Thorn Cycles Forum
Community => Rohloff Internal Hub Gears => Topic started by: jimmer on January 25, 2013, 10:29:30 PM
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Dear All,
I post in the full expectation of nothing but pity, for no other purpose than to spread the pain and to solicit more soothing words than I'm getting from the family who just stare at me with concern for my sanity rather than bike.
I tried to reverse the 'hoff sprocket this evening, thinking that, given the generally cheerful nature of the posts in the reversing sprocket problems thread, I could look forward to a half hour of gentle shed time.
In the two hours that I have been en shed I have sheared the pin of Park Tool's stoutest chain whip, ripped the lugs off the sprocket removal tool and gouged out the rebates on the hub into which the removal tool fits.
Apart from proving I still got it butch wise, I've acheived very little today. Glad as I am to be a latter day Hercules, I'd rather be Croesus; then trashing £800 hubs wouldn't ache so.
It's back together well enough to ride at Cannock tomorrow.
I'll ring SJS on Monday and see if they have any suggestions.
Yours, proper narked, James
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Ohhhhhhhhhhhhhhhhhhhhhhhhhhhh, James... I am so very, very sorry to hear of your dilemma. Truly, I ache for your pain and misery at the moment and would not wish it on an enemy, let alone a nice fellow like yourself (that last statement made regardless of your demonstrably great strength).
Don't lose heart. You're not the first person who has had this happen.
It is even possible to make a remover that will work in lieu of the chain whip (fits in the sprocket holes). As for the retaining bosses for the remover...there are solutions there as well.
Yours in empathy,
Dan. (...who has a proud history of pulling similar stunts and can feel your pain directly)
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Ouch, what a mess! Having heard a few similar stories... though really nothing quite so nasty... I did a trial removal a year ago, with just maybe 1500 miles on the hub, and was careful to put some copper grease on the threads.
How many miles would you say you have on your hub, or since you last pulled off the sprocket if this wasn't the first time?
What can I do to avoid the kind of experience you just went through?! That sort of thought runs through my head quite regularly. So sorry you got stuck running right into such a dreadful obstacle.
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copper grease should keep things from seizing .
sounds like a trip to the rohloff doctor. :-[
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...What can I do to avoid the kind of experience you just went through?!
Jim, I have this concern as well. Though nearly all the procedures I've read (even Rohloff's own, shown here: http://www.youtube.com/watch?v=TqpgkyQ5tkI ) involve standing the wheel on edge and removing the cog with a chain whip while using a stout wrench to hold the remover (secured with a q/r)...Andy Blance details a different procedure in the Thorn Cycles FAQ: http://www.thorncycles.co.uk/reversingarohloffsprocket.html
It involves use of a large bench vise and cautions the direction of removal will appear reversed because you'll be viewing the hub from the opposite side.
Poor Jimmer! I really feel for him.
I do know one thing that is supposed to make removal easier is "the sudden shock action" Rohloff describe in their video. When I was repairing cars for money, I know the sudden application of sharp torque would remove seemingly unremovable fasteners when titanic force applied steadily would not do anything but round the corners off the fastener heads. Don't ask how I learned this or how expensive it was the first time. There are things even more expensive than Rohloff hubs. Things like, oh, the bolts holding harmonic balancers on crank shafts. I wonder if Jimmer applied a steady titanic force /or/ a "sudden shock action" the first go-'round.
I have also found from my days of 12" low derailleur gearing when the screw-on freewheels were practically galvanized to the hub and I used a q/r to hold the remover in place...it pays to use a spare q/r rather than your nice titanium-shafted one 'cos when the freewheel finally does break free, it is a bit hard to avoid a full-on follow-through that can strip the nut clean off the q/r and bend the shaft in one fluid motion. Don't ask how I know this, either. It also pays to watch your teeth as they approach the rim, 'cos...well, you know....
All the best,
Dan. (...who's been there, done that in slightly different contexts)
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This may prove helpful for those who follow...
http://forums.mtbr.com/internal-gear-hubs/speedhub-cog-removal-bloody-knuckles-250041.html
I really like the fender washer part of the idea described above if one does not have access to a suitably stout vise (I do, fortunately).
Best,
Dan.
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standing the wheel on edge and removing the cog with a chain whip while using a stout wrench to hold the remover (secured with a q/r)...
That's how I did it. I don't have a vise anyway (though plenty of vices, trust me!) and yeah maybe it is a vice but for sure I would be 50/50 at best on getting the direction right. I didn't have any trouble getting the sprocket off. I did buy a monster Crescent wrench and a stout Park chain whip so I wasn't leaving much to chance anyway!
