Emergency Fixed Gear Cog for Rohloff?

[vik]

In this thread:

http://www.lonelyplanet.com/thorntree/thread.jspa?threadID=1708354&tstart=0

....over at the Lonely Planet website a guy suggests that you can get a spare cog for your Rohloff to turn it into a fixed gear should you have an issue with your hub. Has anyone heard anything about such a product and if so point me in the right direction to find it.

If it was cheap and light enough I might be convinced to carry one as a "just in case" measure on longer more remote tours.

cheers,

Vik
www.thelazyrando.com

[julk]

This sounds most unlikely, do you think this is just a wind-up?

But putting the thinking cap on --- the only way I can imagine this working with a reversed wheel would be with a cog bolted on to replace the disc brake rotor, this also assumes the hub gear internals are out of action yet the axle and bearings are still functioning.

As I don't have a disc brake hub I cannot check if the chainline would be ok.

If the chain line works out, then it would of course be interesting riding with the original cog potentially running through the disc brake caliper area!

[jawj]

It is indeed possible to run your Rohloff hub fixed! (Using the disc rotor mounting, as suggested)

The bolt pattern and spacing of the Rohloff disc rotor is exactly the same as that of an inner chainring on a four-arm chainset. It's almost as if they designed it that way...

I don't know, but I'm guessing this is for situations when the Speedhub is used as a gearbox rather than being in the centre of a wheel (e.g. recumbents, trikes, other HPVs, etc.)

In an emergency you could run your bike as a fixie and all you'd need would be the inner chainring and fixing bolts (assuming you have the disc brake version of the hub in the first place...)

Both the chainring & the original Rohloff sprocket are much smaller than the disc rotor so wouldn't foul the disc caliper.

If you want a 22 tooth four arm chainring for free, just say the word, as I have literally piles of them lying around unused, and I'm sure I'm not the only one!

[stutho]

So those of us without a chain tensioner would also have to extend the chain by a number of links to get this to work? (unless you can get a  16T  4 bolt chain ring?)

Given that a totally knackered hub in all gears is so unlikely this sound like too much hard work to me. (But I am lazy, that is why I got a Rohloff in the first place! I would rather be riding than fixing / cleaning.)

 

[brummie]

 I think this all stems from a product review in C+ magazine a while back - They reviewed a fixed cog which bolts onto a 6 bolt disc hub ( sold on the London fixed wheel website  - I think ) & the reviewer WRONGLY suggested it could be used as an 'emergency' back up on a Rohloff disc hub - which of course has a larger 4 bolt fitting !

[jawj]

So those of us without a chain tensioner would also have to extend the chain by a number of links to get this to work?

I'm guessing that if you're on tour and have sufficient forethought to include a 22T chainring on your list of kit, 'just in case', a few extra links would probably also be in your bag. Using a SRAM chain and a second Powerlink, it would take seconds to install the extra links needed.

Having said all this, as you say Stu, a totally knackered hub is extremely unlikely. I don't think Rohloff ever intended that their hub should need a fixie backup (see my last post re gearbox, etc.) but it does just so happen that a Speedhub WOULD indeed work as a fixed hub

[Dave Whittle Thorn Workshop]

We had a go at it in the office on Friday, looks like it would work, you would need to run a steel chainring though and file underneath the bolt holes to fit over the disc brake lip, you would also need to remove the EX transfer box to fit it, as said above there are some points to note:

• We are yet to see one thats failed so no gears are selectable at all
• How far could you travel on a fixed with panniers with only a minimum 22 gear as the back sprocket?

In short, only worth considering if your a really paranoid person!

[brummie]

I didn't realise you were paranoid Dave? - I guess you locked the doors  in the office too ?

[vik]

Thanks for all the replies.  I was just curious as I had never heard of such a thing, but it's worth running such ideas down just to see what options one has.

I was down in Baja Mexico torture testing a Shimano Alfine hub.  The bike I was using has a rear hub in the front wheel that can be run as a fixed gear [or single speed] should the rear hub pack it in.  So you are able to swap front and rear wheel should the need arise.

http://www.flickr.com/photos/vikapproved/sets/72157610461277546/

I agree that a total Rohloff failure is unlikely.

safe riding,

Vik

[Lukanga]

There is a legendary solution to the problem of converting a Rofhloff hub into the world's most expensive single speed hub. It's based on polyurethane foam or insulation foam that is injected into the hub. This has been widely discussed in the German single-speed-bicycles forum www.eingangradforum.de. True! 

Lukanga

[geocycle]

There is a legendary solution to the problem of converting a Rofhloff hub into the world's most expensive single speed hub. It's based on polyurethane foam or insulation foam that is injected into the hub. This has been widely discussed in the German single-speed-bicycles forum www.eingangradforum.de. True! 

Lukanga

Wow!  That must be the cyclist's equivalent of the point the explorer decides to eat his shoes!