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Discussion Starter · #1 ·
How well does a Rohloff Speedhub shift under load? I am asking because I have a special project bike that may need a Speedhub, but if it is impossible to shift under load, particularly in the lower gears (I want the bike to be able to downshift under full load while riding up a hill), then I am not sure I will go through with the project at all.
Your knowledge is appreciated!
 

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You aren't going to shift a Rohloff well under load. In particular the shift from 7-8 and back is going to cause problems. The amount of hesitation required is very small since the cables shift the hub instantly as opposed to moving a derailleur which then moves a chain.

If you have to ride in full power all the time I'd say a Rohloff is poor choice. A standard derailleur system will shift better under load than a Rohloff.
 

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Discussion Starter · #3 ·
What about the lower gears? This is the most important thing. Hesitating for a second at speed to let the internals pop into place is a minor inconvenience, but facing a steep uphill where it is imperative that you not lose one split second of power and not being able to shift is a deal breaker.
How is shifting under load in the critical lower gears- 1, 2, 3, 4?
 

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You'll have to unload the pedals for an instant in any gear change on a Rohloff. I don't have issues climbing steep hills with my Rohloff'd Surly Big Dummy even with my GF and a cooler full of beer onboard, but it does require some skill to shift efficiently.

I can't tell you if you'll have a problem or not. Most people who get a Rohloff figure out the shifting pretty fast and get on with riding.
 

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One of the few drawback of iGH is this.

IME the shifting varies from speed to other.
Between 1 and 2 you can shift almost full power
Same with 8 and 9

7 and 8 need no pressure at all

To shift to speed #5 from up or down , you need to lower the pressure.


Other may chime in
 

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1*14*29*2.1 & 1*1*29*2.4
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I haven't thought about it analytically, but I usually have more issues trying to shift to a lower gear while standing, and the lower ranges seem more problematic. Probably jsut a speed/momentum/coasting thing. Really, anyone who is old enough to have lived through friction shifters would hav no issues with the shifting style. There are a lot of other advantages that make that issue a small one, but if you want to race, or not learn the skill, then the rohloff may not be for you.
 

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If it's imperative that you not lose one spit second of power going up steep hills Rohloff is not for you. Rohloff's are impossible to shift under load. You must unload the peddles for an instant which takes a little practice. It will become an automatic response, but in the beginning you will need to work on timing and muscle memory. Nevertheless, it doesn't sound like a Rohloff will meet you're needs. Also consider the weight penalty if you're racing. Rohloff's are heavy.
 

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Rohloffs also have a lot of drag internally running the planetary gear set. If you break a Rohloff shifting under load and it's out of warranty, the results could be very expensive. No gearbox will take well to shifting under full load where a drop in rpms without some sort of buffer, slip, or lag time in reduction in load is forced upon the gearbox.
 

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Discussion Starter · #12 ·
Good to see this is an informational board and not a fan board.
How long is the warranty? Has anyone heard of one of these breaking in conditions where it was used as directed (not going below the minimum gear range, not using aftermarket components...)? I weigh 170 or so.
My project (still a concept actually) is a super-short chainstay 29er with shifted forward seat tube. One builder has said he could make such a beast, but it seems the only sure way to get a working drivetrain with a full range of gears is to have an IGH- and Rohloff is the only one worth having for serious MTB use. Thing is, I need an 83mm bb shell to get the tire to fit. Will an extra 5mm of chainline have an ill effect?
The lowest two gears are the ones I am worried about. Everything else- friction, weight, etc, is rounding errors.
Thanks again for your help, everyone.
 

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RandyBoy said:
Rohloffs also have a lot of drag internally running the planetary gear set. If you break a Rohloff shifting under load and it's out of warranty, the results could be very expensive. No gearbox will take well to shifting under full load where a drop in rpms without some sort of buffer, slip, or lag time in reduction in load is forced upon the gearbox.
But have you experienced a derailleur setup that shifted well under full load? I have never ridden a bike that would not create chain suck or other issues - the Rohloff has been the least of these to date, albeit with the 7-8 shift not running under load and with the perceived drag issue. If you've found better, I'd love to try it.
 

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uphiller said:
If I run an 83mm bb shell and the Rohloff with a 135mm axle, will I still have a normal chainline?
What you have to do is get your 54mm chainline with your ring. This is dependent on your spindle width and/or offset not so much your BB shell width as such. A normal chainline usually runs off an outer ring (correct me if I am wrong), but I run off the middle, which is a 50mm chainline. I have to bring that out 4mm +-1-2mm. that can be done with either BB spacers, different axle lengths, or BB designs. You need to work out what will fit into your 83mm BB shell. My guess is you may need to go to a Phil wood square taper to bury the BB into the shell, leaving some shell sticking out, and tailor the spindle length to provide enough clearance for the crank arms and get the chainline right, Why do you need it? Is it a tyre clearance thing?
 

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Discussion Starter · #18 ·
The issue is that I am building (or hoping to build) a bike with super short chainstays and a 29" wheel. The stays are 15.75" long, and the seat tube is pushed forward onto the downtube and attached to the bb with a small strut. A setup with a front derailleur may work, but it means finding the right derailleur, as a lot of derailleurs have a cable fixing bolt that hangs way, way off the back, which would make it rub on the tire.
The bb is wider so there is space for the chainstays.
I hope not to use a square taper bb- I will hopefully be able to manage with the right cranks. Probably something to be tackled with the frame builder.
 

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Thinking about it, maybe you can just run it off the inner position on your cranks, with the right BB. Something you and your builder will need to sort out of course. I have gone to a square taper BB but I am much more xc oriented than what you and your bike would be.
 

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The Rohloff is very easy to shift while climbing even the steepest grades...you just have to hesitate for a microsecond. The road to my house has several very tight switchbacks which my Garmin shows at 24% grade...I can shift from 3-2 or 2-1 while standing going up these with no problem and lose no appreciable momentum...it's just a matter of experience and timing.

Re the chainline, I had Phil Wood fab a couple of 16t 1/8" stainless cogs with a 58mm chainline last year; they still have the pattern and can run it if you want one. This lines up exactly with the outer chainring position on a XTR 970 crank and might give you the clearance you need.
 
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