Author Topic: Old hub has started slipping. Need suggestions for servicing.  (Read 14480 times)

Matt2matt2002

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Re: Old hub has started slipping. Need suggestions for servicing.
« Reply #15 on: April 24, 2023, 08:54:54 PM »
Am I correct in thinking that those 2 springs are only used with the ex-box?

Best
 Matt
No. the pawls and their springs are identical regardless of shifting mechanism.
You can see them in this vid
https://www.youtube.com/watch?v=WGNFZjavXcI

Thanks. A great video.
I have no issues with my hub but is changing the pawl springs considered part of a planned preventative maintenance schedule?

My hub is from around 2008.
Just about run in nicely.
Never drink and drive. You may hit a bump  and spill your drink

PH

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Re: Old hub has started slipping. Need suggestions for servicing.
« Reply #16 on: April 25, 2023, 10:02:32 AM »
is changing the pawl springs considered part of a planned preventative maintenance schedule?
I've never seen that recommended and haven't done so myself. 
 

beagley

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Re: Old hub has started slipping. Need suggestions for servicing.
« Reply #17 on: April 26, 2023, 03:48:19 PM »
The freewheel springs (sometimes referred to as pawl springs) and paper gaskets arrived today so I set to work. While disassembling it became apparent that the inner gear change cable is frayed and needs replacing. (I assume the part I need is https://www.sjscycles.co.uk/hub-spares/rohloff-speedhub-50014-spare-hub-cables-cc-ts-internal-8271/). Not looking forward to this job; done it once before and struggled. If anyone can recommend a good video and/or any tips for wrapping the cable round the spiral bobbin thing I'd be most grateful.

So now wondering whether this might have been the cause of the slipping gears.
 

hendrich

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Re: Old hub has started slipping. Need suggestions for servicing.
« Reply #18 on: April 27, 2023, 12:20:35 AM »
It is difficult to believe that those two little springs are the main freewheel pawl springs for the wheel. They are axial rather than radial and too few. Perhaps the 2 springs are relevant to the gear cam? My rohloff has 15000 miles and going strong, but always interested in information that may help future repairs.

PH

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Re: Old hub has started slipping. Need suggestions for servicing.
« Reply #19 on: April 27, 2023, 11:55:03 AM »
.... While disassembling it became apparent that the inner gear change cable is frayed and needs replacing. (I assume the part I need is https://www.sjscycles.co.uk/hub-spares/rohloff-speedhub-50014-spare-hub-cables-cc-ts-internal-8271/). Not looking forward to this job; done it once before and struggled. If anyone can recommend a good video and/or any tips for wrapping the cable round the spiral bobbin thing I'd be most grateful.

So now wondering whether this might have been the cause of the slipping gears.
Yes that's what you need and I think it highly likely a frayed cable was the original cause of the problem.
I've only changed an internal once (maybe twice) it is a fiddley job, I just followed the Rohloff instructions, I have someone hold the ends of the cable, mainly to keep them out the way, but also gently under tension.  Alternatively, you can build the complete thing outside the hub and insert as one, I think I'd have done it this way if I'd needed to again, you just have to be sure you cut the cable the right length.  Rohloff sell a complete quick ring replacement kit, but it's expensive for the times you'll use it.
https://www.sjscycles.co.uk/hub-spares/rohloff-hub-cable-easy-set-8573/

The external parts are different, two cables and the parts are bigger, the size of the pulley makes it less fiddley.

PH

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Re: Old hub has started slipping. Need suggestions for servicing.
« Reply #20 on: April 27, 2023, 11:57:11 AM »
It is difficult to believe that those two little springs are the main freewheel pawl springs for the wheel. They are axial rather than radial and too few. Perhaps the 2 springs are relevant to the gear cam? My rohloff has 15000 miles and going strong, but always interested in information that may help future repairs.
Have you downloaded Rohloff's exploded diagram? You can see the springs and their purpose in that:
https://www.rohloff.de/de/erleben/technik-im-detail/explosion


mickeg

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Re: Old hub has started slipping. Need suggestions for servicing.
« Reply #21 on: April 27, 2023, 12:46:05 PM »
In that graphic, parts numbered 31 and 42 are pawls and springs, 44 is called a freewheel spring.  If you look at the right hand side of gear number 37 and also gear 38 and the left hand side of gear number 14, that also appears to function as a pawl.

I can't figure out what is going on in that diagram and I have looked at diagrams like that since before I bought my Rohloff almost a decade ago.  So, I am inclined to believe just about anything.

But back to the topic of this thread, those two springs, numbered 44 in the graphic, they are called freewheel springs, thus I am inclined to believe that they could cause gear slippage if they are not functioning right, simply because of their name.

When I am coasting, as I change gears I hear different sets of pawls or clutches engage or disengage, especially when shifting between 7 and 8, so there are lots of different things going on that could cause some slippage.

Ph, thanks for the graphic, most pertinent here.

beagley

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Re: Old hub has started slipping. Need suggestions for servicing.
« Reply #22 on: May 02, 2023, 05:16:49 PM »
OK, so after replacing the two freewheel springs, the frayed inner gear change cable and, while I was at it, the two paper gaskets, the net result is [drum roll please]: gears are slipping worse than ever! In fact gears 8 and 10 and now permanently in neutral. And now that the problem is more easily reproduced (like 100% of the time) it's now evident that gears 1 and 3 are not working either (which of course is not surprising since, ignoring the reduction drive, they are the same as 8 and 10 respectively).

