The right Rohloff for your Big Dummy?

7 05 2011

A Big Dummy love a Rohloff!

This is is a repost from an old blog. I figured it would be useful to have here in case someone was searching for Surly Big Dummy Rohloff information.

One problem with buying a Rohloff hub is that there are a TON of options to navigate if you want to get the right hub. In this post I’ll run through the options to let you know what works and what I chose.

Colour:

  • available in red, black and silver
  • the anodized cases [black and red] should withstand salt and other elements a bit better than the polished aluminum case
  • cases are now laser engraved. If you see one with a sticker on the hub it is older stock.
  • I chose black for the stealth Big Dummy look
Axle:
Internal or External Gear Mechanism:
  • the external gear mechanism is a box that attaches to your hub and your cables terminate there
  • this means you can easily detach it for removing the rear wheel
  • cables are run fully covered to the external gear mechanism so they are immune to the elements
  • it is easier to field service the external gear mechanism
  • the trade off is the shifting is slightly less smooth
  • you cannot use disc brakes with the internal gear mechanism
  • I went with the external gear mechanism for the ease of maintenance and so I could use disc brakes.
Disc Brakes:
  • you will need to use the external gear mechanism
  • you will need to specify disc brake use when ordering your hub
  • you will need a Rohloff specific disc rotor
  • you can use a Rohloff disc hub on a rim brake bike as long as you use a rim with a braking surface
  • I went this route as I wanted to use Avid BB7 disc brakes on my Big Dummy
Torque Support:
  • without any torque support the hub will want to spin and will not drive the bike forward
  • you can get a Rohloff with the following torque support options:
  • you need to be sure you get the OEM2 axle plate
Accessories you’ll need:
  • chain tensioner - you’ll need this as the Big Dummy has vertical drop outs. Keep in mind there is a standard and DH version. You want the standard version.
  • Tandem length cables – due to the length of the Big Dummy you’ll need the longer tandem length cables.
  • Rohloff specific disc rotor – you cannot use the rotor supplied with your brakes as it will have the wrong bolt pattern.
Accessories you may want:
  • chain guide - keeps your chain on the front ring
  • oil change kit - you’ll need one of these every 5,000kms so it migt be easiest to buy one or two when you get your hub.
  • Sprockets -all hubs come with a 16T sprocket. You can also get 13T, 15T & 17T sprockets.
Non-Rohloff specific parts you’ll need:
  • 38T or larger front chain ring that will fit on the outside of your cranks – same position as big chain ring on a MTB triple. You want a ~54mmm chain line. This chain ring does not need to be pinned and ramped. You’ll be able to flip it around and use the other side when it wears out.
  • 2 chains – you’ll only use 1 and a bit, but you can save the extra portion and use it dnotw h road. You’ll also be able to flip your chain and rear cog around when things start to wear out and get more miles out of your drive train. I bought two 8 speed SRAM chains as they were cheap.
Rohloff Part Numbers

To make your life easier here are the part numbers you can use to ensure you are getting exactly what you need when you order your Rohloff hub:

  • Silver disc brake CC External Gear Mech OEM hub [specify OEM2] – #8025
  • Red disc brake CC External Gear Mech OEM hub [specify OEM2] – #8026
  • Black disc brake CC External Gear Mech OEM hub [specify OEM2] – #8027
  • Axle plate OEM2 [if you forgot to ask for it like I did and got an OEM hub] – #8227
  • Tandem Length cables – #8267
  • Chain Guide – #8290
  • Avid/Shimano 160mm disc rotor – #8281S
  • Hayes 160mm disc rotor – #8281H
  • Magura 160mm disc rotor – #8280
  • Oil Change Kit – #8410
  • 13T Sprocket – #8219
  • 15T Sprocket – #8220
  • 16T Sprocket – #8221
  • 17T Sprocket – #8222

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4 responses

7 05 2011
Snoogly

Thanks for reposting this info. It helped me a lot when buying a Rohloff for my bike. I wish Rohloff would include such a pithy summary on their web site.

7 05 2011
runjikol

This one of your most informative articles. Thank you for reposting.

8 05 2011
Mike McArthur

thanks for this contribution Vik. Since your original post, the Surly Troll was released with Rohloff compatibility. Is it safe to say everything in your post, but the long cables and long chain spec, would apply to the Troll?

8 05 2011
thelazyrando

@Mike – based on what I read on the Surly Troll page it sounds like you’d need the same stuff [less the chain tensioner as it has horizontal dropouts] as the BD, but with standard length cables.

I’ve never seen a Troll in the flesh so I can’t say 100% if there are any hangups I’m not aware of, but given Surly specifically mentions the Rohloff you should be fine.

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