Thorn Cycles Forum
Community => Rohloff Internal Hub Gears => Topic started by: jawj on October 17, 2006, 05:47:22 AM
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Hello Everyone,
I am on the very cusp of buying a Rohloff-equipped bike as it must surely be the way forward. Much noise is made about the reliability and longevity of the gearing system, and rightly so it would seem BUT...
i can't find anything anywhere about how the hub performs the most basic function of being a hub i.e. allowing your wheel to go 'round.
Anybody got any ideas/tales of how the wheel bearings perform and hold up and, crucially, how easy they are to replace...?
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I'm not sure I understand your point. From looking at the exploded diagram and animation of the hub it doesn't have anything comparable to normal wheel bearings.
http://www.sjscycles.com/forum/topic.asp?TOPIC_ID=710
There doesn't seem to be any user servicable parts inside the hub itself, so I'd guess Rohloff designed any bearings to last the lifetime of the hub and nobody knows what that is yet[;)]
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It is all about trust (without the h)!
Rohloff is a small family enterprise who has been producing this unique product in modest numbers for over ten years; without great fanfare.As a small (very small) business owner myself I believe in underpromising and overdelivering: the customer gets more than he or she expected.Big Business does it the other way with lots of advertising and marketing and using their product is often less exciting than reading the promotional material.
Producing high volumes of anything always comes at the cost of quality: to sell big numbers of anything you have to bring the price down and spend heaps on advertising to reach the masses; this reduces what you can allocate to making the product itself.
I am not an engineer but I am convinced that Rohloff spends less on marketing and more on quality bearings than the big boys in the game.
I trust the guys.
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Mmmm... interesting. Surely Rohloff hubs DO have something comparable to normal wheel bearings: there appears to be three sets of cartridge bearings on the axle in the movie. Cartridge bearings are great cos of their ease of replacement so my pondering is: how easy are they to replace in a Rohloff hub? Even really great quality bearings need replacing eventually... unless the bearings DON'T need replacing, which would be the best thing in the world EVER!
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As you say it appears that there are three sets of cartridge bearings, with two on the drive side to cope with the additional stresses present. I'd hazard a guess that they probably aren't easily user replaceable, but given that they appear to be quite chunky by bicycle standards and that they run in an oil bath, I'd reckon that they ought to last the life of the hub just as the bearings in a car gearbox will generally last for the useful life of the gearbox.
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quote:
Originally posted by jawj
Mmmm... interesting. Surely Rohloff hubs DO have something comparable to normal wheel bearings: there appears to be three sets of cartridge bearings on the axle in the movie.
They're not comparable because they're not load bearing in the same way as they would be on a freewheel hub. I'm not saying they don't bear any load, but when you remove the inner workings from the shell it's obvious that the load is not on them. The Rohloff handbook lists the wearable parts, bearing aren't included. If they needed servicing or replacing, I'm sure there be some information available and the parts would be listed on someones price list.
If you're the sort of person who enjoys servicing, maybe the Rohloff isn't for you. There really is very little to do[;)]
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As I understand it the bearings are NOT user serviceable. BUT the expected life is greater than 100,000km. This is partly due to the bearing being sealed inside an oil bath.
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They're not comparable because they're not load bearing in the same way as they would be on a freewheel hub.
Wow, it's taken me more than two years to read what was written here!
What I was skeptical about was what seems to be a denial that the Speedhub has bearings, or something along those lines. It must run on bearings or bushings and since bushings aren't that great for this application, it MUST be bearings and those bearings MUST bear the weight of the bike, rider and load when the wheel is spinning.
What I wanted to know at the time was do those bearings ever need replacing or servicing. It appears the general consensus is that they run in the oil bath and so will last as long as the rest of the hub internals. Right...?
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That about sums it up!
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I agree with stutho and grossander, and put some FACTS:
All bearings do need replacement sometime on remote future;
Rohloff has bearings and they're BIG;
They are of a superior material, are sealed and work in oil bath;
Tey are not supposed to need replacement;
Nobody knows how much they will last;
You need to trust what they say in order to be happy with one of these.
