Creaky, Grindy Chain

Recently the chain on the Sram Dualdrive shifter of my recumbent
trike, Widdershins, seems to have gone very noisy. The changing from
gear to gear is clunky and slow, and I have the impression that I'm
pulling extra weight. In the lowest gears, especially, I can hear the
chain almost churning.

I've checked that there isn't a broken spoke on the back wheel but I
can't find one. When I spin the back wheel in a forward direction it
is slow but it doesn't seem stuck. OTOH when I spin it backwards it is
stiff and the chain grinds noisily.

The chain seems to be on the right gear, as far as I can tell. I.e. in
the lowest gear it is properly on the biggest gear.

Since this is a recumbent the chain is very long. For most of its
length it is housed in a kind of rubber tube to kee^p it clean, so I
can't really see what's going on.

Any ideas what could be wrong?

Thanks,

On Jul 4, 9:13*am, Artemisia wrote:
Recently the chain on the Sram Dualdrive shifter of my recumbent
trike, Widdershins, seems to have gone very noisy. The changing from
gear to gear is clunky and slow, and I have the impression that I'm
pulling extra weight. In the lowest gears, especially, I can hear the
chain almost churning.

I've checked that there isn't a broken spoke on the back wheel but I
can't find one. When I spin the back wheel in a forward direction it
is slow but it doesn't seem stuck. OTOH when I spin it backwards it is
stiff and the chain grinds noisily.

The chain seems to be on the right gear, as far as I can tell. I.e. in
the lowest gear it is properly on the biggest gear.

Since this is a recumbent the chain is very long. For most of its
length it is housed in a kind of rubber tube to kee^p it clean, so I
can't really see what's going on.

Any ideas what could be wrong?

Sounds like the rear derailleur cable is simply in need of adjusting.
You can use the barrel adjuster of your derailleur to take out any
slack that may have gotten into the system. Easy enough to align the
jockey wheels to ride right under the sprockets. Probably 1/4 to 1/2
turn c-clockwise to take out your average annoying build up of bedded
in cable.

landotter wrote:
On Jul 4, 9:13 am, Artemisia wrote:

Any ideas what could be wrong?

Sounds like the rear derailleur cable is simply in need of adjusting.
You can use the barrel adjuster of your derailleur to take out any
slack that may have gotten into the system. Easy enough to align the
jockey wheels to ride right under the sprockets. Probably 1/4 to 1/2
turn c-clockwise to take out your average annoying build up of bedded
in cable.

Fair diagnosis, I'd say.

Alternatively, if you have bar-end shifters you could just turn off the
indexing (there's a D-ring on the side of the shifter than lies flat in
normal use, pull it down and twist it until it stops and that's the
shifter on friction only without specific stops). Indexing doesn't
actually get you much advantage with a bar end shifter on USS recumbents
because the gear lever's always to hand: my wife prefers hers in
friction mode to indexed and leaves it that way the whole time.

Without indexing you just keep moving the lever until the chain is in
the sweet spot. It's actually useful to turn off indexing in the first
instance to check that landotter's diagnosis is correct, even if you put
it back on: if it's still grinding the whole time with continuously
variable friction shifting then the problem is probably in the cable to
the 3 speed hub being incorrectly tensioned.

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net http://www.dundee.ac.uk/~pjclinch/

Probably worth checking the alignment of the power side (upper) chain
tubes with the main idler pulley (under the seat) as, IME,
misalignment here can lead to excessive noise / drag.
(I'm assuming that the chain is well lubricated?)

"Peter Clinch" wrote in message
...
[...]

Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net http://www.dundee.ac.uk/~pjclinch/

You are one god damn ****ing stupid idiot to parade such a signature before
the entire world. I urge you to get a modest and humble signature like
mine - you dumb jackass!

Regards,

Ed Dolan the Great - Minnesota
aka
Saint Edward the Great - Order of the Perpetual Sorrows - Minnesota