Thorn Cycles Forum
Community => Rohloff Internal Hub Gears => Topic started by: keleher on August 28, 2012, 04:47:02 PM
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So I've been leaking oil on the gear box side for a while, and when servicing the chain I discovered that the various parts on my rohloff are not actually secured properly (this is undoubtedly my fault, I undid this stuff when I was installing a different cog last year).
Looking at the first picture here, the part I'm holding is the "OEM axle plate", and the piece secured to the hub w/ two philips screws is the "transfer box".
(http://kelehers.me/pics/rohloff/IMG_0604.jpg)
The issue is that the axle plate does not secure tightly to the transfer box. The axle plate's screws will thread into the hub thorugh the transfer box w/o the axle plate, but they only seem to tighten about a half turn. In other words, the tolerances are very tight.
W/ the axle plate on, the screws just don't engage at all.
The second picture shows that the transfer box really is pressed tightly against the hub, w/ the philips screws fully engaged.
(http://kelehers.me/pics/rohloff/IMG_0614.jpg)
How do I get the axle plate's screws to engage?
Edit: fixed terminology
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Dan to the rescue ;)
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I am looking at pg 94 of the speedhub manual. Figure 8 has a caption... "There is one mounting position out of the possible six, where the teeth of the cog D and the sprocket C line up. In this position the screw holes of the cable pulley remain as close as possible along the centerline F. "
Fig 9 says: "The five other mounting positions result in the screw holes of the cable pulley being substantially more out of line with the center line F. In this case, remove the cog D and try the next mounting position."
Not sure if this is on target, but maybe close at least!
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Dan to the rescue ;)
No, this is way above a Rohloff newbie. Give Dan a fortnight to catch up...
Andre Jute
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yeah wasn't thinking right ;D ;D
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First thing I notice is that the axle plate is not one of the standard Rohloff versions, unless its an old one I'm not familiar with?
Are the torx screws for the axle plate the originals and the correct length?
Hard to tell from your picture but this is what the screws should be like http://www.sjscycles.co.uk/axle-plate-torque-screws-for-rohloff-speedhub-500-14-8236-prod10974/ and yours look shorter?
Have you owned this hub from new?
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Hi Guys!
Sorry, I was out of town today (over at Yachats on the Oregon Coast, meeting with an estimator for some electrical work there), but I just caught this before I left. I found the same passage in the manual as Jim and wondered about it, but decided -- just as Andre said......this is way above a Rohloff newbie. Give Dan a fortnight to catch up...
... <nods, vigorously> Yes, I know my limitations and no, I'm not there yet! Give me time and I'll make progress on the R-box. Meantime, my nomination for this one is Dave (Expr), whose wonderfully encyclopedic, firsthand knowledge of Rohloff innards has my full and complete respect.
All the best,
Dan. (Primum non nocere..."first, do no harm"; not just for medicine)
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Try going here
http://www.rohloff.de/en/service/download/description/index.html
and downloading the
Service_en.pdf document.
The info (with pics) on p129 (appendix section) is what you need I think.
The axle plate used here is the Thorn tandem type that I think they now fit to all hubs they supply. Apparently there were some failure issues on the oem axle plate where the dog separated from the plate, however Rohloff have now modified theirs from what looked like 2 piece welded construction to 1 piece solid construction. Does anybody sell Rohloff anoraks? :)
Good luck
Ian
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The torx screws on my rohloff are all 20mm, not the 25mm spec'd by the manual. So I bought 5 new m4x25 screws, tried to put them in, but though they engaged, they didn't go all the way down. Maybe thorn's axle plate is thinner than standard?
So I hacksawed 2mm off each, they all fit, and I clamped them down. Hurray!
Then I fixed the chain link that was the original problem, and put it back together.
It doesn't shift. Not one single gear. Even when I take it all apart again and try to shift w/ plyers it doesn't work.
The hub has been lying on it's side for a couple days, but I can't understand how that would be an issue.
??
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Hi Keleher,
If the Rohloff Service Manual passage which Ian generously provided applies, then Rohloff's caution would also apply, when they say [page 129]...If the external gear mech should be falsely mounted then the fitting of an axle plate screw into hole (C) would cause the grub screw (A) to be forced into the axle. This in turn will lead to a complete blockage of the gearbox.
What you have described most recently sounds much like a "complete blockage of the gearbox".
Your situation of too-short screws might also be explained by the pointer on that same page, which says...In an axle plate screw cannot or only with force can be screwed into hole (C), then it must be checked that the grub screw (A) is not sitting directly behind this hole. If this is the case, then the external gear mech must be disassembled turned around 180° and mounted again in this position. The grub screw stays in its original position (2mm protruding).
