. As you will see, they thought people rode bikes in tennis gear. The music is classic.

https://youtu.be/k10233DdFi0

Fiery

Exceedingly rarely these days; like, less than 1% of the pro peloton.

Regarding Dave Mayer's amazing statement, let's see... How many horisontal top tubes do we see here?
Bikes of the 2015 WorldTour | CyclingTips

tekhna

I'm saddened to announce the passing of tekhna and his commuter bike (RIP) this morning in a fiery explosion. The rim brakes on his commuter exploded on contact with wet sloppy wintery mix; there were no survivors.

Tekhna's commuter is survived by a Hong Fu frame built up with Record and a Giant TCR built up with Veloce. They should be considered unsafe at any speed due to possible rim brake explosions. His Redline Mongocog will be handed down to tekhna's brother due to the presence of disc brakes. Tekhna's winter commuter is being tested for possible brake explosions due to the presence of cantilever brakes.

Tekhna's commuter is preceeded in death by his childhood mountain bikes (mostly Fujis) and his first road bike, a Specialized Allez, which thankfully was hit by a car before the rim brakes could explode.

cale

tekhna sounds like a bit of a hoarder.

Dave Mayer

[QUOTE=Fiery;17706713]Regarding Dave Mayer's amazing statement, let's see... How many horisontal top tubes do we see here?

The marketing companies use sloping top tubes. The real bike companies use horizontal top tubes.

Brian Ratliff

And any engineer knows that is doesn't matter in the slightest... BUT... you can get a taller head tube on a sloped top tube frame without things starting to look stupid. The pro peloton, and most pro racers, don't need tall headtubes... so their frames look a lot more like horizontal top tube frames (they aren't, not quite, but they are a lot closer than some "comfort fit" roadbikes).

My new Trek Madone (warranty replacement for a horizontal top tube Trek Madone 5.2) has a "comfort fit" headtube, but I like low bars, so I had to get a smaller frame... thus, I have an insane amount of seatpost showing. But, as per my first sentence: it doesn't matter. The bike handles, fits, and behaves exactly like its horizontal top tube predecessor.

grolby

Yes, they do sell it that way, but that is in fact exactly what compact geometry generally accomplishes: a higher head tube without a junk-crushing standover height. But my point was more that "expanded geometry" is, trigonometrically, exactly the same thing as compact geometry. There is no actual difference between a Riv expanded geometry frame and a compact geometry frame except that Rivendell likes the head tube nice and high.

I don't really have a problem with these bikes, though I think the Riv look of a handlebar towering over the saddle on a long quill stem is aesthetically awful*. And I don't have a problem with them using a marketing term to distinguish their use of compact geometry from other manufacturers. I just think it looks funny to have all of this copy on their website decrying a kind of frame design that they ultimately decided, reasonably, to use themselves.

I have read Just Ride, believe it or not, and I thought it was okay. Buried beneath Grant's crusty exterior is a reasonable guy just screaming to be let out. But I don't recall a chapter on expanded geometry. Doesn't mean it wasn't there, only that it didn't make much of an impression.

*I have Many Opinions on Rivendell geometry, both aesthetic and functional, but no one wants to know.

Dave Mayer

Whoa - a whole bunch of loose assumptions and language here. First, I am an engineer, and frame design/geometry does matter. It justifies many iterations of finite element modeling, materials research and testing, many cycles of destructive testing. And thousands of miles of test rides. The goal of frame design is to get the maximum strength and longevity out of the minimum amount of material. Comfort is another key goal.

OK – so you say that a sloping top-tube frame allows a taller headtube. Fair enough, it supports a more comfortable riding position. But a more upright riding position can be accomplished with a horizontal top tube, combined with a taller stem, more spacers, and a taller (extended) headtube. Or a combination of all of these. This is a lighter overall solution than adding a bunch of frame material to the headtube area.

So on your bike, you are telling us that you have a sloping frame design, which adds unnecessary weight to the front of the bike, and then you’ve slammed your stem to get a lower riding position? Is this not the worst of both worlds?

Brian Ratliff

Then, as an engineer, you should go tell them that. I kinda just assume my fellow engineers in the bike biz know what they are doing. I'm not in their business, so I mind mine. They make some cool stuff that is way lighter than I thought possible. I'm not going to second guess their engineering work with chicken scratch scrawled on the back of an envelope.

You do know they optimize for more than just weight, right? What you've suggested, a tall top tube or a stack of spacers, is not a very structurally stiff design. Yup... they look at stiffness too. The front end of modern bikes are far stiffer than the older designs, and the carbon fiber material allows the stiffer frame to be light enough.

As for my frame, what can I say... it was a warranty replacement for a level top tube bike; had one of the shortest top tubes around. Was great until I busted the bottom bracket shell out of the frame. The new one is lighter and I didn't pay a penny for it, so I am happy. It is not my race bike though.

Psimet2001 

I'm starting to think this guy is the one the rest in the engineering department hates having to go work with because he always thinks he's right even when he's not.

...oh...and DISC BRAKES! FTW!!

Fiery

So what we can conclude from this gem is that the only real bike companies are Giant, Merida and Canyon (even Pinarello has a slight slope).

But let's go back to your original statement, that there are no sloping top tubes on pro-level bikes, and let us reiterate how absolutely false it is. Now, the next claim was that all the leading companies have done their work and that they have concluded that horisontal is better. This is another absolutely false claim, considering the fact that each and every single company that makes pro-level bikes has a sloping frame as one of the top offerings. In fact, the only reason why the abovementioned three also make frames with horisontal top tubes is because they are more aerodynamic. These frames are actually heavier and less stiff than their non-aero, sloping counterparts from the same company.

tumbalacasa

Anyone have this bike or ride this bike before? Road - KTM BIKE INDUSTRIES

This looks interesting Through axle disc break bike with Flat Mounts. Is this the future of road bikes?