My first though was that maybe I didn't fit the springs correctly. But then I remembered that on re-seating the axle ring I could feel a nice reassuring springiness as the two pegs that protrude from the inner face of the axle ring entered the holes where the springs live.

Tried increasing the gear change cables' freeplay (making the gear changer more 'loosey goosey'). No change.

Checked the QR skewer tightness was 7Nm.

Examined the oil drain grub screw to check not tightened too deep. Looks fine to me (about 1mm protruding, see photo).

Unless anyone can suggest anything else I should check, I think maybe it's time to send the hub away for some professional attention. Any suggestions? I remember seeing an ad in Cycling UK's magazine offering "Rohloff servicing" but I don't keep my old issues.

Beagley
 

mickeg

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Re: Old hub has started slipping. Need suggestions for servicing.
« Reply #23 on: May 02, 2023, 07:00:15 PM »
I am completely out of ideas.

Good luck.

steve216c

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Re: Old hub has started slipping. Need suggestions for servicing.
« Reply #24 on: May 02, 2023, 07:00:39 PM »
Did you check and possibly change the gear cables from bayonet to twist grip? You already found the one in the hub was frayed and new cable inners are cheap and are potentially a solution .

Also, did you do oil change recently and screw grub screw too far in? I think this can also cause gear issues.

Hopefully it is not the hub itself.
« Last Edit: May 02, 2023, 07:03:26 PM by steve216c »
If only my bike shed were bigger on the inside...

PH

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Re: Old hub has started slipping. Need suggestions for servicing.
« Reply #25 on: May 02, 2023, 07:59:44 PM »
I remember seeing an ad in Cycling UK's magazine offering "Rohloff servicing" but I don't keep my old issues.

Beagley
What a shame, worth trying though there were no guarantees.
Rohloff list three UK service centres, Cumbria, Manchester and of course Bridgewater.  I'd take it to one of it's in easy traveling distance, but if you have to post it I think I'd go for Thorn, I doubt the others have the same level of experience, or the same relationship with Rohloff. I've been to the Manchester one, Keep Pedalling, an interesting shop, I'd have had them build my Surly if they'd been able to get stock.
I think I know the one advertising in Cycle, possibly in Norwich, I won't name them in case I'm wrong. PM me if you're in that area, you can give them a ring, though as above they're not listed as a service center.
Good luck

JohnR

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Re: Old hub has started slipping. Need suggestions for servicing.
« Reply #26 on: May 02, 2023, 09:42:01 PM »
Did you try manually stepping through the gears without the shifter in place (I think you can use a spanner on the end of the shaft where the pinion fits)? This should confirm if the problem is in the hub. There's part 2 of the video linked to above which reveals one cause of shifting problems https://www.youtube.com/watch?v=-4OmG8T7Uec.

Googling for "rohloff hub gears slipping" provides several hits both in this forum (eg http://thorncyclesforum.co.uk/index.php?topic=3338.0) and other places (eg https://www.mtbr.com/threads/rohloff-skipping.622009/). Hitting the end of the axle with a rubber mallet has sometimes fixed shifting problems!

beagley

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Re: Old hub has started slipping. Need suggestions for servicing.
« Reply #27 on: May 03, 2023, 06:00:08 PM »
Thanks for the latest suggestions.
Tried disconnecting the gear change cables. No change.
Tried hitting the drive-side axle with rubber mallet (a few good wallops). No change.

But I did notice something very interesting: The problem seemed to go away when the bike was upside down for wheel removal! Investigated this further with the wheel removed. With the wheel upright and the gear change cables pointing at 12 o'clock - it slips. With the gear change cables pointing to 3 o'clock through to 6 o'clock - it engages. Then moving to 9 o'clock it starts slips again. I know this sounds incredible so I made a video: https://youtu.be/6XG0zu4_i3k

It feels like this could be a useful clue. Does it suggest something subtle going on within the axle ring (containing the inner gear cable)? Note that the problem got markedly worse yesterday after replacing the inner cable in the axle ring.

Beagley
 

mickeg

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Re: Old hub has started slipping. Need suggestions for servicing.
« Reply #28 on: May 03, 2023, 10:53:43 PM »
I did not look at your video, but I might have an idea what the problem is.

THis link that Ph previously posted has a graphic:
https://www.rohloff.de/de/erleben/technik-im-detail/explosion

Part number 41 is a pawl that is attached to the axle, there are four of them.

This youtube video:
https://www.youtube.com/watch?v=s4UpwoDmOb4

At time 4:36 it shows one of those four pawls on the axle in red in first gear.

At time 7:13 it shows two pawls in red in 3rd gear, one of which is the same as in gear 1.

I think you said those gears, plus 8 and 10 are the gears not behaving properly.

Perhaps that red pawl is not engaging for some reason?

That is my best guess.

Your description of rotating the wheel is what gave me this idea, perhaps gravity is helping that pawl engage when the wheel is rotated just right?  But rotate the wheel again, the pawl is not getting help from gravity?

But of course the bad news is that this is internal, so some significant labor time could be involved, even if the only fault is a pawl or pawl spring.

There is the tiny chance that some grit is stuck somewhere that causes that pawl to hang up, in which case maybe trying to ride some in all gears with lots of shifting through all the gears, with only cleaning oil inside could cause some grit break loose and get out of there?  When was the last oil change? 


PH

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Re: Old hub has started slipping. Need suggestions for servicing.
« Reply #29 on: May 04, 2023, 09:24:08 AM »
It feels like this could be a useful clue.
Beagley
It could be!  It does seem odd behaviour, though I have no practical suggestions.
Good luck