I am a little concerned about the additional length of the screws you have added. If the gearbox held together fine originally and did not leak, then the screws originally supplied must surely have been the correct length, despite being shorter than spec'd by the manual. They must surely have engaged at one time. I believe they seem too short or are difficult to engage now because something is aligned wrong or mis-placed -- I think those passages above from Ian's reference would be worth checking to make sure everything is aligned correctly. That 2mm grub screw would be enough to prevent proper engagement if it is not in its proper locator hole. Once assembled, everything would appear properly assembled except for possibly being 180° out-of-alignment, and with screws too short to engage properly.
Best,
Dan. ("stab in the dark"...using Ian's helpful illumination)
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Hi keleher,
I'm totally familiar with the internal me ch, and not so with the external me ch, however I think you need to start a fresh with the build up and perform some simple tests to let us all know where you are with it...
Can you take off the external box and axles plate, then can you turn the hexagon with a hole through the center, this is the manual override for changing gear in emergency.. There should be an audible click and a definite and positive location for turn.. This will allow you to put the hub into any gear... Things to be carefull for are to make sure you haven't lost or are missing the two small springs located in the two opposing holes on the flange you are looking at to turn the gears.. The grub screw which will be fitted to hubs after ser no 47000 will be in another hole on the same flange.... Do you see it...
If you can change gear via the hexagon gear changing shaft, then report back if not we need to consider the options.. I will help as much as I can..
Dave.. Ps thanks for the referral Dan, appreciate your comments.
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Additional to my last... The grub screw on the main flange serves the purpose only to blank the screw hole up as its not used in the mounting of the external box, the grub screw must be flush if the serial number is between 47000 and 48500, and if it's 48501 or higher then the grub screw should protrude around 2mm to act as a locating peg for the external box, also as mentioned earlier by rualelexander, the axle plate doesn't look to be standard, this may have some affect on how much the Torx screws are going in by. If the grub screw has been allowed to screw to far in to the hub then this will Come into contact with parts of the hub on the adjacent side, which inturn will stop the hub from functioning. the two springs which should be present and in the correct holes are responsible for making the ticking sound when freewheeling...
Dave.
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Try going here
http://www.rohloff.de/en/service/download/description/index.html
and downloading the
Service_en.pdf document.
The info (with pics) on p129 (appendix section) is what you need I think.
The axle plate used here is the Thorn tandem type that I think they now fit to all hubs they supply. Apparently
there were some failure issues on the oem axle plate where the dog separated from the plate, however Rohloff have now modified theirs from what looked like 2 piece welded construction to 1 piece solid construction. Does anybody sell Rohloff anoraks? :)
Good luck
Ian
Sorry didn't see this, ok that explains the axle plate difference...
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Additional to my last... The grub screw on the main flange serves the purpose only to blank the screw hole up as its not used in the mounting of the external box, the grub screw must be flush if the serial number is between 47000 and 48500, and if it's 48501 or higher then the grub screw should protrude around 2mm to act as a locating peg for the external box, also as mentioned earlier by rualelexander, the axle plate doesn't look to be standard, this may have some affect on how much the Torx screws are going in by. If the grub screw has been allowed to screw to far in to the hub then this will Come into contact with parts of the hub on the adjacent side, which inturn will stop the hub from functioning. the two springs which should be present and in the correct holes are responsible for making the ticking sound when freewheeling...
Dave.
The springs are present. However, I can't find any sign of the grub screw. Presumably it would have a 2 or 2.5 mm hex opening on top, but sticking either of these in the holes and turning results in nothing catching. If there was a grub screw, I assume it's somehow deep inside.
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hmmm its highly unlikely that the grub screw would have gone inside the hub, it would just butt up against the internals, when you say nothing is catching, can you clarify that the sprocket when you turn it just spins? or do you mean something else...
good that you have the springs... are they in the correct holes.... did you try to turn the small hex nut with the hole through the center that allows you to change gear. this must be done with axle plate and external changer removed...
can you explain in a little more detail what you have done and what happens, if its easier for you to call me on the phone please pm me.....
Has this problem come about since you've had it apart... it could be that the grub screw was never there if you have acquired the hub or its been changed from an internal to external changer, however we need to get to the bottom of this properly... I seem to recall that if you take the two springs out and assemble back together then it will only freewheel and there will be no drive...so when looking for engagement put the two springs in there respective holes and place the external gear changer box ontop using the two locating dowels within the box to compress the two springs then check for drive and freewheel...
Dave.
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to expr....
By "nothing catches" I mean that when I put a 2/2.5mm allen wrench into the holes in hope of it engaging w/ a grub screw, it doesn't.
