Dropout spacing and wheel axles.

[webhead]

Currently I'm squeezing a 126mm rear wheel into a steel 130mm frame.
Works well, and from what I've gathered innocent and common.
The problem is that I see the derailleur dropout bend a few mm inwards
(obviously) and being somewhat uptight it ticks me off.

I'm having some problems getting the shifting exactly perfect and I
think it's an indexing thing but could the small bending of the
derailleur cause an issue?
Is it possible to swap the axle in the hub, add some spacers and make
it a 130mm wheel or is this simply not done 'cause I'm having trouble
locating loose axles.

 

[Hank Wirtz]

On Dec 22, 9:16 am, webhead <[email protected]> wrote:
> Currently I'm squeezing a 126mm rear wheel into a steel 130mm frame.
> Works well, and from what I've gathered innocent and common.
> The problem is that I see the derailleur dropout bend a few mm inwards
> (obviously) and being somewhat uptight it ticks me off.
>
> I'm having some problems getting the shifting exactly perfect and I
> think it's an indexing thing but could the small bending of the
> derailleur cause an issue?
> Is it possible to swap the axle in the hub, add some spacers and make
> it a 130mm wheel or is this simply not done 'cause I'm having trouble
> locating loose axles.

You can probably just add a 4mm spacer to the left side, recentering
the axle with 2mm less on either side, then redishing the wheel (the
added tension on the non-drive side will make the wheel stronger, too
- bonus). When clamped into the dropouts, 3mm of axle on each side
works just as well as 5mm. Honestly, bottoming out on a too-long axle
is a bigger problem.

 

[Hank Wirtz]

On Dec 22, 9:29 am, Hank Wirtz <[email protected]> wrote:
> On Dec 22, 9:16 am, webhead <[email protected]> wrote:
>
> > Currently I'm squeezing a 126mm rear wheel into a steel 130mm frame.
> > Works well, and from what I've gathered innocent and common.
> > The problem is that I see the derailleur dropout bend a few mm inwards
> > (obviously) and being somewhat uptight it ticks me off.
>
> > I'm having some problems getting the shifting exactly perfect and I
> > think it's an indexing thing but could the small bending of the
> > derailleur cause an issue?
> > Is it possible to swap the axle in the hub, add some spacers and make
> > it a 130mm wheel or is this simply not done 'cause I'm having trouble
> > locating loose axles.
>
> You can probably just add a 4mm spacer to the left side, recentering
> the axle with 2mm less on either side, then redishing the wheel (the
> added tension on the non-drive side will make the wheel stronger, too
> - bonus). When clamped into the dropouts, 3mm of axle on each side
> works just as well as 5mm. Honestly, bottoming out on a too-long axle
> is a bigger problem.

Oh, but if you do need an axle, check http://biketoolsetc.com in the
"repair parts" section. You'll need to figure out beforehand what the
threading is on your current one. I think most modern ones are
M10x1mm, but others are 3/8"x26 or 24 tpi. M9x1mm is also used for
fronts.

 

[daveornee]

On Dec 22, 9:16 am, webhead <[email protected]> wrote:
> Currently I'm squeezing a 126mm rear wheel into a steel 130mm frame.
> Works well, and from what I've gathered innocent and common.
> The problem is that I see the derailleur dropout bend a few mm inwards
> (obviously) and being somewhat uptight it ticks me off.
>
> I'm having some problems getting the shifting exactly perfect and I
> think it's an indexing thing but could the small bending of the
> derailleur cause an issue?
> Is it possible to swap the axle in the hub, add some spacers and make
> it a 130mm wheel or is this simply not done 'cause I'm having trouble
> locating loose axles.

You can probably just add a 4mm spacer to the left side, recentering
the axle with 2mm less on either side, then redishing the wheel (the
added tension on the non-drive side will make the wheel stronger, too
- bonus). When clamped into the dropouts, 3mm of axle on each side
works just as well as 5mm. Honestly, bottoming out on a too-long axle
is a bigger problem.

+1 agreement with Hank. You also might want to check the derailer Hanger alignment.

http://www.parktool.com/repair/readhowto.asp?id=39

Are your shifter, derailer, and chain all specified for 7 (or 6 as the case me be) speed?
Are your cable, housings, and cable ends all in good shape (including clean and well lubed guide under the bottom bracket)?

 

[Werehatrack]

On Sat, 22 Dec 2007 09:16:28 -0800 (PST), webhead <[email protected]>
may have said:

>Currently I'm squeezing a 126mm rear wheel into a steel 130mm frame.
>Works well, and from what I've gathered innocent and common.

