Turning my nexus setup into a tourer
So I've decided to turn my Surly Crosscheck with Nexus 8 hub into a tourer. My plan is to add a small chainring so when I hit steep hills, I would manually shift the chain with my hand. Here are my questions.
1) Currently, I have a 103 BB with a Sugino RD 48T crankset. Would I be able to add a smaller chainring? Do I need to get another size BB? What chainring do you recommend? (rear is currently 22T)
2) I believe I need a chain tensioner, but I don't know which one to get. In my mind, all I need is a rear derailer to pull the chain back, but I have been reading about chain tensioners. Any suggestion for one?
Any help will do, as I am really excited about this. I almost thought about scrapping the nexus and getting a traditional derailer setup.
"I almost thought about scrapping the nexus and getting a traditional derailer setup."
I think that might be preferable. I did a lot of work on the nexus at one time, and I really wanted to make an all Nexus red quality touring bike. In the end, spotting a rise in the Rohloff price I figured that was the way to go. I do think though that if you have the Premium Nexus, it can work fine without any of the stuff you mention. It will have a range that is narrower than normal, but it can span the what you need vs. want scale pretty well. I find I need the lower two rings on a triple most of the time, and am only missing a few high gear if I go to the 8, I would be willing to go that route, heck some people are touring on Pennyfarthings.
For me though, you are about even money to going for a derailleur at the moment when you price out a singulator or something, you could even possibly just swap a derailleur from a bike you already have. You will be giving back the main efficiency gain of the gearhub if you add in some kind of derailleur, You will loose the easy shifting in place feature if you add in a front gear and gain some chain suck as well.
I didn't get far enough to know whether you can eve use a blend of gears up front. You would have to look at whether you can legally go low enough on the front gears to get enough added range. Even the redoubtable Rohloff has front end gear limits.
Shimano does not even rate the red Nexus as strong enough for off-road, and similar concerns for hilly fully loaded. Many MTBers have tried it and I haven't heard of many problems, but I have heard universal concern over the earlier/cheaper version, as not being efficient or strong enough, so If you don't have the red I wouldn't even go down this path.
I would also want to be sure my set-up was simple to change tires on.
Overall, I'm not against the Nexus for normal touring use. I would just be a little more conservative about it than your current plan. There are other Nexus threads here search the forum.
Yeah, if you have an extra RD hanging around that would do the trick. I think that Singleator that PP mentioned is just an RD without a parallelogram for a cleaner look. Check with the SS folks about the options. I don`t know about your crankset.
As to the whole project, I kind of cringe at the thought of touring with a Nexus. Must confess that I`m not a tourer but I do have a Nexus on the bike I mostly ride (commuter/grocery getter) and I love it for that purpose. If you want to do something REALLY cool, maybe you could get a custom axel with pinion ends for the Nexus, file rack teeth in the dropouts and add a Cambio Corsa shifter. No tensioner needed for that method.
EDIT: As long as you want to go with multiple rings, you may as well go with a FD and not have to stop and stick your fingers in the chain.
Last edited by rodar y rodar; 01-29-08 at 07:23 PM.
what the shrek are you talking about? do you have a picture of that something really cool?
Originally Posted by rodar y rodar
i guess i will try the nexus experiment on a short tour though
Though I prefer a wider range, I have toured loaded a lot on this system:
26, 36, 46, 11-30
64.6 89.4 114.2
54.6 75.7 96.7
47.4 65.6 83.8
41.8 57.9 73.9
35.5 49.2 62.8
30.9 42.8 54.6
27.3 37.8 48.3
23.7 32.8 41.9
An example of the Nexus 8
72.2 72.2 72.2
63.4 63.4 63.4
54.6 54.6 54.6
44.7 44.7 44.7
38.0 38.0 38.0
33.4 33.4 33.4
28.8 28.8 28.8
23.5 23.5 23.5
Of course you can't use all the 24 gears there above. As far as range is concerned you only get the additional 3 gears a 89, 96, and a 114. They can be used, but not having the longest two would not seriously handicap me. I might miss a thrilling few high speed seconds, but rare would be the day where I would camp earlier for having them. With the 24 gears one gets narrower steps between most gears, which is the case even against the expensive Rohloff.
Here is one pros favorite densely spaced arrangement. More dense, of course, but look at the range:
48.9 79.1 82.8
42.4 68.5 71.8
37.4 60.5 63.3
33.5 54.1 56.7
30.3 48.9 51.3
27.7 44.7 46.8
24.5 39.5 41.4
Here is a stock megarange:
64.2 88.9 113.6
54.3 75.2 96.1
47.1 65.2 83.3
41.6 57.5 73.5
35.3 48.9 62.5
30.7 42.5 54.3
27.2 37.6 48.1
20.8 28.8 36.8
I think the singleators are different in tensioning the chain with one wheel. That reduces the amount of chain required and the drag significantly, whether it would be enough for someone wanting to change chainrings, I don't know.
No, no pic with a Nexus- I was just kidding. It really WOULD be cool, though.
Originally Posted by mosquito
One lever unlocks the axle and it floats free in the dropouts while you backpedal and force the chain onto another sprocket with the second lever, then lock the axel again. No tensioner needed.
Sorry to get off topic, hope you get it worked out.