Road Cycling - Frame shape/advantages

What are the supposed advantages of a sloping frame vs. a standard frame and vice versa? It seems more and more fabricators are producing these frames. Is it a trend/sell thing or are there distinct advantages? I own a sloping K2 frame which I like alot, btw. I also have a traditional frame as well on another bike.

What are the supposed advantages of a sloping frame vs. a standard frame and vice versa? It seems more and more fabricators are producing these frames. Is it a trend/sell thing or are there distinct advantages? I own a sloping K2 frame which I like alot, btw. I also have a traditional frame as well on another bike.


The main advantage is commercial. if the top tube is sloping, the stand over size doesn't matter that much, and the other sizes can be managed (to a point) by seat post, stem height and length. which means that a manufacturer can get away with 4-5 sizes that fits all.. that cuts down on model numbers and size of inventory of bikes at the store and parts/frames for the manufacturer..
Also, as bikes become more compact, it is easier to build them with a sloping top tube...

Which one is better? the one that is more comfortable and fits you best..

There has been meany threads on this topic. Do a search.

I fully agree with sorebutt .. its a pure supply chain issue. I don't see any evidence that they are better.(slope)

Does not help .. but feels good saying it.

Cheers

these discussions will keep you going for days :)


EDITED

http://www.bikeforums.net/showthread.php?t=26661&highlight=compact
http://www.bikeforums.net/showthread.php?t=9099&highlight=compact
http://www.bikeforums.net/showthread.php?t=49639&highlight=compact

I understand the marketing part... but does anyone have any idea why seven have compacts for their lightest bikes while cannondale abhors the idea?

oh and...i know its strictly a personal issue whether which style fits you... but why are there people bashing compact frames just because they ride the standard?

Here it what happens if you looks at engineering data.

1. When riding sitting down.
Basically, the largest bike you can straddle is the strongest one, because there is less seatpost showing. Since the frame is triangulated and the seatpost isn't, it makes sense that the larger the frame -- and the shorter the seatpost -- the stronger the bike (if all is equal, and it rarely is the case anyway).
Also, if you have a rear rack for cargo (as for touring), a larger frame means shorter horizontal bars to hold the rack, hence a stronger rack.


2. When riding standing up.
The seat obviously doesn't matter anymore, but the flex happens between pedals, drivetrain and arms. A smaller frame or one with an inclined top tube is stronger for those efforts.

As for "why inclined vs horizontal?" If you get a compact frame, want to show a lot of seatpost and still want handlebars at a decent height, then an inclined horizontal allows one to have decently high handlebars without having a huge amount of stem.

The origins for the slope top tube come from ATB bikes where the addition of the
shock absorbing fork pushed the front end of the bike way up, 4 to 8" higher than
an equivalent standard frame road bike. To keep the standover height acceptable
the slope top tube was used. The cross over to road bikes was a happy juxtaposition of fewer frame sizes needed to cover the adult range of ~58" to 78" body height
typically five frame sizes needed versus straight top tube frame needing 7 or 8 frames
to cover this range of rider heights. Makes it easier for the manufacturer, a bit, but
a whole lot easier for the stressed out LBS who have a hard time stocking more than
2-3 frame sizes in a given bike, say a Trek 5200. ATB riders used to slope top frames don't feel off put by the slope top tube. The trend to smaller frame sizes has helped
also. Steve