Certainly not unusual, at least.

>The problem is that I see the derailleur dropout bend a few mm inwards
>(obviously) and being somewhat uptight it ticks me off.
>
>I'm having some problems getting the shifting exactly perfect and I
>think it's an indexing thing but could the small bending of the
>derailleur cause an issue?

Yes, just enough to be annoying, in my experience. It works, but with
some finicky action at one end of the range; one or two gear need a
little extra push to get the shift to happen, for instance.

>Is it possible to swap the axle in the hub, add some spacers and make
>it a 130mm wheel or is this simply not done 'cause I'm having trouble
>locating loose axles.

As long as it's 10x1.0 thread, you can probably pick up a suitable
axle here:

www.loosescrews.com
www.biketoolsetc.com

Add a 2mm thick washer on each side, and you're set.

--
My email address is antispammed; pull WEEDS if replying via e-mail.
Typoes are not a bug, they're a feature.
Words processed in a facility that contains nuts.

 

[webhead]

> Yes, just enough to be annoying, in my experience. It works, but with
> some finicky action at one end of the range; one or two gear need a
> little extra push to get the shift to happen, for instance.

Exactly ! I just don't seem get it fixed by indexing adjustment alone.
Not that it don't work but it gets on my nerves.

 

[* * Chas]

"webhead" <[email protected]> wrote in message
news:440b7d93-1a07-4d77-885e-8fb5afacbc70@e25g2000prg.googlegroups.com...
> Currently I'm squeezing a 126mm rear wheel into a steel 130mm frame.
> Works well, and from what I've gathered innocent and common.
> The problem is that I see the derailleur dropout bend a few mm inwards
> (obviously) and being somewhat uptight it ticks me off.
>
> I'm having some problems getting the shifting exactly perfect and I
> think it's an indexing thing but could the small bending of the
> derailleur cause an issue?
> Is it possible to swap the axle in the hub, add some spacers and make
> it a 130mm wheel or is this simply not done 'cause I'm having trouble
> locating loose axles.
>

Squeezing the dropouts like you are doing can cause them to be misaligned
putting undue pressure on the rear hub axle which can eventually cause it
to bend or break.

Many rear dropouts are misaligned to begin with. Offsetting them 4mm
(.157" or 5/32") is enough to cause shifting problems with some
derailleurs.

You can easily check the alignment of your dropouts. This link shows you
how it's done with dropout tools:

http://www.parktool.com/repair/readhowto.asp?id=40

You can measure them the same way using two 10mm or 3/8" bolts and 4 nuts
to fit the bolts. Some flat washers will help insure that the bolts sit
correctly in the dropouts.

Here's another link with a lot of good info on frame alignment:

http://www.bcltechnologies.com/document/products/magellan/samples/sample.pdf

Chas.

 

[still just me]

On Sat, 22 Dec 2007 12:56:03 -0600, Werehatrack
<[email protected]> wrote:

>
>As long as it's 10x1.0 thread, you can probably pick up a suitable
>axle here:
>
>www.loosescrews.com
>www.biketoolsetc.com
>
>Add a 2mm thick washer on each side, and you're set.

Assuming the geometry of the bike works out. I'm thinking that adding
4mm to the left side is more likely to result in the cluster ending up
the original distance from the right stay. I don't think the original
130mm wheel would have had 2mm of extra space on that side. But,
depending on a lot of other variables, you might have to fool with the
spacing a bit to get the overall alignment correct.

 

[webhead]

On Dec 23, 12:08 am, still just me <[email protected]> wrote:
> On Sat, 22 Dec 2007 12:56:03 -0600, Werehatrack
>
> <[email protected]> wrote:
>
> >As long as it's 10x1.0 thread, you can probably pick up a suitable
> >axle here:
>
> >www.loosescrews.com
> >www.biketoolsetc.com
>
> >Add a 2mm thick washer on each side, and you're set.
>
> Assuming the geometry of the bike works out. I'm thinking that adding
> 4mm to the left side is more likely to result in the cluster ending up
> the original distance from the right stay. I don't think the original
> 130mm wheel would have had 2mm of extra space on that side. But,
> depending on a lot of other variables, you might have to fool with the
> spacing a bit to get the overall alignment correct.