Helton
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There are five bearings in a rohloff, three at the drive end and two at the non drive side. The two large main hub bearings are 47mm od x 35mm id x 7mm wide. The two smaller 28mm x 12mm x8mm are fitted in the driver itself and the smaller 22mm x 9mm x 7mm is fitted to the shifting shaft. The two larger bearings (47mm) use the hub oil as lubricant as they are open sided, the two driver bearings are sealed and use the grease within them to lubricate along with the shifting shaft bearing which is also sealed.
They are certainly not superior bearings and will not withstand any water within the hub which has caused problems for some people, due to the fact that the oil seals on the outer of the hub have let water in and corroded the bearings.
All of the bearings can be replaced by the user if you have the knowledge and tools.
47mm bearing code - SKF # 61807
22mm bearing code -This is a custom bearing only, I can supply, if you have difficulty getting one (which you will)
28mm bearing code - SKF # 6001 2RSH
The bearings fitted are of standard supply and are available from most bearing supplies although the 47mm ones are not listed at some suppliers.
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@expr
Well, that's what I call a lot of facts. Thanks for the information on bearings!
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just to update this thread there have been quite a few complaints re worn/wobbly bearings needing to be sorted at the factory (sometimes more than once on the same hub). I have personally seen at least a dozen different people mention this on various cycle forums and have had the problem myself , so in essence they are certainly not as indestructable as the sales blurb likes to pretend. On the bright side their customer service seems very good if things do go pear shaped and are sorted fairly quickly even on hub's out of warranty .
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Rohloff and Thorn have done a fine job of brainwashing people into thinking these hubs are indestructable. Bearings are largely er, bearings and even in oil bath sooner or later they'll need replacing.
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Any advice on replacing the drive side bearing myself ?
Looking at this picture (http://3.bp.blogspot.com/_vUEhS0lU3eU/SQdr26SqYRI/AAAAAAAAGN8/ro97e8NQ98M/s1600-h/rohloff_speedhub_50014_explosion.jpg), it's item number 3 I want.
Looking at this picture (http://www.greenspeed.com.au/OldWebPics/Rohloff768.jpg), it looks like it's simply a matter of removing the sprocket, then splitting the main hub body and tapping the bearing and seal out.
I take it that's the 61807 bearing ?
Does anyone know the dimensions of the seal, as I might as well replace that at the same time ?
I've got three hubs and the side play at the rim is 3.22mm & 1.54mm on the two 29er rims and 0.83mm on the 26er rim.
3.22mm feels pretty bad to ride.
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Hi,
The changing of the bearings can be done by yourself with the right tools and knowledge / advice.
The first thing to do is to remove the sprocket from the driver body with a good strong chain whip, and the removal tool from thorn/ rohloff.
Once the sprocket has been removed you can tip out the oil into a container through the bearing itself for re-use later if required. Then remove the torx screws from the hub cap, carfully remove the gear hub from the casing and place on a very clean cloth out of the way.
You may find that the small nylon (white) joints have also come out loose, don't worry keep to one side for later you should have 9..
Also be carefull with the paper gasket this is delicate, but can be reused if OK. Then with a Small plastic trim tool the oil lip seal can be removed but its advisable to use the rohloff lip seal tool to do this, the only difference there would be it has to be taken off with the hub still complete, as long as you can be carefull putting the lip seal in after its OK without the tool.
Once the oil seal is out of the way pay attention to the dimensional measurement in depth that the
http://simplybearings.co.uk/shop/product_info.php?products_id=5170
bearing has been inserted to as this is a (floating) bearing but must be put back in the (ball park) area for good fit. It still has an interference fit for integrity, but there is no backstop to push the bearing up to..
After taking note of the depth, I can think of many several ways to remove the bearing with out using a conventional / bespoke manufacturer specific tool, but with carefull intuition this can be achieved with a little imagination. Using the (Tapping out) method is always a last resort on my list , only due to the fact that this can cause marring of the soft aluminium casing and because this is a (floating) bearing it is essential that its mating surface is kept perfect.
I used some 16mm threaded rod with various sockets and end caps to remove my bearings and this acts as a pusher and a puller also so is great for installation.
Put a socket in the hub with a large flat washer (backstop) on it then a nut with the threaded rod coming out of the driver side long enough to go through a larger socket 50mm id or larger for the bearing to pull in to, then fit a (backstop) washer and another nut, then simply tighten the nut slowly to release the bearing into the socket and remove.
