Low friction easy clean chain guide?

"peter" <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

Have a bike I use for long 2000+ slow and leisurly rides mostly on roads or paths but also some
light trail riding. It has vertical dropouts, a single chainring and a Rohloff hub, so its fitted
with a rohloff tensioner, like a deralleur.

Using a rear disk brake I want to retain. I don't want to switch to horizontal dropouts with
sliding plates or use an eccentric BB unless I have to, but would like to discard the tensioner. I
am going to play around with half links and changing sprocket sizes to get as near as possible
correct tension. Wondering if there is a device that doesn't hang from the dropout thats low
friction, very easy to clean on tour and would help hold the chain on? Any advice, links to
information etc ? Thanks peter

Dear Peter,

If no better bicycle-related questions appear, you might visit a local motorcycle shop that sells
observed trials machines. They usually feature a spring-loaded chain-tensioner hung from the middle
of the swing-arm that uses a hard white plastic block.

They're likely to be heavier and more powerful than what you have in mind, but they could give you a
fair notion of how such arms, springs, and blocks are constructed. Perhaps an idler pulley instead
of a plain block would serve?

Carl Fogel

peter' may have said:

Have a bike I use for long 2000+ slow and leisurly rides mostly on roads or paths but also some
light trail riding. It has vertical dropouts, a single chainring and a Rohloff hub, so its fitted
with a rohloff tensioner, like a deralleur.

Consider the extra steps that would be needed if a tensioning method was used that did not permit
easy disengagement of the chain when dismounting the rear wheel to change a tire. There may be more
reason to retain the Rohloff tensioner than it appears.

If you're just looking to get the lower chainline a bit higher above the road at the rear, it might
be possible to work up a spring-loaded idler arm closer to the crank. Perhaps someone at a shop that
specializes in recumbents might have something that would adapt.

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peter <[email hidden]> wrote:
: Have a bike I use for long 2000+ slow and leisurly rides mostly on roads or paths but also some
: light trail riding. It has vertical dropouts, a single chainring and a Rohloff hub, so its fitted
: with a rohloff tensioner, like a deralleur.

: Using a rear disk brake I want to retain. I don't want to switch to horizontal dropouts with
: sliding plates or use an eccentric BB unless I have to, but would like to discard the tensioner. I
: am going to play around with half links and changing sprocket sizes to get as near as possible
: correct tension. Wondering if there is a device that doesn't hang from the dropout thats low
: friction, very easy to clean on tour and would help hold the chain on? Any advice, links to
: information etc ? Thanks peter

There's an assortment of chain guides and tensioners here:

cambriabike.comchains.htmOpen ↗

The only one I've tried is the Surly Singleator, which I couldn't get to work properly. Don't know
if I installed it wrong, or if the bushing was out of spec, but I couldn't get the spring to
maintain tension in either direction.

- mark