An older, 70s or earlier, Olmo bike I have. 56cm seatube, and 54cm toptube with an adjustable stem that goes up or down 9cm, and only adds 6cm forward reach to the bars.

A 56cm seattube trek1000 has 56cm toptube +12cm of stem. That's effectively 8cm longer than it used to be. I have some 80s bikes that are in between these 2 measurements. In fact, I'm very happy with the fit of an 80s 50cm seattube, 55cm toptube bike (I guess 8cm stem).

Why have bikes stretched out over the years? Is there an advantage to a longer reach beyond knee clearance?

It is difficult to generalize. My European bikes span the 1960s and 1970s, and all of them have significantly longer top tubes than did my 1971 Nishiki. The one consistent trend I have observed over the years is toward shorter chainstays and reduced fork rakes, to the point that many of today's harsh-riding, twitchy road bikes are suited only for racing or aggressive club riding. This is one reason so many of us enjoy riding the classics.

Various mfgs. had different ideas, take Gios, top tubes way to short for me at my size. Nishiki also had short top tubes for a given size, for comfort basically, except the smallest that were too long to avoid toe clip overlap). Do not forget that seat tube angle makes a big difference. My first track bike, a Bob Jackson had a 22-3/4" top tube! but I used a 125mm stem on it as to put my seat in the correct position I had to bypass the shallow seat tube angle. While top tube length is a guide, seat tube angle can mean even more regarding on where the builder expected you to sit.

In the 70's and 80's, most larger companies made three "styles" of road bikes. Hard core racing bikes, with the top tube as long as the seat tube. Sport touring bikes, with a top tube slightly shorter than the seat tube. And, recreational/commuting bikes with the top tube notably shorter than the seat tube.

Today, the trend is for even entry level road bikes to be a "pretend" race bike, and use geometry similar to that on bikes used by pro cyclist. This is a nutty as selling people SUV's that are replica's of Indy race cars, but that's what the industry is pushing.

Also a factor - Greg LeMond. He rode with different geometry to other riders of his day - a more stretched out position. He had a big influence.

LeMonds geometry is a real throwback to Merckx, Bartalli, Poulidor etc.
Older racers had more relaxed geometry with shorter stems.
I agree with the timeline for top tubes shortening but not sure
the wherefor and why of it.

marty

But what's the reasoning for all this? A more stretched out position is better for racing on downhills b/c of the air resistence, but a shorter top tube allows a rider to get more responsive handling, right? Does a shorter length also allow for better leverage when pedalling, esp. uphill? Track cycles have the tight geometry--is this simply for getting around the bends as quickly as possible? Doesn't the track cyclist give up something in air resistence?

What about the "ideal cyclist" or the "racer's" physique? Has that changed over time?

I'm guessing alanbike has the essense of it. Road bikes have racer-only prices today, and if that's not for you, the hybrids over in that corner come in pink too.

I would also guess that climbing would be easier with a shorter toptube.

On the other hand, there are longer seatposts today, and smaller frames are lighter, and it seems as though pros have a ton of seatpost showing, and so most tend to be going with smaller frames. Its just strange that fitting has changed so much.

evolution !

Curious, was this Trek 1000 a compact-frame machine? I'm pretty sure it isn't, but I thought I'd ask.

-Kurt

I agree that alanbikehouston has it figured. In essence, it's marketing. All those folks I see riding with their race suits on (which seems to be almost everybody) couldn't stand to think of riding anything but the stretched out racing geometry that the guy at the bike shop told them was so important. Never mind the back ache, and the ridiculous out-of-the-saddle lunging they do as they heave their way up the hills around here on their huge-geared bikes, trying to be like Lance and the gang. If a rider is actually a racer and can do it, more power to them. But almost all of them aren't, and never will be, but they know no other way because that's what everybody else is doing. And everybody who bought this year's carbon fiber frame better get back to the bike shop because next year's is going to be ten grams lighter, so this year's is now obsolete.................sorry, what was the question again?

by that you mean sloping downtube? I'm pretty sure its not sloping at all, but I measured level to the center of the seatposts if the frame isn't.

Didn't think so.

Now if it was a compact frame, the longer top-tube measurements would have made a bit more sense, as sizing for a C-frame from the BB/seat top measurement would be about 3" smaller or so then a frame sized for the same person in the conventional fashion.

Take care,

-Kurt

Don't shorter stays allow for a stiffer rear end and thus more efficient climbing?

Yes, and Trek 720s ride like tandems

-Kurt

A lot of it was style and what as accepted during the time that one was riding. I'm a prime example of that: My first Schwinn Super Sport was a 24" frame, followed by a 25-1/2" Sprite 10, and a 24-1/2" Gitane Super Corsa. Most of my three-speed commuters then were 23-1/2" frames.

About 1972 (four years into cycling), I got a 22-1/2" Falcon, basically at the browbeating of the dealer. What an amazing change! OK, the bike wasn't quite as comfortable on the long haul, but then I didn't use the Falcon for long hauls, that was my 23-1/2" World Voyageur. At that point, I stopped riding.

Getting back into it, I'm preferably running a 56cm frame, which I believe is roughly 22-1/2". My Raleigh and Gitane are 23-1/2's, and are the largest bikes I'll consider riding. I love the Raleigh that way, it's a wonderful long haul tourer. The Gitane is OK, the responsiveness of the frame makes me wonder what it's be like to find a frame an inch shorter (I'm kinda looking in the back of my mind, but no big rush). Meanwhile the Rossin and Fuji's at 56cm are an absolute hoot . . . . . . . but there's no way I want to do 100 mile days on either of them.

There's definitely a move towards race rep bicycles (boy, talk about a parallel with motorcycles!), which are wonderful for short runs, sprinting, and general goofing off - but really rather lousy for actually going somewhere a distance away.

Watching both markets in parallel nowdays, I'm both amazed and amused at the way bicycles and motorcycles are trying to do the same thing. Makes me wonder if they both haven't figured out how to milk the poseur market.

Syke
Deranged Few M/C

Im riding a smallish super vitus frame for my height (it has a 53cm TT and I am 6' tall) however, with my tall seatpost and 90 degree, 130mm stem, my bars are only 2 inches lower than my seat. I am happy with the light weight, responsiveness and comfort of this machine.

rk

In recent decades cyclists have definitely been selecting frames with shorter SEAT tubes. For a contrast, see the attached early 1960s racing photo of Adolph Christian and an unidentified comrade. I show at least twice as much seatpost on MY Capo.

Is it just me, or are both saddles sitting about 2-3" too low for each rider? Fellow on the left looks as if he could use a lot more leg extension there.

P.S.: Shorter seattubes make for wobbly out-of-the saddle sprints and climbs. I'm 5'10", 32" inseam, and find that my gargantuan 26" (BB to seatlug) Nishiki Prestige is one of my best bikes for riding off the saddle - the taller frame and higher top tube balance the machine extremely well.

-Kurt