I think we have about the same level of experience, Jur. But our respective experiences seem to produce different opinions.
Ahhh, but you see, for a rider with your sort of experience that could be correct, but for the greater unwashed public who want a bike and vaguely think "I'd like a bike with gears", they haven't got the next clue.
I guess, but I remember thinking "wow, these folding bikes are great, but definitely not for everyone" shortly after I got my first one.
I would agree that for a 5- or 10-mile jaunt, though, the differences are marginal; and that there is some room for growth in the folder market. I tend to ride quite a bit so my impressions are based on 100-150 miles a week.
Originally Posted by jur
In fact if the bike as a whole is considered, it is to the contrary - the long seat posts and handleposts more than cancel out harshness, conferring a certain amount of flexing, absorbing sharp impacts better than say a road bike with the same tyres. There is no way a diamond frame (the strongest design that exists) with a short seat post and 700c wheels, is less harsh.
I can only say that in my experience, my 700c bikes are smoother than my folding bikes. Diamond frames will definitely be stiffer than the typical monotube folder, but the larger wheels more than make up for it. And, of course, "more flexible" = "less efficient" = "worse performance."
FWIW as best I can determine, my Swift is about as stiff as a diamond frame.
Originally Posted by jur
Specialised admit this by producing their Spec. S-Works Roubaix frame with little elastomer inserts in the seat stays, fork and seat post. Other manufacturers introduce snake stays, wavy tubes which are supposed to flex in an attempt to remove the harshness. But if you press down on those bikes, the amount of flexing you get is less than a stalky folder seat post.
Well, let's try not to mix too many apples with too many oranges. And you forgot to mention the proliferation of carbon bits.
Most novice riders won't find road bikes especially comfortable, due to rider position and skinny tires; that's why MTB's became popular and morphed into hybrid bikes. Most folding bikes are set up like hybrids, ergo it would make sense to compare a typical folding bike to a typical 700c hybrid.
"Roubaix" style bikes were originally made for the Paris-Roubaix cycling race, which is infamous for its extensive cobblestone sections. They profess to be both fast and comfortable. The reality is that stiff racing frames with aggressive geometries and low spoke count wheels will have a harsh and twitchy ride. Ergo, the mass-market Roubaix bikes are a tad more relaxed, use 25c tires, and have different decals.
(I don't place much stock in the elastomer inserts, by the way -- I think it's a bunch of marketing hooey.)
As to "wavy tubes," I assume you're talking about something like this....
*sigh*
Err, anyway...
In these cases, theoretically they are taking advantage of the ability to manipulate the carbon frame in order to allow for more vertical compliance, while maintaining lateral stiffness. (Maybe it's true, maybe it's an excuse, maybe it's purely aesthetic -- not really sure.) I.e. the goal is to maximize pedaling efficiency without making the ride excessively harsh.
However, you're talking about serious road bikes. Realistically we'd have to compare a race-capable folder to a road bike. The only 20" bikes I can think of that would favorably compare are the high-end Moultons and the Air Friday -- both of which are pretty expensive, and as best I can tell, will ride about the same as any entry-level road bike.
Or to put it another way, I'm fairly confident that you could kit out an aluminum Swift as an uber race machine and it will still ride harsher and twitcher (and a tad slower) than a Cervelo Soloist Team....
Originally Posted by EvilV
I defer to other people's experience, but make this comment - we can't talk as if all folders and demountable bikes are the same. They vary in ride quality, speed, efficiency and handling....
And price.
I have little doubt your Moulton rides superbly, but at a significantly higher cost than most Dahons.
Plus, we definitely can't talk as if all 26" and 700c bikes are the same. A meaningful comparison would compare like to like -- e.g. road to road, touring to touring, general purpose to hybrid, and so forth.