School me on Sturmey-Archer 3 Speeds

[GTV]

Since my Bendix 2 speed kickback works great on my '60 Jaguar, now I'm thinking of building a work commuter road bike. Each way would be 13+ miles of flat roads. So light weight, TALL gears, and low rolling resistance are key. But still kinda sorta period correct-ish. I'm a Schwinn guy, so I'm keeping an eye out for an original paint 50's-60's Racer, Speedster, or something similar. The only thing I've got so far is a 52t Mag chain ring to replace the stock 46t. I'd like to know more about the S-A 3 speeds. Like what gear ratios they have, how many teeth on the sprocket, what can be swapped around, etc.

It just started getting hot here in Phoenix, so I figure I've got all summer (6 months of it!) to get a bike built in time for cooler weather

[Sinner4]

I have one laced to a normal 26 inch mtb wheel, I have a 36t up front and 19 out back iirc on a heavy elgin. I can muster 25 mph for a short bit, but in first and second gear its like a rocket. For me 3rd gear is tall enough.

[expjawa]

Most S-A three-speeds (and Shimano 333 & Nexus) have 2nd gear as direct drive with a 1:1 ratio, then multiply 1/3 up for third or divide 1/3 down for first. So, your ratio spread is 0.75, 1, and 1.33:1. They use the common 3-tab cog, so you can swap around rear gears from 14T up to 23T by popping off the snap ring and changing it out. Sheldon Brown wrote a handy ratio calculator that you can use to figure out what your road speed/gear inches/gain ratios would be for different combinations.
http://sheldonbrown.com/gears/internal.html

[GTV]

My kickback now is the overdrive unit (1:1 low, 1.5:1 high) with 46/20 front and rear sprockets turning a 27" tire. I really like it for the terrain I'm on. Plenty of get up to move my heavy bike out of the hole, and a nice lazy top gear- I use it everywhere!

Being able to change the rear sprocket is a definite advantage. Even if I geared it all the way down to 52/14, the underdrive .75 first gear would still probably be ample enough to get a light bike moving. Anyone have experience with this?

What hubs should I look for? Anything to watch out for? Are they easily rebuildable?

http://en.m.wikipedia.org/wiki/Sturmey-Archer#section_1

[Wildcat]

Most SA 3 speeds have 18 teeth on the cog with 46 on the chainwheel, usually on a Raleigh or Hercules lightweight bike. 3rd gear was pretty tall on those, but to use your 52t chainwheel, it would be very very tall. I had that setup on an old junky bike when I was younger, 52/18 on a standard SA 3 speed, only no shifter, so you had to get a running start to pedal. I couldn't use that high a gear now, I seldomly travel faster than 15mph.

[GTV]

Most SA 3 speeds have 18 teeth on the cog with 46 on the chainwheel, usually on a Raleigh or Hercules lightweight bike. 3rd gear was pretty tall on those, but to use your 52t chainwheel, it would be very very tall. I had that setup on an old junky bike when I was younger, 52/18 on a standard SA 3 speed, only no shifter, so you had to get a running start to pedal. I couldn't use that high a gear now, I seldomly travel faster than 15mph.

A 46/18 with the 1.33 top gear is the same (actually a scosh lower) as the 46/20 with the 1.5:1 set up I have now. I'll need more gear than that for sure. The 52/14 sounds extreme, but coupled with the .75 low gear it's only a bit taller than the low gear I have now. It makes it a 50/18 if such a thing existed. And then I'll have two more gears to go! Mathematically, it sounds like it will work. In top gear, for every crank revolution, the wheel would make 5

[kingsting]

SA hubs are fairly easy to work on and don't require any real special tools to service them. There are plenty of good online resources should you decide to overhaul one. They're quite reliable and usually only require a squirt of oil every now and then to keep them happy. (Plain 30W is fine for these) They made bazillions of the AW model and parts are still easy to come by. Most three speed problems are with the cable adjustment and not the hub anyway.. There are coaster brake versions but they are a bit trickier to service. Make sure you have good instructions before tearing one of those apart. (Something I didn't do when I overhauled my first one and couldn't get it back together... ) Avoid the somewhat rare and troublesome SW model from the late 50's.
Most of the guys that are into Raleigh three-speeds change the gearing. They're geared fairly tall so they swap out the rear cog with a larger one - usually 20-22T.