When fitting the new bearing, do not fit any retaining compound on the bearing just a little oil, you may now have to tap the bearing around the periphery to get it started, this MUST be square going in before using the puller/ pusher to reinsert the bearing. Turn the puller around so that the bigger socket is inside the hub this time and a socket of 46mm od approx is now on the outside which will pull the bearing back in taking note of the depth required for installation.
Once the bearing is back in and at its correct dimension the oil must be cleaned with solvent around where the lip seal will go, if you are pushing this in manually this can be done now, if using the rohloff tool this will have to be done when the hub is back in the casing, if doing now then using loctite seal put a smear around the OUTER of the lip seal and around the id of the hub case and carefully press in with a flat face until flush with the case and leave to dry for an hour.
After an hour wipe the inside of the lip seal with oil and proceed to fit the hub back in to place, this will require you to put a little grease on to the nylon joints to stop them from falling while inserting in to the hub, also taking care not to damage the paper gasket.
Then fit the torx screws using loctite blue 243 and being carefull not to over tighten, the oil can now be fed back through the open bearing face on the driver side, once in screw the sprocket back on, because you have taken the hub apart and because the driver bearing is floating this can cause misalignment of these to components which is rectified by whacking the non drive side as close to the hub center a few times to re align the two parts, DON'T WORRY this is normal procedure for this hub and no damage will be caused although the use of a soft faced rubber shock hammer is much preferred or a small piece of wood with a normal hammer to absorb the shock or prevent hammer rash etc..
This is to bring the axial line of the driver in to the axial line of the floating bearing, and the symptoms of a poor alignment are very poor freewheeling with the bike turned over..
The only other part that could cause the freeplay on the driver side is the driver bearings which sit inside the driver which in turn sit inside the main 47mm outer hub bearing, double check that the freeplay is in the outer bearing first.
Once this is complete tighten the sprocket fully and test the hub.
Regards
Dave.
http://www.photobox.co.uk/album/168875892
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Welcome back. This is the kind of knowledgable, contribution that we could have missed out on.
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Thank you Jimmer, PM sent.
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Thanks, expr, that's very helpful.
I'm a bus mechanic, so I've got access to big sockets and experience at making improvised pullers.
It's definitely the single, larger bearing that's faulty. There is clearly movement between the hub body and the sprocket, while the sprocket appears secure in relation to the axle.
Do you happen to know the dimensions of the seal and if it's available ?
I guess it must be 47mm OD to match the bearing and I could measure a sprocket to get the ID.
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Yes that's correct, the od is 47mm the id is the same as the od of the sprocket, plus the thickness of the lip, I'm not a 100% but do seem to recall its got a wound spring tensioner also as standard lip seals do, to keep tension on the axial load, its a single lip too. it would be advisable to get one from Thorn they have them in stock and the seal puller and inserter although its quite expensive for a one off, also note that rubber of the oil seal is on the rohloff specific has been made to suit the oil.
The one size specific socket or alike is 45/ 46mm this is requires to pass through the body when pulling in either direction, the larger socket that you pull in to you can wrap soft tape around the edge to prevent marring on the body etc...
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Rohloff and Thorn have done a fine job of brainwashing people into thinking these hubs are indestructable. Bearings are largely er, bearings and even in oil bath sooner or later they'll need replacing.
I was under the impression that no hub had failed in terms of the gears & providing drive?
My hub was performing flawlessly despite ( IMO ) 'the excessive play in the bearings' prior to returning it to Germany for 'tinkering' & bearing replacement.
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Yes there seems to be a bit of misnomer surrounding the failure of hubs, there are several cases that I can recall that have ruined the hub bearings beyond use. This tends to be swept under the carpet most of the time.
I remember one case where straw had become lodged in the oil main oil seal which although not much oil was lost, there was water ingress which resulted in rather a poorly set of main hub bearings..
So I guess in that case you can't really blame rohloff, but non the less this has caused problems for the rider.
I've known a few cases similar too, but what rohloff are suggesting is that there has not been a case where a rider has not been able to carry on with their tour due to mechanical failure, so you take from that what you will.
What I can say though, is that the wheel / hub did have to go back to Rohloff for repair. Whilst on tour...