Oh god, it's me again.

Was fiddling about with a three speed hub today. It shifted alright, but when set to first gear on the shifter it liked to glide between first and second. So I found myself playing around with the barrel adjuster / link bit near the hub. Loosening it made it worse (to the point of being unable to shift), so I decided tighter might be the ticket.

Anyways, I was tightening the thing and got it almost all the way to the end when I heard a pop. Figured I had snapped the cable, but that doesn't appear to be the case. So I disassembled the shifter, figuring that was the issue, and spent some time figuring that out. I used this guide:

https://chestercycling.wordpress.com/...3-3-speed-hub/

Unfortunately, even though I have the thing assembled what appears to be properly, the shifter cable itself is still too slack. Because of this, even when taken to the first gear setting on the shifter (where the cable should be tightest) there is still significant play. At no point does the gear...arm thing...actually get pulled, so it stays in high gear.

How does one get rid of this extra slack?

M.

You can move a cable stop or guide pulley to pick up the slack. If there is a pulley on the seat tube, slide it down towards the bottom bracket. If there is a clamp-on cable stop on the chain stay or down tube, slide it forward.

How is the cable routed? Has a housing stop or pulley slid on the frame?

The cable goes from the shifter, outwards and then down along the down tube. There's one secure spot for it along the downtube - it's held by a metal band with a plastic guide through it. I'm guessing that's the adjuster (cable stop) in question. I think I can adjust it upwards and take some of the slack out (I'll do it tomorrow, it's coming up on 22 here). Now the question is: How was it fine before but not now?

M.

"How was it fine before but not now?" It seems pretty clear to me that the "pop" you heard was something moving due to the tension on the cable. Now you are going to have to make an adjustment to take out the slack which that movement introduced. Check all of the places where stops, pulleys, etc. are clamped and secure them to avoid another "pop" and getting stuck in high gear again. Make sure that the cable is not moving within the adjuster and that the adjuster and indicator chain threads are not stripped.

Threads are good; I'll take a crack after work tonight and see what I get out of it.

I'm assuming that, when the shifter's set to 3, I need to have just a bit of slack, which gets tightened up at 2 and is gone at 1?

M.

I'll make the assumption you're talking about a Sturmey Archer hub? If you mentioned that I missed it.
If so, you've got it about right, but you should still be able to pull a wee bit of chain when the shifter is in first. Don't make it super tight.
I've always adjusted 3 speeds by this method rather than trying to align marks on the indicator that are hard to see when new, impossible after extended use.

I Note: its OLD Shimano , bell crank, the adjustment is done in 2nd (of3) ..
theres a window to line up .

maybe the barrel adjuster is rusted to not turn anymore.. free that so it turns ..




Seems people are bloggers and do videos before learning mechanics nowadays .

Dan, I'm pretty sure it's a Shimano. Not a high end bike in it's day. The hub itself is basically featureless except the oil drop in nipple thing. It's from the early 70's if that helps any. I was able to deduce Shimano hub based on a few other parts being labled "Shimano", but I have no idea how interchangeable anything was in those days - new territory.

So I should shift to second and do all my adjusting, then, Fietsbob? Also, the barrel adjuster's just fine, which is a lucky thing (actually the whole bike is in pretty good shape, all considered). Wherein should one position it to have proper setup? Half way down the connection?

M.

High gear is just barely slack , 1st gear is Tightest.

Shimano three speeds are fairly easy to set up... the "N" is centered on the window on the bell crank when the bike is in second (normal).

Cable stops can slip and if the cable is not secured at the pinch bolt it can also slip here.

OK! I have been a busy bee these last few days so I just now got a chance to take a look at the bike. Turns out what seems to have "done it" was a pulley cleverly hidden near the chainwheel! Apparently the cable came off of it. So, armed with the knowledge you guys have imparted on me above, I've adjusted things so that the N in the bell crank window shows when I'm in second gear. It certainly shifts out of centre when I'm in first and third, so that's a good sign.

Problems I ran into and have resolved: I thought "bell crank" was another tern for "thumb shifter". This is no longer the case - I now know the "bellcrank" is the bit that juts out the side of the hub gear. The "Window" was caked in soil - the thing appears to have been stored in a barn for the last 40 years - so that's clear enough that I can see the N. This also answers my unasked question "How the hell do you know what gear you're in if your thumb shifter's knackered for some reason?"

I don't know if it shifts properly right now, as it's 3:11 in the morning, but when it's light out I'll give it a spin.

Tangentially related: The hub itself probably hasn't been oiled since manufacture in the early 70's. I've located the hub's oil nipple (at least, that is what I think it is). What kind of stuff should I be oiling it with? I'm one for thinking the answer's probably changed over the eons.

M.