The small hex nut will not turn. This is the nut that the cog fits over. In other words, the obstruction is deeper down. The ex gear mech works fine.
What will checking for drive give me? It doesn't shift..
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Rohloff says that the torx screws must all have sheared off somehow. Sending to germany.
Back to derailleurs for a few weeks.
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Sorry keleher, with regards to the drive, I was just trying to ascertain what is and isn't working. I'm not convinced that the screws are all sheared off, and the shifting shaft moves independently of the hub internals which seems odd as to why it will not adjust either way..
Keep us posted as to what rohloff suggest was the cause.. Hope you get sorted soon.
Dave.
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Here are some pics img 2217 shows the reverse side of the part your screwing into, also note the pawl springs which although ive never heard of it could also be cause for jamming up the hub....http://www.photobox.co.uk/album/168875892
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...Rohloff says that the torx screws must all have sheared off somehow....
Yikes! That is really...something...! Keleher, may I ask if you contacted CycleMonkey, who list themselves as "...the sole North American Service Partner for the Rohloff" ( http://www.cyclemonkey.com/ )? If you haven't yet posted the hub, it might save a bit of time and shipping cost for you.
Dave, just want to pause a moment to bestow a "Shining Star Award" on you for a fantastic helping job! We all benefit from such an impressive and dedicated effort; my sincere thanks.
All the best, hoping for a great outcome,
Dan. (...reminded of Honda transaxle synchro-ring replacements, back in the day...)
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Thanks Dan, I do hope he gets it sorted out OK with rohloff or cyclemonkey, I don't feel like I've really done anything to help much...
The one thing that does make me wonder with regards to the "rohlof design" is why they decided to drill and thread all the way through, apart from the fact it's easier to extract broken off screws.. It's a double edged sword in some respects with good and bad points either way.
I'm not sure we might get the answer were looking for from Germany, I think sometimes their opinion of fault is a little bit of smoke and mirrors to help keep the rohloff records of achievement as good as possible, we will have to see what the outcome is...
I wouldn't mind getting my oily mits over it to spread a little ray of light over the situation, does seem odd.. It's always difficult to diagnose some faults but this one should stand out like a soar thumb, there must me something in there blocking the shifting shaft...
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Are you sure you don't have the problem I faced - shiftiing was extraordinarily hard using a spanner on the pivot under the external box, and not possible using the handlebar shifter.
The reason - in adjusting the position of the EX box I had taken the cover plate out and the little shifting cog fell out. I put it back in, but it was the wrong wa around. It's not symmetrical. When I reversed it and suddenly I could shift ;D
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Padrone, certainly didn't see any such thing.
Andy Blanch talked to Rohloff, who said to ship it to Neil at Cycle Monkey. I have been talking to Neil, by the way, and he offered to ship me new screws gratis.
Unfortunately, I think he's in the process (yesterday or today) of moving back to California from DC, where I'm at :-(.
So presumably we'll talk in a few days and I'll get it shipped off.
Meanwhile, I've been working on my venerable long haul trucker to ride in the interim.
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This is the cog I'm referring to. It has the teeth on one end (the outboard end) of it that engage with gears in the EX box.
(http://forums.mtbr.com/attachments/internal-gear-hubs/702281d1339122289-rohloff-hiccups-img_6327.jpg)
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Finally got wheel back from Cycle Monkey (US service partner for Rohloff). The screws had indeed sheered off inside the hub. The fix was just to remove them, as I hadn't exerted any great pressure that would have damaged things.
I'm a big guy, but this still shouldn't have happened. I suspect it occurred when I hit a huge railroad-gap doing 30+ mph, fully loaded for touring. I was almost unbelieving that the bike and wheels survived, but they seemingly did. To be clear, the screws presumably sheared at this point, but they weren't forced into the hub until I attempted to use new screws later.
It's not good that this happened, but that was a very unusual circumstance, and all is now well.
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Hi Pete!
Good to hear from you, and terrific news that you finally have your hub back -- yay!
Boy, what a story of the failure and events that led up to it. Sometimes a person can't see how bad those railroad crossings are till you're you're already there and it is too late (I've been caught out on those once or twice myself!). The impact-shock can be tremendous, especially if one doesn't have enough warning to stand up in time. The screws had indeed sheered off inside the hub. The fix was just to remove them, as I hadn't exerted any great pressure that would have damaged things.
So glad it wasn't worse, and apparently no damage was caused inside. Whew!It's not good that this happened, but that was a very unusual circumstance, and all is now well.
Agreed! So glad it is now back with you so you can use the bike once again.
Thanks for followup and telling us the "rest of the story".
Best,
Dan.