[gcrank1]

I think you would have to have way more horsepower than me to make 1 crank rev actually do 5 wheel revolutions!
FWIW, if the cable snaps on a SA it gets 'stuck in 3rd', or better said, 3rd is what you are going to be in for the rest of the trip. The typical 46/18 for me results in a 3rd that is good for downhill and flat, until Im tired or lazy, then its too tall. A 46/22 would give me a 3rd more like my 44/16 sgl speed, IIRC, and it is a decent all rounder. That big chainring of yours I have no experience with to hazard which rear might be a good start.
So, I recommend using a ratio that lets your 3rd be what you want for good rolling and let 1st and 2nd fall where they may, they will be fine.

[GTV]

Thanks for the info guys

I think I'll give this super tall combo a try. If it does end up being too much (and it very well may), I can easily swap the rear sprocket out. This project would also be a great cantidate for a longer crank, and maybe 700C's if they'll fit...

Now I gotta find a bike!

[spectratone]

Sturmey Archer and SRAM both makes 5 speed hubs that are available domestically.
Both hubs give an extra ratio above and below a three speed, so you would have fewer
worries about getting a good range of gears.

I just purchased an SRAM 5 speed for the 20's Elgin 28" wheel (soon to be 700C)
that I'm building up as my roadbike/cruiser - commuter hybrid. I'll be posting
build pics and riding impressions once I get started.

I currently have a couple of three speed bikes, and had to drop the gearing to make
them usable, since I live in a somewhat hilly area. They are top speed 'challenged' (12-15MPH)
now and I sincerely hope I don't have to try and outrun any dogs

[gcrank1]

On the 5 speeds is there really a ratio below 1st and above 3rd of the 3 speeds, or are the bottom and top ratios about the same as the 3, but with an intermediate ratio either side of the middle gear?

[Wildcat]

Someone had a SA 5 speed up for trade here, so I looked it up, it had about the same ratio as a 3 speed, with a lower low and higher high.

[MplsCoaster]

Great thread! Found the gear heads
What is your weight target? that can factor into gearing too
Schwinn Racer with 3 spd could be 27-30 lbs
My Spaceliner is 27 lbs with 52/16 (1spd), 14 was too tough for hills
My Felt is 20 lbs with 52/13 (1 spd), slightly harder than the Spaceliner
Both are not quick but fast

I have 2 SA 3 spds but am waiting for the right build

Hope that helps
Looking forward to your build
Good Luck,
Steve

[spectratone]

The SRAM 5 speed also goes lower and higher than a 3 speed. If you want
intermediate steps then a Shimano Nexus 7 or 8 speed will give you those.
I don't think the intermediate steps are really necessary unless the bike is
heavy/loaded down.

I seriously looked at the Nexus 7, but it cost more, weighed more, had more
pieces to break and just didn't seem necessary on the Elgin, which I'm guessing
should weigh in the low to mid 30 lb range.

I find I do less downshifting on my 5 speed Collegiate simply because, at 38 lbs,
it weighs less than any of my other bikes. I don't know what I would with a bike
less than 30 lbs.; probably die of a heart attack from lack of exercise.

[MplsCoaster]

I don't know what I would with a bike
less than 30 lbs.; probably die of a heart attack from lack of exercise.

They actually are both pretty good workout bikes.
Here's the Spaceliner on my river road ride
2 miles of it is stop signs every 2 blocks But still 380 calories


I agree about weight, expense, and cost of Nexus 7.
A lighter bike might need less gears (and go faster)