Converting a deraileur bike to use a Rohloff hub

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mercalia
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Converting a deraileur bike to use a Rohloff hub

Postby mercalia » 19 Dec 2020, 3:43pm

How hard is it to adapt a derailleur bike like my 26" dawes 1-Down to use a Rohloff hub?

What are the issues

PH
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Re: Converting a deraileur bike to use a Rohloff hub

Postby PH » 19 Dec 2020, 3:53pm

Pretty simple, though not pretty
You need the right version of hub obviously, then a way to tension the chain and a torque arm to stop rotation. The cable run is simple, either via the V brake mounts on an internal shift version, or any route you like with external shifting. If buying new, everything you need comes with it.

KM2
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Re: Converting a deraileur bike to use a Rohloff hub

Postby KM2 » 19 Dec 2020, 4:16pm

Even with vertical dropouts you can put in a half link, so the chain doesn’t sag.

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Mick F
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Re: Converting a deraileur bike to use a Rohloff hub

Postby Mick F » 19 Dec 2020, 4:23pm

Dropout width.
Rohloffs are 135mm .................... am I correct?
Mick F. Cornwall

rotavator
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Re: Converting a deraileur bike to use a Rohloff hub

Postby rotavator » 19 Dec 2020, 4:29pm

According to my Rohloff service manual (?2017) versions with 135, 170 and 190 mm OLN are available.

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531colin
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Re: Converting a deraileur bike to use a Rohloff hub

Postby 531colin » 19 Dec 2020, 4:45pm

There is a thread running here https://forum.cyclinguk.org/viewtopic.php?f=5&t=137395&hilit=rohloff&start=45 which I ought to update a bit, although I haven't been concentrating on this particular job.
Mine is 135mm OLN, the "external shifting" which PH refers to is the modern one and is to be preferred, I think.
You have to decide on your own compromises; my frame has rear-facing dropouts and disc brakes. I decided early on to use a chain tensioner to make it quick and easy to get the chain off to take the wheel out for punctures. After some discussion the torque arm anchor turned out to be a doddle....picture in the page I linked.
[Currently sorting out chainline, some discussion of BB axle lengths here https://forum.cyclinguk.org/viewtopic.php?f=5&t=105385&start=15. A few unknowns for axle length; Shimano have discontinued UN55, its a 73mm bracket shell and the chainset is nearly 20 years old! (at least with an existing assembled bike you can measure the chainline and go from there, particularly if you will use the existing chainset.]

Brucey
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Re: Converting a deraileur bike to use a Rohloff hub

Postby Brucey » 19 Dec 2020, 4:58pm

IIRC the one-down has 135mm OLN rear hub and vertical dropouts, and uses V brakes.

Simplest conversion is to use a 135mm Rohloff hub (the most common sort), a tensioner (lots of different ones available), and external reaction arm (which clamps to the LH chainstay).

Hubs come with QR or nutted axles; you could use either. Hubs also come with and without disc mounts. Ones with disc mounts usually come with the externally mounted shiftbox, older hubs without a disc mount tend to come with a so-called internal shifter, which means the cables disconnect differently from the hub when the wheel comes out, and with an internal shifter, you need two cable housing stops on the frame near the rear hub; as PH mentions, this is commonly achieved via a fitting which bolts onto the LH V-brake boss.

You need to be able to fit a sensibly sized chainring at a chainline of about 55-57mm.

But overall, the answer is 'not very hard'. Rohloff specifically designed their hub so that it could be used to convert derailleur geared bikes.

cheers
Last edited by Brucey on 20 Dec 2020, 7:51am, edited 1 time in total.
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slowster
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Re: Converting a deraileur bike to use a Rohloff hub

Postby slowster » 19 Dec 2020, 5:34pm

If you were to convert to a Rohloff, you need to do your homework/research to make sure that you choose the right hub option for you.

In your shoes, I would get a disc brake version for future proofing, i.e. in case you wanted to use the hub later on a disc braked frame. It's possible to send the non-disc versions of the hubs to Rohloff for a disc conversion, but that would involve disassembling the wheel in addition to the extra cost and delay. Buying a disc compatible hub to begin with avoids that.

All the disc compatible hubs come with the external shifter box, which I think is a better option than the two bare cables and internal shifter.

