Originally Posted by
Tourist in MSN
Sorry for being off topic, did not mean to hijack the thread.
That explains it, you have a crank that you specifically wanted. And the crank choice was more important that chainring sizes.
When I built up my Rohloff bike (a Thorn Nomad), I decided to keep the standard 16T sprocket and calculated that a 44T chainring would be ideal for around home use where it would then have gear ratios similar to my other bikes. But for touring, I switch to a 36T chainring, with that in my first gear I have 3.5 mph at a cadence of 72. I think that cadence is the slowest where I feel like it is pretty smooth pedal stroke and I need 3.5 mph to maintain vertical and directional stability. My bike is 26 inch wheels, so if you used your 36 inner, your gearing would be slightly higher than mine, but not by much.
To switch rings, I have to add or subtract four links, can do that easily with two quick links. You would have a slightly bigger difference. I assume you have an eccentric for your bottom bracket to adjust chain tension. I do not see any other option on the bike.
I use a cheap compact double (110mm BCD, five arms) and put the chainring on the inner position, a bashguard in the outer.
I have a chainline error about 5mm, but that is intentional, I wanted my Rohloff bike to have about the same Q factor (pedal width) as my other derailleur bikes, thus my bottom bracket spindle is 10mm shorter than it should be for a perfect chainline.
You mention half step. My Nomad does not have a derailleur hanger. If it did, I might have considered half step because when I first started using the Rohloff, I thought that the 13 percent change between gears was pretty big, my derailleur touring bikes had smaller steps in the range of gears that I mostly use. But I got used to the step size in the Rohloff and I really like the Rohloff for touring where there are a lot of hills because it is so quick to shift gears. I just finished a five week tour in very hilly terrain, I often shifted two or three gears at a time instead of one.
I do not see a shifter on your bike other than brifters, so I assume you have something like the Rohbox (spell?) that allows you to use brifters for shifting. I use the standard twist grip shifter on a hubbub adapter on the right side handlebar end.
Nice bike, I am sure you will really love it.
I cut some sleeves out of inner tube rubber to slide over the ends of my S&S "nuts" to keep the dirt out of the threads. You might want to consider that too. See photo.
Ah, ha! I see. The tube idea is pretty neat.
Actually the crank is a cheap square taper Origin8. But, yes; The C1 rings come as a pair mated to the sensor spider & that was the predominent factor. I
needed flat pedals for utility purposes. So that ruled out Powertap pedals. A crankarm based sensor wasn't compatible with square taper & adding a torque wrench to the airplane travel tool kit for other significantly more expensive brands/options was a non-starter. Obviously the Rolhoff rules out a hub power sensor. So, my options were severely limited & the C1 was uniquely suited. It's too bad they are discontinued & now unavailable.
You're right! Rohbox & SRAM Apex shifters is the name of the game for ergonomics reasons. The shifting is a bit klunky at first but it gets better. If only I could run through a few gears at a time! But it works well enough. Yes, the 13% (and at least 10 rpm change) is a big jump, but for the intended purpose it works well enough, all things considered. I think I'll just chalk it up to being spoiled by Ultegra on my other bikes.
The 26 inch wheels fit rather nicely in the travel case. The frame was spec'd to have clearance for 2 inch mountain bike tires should I ever decide on gravel road touring. (You can travel all of the Americas on dirt roads.) It was designed around the Continental 559x28 road tires it has on it now, and is designed to have a fairly neutral 58mm of trail nominally but up to 65mm depending on tire selection.
Rodriguez owns Bushnell. All Bushnell eccentrics are made in the basement of their shop in the University District. So that is the eccentric of choice. Truly superior to the wedge style on my tandem.
Thanks for admiring my bike. I am penciling out a week long Washington peninsula-Victoria-Vancouver, Canada tour as I write this. I'm excited to put it through it's paces.
