Wednesday, December 17, 2014

Sturmey Archer Hub Gear Ratio Notes

One of the nice things about Sturmey Archer AW hubs with the 3-spline cog is that you can change your gear ratio as needed.

For Sturmey Archer AW sizing in a 26 inch wheel I like:

[Front] - [Back]

(Note if you are running a conversion cog and inch pitch gearing, divide these numbers of teeth in half)

Very Hilly Terrain:

2-1 (46-23), (48-24)- this ratio is the max low that Sturmey Archer suggested back in the day for the AW hub. They suggested not going lower because they believed it exerted too much force on the hub internals. I've not tested this theory, but 2-1 is pretty low. N is mostly a climbing gear but not bad on a flat into the wind. I suppose you could go lower, but I don't press it with older hubs and I stick to the old Sturmey Archer advice. Perhaps the modern hubs will tolerate it, but I haven't messed around with new hubs much.

Moderately Hilly: 

46-22, 48-23- works reasonably well. Goes OK on a flat. Can climb in L, or smaller hills in N. Has slightly more top end than 2-1 but not much.


Somewhat hilly, or if you like a lower gear a little below stock: 

46-20, 46-21, 48-22, 48-21- Climb mostly in L, N is peppy enough to run well on a flat or into a breeze. I like this ratio for all-around riding. It's a little slower than stock, but I like how it lets you "spin" a little more and is easier on the knees than stock.

Flat:

46-18, 48-18 (18 is stock), 48-20- I think Sturmey Archer set the stock gear ratio too high on these hubs. 18 strikes me as not making the most of that low gear for climbing. On a flat, stock goes well (or 20 on a 48 tooth sprocket), but your climbing is somewhat limited and you may need low gear for going into the wind. I don't run any of my AWs with an 18 tooth cog anymore.

Top end boost:

46-16, 48-16 (this is if you want a really high gear and a lot of top end speed) I fooled with this briefly but didn't like it. It's fast but you had better live in a very flat area.

FW and SW Notes:


The rule I follow for the FW-  the gear ratio when converting between AW and FW is that the FW should be 1 tooth on the rear cog higher (smaller cog) than for the AW. The reason for this is that the FW has a lower high gear than the AW does, while providing a bottom gear. The second gear "L" is slightly higher than the AW's L but the AW doesn't have Bottom. That said, if you want max climbing, go 2-1 on the FW and you'll have better climbing than the AW. I run my Raleigh 4-speed (1958) sports 2-1 because I wanted a "climber" alternative to my standard 3-speed sports (1974). The FW is a lot of fun as well and a nice alternative if you want bottom gear.

For the SW, I don't like changing the ratio substantially because the hubs tend to cam-out more if you put a big cog on the rear, at least in my experience. I also suggest swapping out the SW on any bike you're going to ride substantially, or be climbing with. The AW is the way to go over the SW.
 
For Sturmey Archer sizing I like:
[Front] - [Back]
Very Hilly Terrain:
2-1 (46-23), (48-24)- this ratio is the max low that Sturmey Archer suggested back in the day for the AW hub. They suggested not going lower because they believed it exerted too much force on the hub internals. I've not tested this theory, but 2-1 is pretty low. N is mostly a climbing gear but not bad on a flat into the wind.

Moderately Hilly: works reasonably well. Goes OK on a flat. Can climb in L, or smaller hills in N.
46-22, 48-23

Somewhat hilly, or if you like a lower gear: Climb mostly in L, N is peppy.
46-20, 46-21, 48-22, 48-21

Flat:
46-18, 48-18 (18 is stock), 48-20

Top end boost:

46-16, 48-16 (this is if you want a really high gear and a lot of top end speed)

For Sturmey Archer sizing I like:
[Front] - [Back]
Very Hilly Terrain:
2-1 (46-23), (48-24)- this ratio is the max low that Sturmey Archer suggested back in the day for the AW hub. They suggested not going lower because they believed it exerted too much force on the hub internals. I've not tested this theory, but 2-1 is pretty low. N is mostly a climbing gear but not bad on a flat into the wind.

