Monday, July 18, 2016

Broke My Hub ...

... and then the Lotus sat for a week, and when I finally amassed enough willpower to tear it down, I naturally used the chance to perform another series of updates.

Pictured above are the high gear pawls from the 1966 Sturmey-Archer AW 3-speed hub that I built into my Lotus mixte. While this is not exactly what failed in the hub, I did figure out why it was previously so hard to get it to say in 1st gear. You'll see a sort of round, dished-in area on the right side of each pawl. That was the ramp that previously allowed the clutch to push the pawl in as the hub was shifted into first gear. However, after a particularly high number of miles, possible inadequate lubrication, and lots of shifting of gears over the course of 50 years, the ramp was worn further and further in, eventually to the point where the pawl was not being fully pushed in. I also found a slightly kinked pawl spring so while that wasn't causing any problems, I had NOS spares of pawls and springs so I replaced them all.

So how exactly did my hub break? Aren't AW hubs supposed to be unbreakable? Well. usually. I didn't have "carfax" for this hub so there obviously wasn't any way to know what kind of abuse it suffered throughout its previous life. One day, I was exploring the particularly hilly neighborhood of Angell, looking at all of the nice mid-century houses, grinding up hills while standing out of my saddle without a care. Now, I know you're not supposed to do this with internal gear hubs, which is why I have so many spare parts. Anyway, I had finished my exploring and was already on my way home when I started feeling a slight chunking sensation while pedaling and freewheeling. Knowing there was a risk of damaging the rest of the internals with loose shrapnel, I still decided to ride it back softly. A week later, I tore down the hub and found that pieces of the ring gear had broken off and after circulating through the gears, embedded themselves in the sun gear. I spent some time picking out the smithereens and made sure the rest of the gears were fine. The planet gears had a few teeth that were slightly roughed up but I figured they were good enough to ride. Nothing else felt like there was excessive play. I took another ring gear out of a spare parts hub, put the Lotus back together, and that was that.

While the bike was upside down, I also swapped my juicy pair of Continental Sport Contact II 700x37 tires for some Vittoria Randonneur Cross 700x35's. I liked the Continentals a lot but realizing that this bike saw more dirt and gravel roads than I initially planned, I wanted a bit more tread. Also, the wide 37mm tires always seemed a bit fatter than usual. Aside from sometimes rubbing the fenders as they shook around, I felt that they also affected the ride quality. I chose the Randonneur tires not only because they had the tread and width that I wanted, but also because I have been using them for a while on my old Sports and really liked them. I got lucky because not only were they heavily discounted (someone had bought a bike with them and swapped out the tires immediately) but all other 700x35 tires for sale anywhere were dedicated cyclocross tires. So, with new hub parts and new tires, I rode to Dexter to eat and explore the trails, a 40 mile round trip.

The tires are lovely, exactly how I had expected them to be in every way. Fast rolling, not too heavy or "jiggly," and I wasn't able to test the limits of traction on that trip but later on the tires did feel better on the gravel roads near my home. However, the whole time during the trip, my feelings of the bike being geared too highly were made even more apparent over the long distance (which no doubt played a part in my breaking of the hub earlier). Therefore, the 44/19 tooth ratio was switched to 44/20. I had to add two extra links in the chain which then made the tensioner hang lower. That, and the fact that the 20-tooth cog brought the chain closer to the chain guard made the bike incredibly noisy over bumps so I then removed the two extra links and went back to the 40/18 combo I first had on the bike when I was running two front chain rings (minus the larger ring). That ended up being ideal. I am now even quicker out of the hole in the city and still, the only time I max out 3rd gear is when I go down the long hill on Glen/Fuller.

I wrote in the previous post about this bike that the two things that would definitely change were the pedals and the bottle cage. I didn't end up moving the cage, since that was literally the only place I had available, but I replaced it with a Elite Cuissi one that had little wings on the side to prevent a bottle from falling toward me. When I have cups from a fast food place, I just put those in the side pockets of my pannier. As for the pedals, I finally removed the lovely Nashbar Double Track pedals after the trip to Dexter since this was primarily a town bike, not a road bike. The new Diamondback Bigfoot pedals are really nothing to complain about - if I was to be really picky, I'd pick a pair that was thinner and not quite so toothy, but I'm happy with these.

Another major update is the Brooks Cambium C17 saddle in "slate." The used B17 I initially planned to keep on the bike turned out to be less "lightly used" than advertised and within weeks, cracks started showing up at an alarming pace, showing that, when coupled with the bowed-in middle, the saddle had seen excessive stress with the previous owner. On top of that, since this is a regularly-ridden city bike, I didn't want to have to worry about covering the saddle from sun and rain. The C17 is the rubber/canvas version of the B17 and true to the words of Brooks and the many reviewers, it does ride like a properly broken-in leather one. It was stiffer than I had anticipated but over the next week, my bum got very used to the saddle and I stopped feeling it under me. It is the first Brooks saddle I bought brand new and because it came at a huge discount, the price made it well worth it. I chose the "slate" colored version because I liked the gum-colored underside, but "black" would have been a better match for my bike. Not that I really care anymore. If only they made a black-topped one with the natural gum-colored underside, though.

It was suggested that I disassemble the saddle and Loctite the rivet-looking-things which are actually Torx screws. They have a reputation of working loose because of the way the rubber moves and are reportedly quite expensive to replace. While I did that, I also moved the one that with the "C17" engraving from the right rear corner of the saddle up to the nose just to change things up. When I started undoing the screws one by one, I noticed the saddle was under tension and got worried that I wouldn't be able to get the top back on, but the way it's designed actually makes re-assembly very easy once the rail is fully removed. I forgot to get photos of this, but once you screw the aluminum front and rear pieces to the rubber top, you stick the rail in the rear of the saddle, place the last "nose" piece at the nose of the rail, and wrench the whole thing into place using the leverage to tension the saddle. It's a clever design and I'm really kicking myself for not getting photos.

That's about it, I think. I masked, sanded, and painted the rear fender again to extend the white tail upward a bit for the sake of aesthetics but that's a minor thing. I haven't done this yet but I also have to add a support to the top of the Banjo Brothers bag, as I also wrote in the previous post, because it's sagging too much. After I do that, I can say that the bike is truly set up in a way that is ideal for my usage.