To pivot or not to pivot? Is my rear derailleur mounted correctly?

Pictures of the problem are he

http://webpages.charter.net/mrfixiter/images/Azuki/

This is an old 10 speed road bike from the '70's. In photo 1, if you push on
the lower gear in the direction shown, the arm pivots on its mount.

In photo 2, that arm does not pivot if you push in the same place as shown
in photo 1. However, if I loosen the screw (shown in photo 3) in the
non-pivoting arm just a smidgen, that arm pivots too. Also, the washer shown
in the picture mounts under the screw head. There is no washer on the other
side of the derailleur (missing perhaps?) that attaches to the frame (see
picture 4)

I initially thought since the screw threads don't go all the way up to the
top of the head, that that part of the derailleur should pivot, and since it
didn't pivot, something was worn out. But I thought I'd ask the experts and
find out for sure.

Thanks for your reply.
--

David Farber
Los Osos, CA

On 8/09/2011 10:11 AM, David Farber wrote:
Pictures of the problem are he

http://webpages.charter.net/mrfixiter/images/Azuki/

This is an old 10 speed road bike from the '70's. In photo 1, if you push on
the lower gear in the direction shown, the arm pivots on its mount.

In photo 2, that arm does not pivot if you push in the same place as shown
in photo 1. However, if I loosen the screw (shown in photo 3) in the
non-pivoting arm just a smidgen, that arm pivots too. Also, the washer shown
in the picture mounts under the screw head. There is no washer on the other
side of the derailleur (missing perhaps?) that attaches to the frame (see
picture 4)

I initially thought since the screw threads don't go all the way up to the
top of the head, that that part of the derailleur should pivot, and since it
didn't pivot, something was worn out. But I thought I'd ask the experts and
find out for sure.

Nice pics!

That part (where the derailleur bolts to the frame) pivots on most
others I've seen.

Often there is a spring washer (circlip) that fits in a groove in the
bolt, to prevent it from tightening against the frame hanger.

It could be that this is just missing, or that the shank of the bolt
that is not threaded, is expected to meet the face of the hanger and not
move past the surface of the hanger.

It looks like the surface of the hanger might allow the bolt to screw in
too far.

Either a washer, or perhaps a light file of the hanger face to yield a
nice flat surface that the bolt comes to rest against, and not screw in
too far. Maybe even just remove the paint! It might be binding on
that. Keep oiled so that it doesn't rust.

You might even remove any dirt or perhaps a little metal from the mating
surface of the derailleur, to allow a clearance.

No doubt someone like AMuzi will have more or better advice.

Regards,
James.

David Farber wrote:
Pictures of the problem are he

http://webpages.charter.net/mrfixiter/images/Azuki/

This is an old 10 speed road bike from the '70's. In photo 1, if you push on
the lower gear in the direction shown, the arm pivots on its mount.

In photo 2, that arm does not pivot if you push in the same place as shown
in photo 1. However, if I loosen the screw (shown in photo 3) in the
non-pivoting arm just a smidgen, that arm pivots too. Also, the washer shown
in the picture mounts under the screw head. There is no washer on the other
side of the derailleur (missing perhaps?) that attaches to the frame (see
picture 4)

I initially thought since the screw threads don't go all the way up to the
top of the head, that that part of the derailleur should pivot, and since it
didn't pivot, something was worn out. But I thought I'd ask the experts and
find out for sure.


In that era the top bolt does pivot but doesn't spring
(patent hadn't expired yet).

Suntour assembled the top pivot with thin shims. Add shims
to tighten, subtract to loosen. See if that shim is actually
two or more stuck together. If so, remove a thin one. If
not, i.e., if there's only one shim, take out the shim and
see if it has good movement or too much play. Lube pivot of
course.

Way back in the dark ages any decent bike shop would have a
selection of these but now you'll need a sacrificial Suntour
changer for extra shims.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

On Sep 8, 1:11*am, "David Farber" wrote:
Pictures of the problem are he

http://webpages.charter.net/mrfixiter/images/Azuki/

This is an old 10 speed road bike from the '70's. In photo 1, if you push on
the lower gear in the direction shown, the arm pivots on its mount.

In photo 2, that arm does not pivot if you push in the same place as shown
in photo 1. However, if I loosen the screw (shown in photo 3) in the
non-pivoting arm just a smidgen, that arm pivots too. Also, the washer shown
in the picture mounts under the screw head. There is no washer on the other
side of the derailleur (missing perhaps?) that attaches to the frame (see
picture 4)

I initially thought since the screw threads don't go all the way up to the
top of the head, that that part of the derailleur should pivot, and since it
didn't pivot, something was worn out. But I thought I'd ask the experts and
find out for sure.

Thanks for your reply.
--

David Farber
Los Osos, CA

First try flipping the washer. Second, take the paint off the hanger,
carefully with a knife, a scraper or file. Thirdly, thin the washer a
little.

On Sep 7, 7:07*pm, AMuzi wrote:

In that era the top bolt does pivot but doesn't spring
(patent hadn't expired yet).

Suntour assembled the top pivot with thin shims. Add shims
to tighten, subtract to loosen. See if that shim is actually
two or more stuck together. If so, remove a thin one. If
not, i.e., if there's only one shim, *take out the shim and
see if it has good movement or too much play. Lube pivot of
course.

