invisiblehand

Well, it seems to me that it is hard to decompose the problem that way. For instance, the indexing mechanism in the Rohloff is in the hub itself. So the cable stretching described apparently has little/no effect on the hub.

Anyway, the point of the thread is if you have an internal hub that cost less than a $1000 USD then you should check the alignment every once in a while and/or learn to recognize when it is out of alignment.

jasong

I don't think this is true: you shift to smallest cog (least derailleur tension), undo the cable splitter then fold the bike. Then the cable housings aren't being pulled as much as the fold pulls the cable inside the housing instead of the housing itself.

While I haven't used these for a folding bike yet, I have used them for 2 S&S frames I have. I really didn't have to fool with derailleur adjustments after undoing these.

So,

con: needing to split cable everytime you fold (at least on davinci designs ones , the ferrule is large enough you can do this with your bare hands)

pro: things stay in adjustment

jasong

I think it would be better to say that it's the cable [length] installation, not the bike design itself. Add $2 worth of new cable housing to make the derailleur portion 2 feet longer and less susceptible to misalignments during folding.

maunakea

I stand by original comments. I have a travel bike with S&S couplers. If one isn't careful, it is possible to reconnect the cable splitters without their being fully seated, which adds length to the cable run = hub out of adjustment.

BTW, S&S has some good hints at https://www.sandsmachine.com/guide_s.htm .

For those not familiar with cable splitters, see https://bessasandackerman.com/blog/?p=14 (pix near the end)

jasong

Weren't you talking about a folding bike in your original post, though ("unpack/unfold")?

S&S are too time consuming for me. A good indicator of when the coupler has become undone a bit is when the shifting starts making noise. Then most likely the sleeve needs to be retightened, because what you said above has happened: a small amount of "extra" frame has appeared throwing off the shifting. I think there's maybe max 1-2 mm tolerance before you start to have the noise.

maunakea

jasong, I think I was talking about both, folders and separables, anything with cable splitters. I've found that if I don't get the metric wrenches out to tighten each cable splitter when reconnecting, the high tension on them will quickly loosen them. IOW, finger tight is asking for trouble.

jasong

That's never been an issue for me. Both S&S frames have the davinci splitters. What kind do you have? I've only finger tightened mine, in fact. PS - at least the shifter cables aren't under high tension, it's very low. You can pull these cables with your fingers and maintain proper tension. That's not the case for the rear brake splitter, but we're talking about shifting performance.

jasong

IH - please see private message.

maunakea

??? I agree, low tension on the smallest cog ... what about tension at cogs 2 to 9 or 10?

geo8rge

"Most dealers won't work on them because an hourly mechanics rate "

Are there enough Nexus problems to justify learning how to repair them? I doubt the typical bike shop mechanic ever looking inside one. They have a lot of parts, not something you can figure out without training or study.

invisiblehand

Probably not ... although it is hard to tell whether the few problems are due to small numbers of Nexus 8 internal hubs, high reliability, or both. As someone else posted earlier, if you look at the hourly labor charge, it might be the case that it is more cost effective to simply replace the hub than try to repair it.

jasong

Same tension, different position. You can shift youself with by pulling a cable with your fingers.

CruiserBob

In regards to my Nexus failure comments: my use of this bike was as an off-season rainy day commuter. I rode this bike in drenching winter rains. I believe that the hub could have been saved if the mechanic cracked open the hub and inspected the grease (proprietary grease from what I understand). Replacing the fouled grease and being aware that there was a seal problem would have saved it. However, at the hourly shop rate, it won't take long before you spend enough to buy a new hub. It is all hind site now, but an expensive lesson.