For vertical drop outs I would get the quick release axle. For track ends/horizontal drop outs many prefer a nutted axle.

As noted above you would need the torque reaction arm attached to the chainstay. If you ported the hub/wheel to a disc braked frame later on, you would need a Rohloff specific disc (4 bolt pattern), to replace the axle plate with an OEM2 axle plate, and to use a 'Speedbone' on the disc mount. All that would cost between £100 to £150.

This is the model I would therefore suggest (also available in black or red) - you can see the various parts supplied with it including the torque reaction arm. 32 hole is the standard and should be more than adequate in a 26" rim given that the hubs build into dishless wheels, but you can now also get some versions of the hub with 36 holes, which would probably be better for a 700C/29 inch wheel.

Note that the supplied twist shifter is only compatible with flat bars. If you want to use drops then you would need one of the various aftermarket solutions, e.g. like this or this.

Sid Aluminium
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Re: Converting a deraileur bike to use a Rohloff hub

Postby Sid Aluminium » 19 Dec 2020, 7:20pm

I'll note the non-disc, internal shift Rohloff version is a fair amount less expensive. In my case, the cost delta funded much of the remainder of the components.

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PH
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Re: Converting a deraileur bike to use a Rohloff hub

Postby PH » 19 Dec 2020, 8:49pm

Internal Vs external shifting.
I think they've both been available from the beginning, if using disc brakes you have to use the external box, though I'm not sure that was always the case. I had one converted when I changed frame, swapped from internal shifting and rim brake to disc and external (The wheel didn't have to be dismantled and it was done in the UK) Pros and cons like most things, the internal shift feels more direct, with more of a click as it changes, after the conversion I was unintentionally changing two gears at a time quite frequently but it's something I soon got used to. Wheel change on the external box is simpler, those connectors with the internal can be fiddley with cold hands. The biggest difference is the cable change, it's simpler to change the entire cable with the external box, but with the internal it's simpler to change the cables from shifter to connectors and changing just those is often all that's needed.
If buying new, I'd get the internal shift and save the money if I was sure to never need disc, but not if I thought there was any possibility I might. If buying secondhand, the non disc versions are often a good bit cheaper. I bought another disc version earlier in the year, I spent a few months looking on Ebay for the right hub, they were fetching silly money, quite tatty abused looking examples selling for £500 and cleaner ones getting over £600. I ended up buying new and surprisingly SJS were offering the best price I could find for the model I wanted.

Billy007
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Re: Converting a deraileur bike to use a Rohloff hub

Postby Billy007 » 20 Dec 2020, 4:14am

mercalia wrote:How hard is it to adapt a derailleur bike like my 26" dawes 1-Down to use a Rohloff hub?

What are the issues


Is this window shopping or a genuine wish to convert your bike?

I would be looking more than just upgrading to a Rohloff for the amount it would cost and the effort involved although it is fairly straight forward with the right bike frame. In addition to the Rohloff hub you should consider what other upgrades you would want for your bike and what you use your bike for and whether it was worth it using your current bike. If not I would get a another bike frame to suit a Rohlof installation and your new upgrades components then build it up yourself or if you cannot afford to do this buy a second hand complete bike fitted with a Rohloff hub. As much as you love your old bike, life is too short tying to fit a Rohloff to old bike frames that aren't really suited to it or it becomes a real faff to make work or the compromises are so great it is not worth it. You need to work out a budget, how much it is going to cost and see if you are comfortable with this. Most people baulk at this stage.

For me I wanted all the benefits of riding a Rohloff hub, etc., no derailleur chain tensioner (seems to defeat the object of a Rohlof hub) meaning you can fit a full chain cover meaning very low maintenance and no oily muck and grime any more, tension the chain by EBB or sliding horizontal rear drop outs, disc brakes. I would only consider a conversion using a Rohloff suitable frame. I wouldn't bother with an old frame or indeed any frame not ideally suited to fitting a Rohloff hub, it's too much hassle. Just my 2ps worth having done it.

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531colin
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Re: Converting a deraileur bike to use a Rohloff hub

Postby 531colin » 20 Dec 2020, 1:33pm

Billy007 wrote:..........the right bike frame. ..............