When it mounts to threads integral to the dropout as
shown in the pics here, doesn't the bolt have to be tight?
If it's loose enough to allow easy pivoting, it is loose
enough to unscrew. I have one of these on my tandem
and I keep it tight enough that it doesn't pivot in use.
It works fine for me that way.

Tom Ace

On 8/09/2011 12:33 PM, Tom Ace wrote:
On Sep 7, 7:07 pm, wrote:

In that era the top bolt does pivot but doesn't spring
(patent hadn't expired yet).

Suntour assembled the top pivot with thin shims. Add shims
to tighten, subtract to loosen. See if that shim is actually
two or more stuck together. If so, remove a thin one. If
not, i.e., if there's only one shim, take out the shim and
see if it has good movement or too much play. Lube pivot of
course.

When it mounts to threads integral to the dropout as
shown in the pics here, doesn't the bolt have to be tight?

Tight in the frame, yes.

If it's loose enough to allow easy pivoting, it is loose
enough to unscrew.

There is supposed to be a clearance between the derailleur body and the
frame so it can pivot on the bolt shank.

--
JS.

THE DERAY mounts tightly and adjusts to pivot as seperate motions ?

The Suntour pivots once only not twice as Shimano's killer design
bringing this adjustment to prominence for operation. The barrel
mechanismcan be taken apart and cleaned, lubed. Finish Line Wax with
teflon is a good lube for the pivot movement if applied every ride.

Check the metallurgy in the cage if you have a top end model-extra
machining obvious: supremely rebendable and necessary with that one
pivot action.

buy a spare Deore for in stock...try Nashbar and Jenson.

All the Suntour equipment is obsolete and brittle. Look to a complete
upgrade over 7000 miles

Tom Ace wrote:
On Sep 7, 7:07 pm, AMuzi wrote:

In that era the top bolt does pivot but doesn't spring
(patent hadn't expired yet).

Suntour assembled the top pivot with thin shims. Add shims
to tighten, subtract to loosen. See if that shim is actually
two or more stuck together. If so, remove a thin one. If
not, i.e., if there's only one shim, take out the shim and
see if it has good movement or too much play. Lube pivot of
course.

When it mounts to threads integral to the dropout as
shown in the pics here, doesn't the bolt have to be tight?
If it's loose enough to allow easy pivoting, it is loose
enough to unscrew. I have one of these on my tandem
and I keep it tight enough that it doesn't pivot in use.
It works fine for me that way.

Bolt should be tight.

Play is adjusted on the outside face of the body (underneath
the bolt head) with shims. Not as annoying as Jaguar E Type
V12 valve shims, but tedious in its own way.

Several shim thicknesses and several bolt configurations.

Later pre-top-spring series had a cute but hard to adjust
recessed locking collar on the back side of the body.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

AMuzi wrote:
Tom Ace wrote:
On Sep 7, 7:07 pm, AMuzi wrote:

In that era the top bolt does pivot but doesn't spring
(patent hadn't expired yet).

Suntour assembled the top pivot with thin shims. Add shims
to tighten, subtract to loosen. See if that shim is actually
two or more stuck together. If so, remove a thin one. If
not, i.e., if there's only one shim, take out the shim and
see if it has good movement or too much play. Lube pivot of
course.

When it mounts to threads integral to the dropout as
shown in the pics here, doesn't the bolt have to be tight?
If it's loose enough to allow easy pivoting, it is loose
enough to unscrew. I have one of these on my tandem
and I keep it tight enough that it doesn't pivot in use.
It works fine for me that way.

Bolt should be tight.

Play is adjusted on the outside face of the body (underneath
the bolt head) with shims. Not as annoying as Jaguar E Type
V12 valve shims, but tedious in its own way.

Several shim thicknesses and several bolt configurations.

Later pre-top-spring series had a cute but hard to adjust
recessed locking collar on the back side of the body.

Lots of terrific answers here. Thank you. I am just a casual cyclist and not
familiar with the evolution of these types of parts. I removed, cleaned, and
lubed the screw and the shaft so there's no binding there. In summary is it
correct to say that this part (is the correct term hanger?) is supposed to
pivot and either the crud on the frame or the thickness of the shim is
causing the hanger to freeze up?
--

David Farber
Los Osos, CA

Tom Ace wrote:
On Sep 7, 7:07 pm, AMuzi wrote:

In that era the top bolt does pivot but doesn't spring
(patent hadn't expired yet).

Suntour assembled the top pivot with thin shims. Add shims
to tighten, subtract to loosen. See if that shim is actually
two or more stuck together. If so, remove a thin one. If
not, i.e., if there's only one shim, take out the shim and
see if it has good movement or too much play. Lube pivot of
course.

When it mounts to threads integral to the dropout as
shown in the pics here, doesn't the bolt have to be tight?
If it's loose enough to allow easy pivoting, it is loose
enough to unscrew. I have one of these on my tandem
and I keep it tight enough that it doesn't pivot in use.
It works fine for me that way.

Tom Ace

Hi Tom,

It sounds like we have the identical situations. Yes, the screw will slowly
loosen more and more if not tightened down completely. No doubt, the bike
does shift gears when the screw is tightened all the way. Though sometimes
the chain does seem to take a while to find the next gear. I don't have
fancy click shifters. It's just the old shift style lever which is
continuously variable and you have to guess how far to advance it to change
gears. Then, you need to make small adjusting movements so the chain stops
making noise.

Thanks for your reply.
--

David Farber
Los Osos, CA