Dahons or Doppels are good bikes and Doppels seems to be trying to catch the market by selling it cheaper but Dahons are more popular. I have seen others using the Dahons 26 inches wheelers folding bikes before but not offroad. They look nice too but they are also quite expensive. I think Joo Ngan son's place (beside Village Nasi Lemak in Uptown) has one on display. If I just want to cycle around roads, I would prefer the 20 inch for their convenience.But if you want to really join touring expeditions, probably you want a 26 inch. If it is 26 inch, there's no need for Dahons or Doppels, right?    There's loads of other cheaper alternatives like Raleighs, XDSs, GTAs etc. These are basically lower end mountain bikes.

Only if you want a folding bike, you should consider Dahons or Doppels or even higher ends like Bromptons, Birdys. Smaller tyres are easier to store into the trunk of your car and also in your home. I can fit 3 bikes in a car with 3 riders. All 3 are Dahons. Many think that in rides, the 20 inch are slower but in fact they are just as fast. Folding bikes lose out because in uphill rides they have insufficient gearing as opposed to the 27 to 30 speeds that mountain bike or roadies has. Unless you modify the same number of speed on foldies ( which is really expensive ) or buy one which is shodded with it ( even more expensive as only the highest end folding bikes comes with it ), you can actually go for hill climbs. But there are folding bike riders that have managed to cycle to Fraser's Hill.

A 2 X 8speed or 2 x 7speed for a folding is sufficient to cover most rides. The cheaper and more manageable way is to get 7 or 8 speed bike first and then upgrade the gearing on the front crank with a set of shifters, RD and 53 or 52/39 crank. I say RD too because it seems illogical not to upgrade the RD to a better one since you are already upgrading although the Shimano Tourney or the Neos ( usual on folding bikes ) can be used for 8 speed. Off course, you can just get an 16 speeds direct like the Java Fit, some XDS and some other brands which uses the more number of gears to entice buyers. If you go for Dahons, Terns or better bikes with the same specs, it will be costly. Also, you may already have improved on your riding ability later and feel there's no need for an upgrade altogether. I did a 12 km all uphill ride on the 32T gear and the standard 52T crank without any problem and it is still manageable. It all depends on you. You first have to determine what rides are you going to do? Mountain biking, hybrid, road bikes or just folding bikes? I have also seen blogs on riders on Strida doing the Taiping to Port Weld and many rides. They use an even smaller 16 inch wheels.