Are there any ultra tall saddlebags for folders? There aalways seems to be so much wasted space over small wheels.
You are right, there is great potential for putting a tall (large) bag on most folders. It is probably easier to put a large bag on the front, a la Brompton, which has mounting features on the bike as standard.
However, this bag is rather wide and very expensive, but it does have has a large volume, and is easily fitted and removed. Rapid removal is important when folding the bike, of course.
Recent Dahon models have two tapped holes in the front of the steering head for mounting a Klickfix bracket which will then permit the fitting of any handlebar bag which has comparable fittings.
On my Dahon Curve SL I have used this system to fit a standard and low cost rucksack, modified by the fitting of a Klikfix bracket from an old handlebar bag, which can then be worn on the back or fitted on the bike. For shopping, or when the bike is folded, it is convenient to carry the bag on my back, otherwise it goes on the bike.
A search of the Internet reveals that Caradice are bringing out a new large front bag, which appears to be Brompton specific.
It is expensive at £70, but looks to be of good quality as most Caradice bags. But I could buy 14 rucksacks (see earlier post) for that price!
A word of warning on Caradice bags though. Their "Rackbox", a carrier mounted rear bag is a good idea, fitting well on folding bike carriers, but a poor design, having inaccessible poor quality zips and an internal pocket so small that it is useless. They now have an updated version which looks to be much improved. Don't buy the earlier model.
Is there a link for the Japanese rear bag? Looks interesting
There are a couple of links here (you may have to cut and paste unless I can figure out how to put a proper link in!)
It is made by a company called Ostrich and is called the LP-02, RRP about £23 / $45 but can be had online for £18 / $35. Other than that there's not much info but let me know if there's anything else I can try and find out.