Rohloff touring bikes

[Bonefish Blues]

Well but no but it doesn't get much simpler than a little sprung wheely-thing that's only doing a bit of tightening I suppose I was thinking. And we know that any/everyone who drops 2-3-more Ks on a bike is likely to have access to rag & oil

Interesting debate along the lines of how purist one wants to be, I guess - purer than pure, simply pure, or a F&R mech type of person!

 

[SkipdiverJohn]

Well but no but it doesn't get much simpler than a little sprung wheely-thing that's only doing a bit of tightening I suppose I was thinking. And we know that any/everyone who drops 2-3-more Ks on a bike is likely to have access to rag & oil

You're missing the point. The sprung wheely thing is unnecessary. It doesn't need to be there, and in a well-designed transmission it isn't there. It also adds slightly to drivetrain friction, which is again counterproductive. One of the big benefits to a one front cog, one rear cog, type of bicycle transmission is that you can design it so the chain runs straight, so it absorbs less energy and the component parts last far longer.
Derailleurs are a fundamentally crap design in principle, even those that are engineered with high quality parts. So the only real difference between, say, no-name budget Shimano and Dura Ace Shimano, is the no-name is a basic quality crap design and the DA is a high quality crap design. But it's all crap nonetheless - and the only reasons derailleurs are ubiquitous is that they are the cheapest way of getting the widest possible spread of gear ratios, and they offer a degree of user-selectability in ratios. Externally mounted chain-driven gears disappeared from motor vehicles over a hundred years ago, because they are a fundamentally poor way to transmit power in a harsh, dirty environment.

 

[Bonefish Blues]

You're missing the point. The sprung wheely thing is unnecessary. It doesn't need to be there, and in a well-designed transmission it isn't there. It also adds slightly to drivetrain friction, which is again counterproductive. One of the big benefits to a one front cog, one rear cog, type of bicycle transmission is that you can design it so the chain runs straight, so it absorbs less energy and the component parts last far longer.
Derailleurs are a fundamentally crap design in principle, even those that are engineered with high quality parts. So the only real difference between, say, no-name budget Shimano and Dura Ace Shimano, is the no-name is a basic quality crap design and the DA is a high quality crap design. But it's all crap nonetheless - and the only reasons derailleurs are ubiquitous is that they are the cheapest way of getting the widest possible spread of gear ratios, and they offer a degree of user-selectability in ratios. Externally mounted chain-driven gears disappeared from motor vehicles over a hundred years ago, because they are a fundamentally poor way to transmit power in a harsh, dirty environment.

I was talking about a chain tensioner as a single potential 'compromise', I understand your points about derailleurs.

 

[DCBassman]

You're missing the point. The sprung wheely thing is unnecessary. It doesn't need to be there, and in a well-designed transmission it isn't there. It also adds slightly to drivetrain friction, which is again counterproductive. One of the big benefits to a one front cog, one rear cog, type of bicycle transmission is that you can design it so the chain runs straight, so it absorbs less energy and the component parts last far longer.
Derailleurs are a fundamentally crap design in principle, even those that are engineered with high quality parts. So the only real difference between, say, no-name budget Shimano and Dura Ace Shimano, is the no-name is a basic quality crap design and the DA is a high quality crap design. But it's all crap nonetheless - and the only reasons derailleurs are ubiquitous is that they are the cheapest way of getting the widest possible spread of gear ratios, and they offer a degree of user-selectability in ratios. Externally mounted chain-driven gears disappeared from motor vehicles over a hundred years ago, because they are a fundamentally poor way to transmit power in a harsh, dirty environment.

As far as I've always understood it, hub gears have it all in terms of longevity and ease of service, but derailleurs, although out in the muck, are, when kept well-maintained, much more mechanically efficient, and lighter. These days, I'm sure the hubs have improved, and sure as hell derailleur systems have got heavier (more sprockets), but one is fundamentally simpler than the other, so still more efficient.

 

[rualexander]

On my Thorn Sherpa with Rohloff, I have neither a chain tensioner, eccentric bottom bracket or sliding dropouts.
I have no means of tensioning the chain.
But I don't need one.
If you choose your sprocket/chainring combination carefully, preferably using an online 'magic gear' calculator, then you can happily run without tensioning.
Sure, the chain gradually gets slacker with wear, but it doesn't matter much until it's so slack that it starts to jump off, at which point (or preferably before), you fit a new chain, and start again.
I find I need to fit a new chain at roughly 2000 miles.
No big deal for me.

