Rohloff hanger?

[Matt2matt2002]

Sorry if this is an obvious question...
Looking at a blog showing a German tourer in the Far East, he sang the praises of this Rohloff hub.
He supplied a picture that appeared to show a hanger off the rear drum.
What's that about?
I thought the chain went around the rear cog straight from the front cog?
He also had 2 cogs on the front. Is this usual?

Many thanks for your patience to what I fear is an obvious question.

I have forgotten the blog address but will endeavour to track it down

[jahwalla]

a picture says more than a thousand words.....

[Matt2matt2002]

https://www.crazyguyonabike.com/doc/page/pic/?o=1&pic_id=1299834&size=large

Not sure if above link will work
It's from a crazy guy blog
Exploring Greece by
Steve Ewer
Here's what he says.....

For this trip I want a bicycle capable of carrying a light touring load while being comfortable. Greece has a lot of hills so the gearing and load must be right. I also want to take to the small offroad tracks and find deserted beaches that a mountainbike is best suited for. So leaving my beloved recumbents at home, I have modified a faithful full-suspension mountainbike by fitting a rear rack for 2 Pannier bags. I tried a handlebar bag but it`s weight up front spoiled the responsive handling so I removed it. I replaced the rear derailleur with a Rohloff hub gear. With a 13T rear cog I have kept the 44/34 front chainrings giving two 14 gear ranges (one for fast cruising and one for loaded climbing) The Rohloff is simply the best for easy use and reliability. The QR hub skewers and seatpost clamp will be replaced with bolt fixings to deter theft.

I think the picture shows the chain on the rear sprocket going around a hanger?

Anyone any thoughts?

[JimK]

Yeah Rohloff says in a manual that you can do this:

http://www.rohloff.de/uploads/media/ENGLISH_OEM_2010.pdf

I have seen many pictures of bikes with rear suspension using that kind of hanger just as a chain tensioner or to manage the variable distance from hub to bottom bracket.

It's a perfectly reasonable way to extend the range and/or get finer choice of ratios. My Brompton has a 3 speed IGH on the back and two chainrings on the front. The IGH has a very wide range. The front ratio is a half step, but that does widen the range meaningfully too.

[rualexander]

The photo shows a Rohloff chain tensioner attached to a rear derailleur hanger, and the bike is fitted with a triple chainset. It will work fine assuming the chain tensioner has enough range to cope with the different chainrings, but seems a bit unnecessary given the range of the Rohloff hub itself.

[Andre Jute]

On a bike with rear suspension, unless the bottom bracket and the rear dropout are both on the same pivoting arm, it is essential to have a chain tensioner on an IGH installation to take up variations in chain transmission length caused by the play of the suspension.

Whether a hardtail Rohloff installation requires an external chain tensioner depends on whether transmission length adjustment is available by horizontal sliders, horizontally slotted rear end, or eccentric bottom bracket. If not, if the dropout is vertical and there is no EBB, a chain tensioner must be used, unless you get lucky and the chain fits just right, or a half-link adjusts it perfectly.

This is a different question from whether an external torque reaction arm is required with a Rohloff gearbox.

Andre jute
who lives under the Boole Tree