On 2018-09-21 23:57, Sir Ridesalot wrote:
On Friday, September 21, 2018 at 5:34:11 PM UTC-4, Joerg wrote:
Snipped
He is a machinist and tool & die maker by trade, has a fully
equipped garage with lathe, mill and so on. He is building stuff
for his various vehicles all the time and made a couple of parts
for my MTB so I could build a sturdy rack.

120mm is a pain though, 10mm is a lot of widening. Looks like this
one can be shortened by grinding off the outer cog:

https://www.ebay.com/itm/Shimano-TZ3...4/322007138705


Snipped

Is he going to grind down the body too?

He should read Sheldon Brown:
https://www.sheldonbrown.com/speeds.html and
https://www.sheldonbrown.com/freewheels.html

"The freewheel threading on these older hubs is generally
interchangeable except for some very old French units. If you go from
a 5-speed freewheel to a 6- or 7-speed freewheel, you will usually
need to add some spacers to the right end of the axle between the
cone and the locknut. Once you have done this, you'll also need to
re-dish the wheel to bring the rim back to the centerline. You may
need to re-space the frame if you have added spacers to the axle. See
my Frame Spacing Article for details on this."


Right. I also had to re-dish my rear wheel after UG freehubs were no
longer available. It wasn't fun but I got it all done in under an hour
including replacing the freehub.


"How Many Speeds?


Doesn't matter. Actually, the less speeds the better.


The first multiple-speed freewheels had 3 sprockets, using the
traditional 1/8" chain.


Well, the bike isn't quite that old :-)

BTW, the first ones were even simpler. They had one cog on either side
and you had to reverse the whole wheel to "shift".


In the 1950s, narrower 3/32" sprockets and chains were introduced,
permitting the move to 4-sprocket freewheels within the then-standard
114 mm (4 1/2") frame spacing 5 Speeds In the late 1950s, spacing was
widened to 120 mm to permit the use of 5-speed freewheels. This
required adding spacers to the right-hand end of the axle to keep the
chain from rubbing on the frame. The added spacers required
additional dish to the spokes, causing wheels to become somewhat
weaker. 6 Speeds In the 1970s, there was a move toward 6-speed
freewheels. These were of two types:

"Standard" spaced 6 speeds had sprocket-to-sprocket spacing the same
as the existing 5 speeds, around 5.5 mm

Standard spaced 6-speeds required increasing the frame spacing to 126
mm, aggravating the problems introduced with the move to 5-speed, but
still providing satisfactory service in most cases.

'"Ultra Six ®"' spaced 6 speeds used a closer spacing, around 5 mm.
This permitted an Ultra Six ® freewheel to directly replace a
standard 5-speed unit on a 120 mm hub. The key to making this work
was the use of a narrower chain. The interior width of the chain was
the same as always, but the new narrower chains used shorter rivets,
so the ends of the rivets didn't protrude past the outer chain
plates, as the rivets in traditional chains did.

7 Speeds In the 1980s, these two approaches were combined to create
7-speed freewheels, with 5 mm ("Ultra") spacing that would fit the
same 126 mm hubs as "standard" 6-speeds."


My bike had 6-speed yet is 126mm. Soon I will have to bend that open to
130mm to accommodate a new wheel set. It is quite possible that my
friend's Peugeot is still 120mm and that'll be a stretch.


So, to cold set a steel frame you only need to move each dropout 3mm.
That's not hard to do and Sheldon tells you how to do it easily.

https://www.sheldonbrown.com/frame-spacing.html

"Do You Need To Permanently Spread Your Frame?

Ideally, the frame spacing should exactly match the hub spacing. This
makes for easiest wheel replacement. In practice, however, there's a
fair amount of latitude in fit. In fact, when the first 130 mm
8-speed hubs were introduced, they had locknuts with beveled sides,
so that you could "spring" apart the rear triangle of a frame made
for the then-standard 126 mm spacing.


126mm to 130mm isn't too bad even if you don't true the parallelism of
the dropouts. The PX-10 might be 120mm.


A conventional cup-and-cone hub tolerates some bearing misalignment,
and in general, you can safely go up one size in spacing this way,
just springing the frame apart. I can't give you an absolute
guarantee that this won't cause damage, but the odds are very much in
your favor.


I'll bend mine up when the time comes though. Makes it easier to swap
the wheel.


Having to spring the frame every time you replace the wheel is
inconvenient, especially if it has a quick-release axle .An
internal-gear hub or sealed-bearing hub is very likely to be damaged
if the dropouts are not parallel. In this case, cold setting is the
better way to go.

If you're going up more than one size, say from 120 to 130, or from
126 to 135, you should definitely cold set the frame.

Spreading the Frame

There are a number of ways to do spread a frame. Probably the easiest
way is to use a lever. A piece of 2 x 3 or 2 x 4 lumber, roughly 5-6
feet long works well for this:

1.Remove the wheels, fenders and any seat-tube mounted bottle cage.
2.Lay the bicycle on its side with the handlebars turned to face
upward 3.If you are unsure about the strength of attachment or tubing
at the chainstay or seatstay bridge, you might clamp them together
with supports made by drilling a block of soft pine wood and then
sawing it in half along the middle of the drill hole. This precaution
is usually unnecessary, but it might be a good idea if you are making
a major change in spacing. 4.Insert the lumber through the rear
triangle, so that it goes underneath the upper rear forkend, and
above the seat tube. The lumber should extend out past the rear end
of the frame. 5.Place the far end of the lumber onto a chair, crate
or other raised structure, so that only the head-tube/fork area of
the bike is in contact with the floor. 6.Press down gently on the
lumber where it crosses on top of the seat tube. 7.Measure the
spacing to see if it has changed. 8.If the spacing hasn't changed,
try again, pressing a little bit harder. Repeat until you get a
result, applying a bit more force each time, until the spacing has
increased by about half the total amount you are seeking. 9.Turn the
bike over, and repeat for the other side.

In the illustrations below, the stays will be bent to the left (up in
the photos) by pressing down on the end of the 2 x 4.

The other end of the 2 x 4 is on top of a stool. The longer the 2 x
4, the less force is needed.

The bike does not actually need to be stripped down this far, most
parts can remain in place."

If you're not ham fisted cold setting a steel frame is NOT hard.


Certainly not for my MTB uddy with the PX-10. He also has all kinds of
clamping gear abnd stuff.

--
Regards, Joerg

http://www.analogconsultants.com/