August 25, 2008

The Rohloff is Here


What is a Rohloff Speed Hub, you ask?

It is, it turns out, a large and fairly heavy internally geared hub for the back wheel of the bicycle I'm building (putting together, not welding, since Dean asked). It has 14 gears with over a 500% gear range--something of an engineering marvel.

So I've got the hubs for the front and rear wheels and I just picked up the rims this weekend. Now I'm waiting for the truing stand, spokes, and nipples. Both wheels will be 32 spoke (that is the only number the Rohloff will do) with a double crossing pattern. These will be the first wheels I've ever built, so I'm a little nervous. The good thing is that with the Rohloff there is no rear cog set so there is very little dish in the rear wheel and both sides of the wheel have the same length spokes--kind of like a front wheel. I am going to be running hydraulic disc brakes, so there will be some dish and difference in the spoke tension. I haven't quite figured out the exact numbers yet.

This evening I finished installing the cranks after removing the inner chainrings and double checking the chainline (had to rearrange the spacers on the bottom bracket). Measured in millimeters, I'm not sure how exact this needs to be. Plus with the long wheel base and extra long chain I'll be using I think it may be less important. The Rohloff hub has a chainline of 54 mm. As near as I can tell with the grade school ruler I was using, the front crank chainline is either 54 or 55 mm. At this point I think it is as close as I care to get it but will watch it closely once I have the wheels on and can get a sense of the chain tension.

I also mounted the rear chain tensioner, the front chain guide, and the torque bolt which fixes the axle plate of the Rohloff in place. This probably doesn't mean much to many of you reading this, but you'll just have to humor me (I read many of heylucy's craft tips and don't complain :)). This is the first time I've done most of these things so I'm sort of savoring it all and trying to learn as much as I can. It's pretty fun using all kinds of tools. I love specialized tools that work well. I've got some new torque wrenches and allen wrenches as well as a star wrench set that made everything nice and easy, no frustration. It's kind of nice to grease things and get everything nice and neat.

Hopefully later this week I'll get a stem and skewers at the bike shop, and the handlebars and pedals I ordered will come in the mail so I can get the steering mechanism set up. I keep reminding myself that I'm not in a huge hurry to finish this project, I just want to make sure I do things correctly and end up with a well tuned machine. Plus I think with the sort of unconventional drive train, extended frame length, hydraulic brakes, and wheel building I'm biting off quite a bit for my first time and should allow myself plenty of time to take it all in.

Enough about the bike for now. I'll have to include an update of our week in Seattle next time. My experience is easy--work 9 hours, find dinner, watch some Olympics, read a little, sleep. The highlight for me is making it to Thai Tom's in the U district twice. Yum.


  1. You're right! I didn't understand much, but plowed through it anyway! Just like know that you are alive and well and busy doing things you like to do!

  2. I'm very impressed with your expert knowledge of and technical expertise of bicycles. You have come a long ways since the little yellow bicycles that you and Dean had. I think they came from K-Mart. I hope that new Rohloff Speed Hub does the job for you.

  3. sweet. If I were a bettin' man, I'd say you're likely the first guy in Spokane running a Rohloff. What kind of frame is it going on? What's the rest of the build? With the beefy brakes, I'm assuming you're building some kind of expedition-y -- all rounder tough bike? If so, you might investigate 3-cross on the wheels.

  4. I'm guessing that since lots of people have been building spoked wheels for years you'll pick it up pretty quickly. Only question is how quick is quickly. ;-) Sounds like a fun project.

  5. Huh? Wow, I'm lost.

  6. John, it is for a Surly Big Dummy. Rohloff actually specifies to use a two cross pattern on 26 inch wheels because of the large hub flanges. With the same length spokes on both sides they claim the wheel is as strong as a 48 spoke tandem wheel. Whole lot of physics hocus pocus that I don't really understand. Here is their explanation:
    I'll be posting more about the bike as I build, but the Rohloff, the brakes, and the longtail frame are the main things I'm focused on. Oh yeah, and learning how to build wheels.

  7. Fun project. Like a bike-SUV. Reading the Rohloff hocus-pocus, a lot of that makes sense: the large flange/shorter spokes/symetrical part make stronger wheels. Got that. Where they get into the angle of a 2-cross being the same as the 3-cross and the relationship with the spoke hole diameter, I'm not following. But they've clearly thought this through...
    Can't wait to see pics.

  8. Threading and then truing (or is it truning? I've never quite gotten it straight) a wheel sounds like quite a job. I've replaced a few spokes, but not built a whole wheel. How much time is that going to take?