I just checked and I'm pretty sure adding washers alone will be
sufficient. Now, if I add 2mm to each side I think a 130mm wheel would
not have this extra space, like you said. But, if I add the 4mm to the
left that would mean redishing/trueing the wheel and I don't think I'm
up to that. Couldn't I adjust the 2mm offset with derailleur
adjustment ?

 

[RicodJour]

On Dec 22, 2:12 pm, "* * Chas" <[email protected]> wrote:
>
> Squeezing the dropouts like you are doing can cause them to be misaligned
> putting undue pressure on the rear hub axle which can eventually cause it
> to bend or break.

Why would squeezing the dropouts closer together put any more strain
on the hub? Seems to me the only additional strain on the wheel would
be on the axle, and it would be entirely an axial strain with no
additional bending moments.

R

 

[* * Chas]

"RicodJour" <[email protected]> wrote in message
news:[email protected]...
> On Dec 22, 2:12 pm, "* * Chas" <[email protected]> wrote:
> >
> > Squeezing the dropouts like you are doing can cause them to be
misaligned
> > putting undue pressure on the rear hub axle which can eventually cause
it
> > to bend or break.
>
> Why would squeezing the dropouts closer together put any more strain
> on the hub? Seems to me the only additional strain on the wheel would
> be on the axle, and it would be entirely an axial strain with no
> additional bending moments.
>
> R

Because squeezing or spreading the dropouts can change the parallelism
between them and this can put uneven pressure on the axle end flanges.

For a lot of different reasons many bikes have dropouts and forkends that
are out of alignment.

The bearings on most cassette style hubs are located near the outboard
ends of the axles and are less likely to have problems with misaligned
dropouts. The right side bearings on the axles in freewheel style hubs are
further inboard leaving a long section of unsupported axle hanging out
which is susceptible to bending and breakage.

Chas.

 

[Ted Bennett]

RicodJour <[email protected]> wrote:

> "* * Chas" <[email protected]> wrote:
> >
> > Squeezing the dropouts like you are doing can cause them to be misaligned
> > putting undue pressure on the rear hub axle which can eventually cause it
> > to bend or break.

> Why would squeezing the dropouts closer together put any more strain
> on the hub? Seems to me the only additional strain on the wheel would
> be on the axle, and it would be entirely an axial strain with no
> additional bending moments.


When the stays are bent inwards, the dropout faces don't remain
parallel. Now when you clamp in (or bolt in) your wheel there is indeed
a bending moment, which can and does cause the axle to fail in some
circumstances.

Yes, the bending moment is small. I will leave the calculations to
someone else. However the axle is not designed for that loading; best
to avoid it by adding spacers as necessary, or by cold-setting the frame
so that the spacing is correct for the hub and the dropout faces are
parallel.

--
Ted Bennett

 

[RicodJour]

On Dec 23, 2:01 pm, Ted Bennett <[email protected]> wrote:
> RicodJour <[email protected]> wrote:
> > "* * Chas" <[email protected]> wrote:
>
> > > Squeezing the dropouts like you are doing can cause them to be misaligned
> > > putting undue pressure on the rear hub axle which can eventually cause it
> > > to bend or break.
> > Why would squeezing the dropouts closer together put any more strain
> > on the hub? Seems to me the only additional strain on the wheel would
> > be on the axle, and it would be entirely an axial strain with no
> > additional bending moments.
>
> When the stays are bent inwards, the dropout faces don't remain
> parallel. Now when you clamp in (or bolt in) your wheel there is indeed
> a bending moment, which can and does cause the axle to fail in some
> circumstances.
>
> Yes, the bending moment is small. I will leave the calculations to
> someone else. However the axle is not designed for that loading; best
> to avoid it by adding spacers as necessary, or by cold-setting the frame
> so that the spacing is correct for the hub and the dropout faces are
> parallel.

But the clamping action of the skewer (I said axle in my first post
when I meant skewer) will tend to pull the dropouts against the
essentially immovable, parallel axle lock nuts. I just don't see an
appreciable difference in. Once it's clamped down, the force is all
axial. Put it this way, there's no more twisting force on the
dropouts, and probably far less, than when the wheel experiences a
sideways load while riding.