Ease of fitting a Rohloff is a valid reason for choosing a particular frame, however we don't know the reason for "Mercalia's" enquiry.
I chose my particular frame because I wanted to try (on trails) a bike with as close as I could get to "modern mountain bike geometry" (slack head angle, long trail, long wheelbase) without the often-associated steep seat tube angle, and with a short enough reach that I could use a handlebar shape which suits my arthritic hands. I also wanted the bike to accept a crank drive electric motor, yet retain really low gears; it was only that requirement which brought me to Rohloff.

You seem highly averse to chain maintenance, I wonder why you didn't go for belt drive?

Brucey
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Re: Converting a deraileur bike to use a Rohloff hub

Postby Brucey » 20 Dec 2020, 1:53pm

If anyone fancies trying a rohloff, and has a frame that can accept one, I'd always suggest that they fit one in the current bike and see how they like it; for one thing it is a fair comparison that way, it is the same bike with different gearing; what better way of seeing if that is important to you or not? If they don't like it, the hub can be sold on and the bike converted back. If they do like it, then is the time to think about whether they would like a different frame to fit the hub in.

Otherwise you are in danger of buying a complete new bike (more or less) just so you can use a particular sort of chainguard with the rohloff hub, before you have even worked out if you like the hub or not yet, leave alone the chainguard. This way madness lies, IMHO.

FWIW I like my peace and quiet; this means a chainglider is not an option; IME they are noisy things.

cheers
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Billy007
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Re: Converting a deraileur bike to use a Rohloff hub

Postby Billy007 » 20 Dec 2020, 3:13pm

Brucey wrote:If anyone fancies trying a rohloff, and has a frame that can accept one, I'd always suggest that they fit one in the current bike and see how they like it; for one thing it is a fair comparison that way, it is the same bike with different gearing; what better way of seeing if that is important to you or not? If they don't like it, the hub can be sold on and the bike converted back. If they do like it, then is the time to think about whether they would like a different frame to fit the hub in.

Otherwise you are in danger of buying a complete new bike (more or less) just so you can use a particular sort of chainguard with the rohloff hub, before you have even worked out if you like the hub or not yet, leave alone the chainguard. This way madness lies, IMHO.

FWIW I like my peace and quiet; this means a chainglider is not an option; IME they are noisy things.

cheers


I take it you are having a dig at me regarding your comment suggesting buying a complete new bike merely to use of a particular sort of chain guard with the Rohloff hub is madness? How do you know that decision making process I went to choose a new bike and how dare you be so rude to infer that this is madness, You seem to dominate these forums judging by the huge number of posts you have made. Do you feel this qualifies you to have a pop at other forum users particularly new ones? Not very friendly or welcoming is it? I would suggest you are quite mad, mad as fruit loop suggesting some one buy a new Rohloff and fit it to their bike if it will indeed fit, to see whether they like the gearing and whether it is important to them or not? Who is going to drop the best part of £1200-1,300 on a new Rohloff hub and wheel build plus all the fitting just to see if they like it and sell it on if they don't and convert their bike back!!!! This is a crazy idea and suspect NO ONE would ever do this unless they have rocks in their head. I would suggest they try and find some one or a bike shop with a Rohloff equipped bike and test ride it and see how they like the hub. Certainly a lot cheaper than buying a Rohloff hub out right, wheel build and fitting it to your bike and all that that entails, then realising after a few miles you don't like it, then selling it on at a substantial loss. This is madness, probably only done by people with more money than sense.

Billy007
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Re: Converting a deraileur bike to use a Rohloff hub

Postby Billy007 » 20 Dec 2020, 3:19pm

531colin wrote:
Billy007 wrote:..........the right bike frame. ..............


Ease of fitting a Rohloff is a valid reason for choosing a particular frame, however we don't know the reason for "Mercalia's" enquiry.
I chose my particular frame because I wanted to try (on trails) a bike with as close as I could get to "modern mountain bike geometry" (slack head angle, long trail, long wheelbase) without the often-associated steep seat tube angle, and with a short enough reach that I could use a handlebar shape which suits my arthritic hands. I also wanted the bike to accept a crank drive electric motor, yet retain really low gears; it was only that requirement which brought me to Rohloff.

You seem highly averse to chain maintenance, I wonder why you didn't go for belt drive?


I am. I don't like grime and oily muck that derailleur bikes create. I have done my time with primitive derailleur gears. Maintaining them is a chore and dead time. I have got a belt drive bike. It's brilliant, but