Folding Bikes - Difference in frame between Dahon Speed 8 and TR?

At first I chose a Downtube, but unfortunately the riding position was not as comfortable as the Dahon for my bad back.

So I'm looking for a folder for commuting that can carry a heavy load of groceries and the ability to carry a load for touring. So given that, the TR would be the obvious choice. However, I already own a 20" wheel with a Dual Drive hub and shifter (from another bike) that I could install on a Speed 8. And the S8 costs half as much.

Does anyone know if the TR frame is stronger or has a different geometry than the S8? I searched everywhere, and the Dahon website is lacking in frame comparison info.

thanks in advance.

I can't answer your original question. But I have one of my own...

How do you know the Dahons will be suitable for your back? What's different between those two bikes and the Downtube? Should you be looking at a recumbent instead?

There was a guy over on the dahon.com forums who asked a similar question recently. The frame is the same for all the Speed models. So if you stuck your DD gear on the P8, added a rack or two, basically you'd have a red TR.

What's the difference? At first glance I see.

Three speed hub giving you 24 speeds at 21" - 114" GEAR INCHES.
Better stiffer steering stem.
HANDLEBAR adjustable CLAMPS "Syntace VRO"
Ergon greps and bar ends.
Rear and front rack.
Frunt BioLogic™ Joule dynamo hub.
Lights front and back.
MKS EZY quick release pedals.
SKS MUDGUARDS.

More and up a grade on most all equipment.

The frame I believe is the same. At least they fell the same to me by the seat of my pants.

It also looks like the Speed TR has a chromoly fork and the Speed P8 has the Puro U7 aluminum fork.

Also Derailer Neos vs Dual Drive.

The fork and headset would be the most important one to help with your decision because they would be hardest to change to your preference.

Thanks for your responses, I'm glad the frame is the same, but bummed that S8's fork is aluminum. I see a bunch of inexpensive steel 20" 1 1/8 threaded forks on the market, even with disc tabs, maybe I can swap one in.

SesameC, actually a recumbent is worse for my back, because road shock goes straight up the spine. When I lean forward on an upright bike, it opens up the spine and gives my disks more space and no compression.

The Downtube 8H has a slacker seat tube angle than the Dahon Speed 8. So in other words the saddle is further back from the bottom bracket. I know this by riding and measuring both bikes. Yes you get some adjustability sliding the saddle forward in the seatpost clamp, but the rails aren't long enough with my B17.