# Service-Repair of Unusual Vintage Hub



## Doohickie (Feb 1, 2009)

I picked up a bike recently; all it really needs is cleanup and tuneup, except for one thing-

A previous owner stripped the axle nuts, then replaced the metric-thread nut (M10 x 1) with an SAE-thread nut.  It held on.  Kind of.  But not tight enough to hold the axle in the dropout without sliding around, resulting in the tire rubbing the chain stay.I picked up a bike that should be an easy flip; all it really needs is cleanup and tuneup, except for one thing-

A previous owner striped the axle nuts, then replaced the metric-thread nut (M10 x 1) with an SAE-thread nut.  It held on.  Kind of.  But not tight enough to hold the axle in the dropout without sliding around, resulting in the tire rubbing the chain stay.

Here's the drivetrain of the bike, a 1969-70 Sears (I think made in Austria






The unusual aspect of the drivetrain is that there is a 5-speed external derailleur, plus a 2-speed internally shifted hub.  The 2-speed hub appears to be built in to the 5-speed gear cassette.  The 2-speed shifts based on wheel speed and is adjustable by means of setting the rotation of the spoke protector disk:





The non-drive side of the axle has a flat that engages a tabbed D-washer; the tab fits into the dropout to prevent the axle from spinning when the non-drive side nut is torqued.

I was hoping that replacing the stripped nuts with new M10 x 1 nuts would resolve the problem, but the axle threads, while not really stripped, are worn down enough (major diameter is just over 9.5 mm) that there isn't enough meat to engage the nut.

So..... is replacement of the axle the only option?  If so, does that mean I'll have to disassemble that funky 2-speed gearbox?  Since I can't find any literature about it, I'm hesitant to crack into it.  The bike is a cool bike.  The drivetrain works great (other than the stripped axle) so I'd really like to sell it to someone who can use it.  The options I've thought about are these:

. Replace the axle, with the risk of the hub popping apart and never being able to get the pieces back together.  Also, I would need to find rod with metric thread (or a long metric bolt), and machine the flat into it for the D-washer on the non-drive side.

. Retap the axle to a smaller thread, maybe a .375 fine thread, and put it back together with an SAE nut on the non-drive side and a metric nut on the drive side.  I considered retapping the M10 x 1 to an M9 x 1, but there is no such animal; the next thread major diameter is M8.

Any other ideas?


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## JLarkin (Feb 2, 2009)

Gas weld some steel rod to the threads and re-tap.  Might have to thread the tap on and weld the end, backing the tap over it.  Then move toward the center.


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## Andrew Gorman (Feb 2, 2009)

Only thinking about it for a minute, I'd just re-tap it to the next smaller size, either SAE or Metric. Check J&L supply for odd sized taps-
http://metalworking.mscdirect.com/cgi/NNSRHMW
OR just LocTite the bejeesus out of it with the red stuff which should work well enough to get the bike operational, if not quite ready for a century.


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## Doohickie (Feb 3, 2009)

I don't have a welder and I don't want to JB Weld it because my intent is to sell this bike; I don't want to sell something with an issue like that to an unsuspecting buyer- I'm not that hardened yet.

Someone on another forum suggested just replacing the axle & cone nuts with new parts.  I think this is what I want to try.  The more I think about it, the more I suspect that the 2-speed internal hub is built into the cog set as a unit... at least I hope it is.  If so, it should be just a case of removing the gears to get to the drive-side cone nuts.  Once I get it apart, I may come up with other options.


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## Andrew Gorman (Feb 3, 2009)

Depending on how much metal is left, you could try a thread repair file-
http://www.victornet.com/cgi-bin/victor/productlist.html?subdepartments=Thread+Repair+Tools:499,501,500,1250,1487
That's just the first link I found.  These are one of those tools that can really save your bacon on the infrequent occasions you really need them.


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## saxman (Mar 1, 2009)

Doohickie said:


> . Replace the axle, with the risk of the hub popping apart and never being able to get the pieces back together.  Also, I would need to find rod with metric thread (or a long metric bolt), and machine the flat into it for the D-washer on the non-drive side.
> 
> QUOTE]
> 
> If I were doing it, I'd anneal a piece of appropriate diameter drill rod, turn it to the stepped diameters required (I assumethe cernter portion of the axle is greater than the major diameter of an M10 x1.0 thread) thread it up M10 x 1.0, mill the flat, and then draw a temper to a medium straw color (about the same as the temper for a screwdriver). Off hand, that sounds like about an hour to an hour and a half of work. (Plus the time to disassemble and reassemble the hub.)


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## Doohickie (Mar 2, 2009)

Great advice but.... I have no machining capability beyond a hand-held Black & Decker drill.


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## pedal alley (Mar 2, 2009)

*wheel washers*

if you get some bite with existing nuts,
& they don't loosen. why not simply try
putting wheel washers on .according to
the need ? it is a simple fix not a major 
machining issue. 
if nessesary replace the axle,
not a difficult task.

or just sell it as - is.
maybe somebody ..
who knows what their
doing, will buy it.


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## Doohickie (Mar 9, 2009)

pedal alley said:


> if you get some bite with existing nuts,
> & they don't loosen. why not simply try
> putting wheel washers on .according to
> the need ? it is a simple fix not a major
> ...




There is actually plenty of length on the axle; this may be the best solution.  Thanks!  I may have a buyer (trader) for the bike too.  She's looking for an older bike but said she may take this one.  She has a 1950s (?) Hercules for trade.


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## Doohickie (May 23, 2009)

It worked.  On the non-drive side, I simply put a second nut on.  It's only the threads under the first nut that are bad.  The second nut gets a good bite on the threads.  thanks for the idea, pedal alley.

That thing runs like the wind now.


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## pedal alley (May 24, 2009)

glad to hear you got it going.
now you gonna trade for that
fifties hecules ?


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## Doohickie (May 30, 2009)

Huh?  What?


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## pedal alley (May 30, 2009)

Doohickie said:


> There is actually plenty of length on the axle; this may be the best solution.  Thanks!  I may have a buyer (trader) for the bike too.  She's looking for an older bike but said she may take this one.  She has a 1950s (?) Hercules for trade.




huh?what? duh !


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