Dahon.Steve

I would not stand on the pedals on a folder with either Sturmey Archer AW-3 or Sram Spectro 3. Both hubs can and will shift in neutral causing you to go over the handlebars or fall over. Furthermore, the handlebars on Dahon folders were not ment for standing and will get damaged.

noahj

Umm, two things. First, there are hills, and there are hills. Small-wheeled bikes have fairly low gearing, but 8% + grades sometimes demand riding out of the saddle even if you have low gears. There shouldn't be any problem pushing any bike with an internal hub this way. The hubs won't simply shift into neutral unless they're radically out of adjustment or damaged.

And if the handlebars on a Dahon can't handle this, I would say those bike have a serious design problem.

pm124

Not a design problem at all. You just have to learn to push with one leg and lift with the other. If you have standard pedals, you have to stand, but not pull on the bars. You get used to it, and at the end of the day are a better rider because of it.

After a couple of months of riding one, I learned to climb hills on a folder better than I would on a regular bike. And the small wheels help with the intertia problem (I think, though I might be talking out of my bung hole), so it's easier to climb with them apart from gearing.

Simple Simon

.

Thats so true - or you may loose your undercarriage
However, the bars are very stiff so you can really pull on them.

doktoravalanche

I do it all the time, on and off-road on a dahon 20". I did have riser bars and now i have drops, which makes it easier - where i live hills at 17% are not unusual...

spambait11

My experience with a Dahon 20" with a 110mm stem extension and drop bars is that the whole stem post will creak if you pull back on them while cranking, so you're better off staying seated.

Never had this problem on my Bike Friday other than some stem post flex.

Bacciagalupe

I don't think "design problem" is the term I'd use, I'd call it a "design compromise," where you lose a little bit of frame strength in exchange for a pretty good fold.

It's not like pulling back on the bars will cause an immediate failure. It takes a long time for the handlepost to actually break. But it does happen often enough that one bike mechanic denigrated my Dahon as a "Bike-Shaped Object."

So if you're a casual rider and/or know not to pull on the bars, you're fine. If you're a serious rider and/or really like to stand, you are far better off with a different bike (Swift, BF etc).

james_swift

This bike was made for cranking...



The low-set bullhorns give plenty of leverage, and the MTB seatpost binder bolts (in place of the QRs) ensure a creak-less out-of-the-saddle cranking experience. This bike loves going up hills and sprinting away from traffic lights.

Dahon.Steve

There was a web site where a guy who had a career fixing the Sturmey Archer AW-3 posted about how this hub was notorious for slipping into neutral. I've expereinced this too and it was due to the fact that Sturmey Archer took short cuts in developing the hub. Sturmey Archer did produce hubs that did not slip but for some reason, this was not incorporated into the AW-3.

makeinu

Would you recommend a different 3 speed hub? Shimano? SRAM?

Fear&Trembling

I was reading in A to B that someone had put 125mm cranks (from a unicycle) on their Strida as it aided spinning immeasurably.

geo8rge

Lots of parts could creak. Handle bars/headset. Pedals especially if your feet are away from the cranks a bit.

noahj

Ah. I haven't ridden a S-A hub in decades. You may be right.

The Sachs (now SRAM) hub does not have this problem. Don't know about the SRAM DualDrive.

Leisesturm

Reducing the length of the cranks without a corresponding reduction in the overall gear ratios will not help spinning ability. More than once in this thread it has been mentioned that "small wheels have lower gearing than large ones". This is only true in the theoretical sense of things. In practice, the manufacturer will have chosen chainrings and cassettes that compensate more or less for the reduction and thus the gear inches that you feel through the pedals should not differ greatly from what you feel on a standard bike. I really think it should be a matter of geometry as to whether or not a given folder is ok to ride standing. The Swift and Downtube types seem much better suited to it than the Dahon types. I cannot stand on my Giant Halfway (too twitchy) but can and do on my Downtube. Both are well made, strong bikes that are well able to withstand the stresses of out of the saddle lugging. IMO if one's bicycle cannot do so then it is not safe for riding on public roads.

H

jur

The S-A AW3 geared hub only shifts into neutral from the highest (3rd) gear. And that only happend when cranking very very hard like standing on the pedals and giving it all you've got.

It wasn't a "design shortcut" either, more a design shortcoming or a too-late discovered design bug. The problem is that the clutch engages pawl hinge pins in 3rd gear; when big torque is applied, the hinge pins swivel a tiny amount around the support point, making the clutch to pin interface not perfectly parallel. The clutch then starts to slide off the hing pin if the torque is maintained. Worn hubs are worse.

Fear&Trembling

How do you know? It depends on the individual rider in question. If the Strida rider was 5ft 2", with a 28" inseam I can well believe that much shorter cranks would help their spinning ability.

Incorrect. Very few folding bikes offer the same range of gearing as a road bike (with a double) or mountain bike (with a triple). The exceptions include those that employ either a Rohloff hub, double chainring, Schlumpf, or dual drive. Most folding bikes lose out at the top-end...

invisiblehand

I thought that crank length is a determinant of a bike's gearing.

https://sheldonbrown.com/gain.html

makeinu

Isn't that a result of the internal gear hubs used, not the small wheels per say?

Do you really believe that? I don't. Sure, in theory if your cranks are as long as your legs then you'll get maximum leverage, but there's no way you're going to be pushing as hard with your tippy toes as you could be if the cranks were shorter. in other words, when using longer cranks although you get more leverage with the cranks, you get less leverage with your legs.

Fear&Trembling

Folded bikes like other bikes are of course limited by the range of the hub gear chosen. However, with smaller wheels you have to use bigger chainrings and/or smaller cogs to get a similar set-up.

With a Rohloff on Brompton you would have to use a bigger chainring (say 56 teeth or more) and the smallest available Rohloff sprocket, (13t I think), otherwise you would have very, very low gearing...

Leisesturm

'

That was my point exactly. You cannot simply reduce the leverage you do have by as much as 20% and not feel some difference in the pedals no matter who you are. The identical 66" gear will feel very different with 170mm cranks and with 125mm cranks, that is physics, not biomechanics. In order to 'spin' a gear one usually wants to feel less resistance at the pedal, not more. And yes, of course, many folders have less of a gear range than a full size bicycle but that is only because of the limitations of what to do about the large capacity derailleur cage hanging down. With internal gears that limitation goes away and you can have any range of gears with 20" wheels or even 16" wheels as with 27" wheels.

H

makeinu

The leverage at the pedal is increased with longer cranks, but what about the leverage from your muscle to the pedal?

Swing your arm in small circle, then swing it again in a larger circle. Which is more tiring? The large circle. If your body were in the same position relative to the cranks then longer cranks would definitely give you more leverage, but your body is fixed near the center of the crank, which gives the pedals increased leverage against your muscles.

If you want to do the physics properly then you can't ignore the biomechanics.

Fear&Trembling

https://cranklength.info/

makeinu

Your link is broken, but nice site. Much more thorough than Sheldon Brown.
https://www.cranklength.info/