Thursday, June 4, 2015

Rejoice! Gwendolyn's Sturmey-Archer SW Hub Gets Rebuilt (Plus Some Other Stuff)

Before I go into detail on the good news, there are a few updates I have done to make my trusty 1958 Raleigh Sports even more practical.

First, I bought a Greenfield rear kickstand.  The original kickstand, however strong, did not extend far enough from the bike and was located too far forward to provide support with weight on the rack. Actually, it was barely adequate to hold the bike up empty.  I never intended to use a kickstand while the crate was full of groceries, but it is doable with this one.  5/5, would recommend.  Also, I fit a piece of cardboard into the bottom of my new (used) crate but not for reasons you may think.  I am not foolish enough to loosely carry things in there that are small enough to fall through the holes, but when the crate is in my room, I always throw the rest of my bungee cords into it for storage and the cardboard makes them easy to take back out, rather than allowing them to hook onto the bottom of the crate and demand disentanglement.

Second, the bearings in the original left side pedal completely failed.  I was already aware that they were in very poor shape given the amount of play the pedal had in every direction, but adding oil got me by for over a year and a half.  A couple weekends ago, I was on my way to work when the left pedal suddenly stopped spinning on the axle and started rotating under my foot.  It seemed like the ball bearings got small enough to bunch themselves up. I was able to kick the pedal loose and limp the bike to and from the office under half-power.  After work, I temporarily installed the old weighted pedals from the Ross.  The threaded portion was actually quite a bit longer, so much so that it struck the chain guard on the right side so I continued using the original pedal there since it was okay.

I ordered these NOS "Buchel" pedals from ebay.  I had considered alloy BMX or cruiser style pedals because the width and comfort was tempting, but I gave in to my aesthetic-obsessed conscience.  I'm happy with these, though; the metal ends don't have the same protrusion that the original pedals have so they won't punch holes in the bottoms of my shoes.  These are completely flat and very comfortable.

Now for the big news! I finally got around to opening up the SW hub.  Although this video actually shows an AW hub, I used it as a basic reference.  It took a whole lot of hammering but the ball ring eventually came loose. I also had a spare parts hub that a kind soul from Bikeforums sent me but I left that one alone at first.

Well, no chipping of the left side pawls ...

Everything was actually remarkably nice.  Aside from the thick grease that had migrated to non-contact surfaces, everything was extremely clean!

The right side pawls were also nicer than expected.  Inside the ball ring, there was a small amount of grime buildup where nothing touched or rubbed.  That was to be expected.

Prior to opening the hub, I read as much as I possibly could on how these went together and what to be cautious about.  Documents on the SW are few and far between.  I kept the pages open as I worked but found that the hub was so simple and so intuitive that I didn't need the instructions! It was so simple, in fact, that I could throw all the parts in a cup and mix them up (which I did later to clean them) and still put it all back together correctly.

After failing to find any broken parts and reproducing my freewheeling problem by simply tightening the bearings, I was tempted to just put the hub back together and call it good.  However, I did notice that my old pawls (left) were slightly dented so I wondered if the ones in the spare hub were any better.  They were.

Upon closer inspection, one of my planet gears was actually chipped.  My old clutch (left) was also noticeably more worn and chipped than the one in the spare hub.  This is probably due to improper adjustment by a previous owner, leading it to slip out of gear.  The SW hub is a lot more picky about adjustment than the ubiquitous AW is.  Sometimes, half a turn of the cable adjustment barrel is all it takes to make everything sing.

The biggest difference between my hub (November 1958, left) and the spare parts hub (January 1958, right) was the planet carrier.  According to the article on Sheldon Brown's site, the earlier incarnation had a thinner or even no lip below the pawl openings (visible left).  Also, the earlier ones were fixed to the axle with a press-fit washer, making it impossible for me to remove it while the later ones were attached using a spacer and a nut.  I didn't expect the two hubs to be so different.