I also have the long torque arm and yes, it looks a bit agricultural, but it's not that noticeable, and not a problem for me.

Magic gear calculator http://www.eehouse.org/fixin/formfmu.php

 

[DCBassman]

Efficiency actually in use. As far as I'm aware, epicyclic gear trains are inherently less efficient than direct gears. More complexity. But can be put nicely out of harm's way when used in hub gears.
Maintenance time doesn't count in this context.

Edit to add: if I could afford one, and it could cope with the gear ranges needed around these parts, I would certainly have one.

 

[geocycle]

I have a thorn raven sport tourer with a rohloff. It’s done about 40,000 miles since 2006 with no major problems. I don’t think its less efficient than my derailleurs and most studies have seemed to confirm this, especially against real world operation. It is a heavy lump of metal on the back of the bike and you can really feel it when you do the lift test on the back wheel. Overall my RST is round 12-13 kg. I use it alongside a Spa Ti audax which is closer to 10 kg. The spa is my preferred bike for day rides and is definitely more fun. Average speeds are up to 2 mph faster, not all down to the transmission of course as wheels and tyres are more important. The Thorn is my workhorse carries the panniers on tours on road and off, and is my commuter and utility bike. For years I only had the Thorn and I did almost everything I do now, however, the Spa has really delivered in terms of raw enjoyment.

 

[SkipdiverJohn]

Efficiency actually in use. As far as I'm aware, epicyclic gear trains are inherently less efficient than direct gears. More complexity. But can be put nicely out of harm's way when used in hub gears.
Maintenance time doesn't count in this context.

The complexity of an epicyclic gear train depends on how many ratios it needs to cater for. In direct drive, with the internal parts all locked up, a hub gear will have a higher mechanical efficiency than any derailleur system, In the indirect gears, they might be slightly worse, depending how complex the drivetrain is.
The reason the Sturmey AW 3-speed design became the de-facto standard utility bike hub gear is it hit that sweet spot of cost, functionality, durability, and weight. Almost every roadster ever made for a period of half a century either had a SA hub in it, or a clone of one. Even now, if you don't need a huge ratio spread, an AW hub is light years ahead of any derailleur in ergonomics and low maintenance.
If the Rohloff could be made at a more competitive price, even with a few less ratios, it would be infinitely more popular than it is. The bike industry like derailleurs though, because the poor design and exposed operating environment ensures a relatively short component life. That means the manufacturers do a roaring trade in replacement chains, sprockets, mechs and shifters. They design and sell stuff that they know will generate a future revenue stream in maintenance. On the other hand, if you ride something with an AW in it, the hub will last the life of the bike and you might have to replace a gear cable and toggle chain once every decade or so. Good for the owner, not so good for the industry that wants to keep selling you more and more stuff!

 

[Moodyman]

On my Thorn Sherpa with Rohloff, I have neither a chain tensioner, eccentric bottom bracket or sliding dropouts.
I have no means of tensioning the chain.
But I don't need one.
If you choose your sprocket/chainring combination carefully, preferably using an online 'magic gear' calculator, then you can happily run without tensioning.
Sure, the chain gradually gets slacker with wear, but it doesn't matter much until it's so slack that it starts to jump off, at which point (or preferably before), you fit a new chain, and start again.
I find I need to fit a new chain at roughly 2000 miles.
No big deal for me.

I also have the long torque arm and yes, it looks a bit agricultural, but it's not that noticeable, and not a problem for me.

Magic gear calculator http://www.eehouse.org/fixin/formfmu.php

Really? Shouldn't need to change that early. I get around 6,000 miles per chain during all-season commuting in a hilly area.

 

[rualexander]

Really? Shouldn't need to change that early. I get around 6,000 miles per chain during all-season commuting in a hilly area.

Yes, but do you have a chain tensioning method?

 

[Moodyman]

Yes, but do you have a chain tensioning method?

Yes, mine has an eccentric BB.

 

[Flying_Monkey]

Thanks moderators, for the thread clean-up! Hopefully this thread can remain a useful and constructive resource.