R

 

[Werehatrack]

On Sun, 23 Dec 2007 10:18:50 -0800 (PST), webhead <[email protected]>
may have said:

>On Dec 23, 12:08 am, still just me <[email protected]> wrote:
>> On Sat, 22 Dec 2007 12:56:03 -0600, Werehatrack
>>
>> <[email protected]> wrote:
>>
>> >As long as it's 10x1.0 thread, you can probably pick up a suitable
>> >axle here:
>>
>> >www.loosescrews.com
>> >www.biketoolsetc.com
>>
>> >Add a 2mm thick washer on each side, and you're set.
>>
>> Assuming the geometry of the bike works out. I'm thinking that adding
>> 4mm to the left side is more likely to result in the cluster ending up
>> the original distance from the right stay. I don't think the original
>> 130mm wheel would have had 2mm of extra space on that side. But,
>> depending on a lot of other variables, you might have to fool with the
>> spacing a bit to get the overall alignment correct.
>
>I just checked and I'm pretty sure adding washers alone will be
>sufficient. Now, if I add 2mm to each side I think a 130mm wheel would
>not have this extra space, like you said. But, if I add the 4mm to the
>left that would mean redishing/trueing the wheel and I don't think I'm
>up to that. Couldn't I adjust the 2mm offset with derailleur
>adjustment ?

Maybe. Sometimes there's enough throw in the der, sometimes there's
not. It can't hurt to try, if you have the spacers available.

--
My email address is antispammed; pull WEEDS if replying via e-mail.
Typoes are not a bug, they're a feature.
Words processed in a facility that contains nuts.

 

[still just me]

On Mon, 24 Dec 2007 01:27:29 -0600, Werehatrack
<[email protected]> wrote:

>>I just checked and I'm pretty sure adding washers alone will be
>>sufficient. Now, if I add 2mm to each side I think a 130mm wheel would
>>not have this extra space, like you said. But, if I add the 4mm to the
>>left that would mean redishing/trueing the wheel and I don't think I'm
>>up to that. Couldn't I adjust the 2mm offset with derailleur
>>adjustment ?
>
>Maybe. Sometimes there's enough throw in the der, sometimes there's
>not. It can't hurt to try, if you have the spacers available.

Yep, give it a try first.

Another possible issue is the overall alinement of the rear triangle
to the BB. 2m is not much. There's also the displacement of the
chainwheels to consider. Sometimes 2mm causes an issue, sometimes it
doesn't matter. But, as with the derailleur, it depends whether or not
something is at the limit or marginal in the current setup.

Also, keep in mind that you're assuming the wheel is currently dished
accurately. If it's off even 1mm in a good direction for you then
adding 2mm would just bring it 1mm in the other direction. Of course,
if it's off 1mm the wrong way, 2mm would make it off 3mm... that
you're going to see.

Lots of variables. Give it a shot. See what happens.

 

[webhead]

On Dec 24, 4:27 pm, still just me <[email protected]> wrote:
> On Mon, 24 Dec 2007 01:27:29 -0600, Werehatrack
>
> <[email protected]> wrote:
> >>I just checked and I'm pretty sure adding washers alone will be
> >>sufficient. Now, if I add 2mm to each side I think a 130mm wheel would
> >>not have this extra space, like you said. But, if I add the 4mm to the
> >>left that would mean redishing/trueing the wheel and I don't think I'm
> >>up to that. Couldn't I adjust the 2mm offset with derailleur
> >>adjustment ?
>
> >Maybe. Sometimes there's enough throw in the der, sometimes there's
> >not. It can't hurt to try, if you have the spacers available.
>
> Yep, give it a try first.
>
> Another possible issue is the overall alinement of the rear triangle
> to the BB. 2m is not much. There's also the displacement of the
> chainwheels to consider. Sometimes 2mm causes an issue, sometimes it
> doesn't matter. But, as with the derailleur, it depends whether or not
> something is at the limit or marginal in the current setup.
>
> Also, keep in mind that you're assuming the wheel is currently dished
> accurately. If it's off even 1mm in a good direction for you then
> adding 2mm would just bring it 1mm in the other direction. Of course,
> if it's off 1mm the wrong way, 2mm would make it off 3mm... that
> you're going to see.
>
> Lots of variables. Give it a shot. See what happens.

I've realigned the minor difference in the dropouts and added the
washers to the wheel. It seems like the derailleur is well capable of
bridging that amount. At the moment I can't visually find anything
wrong but the shifting still is off, either it shifts properly on the
first 3-4 cogs or on the last (bigest) 3-4 cogs, depending on how I
adjust the indexing. It does shift but there's some chain rattle due
to bad derailleur alignment.
Maybe it still needs a little tweaking but it annoys me. Maybe it's my
old shifters but those seem to shift the cable just fine.
Ofcourse when I take it out to the field and it collects mud it picks
up some additional noise but still...