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You forgot the cardinal rule...Don't mess with the Hoff :D
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;D ;D ;D
I hope Jimmer can get to where this brings as big a smile to him as it did to me. Brilliant!
Best,
Dan.
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FWIW, here are the tools I used a year ago to remove my sprocket:
(http://i140.photobucket.com/albums/r6/kukulaj/IMG_1240.jpg)
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Some encouraging news; it appears SJSC has been known to fix such things...
http://yacf.co.uk/forum/index.php?PHPSESSID=oqb6c5ikipphic1g0caje2phm3&topic=58714.0
Encouragingly,
Dan. (...who sees a light a the end of the tunnel that *isn't* an oncoming train)
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Do these unscrew the opposite way to normal?
I dont have one myself but think that I have read this somewhere before.
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Do these unscrew the opposite way to normal?
I dont have one myself but think that I have read this somewhere before.
They come off anticlockwise, ie like a normal thread but opposite to many cassettes. Sympathy for jimmer. I destroyed my chain whip on my first go but found a neighbour with an industrial size one and all went smoothly. About another year to the next time it needs to one off...
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They come off anticlockwise, ie like a normal thread but opposite to many cassettes. Sympathy for jimmer. I destroyed my chain whip on my first go but found a neighbour with an industrial size one and all went smoothly. About another year to the next time it needs to one off...
You take it off every year? May I ask why?
Honest question - not trying to be a smarty pants
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i reckon a much longer handle on the chain whip Law of the Leaver and all that. ;)
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You take it off every year? May I ask why?
Honest question - not trying to be a smarty pants
No sorry that was ambiguous. I change it roughly every 10000 miles which will next occur be in about another year!
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Pushing doesn't help, longer levers dont help. I've removed 100's as you can imagine in all sorts of conditions and never failed or broken a driver. As Dan said its sharp jolts on the chainwhip thats required and making sure the skewer is rock tight so there is 100% no way the tool can slip.
If you return the hub/wheel to me I can replace the driver shell and return within a day or 2 free of charge if its a hub from us or for a small charge else, just post it to me with a covering letter.
1 day I will get round to doing a video of my own on removing the sprocket.
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Dear All,
Just shown Dave's answer to my wife, who is now starting to understand why I spent what she thought an unconscionable amount on the Catalyst all those years ago.
I ordered a new removal tool before setting out for Cannock this morning. The 'hoff wheel is now on it's side in the shed absorbing penetrating oil. I'll give it another try before sending it back to SJS.
Jags, after toasting the Park chain whip (the same as the one in Jim K's photo) I fashioned one from a 4' length of 2" x 4". He may have been able move the world but I defy even Archimedes to shift my sprocket.
I deployed as much shock and awe as a lummox can muster. I was careful and stealthy in my approach from the other end of the shed and made a final leap onto my unsuspecting quarry. A ninja I am not.
Yours, James
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That Park chain tool is what I use, have bust the chain off a few times doing cassettes, I just bolt a new bit of chain onto it with M4 nuts and bolts.
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The manfriend bust a chainwhip trying to undo cog on his fixed wheel bike. Seems a...classic problem. Local bikeshop may have a Massive F-er of a Brute of a Wrench.
http://www.lfgss.com/thread26713.html there's a doorframe tip here...don't know if that works, never tried it.
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never had a problem myself removing cogs or cassettes but then again i neve over tighted them in the first place .oh btw the law of the lever does work obviously your doing it all wrong. ;D ;D ;D
few smiles in there before i get lashed for that comment. ;)
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never had a problem myself removing cogs or cassettes but then again i neve over tighted them in the first place .
It's not the tightening that really does it, but rather the torque from very low gears* - at least on a derailleur rig, dunno about Rohloff.
[edit] * with a freewheel set-up (fixed/old cluster) not with a cassette.
The door-frame trick was what I once used on a freewheel (cluster) many years ago. But it was a tree at a remote roadside. I also had the cluster tool and just a 6" shifting spanner. The cluster had been used with a granny-gear 26t ring so the torque tightening it on would have been very high and I had done plenty of steep low-gear work. The trick to getting it off was bracing the wheel against a tree trunk, then jolting the shifter with a sharp jolt from a brick. It took 3-4 slams but it worked ;D
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Jags obviously doesn't cycle everywhere fixed else he'd know fixed cogs tighten themselves over time ;D
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The trick to getting it off was bracing the wheel against a tree trunk, then jolting the shifter with a sharp jolt from a brick. It took 3-4 slams but it worked ;D
If you're taking a brick to it, you'd better remember right which direction you want to turn it in to undo it...