Pictured above and to the left are the parts from the spare hub that I chose to put into my hub to ride on.  Since everything in the spare hub appeared to be a lot less polished, I figured it probably had far fewer miles on it.  I also assumed that meant it would be best to replace everything in threes, lest the entire drive train be thrown off center by one slightly larger pawl or gear.  I measured the pawls the best I could and grouped the ones that were most similar in size, hoping to increase the chance that they all engage properly.  On the right is just a photo of the cleaned, degreased spare hub right before the shell went back on.  I'll keep this one clean so I can play with it.  I now see why one bikeforums member kept an AW hub as a puzzle for his kids; these are such a fun, interesting assemblies to look at.

The fun starts again.  I put foil over my vise to try to keep oil off it.  Cleanup is the only thing I hate about working on machines.  I dipped each part in the Pennzoil SAE 30 that I'd been using before adding it to the assembly.  Because everything was so clean when I took it apart, I saw no reason to switch oils (gunk buildup and viscosity are bigger concerns with the SW's springless pawls).

Here are the completed internals.  Since the high gear pawls of the SW hub fall out easily, it's best to feed it into the shell straight up from underneath (had to flip everything over after the photo).  I had to elevate my vise on an overturned trash can because my shell was still in the wheel.  As with the spare hub, it took a few tries to get the ball ring threaded into the shell properly.  I assume it's just from the pawls bumping into the ratchet before getting seated inside it.

All done! As you can see, the drive side of the hub has an anti-rotation washer for the cone (left).  It not only keeps the bearings from loosening or tightening on their own, but helps set the correct amount of slack in the bearings.  You're supposed to tighten the cone down finger tight, then back it off between 1/4 to 1/2 a turn.  To prevent the spontaneous tightening from occurring again on the left side, I took the same washer from the spare hub and put it on the running one (right).

Here she is in all her matching-tire glory once again!.  I'm noticing in this photo that I can never keep my chain clean.  I just cleaned and oiled it last week! Oh well, I guess this is what a high-mileage daily commuter goes through.

I took the bike out and tootled around the driveway to get the hub adjusted right.  Although the AW's indicator spindle works on the SW, the actual indicator part doesn't match up with the axle end so everything has to be adjusted by sound and feel.  Too loose and 1st gear makes noise and 2nd gear skips, too tight and both 2nd and 3rd gears skip.  As I said, sometimes all it took was half a turn either way to mess up the adjustment.  Ridden too hard under that condition, the clutch slips off and gets chipped (among other problems). That's why it's important not to put it under harsher load until everything's just right.

Anyway, after that, Gwendolyn and I went for a longer ride. It was midnight at that point and everything was quiet.  There was no rush to get anywhere and no traffic to keep up with, but as usual, the bike effortlessly settled at a 20 mph cruising speed.  After having gotten used to the bright ticking of the AW, I had nearly forgotten how the SW sounded.  That is, the fact that it made no sound at all.  On top of that, the hub now rode better than ever.  Previously, the pedals would sometimes catch and start turning as I wheeled the bike down the hallway.  It didn't this time.  During the ride, the gears engaged smoothly (smoothly for an SW.  Shifting and engagement are slower and clunkier than on an AW) and the pawls didn't even skip once.  Everything was so perfect and silent.

Aftermath, plus a random SW hub rolling around

Even harder to believe is the fact that I successfully completed my first hub rebuild with flying colors.  I used to be intimidated by the thought, but my fingers now itch to do it again.  Maybe I'll open up the AW hub that I took from the Rollfast.  That one doesn't spin too well so it might need to be cleaned up, anyway.

To be honest, even though I love the super wide ratio spread of the SW, I think I'll keep using the '79 AW hub for Ann Arbor commuting.  As Sheldon Brown's article says, SW pawls are "rare as hen's teeth" so I'd like to save them until I move to flatter land.  Never fear, it will be used again.  I still don't like seeing good machines sitting unused, no matter how precious.  The AW will take up the brunt of the abuse for now since it is tougher and parts are more plentiful.  After a week or so, I think I'll swap tires and put the AW wheel and hub back onto the Sports.