jkucera

Hello all. I inherited a folding bike (a Dahon Piccolo, I guess from the early 2000s) that has a three-speed Sturmey Archer internal gear system. It won't shift, and I wonder if there is a piece missing. (Forgive me, I am pretty ignorant at bike mechanics.) I have another bike with a similar Sturmey Archer system, and in that the black plastic thing (I don't know the proper word) is bigger and has a pulley mechanism. Is there supposed to be something like that here or is this right and it just requires the right adjustment? Thanks in advance!



the situation

dweenk

That black plastic piece is not really functional. A good set of photos showing the whole drive side including shifter and cable routing would help.

madpogue 

The cable appears completely slack. Have you tried pulling on the indicator (the little chain thingy coming out of the axle)? If you have a stand, you can simulate shifting by pulling on the indicator while turning the crank. The chain should move in and out, and you should notice some change, indicating the hub is actually shifting internally.

Hmm, what's that other bit of cable? From the angle, it's uncertain where it goes. I don't think there should be one there.

jkucera

On the other bike I have with this same type of shifter, the black plastic piece is very functional. It redirects the force of the cable pull so it pulls the chain straight out of the hub; as far as I can tell with this setup when you shift the cable will pull the chain at a 90-degree angle, so with a lot of friction (I don't know if I'm explaining this clearly...) Anyway, the rest of the drive train is fine as far as I can tell.

jkucera

Yes, if I pull on the indicator it will shift. The problem is getting the cable to pull in a way that it pulls the indicator out.

And I'm not sure which cable you mean. Do you mean the extra part that is coming out to the left? I'm not sure why the shift cable is so much longer than it needs to be, but that's it.

nlerner

That black plastic piece fits on to the windowed axle nut and is supposed to protect the gear indicator (that little chain attached to the gear cable) when your bike foals over on its drive side. But you don’t really need it. I agree that your cable tension might be too slack. Plenty of online sources to show you how to adjust, particularly Sheldon Brown’s info on Sturmey Archer 3-speeds.

madpogue 

Yeah now I see, that's an extension of the cable further forward. Good news that it shifts; that probably means your whole issue is with the cable.

To the best of my knowledge, that cable is a hack; all the SA cables I've seen are pre-built with the ends attached directly. I would bet the cable broke at some time, and someone hacked in a generic cable, and used that screw and nut and L-shaped piece at the right end of the photo (toward the front) to attach the threaded barrel end of the cable. McGuyver meets Rube Goldberg. You could see if adjusting the barrel will take the slack out of the cable, but you may need to adjust how/where it's hacked together (just outside the frame of the photo).

JaccoW

Nah that's a modern SA cable clamp bolt. You are right though that older models had them pre-built.

madpogue 

Good to know, and looks like a potential option for adapting older SAs. The OP's cable still appears hacked, however, since it has that L-bracket rather than the eye hook shown in the product in the link. Or is that just another version of the product?

rhm

I've never seen a bike foal, but always kinda assumed they'd do it standing, like a horse.

JaccoW

It might be a no-name version. Sturmey Archer used to sell something very similar as part HSL759. What I do agree on is that it appears warped. I had something similar happen to an older model I was putting under a great deal of tension after removing it a few times.

You might be glad to know the old-school crimped ends are also still available: Sturmey Archer (Bofix) Brass press nipple. I will be using some of them on a build of mine soon with a bit of solder.

Moe Zhoost

Some SA hubs have a black plastic thing that seats on the end of the axle nut to ease the cable pull. Yours, instead, has one of their old style barrel nuts that does the same job. Since you can pull the indicator rod in an out, the hub is probably functional; however the cable is too slack. You may be able to adjust by screwing in that cable end on the threaded indicator rod chain. If you can't get it tight enough, you'll need to loosen the cable anchor, pull it tighter, and then tighten the nut again. What you are aiming for as a starting point is for the cable to be barely slack when in third gear.

Good luck.

madpogue 

Hard to tell if it's bent/warped, or just sitting at a funny angle due to the cable being so slack. A close-up of that part would help. But I get the sense, as mentioned above, that getting the slack out of the cable will make the hub operational again.

Nice, half a quid to buy, and probably half a day's pay to ship it over. Still good to know about, inspires me to search for it, or an equivalent, "over here".

JaccoW

If you are not in a hurry I can always ship you some in an envelope when I order something again. They really aren't that heavy.

Glennfordx4

I have been building up a Raleigh Sports 3spd I found in the trash a few yrs ago, I had to use a NOS universal Cable and anchor kit like is pictured and it can be a pita to set up. The first step is making sure the Chain is adjusted and the back wheel is tight, make sure the cable is run the correct way and that the little pulley is in good shape and turns free. The next steps are the hardest, I used a set of cable pulling pliers, small pair of vice grips and a 5/16"/8mm Nut driver. Put the shifter in 2nd gear, adjust the cable adjuster anchor to half way on the chain pull threads. Now for me I used the vice grips to hold the anchor bolt head to keep it from twisting the cable when you tighten it, looking thru the hole on the threaded axle nut you should be able to see the end of the axle, on the end of the shift chain inside the center of the axle is a solid pin, that pin is what you use to make sure it's adjusted correctly, with the shifter set in 2nd you use the cable pliers to pull the cable and chain adjuster till you can just see the pin through the hole in the nut pull it till the pin is just even at the axle end and tighten the cable clamp nut, remove the vice grips once the anchor nut is tight then check and make sure you can just see the pin at the end of the axle if it's not you can now use the threaded adjuster on the anchor to get it right. I hope this helps, kinda hard to explain but if you look up how to adjust a SA 3spd you will see the pin I am taking about and it should be clear.

Glenn

madpogue 

Glennfordx4 , does your kit include the barrel adjuster and locknut, like the OP's? I would think that with a barrel adjuster, you wouldn't need to go through all that trouble. Just pull the cable through the clamp bolt/nut to remove the major slack, then set the final tension/position with the barrel. Wouldn't that work?

Glennfordx4

I have NOS aftermarket SA cables that come with & without that anchor & adjuster, I also have factory SA cables but none were long enough.

It was a pita trying do it that way as I tried, I had enough of this bike by the time I got to installing the new cable. First time I set it up I didn't have the chain on the bike so all my adjustments went down the drain, then when I got the chain on and adjusted I was pedaling the bike by hand while in my repair stand and the cable which I had hanging loose got caught in the chain ring and destroyed the original SA pulley & guide. The anchor bolt and adjuster are not the easiest to work with and do not allow a lot of adjustment so you would have to really close right off the bat, that's when I tried the cable pliers which made the whole thing much easier.

Glenn

jkucera

Thank you all for the responses! So, if this is really how it's supposed to be (albeit with a kludged cable) I'll take another stab at getting the adjustment right.

BigChief 

The most important thing to know about AW hub cable adjustment is that there is a neutral spot between 2nd and 3rd. You just need to have the cable slack enough to engage 3rd and tight enough to engage 1st while avoiding the neutral spot. If the bike slips into neutral while you're riding in 2nd or 3rd, a small adjustment on the barrel one way or the other will fix it.