Setup problem - not all gears working

[satanas]

Hi everyone,

Just registered here, but have lurked a bit in the past. I recently acquired a used Rohloff hub with an internal shift mechanism, and this is now fitted to a Surly Troll frame. After inspecting the small parts, I ended up replacing the rear cog, shift cables and casings plus the internal hub cable as the last was frayed. Despite following the Rohloff manual scrupulously - and having many years experience fixing derailleur gears in bike shops - I have been unable to get all 14 gears to work; top gear is still not functioning. I've tried playing with the barrel adjusters but these haven't made any real difference.

Please note that my shifter has the numbers worn off it, so aligning things precisely isn't possible. When the bayonet connectors are released and the hub cables are pulled, all 14 gears work, but when they are reconnected #14 does not. I must also admit that I found the most opaque and incomprehensible part of the entire Rohloff manual was the section explaining shift cable length.  

Can anyone suggest what I should try in order to get the final gear to work, i.e., what might be wrong and what should be tried to fix the problem? There is plenty of spare length in the casings as I'm still sorting out the position on this bike, so I can trim them shorter if required.

Thanks in advance,
Stephen

[in4]

Welcome Stephen. I'm sure someone will chip in with some helpful advice shortly. In the meantime, take a look at the 'how to' video on the Thorn website. There are a few other resources there that might also be helpful. Here's the link: http://www.thorncycles.co.uk/downloads.html

[Dave Whittle Thorn Workshop]

Hi,

Disconect the cables and see if the shifter rotates completely and pull the hub cable to see if this too rotates completely.

A classic sign that the brass pulley is incorrectly positioned is if the last indexed click is not as well defined when pulling the cable by hand.

If both appear normal, then it is probably an issue with one or both of the cables being trimmed to an incorrect length.

Hope this helps, also worth looking at the Rohloff AG Youtube channel as both the internal cable change and the shifter cable change have video's.

[Andre Jute]

This probably doesn't apply to you if you have worked extensively with derailleurs, but it is always worth saying that with 14 gears you would count only 13 shifts...

[wildrover]

Hi, I know you said you messed with the cable length, but some of us have had the same symptoms with too much slack in one or both of the cables:

http://www.thorncycles.co.uk/forums/index.php?topic=6491.msg40399#msg40399

We tightened at the ex-box.

Let us know how you resolve the issue!

[onrbikes]

Have you tried to disconnect the cable from the grip and pull the cables at the hub instead?

At least this would determine if it's the grip or the hub.

[il padrone]

Please note that my shifter has the numbers worn off it, so aligning things precisely isn't possible. When the bayonet connectors are released and the hub cables are pulled, all 14 gears work, but when they are reconnected #14 does not.

Maybe this will help you ??

[Danneaux]

...or this: http://www.sjscycles.co.uk/rohloff-rubber-grip-for-twistshifter-light-8190-prod27181/



Best,

Dan.

[il padrone]

Actually in my experience that new round twist-grip is a good deal harder to grip and twist than the old triangular-section model, especially when it's a bit wet. My wife has the round one and I have the trianguar one, she often has trouble shifting, I do not. Rohloff now have a new Mk 3 twist-grip to come out soon.

[satanas]

Hi again,

Thanks for the comments so far.  

First, I understand that there will only be 13 *shifts* to get all 14 gears; I am only getting 12 of these when the cables are connected. With the cables off all 14 gears can be selected - I can feel the last shift happen, and the resistance changes.

At present there is virtually zero slack in either cable; I cut one of the cables shorter to get 13 gears to work, rather than 12 after the first attempt. I'm not convinced the cables can be any tighter, but will watch the video and see if that helps explain the process. NB: I followed the manual scrupulously, except for the one or two paragraphs which made no sense to me; these were however the critical ones. Since then, I've adjusted the cable length quite a bit without much success.

Also, FWIW, I have the original style triangular shifter, not the newer "light" shifter, and the internal mech, NOT the EX box, so the other thread isn't very relevant as far as I can see.

Dave Whittle said:

1. "Disconect the cables and see if the shifter rotates completely and pull the hub cable to see if this too rotates completely."

Yes to both.

2. "A classic sign that the brass pulley is incorrectly positioned is if the last indexed click is not as well defined when pulling the cable by hand."

I will check this but was very careful when I replaced the hub cable as I really didn't want to have to take it apart again.

3. "If both appear normal, then it is probably an issue with one or both of the cables being trimmed to an incorrect length."

I suspect this is the most likely problem. What I'd like to know is which cable is likely to be the culprit, and whether it is too long or short. BTW, I've tried disconnecting just one cable at a time at the bayonet connector to see if perhaps the other was restricting movement, and that didn't help either. I'd be inclined to think that the cable under tension needs to be shorter, but I'm dubious that this is possible - there's not much clearance to the barrel adjuster now. As I said before, the last section on trimming the hub cables (just prior to fitting the second bayonet connectors) didn't make sense to me, in part because my shifter has the markings worn off, but mostly because (to me) it seems to be very poorly worded, and thus incomprehensible.

Am I correct in inferring that if the cable length(s) are out, then the cable under tension needs to be shorter, and/or the looser cable needs to be longer? Moving the barrel adjusters through their entire range (independently!) didn't appear to make any difference.  

Since I really need to be able to fix this myself, and since spare Rohloff cables don't grow on trees here in Australia, I'd like to feel at least a little confident there is a correct diagnosis before I resort to cutting things at random!

Later,
Stephen

[ajbenie]

If I've understood your last post correctly then with one of the cables detached you still can't get all 14 gears. This to me would mean that your cables are bit too long. A quick test of this would be to do the same test again and when you have moved through the first 13 gears pull gently on the gear cable housing (as if you were screwing the adjuster even further out). If this then gives you the last shift you may be lucky and be able to shorten the cables so it works.
I would expect that a too short cable would work normally in this setup, unless it was way too short and the act of connecting up the internal mech cables gives the first shift.
/Andy

[geocycle]

Hope you have got this sorted.  The thing I can't understand is that you have all 14 gears at the hub? The brass pulley is easy to misalign, I've done it, and this could limit the gears.  The other thing is that the cables are tight. Rolhoff cables should be relatively slack with gentle cable runs.  There's not much to go wrong in the shifter of the cable is correctly fitted and are the right way round.  One other problem I gave myself was initially not fitting the face plate at the correct angle to allow the cables to exit in a straight line from the hub to the adjusters.  Anyway good luck and let us know the outcome.