Moderately Hilly: works reasonably well. Goes OK on a flat. Can climb in L, or smaller hills in N.
46-22, 48-23

Somewhat hilly, or if you like a lower gear: Climb mostly in L, N is peppy.
46-20, 46-21, 48-22, 48-21

Flat:
46-18, 48-18 (18 is stock), 48-20

Top end boost:

46-16, 48-16 (this is if you want a really high gear and a lot of top end speed)

Sunday, December 14, 2014

1940 Schwinn New World


The 1940 Schwinn New World project nears completion. Just a few final adjustments left. I removed the front spring from the knock-off "Brooks" saddle. I'll post a review of the saddle once I have more miles on it. I also need to get a saddle bag for the bike, probably another Banjo Brothers barrel bag. Now for the important part... pictures.












 The "four peg hole" sprocket looks a lot like the more common "cloverleaf" from the 1950s-60s, but is actually a much less common and earlier part. The telltale sign is the four holes toward the center of the sprocket.





This is the original Yale key for the locking fork. I had a duplicate made for use while riding.

Sunday, December 7, 2014

1940 Schwinn New World

Still working on a 1940 New World project I picked up this fall. I've had to manufacture a few small parts for it, tweak a few things, and adjust a few things, but it is starting to come together.











The bicycle is a mix of old and new. The rims are Sun CR 18 aluminum types. The spokes are stainless, but the hubs are vintage. The rear is the uncommon Sturmey Archer alloy and the front is a Schwinn Script hub. The tires are new Kendas in the English ISO 599mm size.









Shifter is a 1940s Sturmey Archer quadrant, but the shifter cable is new. Grips are reproduction coke bottles.













The stem originally was from a Schwinn Cycletruck, but someone cut it down. I re-shaped it with a Dremel tool to accept a normal wedge. The AS bolts on the stem are reproduction, as is the AS seat bolt. The saddle is a generic, but still leather, reproduction. Rear reflector is original glass Stimsonite.










Brake calipers are original "Schwinn Built" type, as are the brake handles. Pedals are AS stamped originals.







Tuesday, November 11, 2014

Last Project of the Year

I have spent the fall catching up on projects sitting in my barn. This included the Manton & Smith, 1959 Schwinn Tiger, and a 1940 Schwinn New World.

This particular New World arrived as a bike "core": frame, chain guard, fenders/braces, fork/headset, seat post, partial crank set, stem, front brake caliper, and handlebars.


I took apart the core down to the frame, cleaning up everything. Here is the frame along with a complete, 1947 New World for comparison. They're very similar and the differences are subtle, but present.


I also have an array of really nice parts for this build. This box includes: Arnold/Schwinn "AS" stamped pedals; an uncommon, aluminum alloy Sturmey Archer hub from 1954; an original Schwinn script front hub; a matched set of Schwinn brake levers; and a matched set of "Schwinn Built" calipers.






The rims will be Sun CR18 aluminum rims in the English (ISO 590mm) size. Spokes will be straight gauge DT Swiss stainless. I also have a pristine, original Sturmey Archer quadrant shifter to add a nice, period touch to this relatively early New World.





Tuesday, October 28, 2014

1959 Schwinn Tiger Middleweight

Next on my list of projects was a 1959 Schwinn Tiger. This is a classic Schwinn with the cantilever frame, painted fenders, and chrome S7 rims.


The concept here was to build a middleweight cruiser bike with some "adult-oriented" upgrades. This meant heavier duty seat, heavy duty seat post, wider handlebars, multispeed hub, and slightly fatter tires.
















The result is a pretty nice bicycle. The multispeed hub is a Sturmey Archer 3 speed coaster brake (modern). The cable routing is custom fitted so as not to disturb the frame lines. Tires are Schwinn middleweight sized, but slightly fatter "cruiser" tires.
















The bike is fun to ride, and the upgrades are welcomed additions making it a better machine for an adult who wants to get more out of a middleweight that just a short-distance, single speed bike.








They are not true balloon tires, but are a 50 psi, slightly fatter version of the Schwinn middleweight tire.