 

[Michael Press]

In article
<[email protected]
groups.com>,
RicodJour <[email protected]> wrote:

> On Dec 23, 2:01 pm, Ted Bennett <[email protected]> wrote:
> > RicodJour <[email protected]> wrote:
> > > "* * Chas" <[email protected]> wrote:
> >
> > > > Squeezing the dropouts like you are doing can cause them to be misaligned
> > > > putting undue pressure on the rear hub axle which can eventually cause it
> > > > to bend or break.
> > > Why would squeezing the dropouts closer together put any more strain
> > > on the hub? Seems to me the only additional strain on the wheel would
> > > be on the axle, and it would be entirely an axial strain with no
> > > additional bending moments.
> >
> > When the stays are bent inwards, the dropout faces don't remain
> > parallel. Now when you clamp in (or bolt in) your wheel there is indeed
> > a bending moment, which can and does cause the axle to fail in some
> > circumstances.
> >
> > Yes, the bending moment is small. I will leave the calculations to
> > someone else. However the axle is not designed for that loading; best
> > to avoid it by adding spacers as necessary, or by cold-setting the frame
> > so that the spacing is correct for the hub and the dropout faces are
> > parallel.
>
> But the clamping action of the skewer (I said axle in my first post
> when I meant skewer) will tend to pull the dropouts against the

Assumption: For particular values of tend.

> essentially immovable, parallel axle lock nuts. I just don't see an

Assumption: for some value of essentially immovable.
None of this stuff is essentially immovable. It is all elastic.

> appreciable difference in. Once it's clamped down, the force is all
> axial.

No, the bending moment remains non-zero.

It is an Euler strut unevenly loaded with a non-zero
bending moment, and therefore further toward the edge
of its buckling regime than with even loading. That it
has not buckled does not prove the condition benign.

Look up `imperfection sensitivity' in a text on structures.


> Put it this way, there's no more twisting force on the
> dropouts, and probably far less, than when the wheel experiences a
> sideways load while riding.

Assumption: `probably'. And the forces are additive.

That failures have not been attributed to out of parallel
drop outs does not prove that the condition is benign.
Look up `imperfection sensitivity' in a text on structures.

--
Michael Press

 

[* * Chas]

"webhead" <[email protected]> wrote in message
news:847e57f8-4a66-47d0-89f5-e4c43156288c@i72g2000hsd.googlegroups.com...
> On Dec 24, 4:27 pm, still just me <[email protected]> wrote:
> > On Mon, 24 Dec 2007 01:27:29 -0600, Werehatrack
> >
> > <[email protected]> wrote:
> > >>I just checked and I'm pretty sure adding washers alone will be
> > >>sufficient. Now, if I add 2mm to each side I think a 130mm wheel
would
> > >>not have this extra space, like you said. But, if I add the 4mm to
the
> > >>left that would mean redishing/trueing the wheel and I don't think
I'm
> > >>up to that. Couldn't I adjust the 2mm offset with derailleur
> > >>adjustment ?
> >
> > >Maybe. Sometimes there's enough throw in the der, sometimes there's
> > >not. It can't hurt to try, if you have the spacers available.
> >
> > Yep, give it a try first.
> >
> > Another possible issue is the overall alinement of the rear triangle
> > to the BB. 2m is not much. There's also the displacement of the
> > chainwheels to consider. Sometimes 2mm causes an issue, sometimes it
> > doesn't matter. But, as with the derailleur, it depends whether or not
> > something is at the limit or marginal in the current setup.
> >
> > Also, keep in mind that you're assuming the wheel is currently dished
> > accurately. If it's off even 1mm in a good direction for you then
> > adding 2mm would just bring it 1mm in the other direction. Of course,
> > if it's off 1mm the wrong way, 2mm would make it off 3mm... that
> > you're going to see.
> >
> > Lots of variables. Give it a shot. See what happens.
>
> I've realigned the minor difference in the dropouts and added the
> washers to the wheel. It seems like the derailleur is well capable of
> bridging that amount. At the moment I can't visually find anything
> wrong but the shifting still is off, either it shifts properly on the
> first 3-4 cogs or on the last (bigest) 3-4 cogs, depending on how I
> adjust the indexing. It does shift but there's some chain rattle due
> to bad derailleur alignment.
> Maybe it still needs a little tweaking but it annoys me. Maybe it's my
> old shifters but those seem to shift the cable just fine.
> Ofcourse when I take it out to the field and it collects mud it picks
> up some additional noise but still...

