I'm not getting on as well with my 20" Dahon as I'd hoped and I'm considering something that'll smooth out the often mangled London road surfaces better. I've more or less gotten used to getting my Dahon through ticket barriers and other obstacles and I'm wondering if the Downtube FS will be significantly less adept in that area. Things that I'm concerned about are:
Probable greater width when folded combined with the fact that, as far as I know, there's no locking system on the handlebars which are on the outside when folded. I can imagine this causing some trouble and perhaps has more chance of getting tangled. Though looking at the official stats the Downtube claims to be a smaller fold, with 9cm off the height and equal width and length. Something is odd there, unless the Downtube wheelbase is much shorter than the dahon there's no way it could be the same length when folded as it rests differently on the ground.
I don't know how secure the bungee cord lock system is for the frame when carrying and wheeling when folded. I wouldn't want the bike to be flapping around when I'm trying to wheel it through awkward spaces (it's awkward enough already with 20" bikes just due to the size). The Dahon is good in that department: the magnet system works well and the handlebar is secure, sandwiched in the middle.
Then there's the weight factor. I don't know how accurate official stated weights are. According to the Dahon website my Vitesse is 11.9 kg, but I don't know whether that includes all accessories such as the ludicrously heavy rear rack which I've removed. I've tried weighing my bike in its slightly modified state on standard bathroom scales and I think it's closer to about 10.7. The stock pedals were very heavy and I've shaved about 300 gms off there.
According to the downtube website the 9FS is 27 lbs or 12.24 kg. That's only marginally more heavy than the Dahon's official weight, but I don't know if that weight includes rear rack. If, as I suspect, my Dahon with mods/upgrades is more like 10.7kg, then that's a significant difference and I can imagine that extra weight make the Downtube awkward to shift around on trains and the like. On top of that I've seen the weight listed as 28 lbs elsewhere, though perhaps that was the 2008 version, but leaves me uncertain. I don't think I'd be able to lose any weight by component change as the pedals on the 2009 model are already light and the seat looks less chunky than the stock Dahon seat. I'm looking at the Downtube FH with the internal gear hub and the stated weight is also 27 lbs: that can't be right. There must be some inaccuracy in these figures somewhere.
To summarise, I don't know the real weight difference between bikes so any incite there would be appreciated, and I'd like some views on the Downtube fold and it's portability.