Andre Jute
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never rode a fixed to be honest my sons bike is a fixed he loves it just not my thing.
yeah i can see how it would tighten over time but you should neve let it get it to the point where its seized. ;)
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It may not be seized, whatever it is the chainwhip couldn't handle the heat ;D
I doubt I can get my cog off after a year and a half...hrm...time to grease that me thinks :)
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Always grease the threads on a cluster. The lower the gear you use (and the more power from your legs) the tighter the cluster will go on, but the gear is more critical. Rarely ever actually seizes on, just damn tight.
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I do and so does the manfriend however...the cog on his fixie was pretty determined to stay on ;)
Mine should come off except there's no chain whip atm as it snapped :):)
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Dear All,
One of the Rolhoff's great, and much touted, appeals is that it requires little maintenance. Notice I did not say no maintenance. I'm not going to leave the smooth running of the third most expensive thing I own to blind faith in German engineering. The sprocket was unscrewed (with only moderate throbbing of the superficial temporal vein) and copper greased about a year ago. I'm running 40 - 17 and am not Chris Hoy so the input torque isn't huge.
The wheel's still soaking.
Yours, James
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I'm in the midst of doing my annual bike maintenance and so happened to remove my own Rohloff sprocket yesterday. I used a Pedro's Vice Whip rather than a regular chain whip. Because the vice whip tightens onto the sprocket, there is no chance of it slipping. Then I sit down on the floor with the wheel in my lap, put my barefeet against the bottom of the rim (with spokes between my toes), and pull in a rowing action. And yes, jerking is more effective than steady pulling, as long as you don't slip in the process.
Regarding the question about removing the sprocket each year, I think you'd be a fool not to given the sorts of problems being discussed in this thread and discussed elsewhere on the internet. Even with copious grease or anti-seize applied, there is the possibility of this washing off at the very edges of the sprocket and then the metal seizing up there. It seems obvious (to this amateur mechanic) that the more frequently you unloosen the sprocket, the sooner you'll catch any problems before they get really severe.
http://www.amazon.com/Pedros-Vise-Whip/dp/B002NVRIXQ (http://www.amazon.com/Pedros-Vise-Whip/dp/B002NVRIXQ)
(http://ecx.images-amazon.com/images/I/312-UL70%2BCL._AA300_.jpg)
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so true every 100 mile or so take the sproket off clean it and the hub to perfection apply copper grease bobs your uncle. ;D
thats a nifty wee tool you have there btw,
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All this sounds good, I cant recomend it though as i'm still yet to see one here that has seized on... everyone I have taken off still has the coating or grease on the threads i'm fairly convinced its a technique issue to be honest, it just needs a few good jerks, as pushing harder and harder as people have noticed just breaks the chainwhip as the stress is going on the chain on the whip rather than the force being transfered to the sprocket.
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Dear All,
Got the new removal tool in the post yesterday.
The sprocket came off after three sudden hefts, deploying as abrupt and forceful a technique as I'd tried previously. The outer threads were "wet" from what I assume to be the penetrating oil I'd used.
I'll use anti seize to reassemble.
Evidently one jerk is sufficient to remove the sprocket, me.
Yours, James
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Just as well you've kept your sense of humour, James, as well as sorted the hub!!
We have all been there . . . . 'What have I done?' 'How do I get this sorted?'
Good luck
Lewis
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James!
So glad to hear the sprocket is off and things are sorted at this point. Sure sorry you had the stress and difficulty all such things cause; as Lewis said..."We've all been there", so your plight rang bells close to home.
Hopefully the worst is behind and only sunny days ahead.
All the best,
Dan.
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Dear Dan,
Thanks for the kind thoughts but sunny days are the worst. For they are when I pine most keenly for the open road out of Brum, visible through my lab window over the nodding heads of my students.
Yours, James
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...sunny days are the worst. For they are when I pine most keenly for the open road out of Brum, visible through my lab window...
Lab "accident" as shortcut? Or something that simply generates enough harmless smoke for a temporary closure some sunny day?
The mind wanders and wonders when the sunshine calls, and indulging in a trip to Fantasyland from time to time helps it pass a bit more quickly...
All the best,
Dan. (...who doesn't mean to plant ideas but if it makes the papers and evening newscast, Danneaux had nothin' to do with it)
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I had my first crack at this today after chickening out of a 200k audax because of the horrible weather. Glad I had a read of this 1st. I was worried my chain whip might not be man enough for the job however tightly griping it and the spanner with one hand and giving the whip a sharp tap with a hammer with the other loosened the sprocket first go, which was a nice surprise as I thought it would be somewhat more arduous battle.
So I now have a nice new chain running over a reversed sprocket. After 8000km and 2 chains the wear looked quite significant so I expect I will need a new one in another 8K, is that par for the course for a 17T sprocket?