Two other things to consider:

1. The derailleur hanger could be misaligned. The derailleur needs to be
parallel to the wheel axis on 2 plains - front to back and top to bottom.
If the derailleur is angled on either plain then it can cause some
shifting problems.

2. The top jockey wheel in the derailleur could be worn out. The wheel
should move freely side to side but have no angular slop.

Chas.

 

[RicodJour]

On Dec 24, 1:22 pm, Michael Press <[email protected]> wrote:
> RicodJour <[email protected]> wrote:
> > On Dec 23, 2:01 pm, Ted Bennett <[email protected]> wrote:
> > > RicodJour <[email protected]> wrote:
> > > > "* * Chas" <[email protected]> wrote:
>
> > > > > Squeezing the dropouts like you are doing can cause them to be misaligned
> > > > > putting undue pressure on the rear hub axle which can eventually cause it
> > > > > to bend or break.
>
> > > > Why would squeezing the dropouts closer together put any more strain
> > > > on the hub? Seems to me the only additional strain on the wheel would
> > > > be on the axle, and it would be entirely an axial strain with no
> > > > additional bending moments.
>
> > > When the stays are bent inwards, the dropout faces don't remain
> > > parallel. Now when you clamp in (or bolt in) your wheel there is indeed
> > > a bending moment, which can and does cause the axle to fail in some
> > > circumstances.
>
> > > Yes, the bending moment is small. I will leave the calculations to
> > > someone else. However the axle is not designed for that loading; best
> > > to avoid it by adding spacers as necessary, or by cold-setting the frame
> > > so that the spacing is correct for the hub and the dropout faces are
> > > parallel.
>
> > But the clamping action of the skewer (I said axle in my first post
> > when I meant skewer) will tend to pull the dropouts against the
>
> Assumption: For particular values of tend.

Oh, God, here we go...

> > essentially immovable, parallel axle lock nuts. I just don't see an
>
> Assumption: for some value of essentially immovable.
> None of this stuff is essentially immovable. It is all elastic.
>
> > appreciable difference in. Once it's clamped down, the force is all
> > axial.
>
> No, the bending moment remains non-zero.
>
> It is an Euler strut unevenly loaded with a non-zero
> bending moment, and therefore further toward the edge
> of its buckling regime than with even loading. That it
> has not buckled does not prove the condition benign.
>
> Look up `imperfection sensitivity' in a text on structures.
>
> > Put it this way, there's no more twisting force on the
> > dropouts, and probably far less, than when the wheel experiences a
> > sideways load while riding.
>
> Assumption: `probably'. And the forces are additive.
>
> That failures have not been attributed to out of parallel
> drop outs does not prove that the condition is benign.
> Look up `imperfection sensitivity' in a text on structures.

While I'm at it should I look up 'how many angels can dance on the
head of a pin?' Exactly how sensitive is the imperfection to the
fookin' 1/3 of 1 degree out of parallel condition?

My comments were in reply to Chas:
> "webhead" <[email protected]> wrote in message
>
> Squeezing the dropouts like you are doing can cause them to be misaligned
> putting undue pressure on the rear hub axle which can eventually cause it
> to bend or break.

Squeezing the dropouts is not uncommon. How is it different than
spreading them to fit a wider hub? That's way more common and I've
never heard of a broken or bent axle in either situation where the
difference in hub widths was 4 mm. A 10 mm discrepancy is another
matter and could cause a problem, but so can crashing the bike or
running into a curb.

In any event, the OP shimmed the sucker and it's a done deal, but
thanks for the engineering refresher. I haven't been so lulled by
droning since Prof. Oral Buyozkuturk way back when. ~

R

 

[webhead]

> 1. The derailleur hanger could be misaligned. The derailleur needs to be
> parallel to the wheel axis on 2 plains - front to back and top to bottom.
> If the derailleur is angled on either plain then it can cause some
> shifting problems.
Could be but how do I check this? I've aligned the dropouts by
screwing something in it resembling that parktool thing for aligning
them. I sort of used a DIY version of the parktool model.
I'm somewhat scared of taking the deraileur out again because the
first mm of thread in somewhat damaged so it's difficult to screw it
in. I need to get my hands on an M10x1 tap for restoring that but I've
only got an M10x1.5 lying around, anyhow that's not the cause of the
misalignment.
If the derailleur hanger is out of alignment, can this be checked
somehow ?

> 2. The top jockey wheel in the derailleur could be worn out. The wheel
> should move freely side to side but have no angular slop.
It's brand new actually. How much lateral movement are we talking
about ?