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Atlantis Frames and Bicycles

Design | Geometry | Lugs | Specifications | Tubing

Overview

The Atlantis is an all-purpose, all-surface, all-season, all-weather bicycle frame designed by Grant Petersen. It offers comfort, practicality, performance, and durability for loaded touring, day touring, commuting, and trail riding.

For loaded touring, the Atlantis is as good as it gets. The lugged steel frame is built to handle heavy loads, rough terrain, and continuous use. The tubes, currently by True Temper in the US, (subject to change without notice!) are brazed together using Rivendell’s lugs and fork crown. It has every necessary touring braze-on, and enough strength to carry heavy loads on or off-road.

For trail riding, the Atlantis is a refreshing change from today’s macho complexity. It has the clearance to accommodate the fattest practical knobby tires, and a steering geometry that feels correct right off the bat.

For commuting, the Atlantis is ideal. It is agile enough to maneuver around car doors and potholes. It accepts fenders easily, so you can commute all year around and not arrive at work a mess.

Fewer than 350 Atlantises will be made this year. The number isn’t kept artificially small for marketing or any other purposes. Frankly, we’d like to see them all over the place. But to ensure quality, consistency, and attention to detail, Atlantis bicycle frames are made slowly, by hand, and we’re able to get about 350 of them per year.

It is brazed in Osaka, Japan by Toyo, a 10-person custom bicycle frame shop that has built top-quality frames for 30 years, and specializes in high-end, finely made frames. It is a clean and efficient shop, and the lack of frame options (one color, and the geometry and braze-ons are carved in stone) allows for the manufacturing efficiency to be hand-built in small batches, thus saving time and lots of money. The finished frames are then sent to Uemura, another small shop whose quality makes it the first choice for almost every custom, hand-made, cost-no-object bike in Japan. With the signature offset creamy head tube and lug window cut-outs, the Atlantis looks striking and classic.

 

Lugs

Lugs, the things you see at the frame joints, were the preferred way to join bicycle frame tubes until about 1983. It costs more to build frames with lugs, but lugs are good, because they allow brazing, a joinery method that doesn’t melt the parent tube. In brazing, molten silver- or brass-based material is heated and drawn by capillary action into the 0.15 mm gap between the tube and the lug. There, it cools and solidifes, effectively gluing the joint securely with metal.

Lugs also serve as external tube reinforcements, or “butts,” by increasing the joint diameter.

It isn’t normal to talk about the possibility of an accident, but it could happen, and you might bend or break a frame tube. On a lugged bike, and only on a lugged bike, tube replacement is relatively easy. Tube replacements are unheard of on TIG-welded frames, because the base metal has been melted; and it’s easier to just build a whole new frame. One is not as likely to become attached to a TIG-welded frame as to a lugged one, so frame replacement becomes a practical solution.

 

Tubing

Atlantis frames are built with CrMo steel, mainly because steel is tougher than aluminum and titanium. Metallurgically, “tough” refers to a material’s ability to resist cracking, and if a crack should start, to slow its growth. So when we say “steel is tougher” , we mean “more crack-resistant and molasses-like, if you’re a crack.”

 

Frame Design

The Atlantis is built for comfort and versatility above all else. Sized properly, you’ll be able to get the handlebars level with or above the saddle, thus taking weight and strain off your hands, neck, arms, and lower back. A bike should be fun to ride, and feel natural, almost like sitting in a chair. The Atlantis is like that.

One component of versatility is tire clearance, or the amount of space between the tires and the frame. More is better, period. It allows you to ride bigger tires; it allows you to mount fenders.

The Atlantis has double-eyelet dropouts, three water bottles, seat stay hourglass braze-ons for a rear rack, and brake and derailer cable stops. There’s no front rack braze-on. We left it off intentionally, so you can clamp on any one you like.

 

Specifications

(Subject to Change Without Notice!)

Built by Toyo of Osaka, Japan Frame Color: Testor's Interior Blue Green #2135 Window Fill: Dupont Imron Cream #4296 Seat Post: 27.2 mm Rear Dropouts: 135 mm, vertical Seat Tube: 1-1/8" (28.6 mm clamp-on front derailleur) Pump Peg 3 water bottle mounts Stem quill: 22.2mm 1" threaded headset installed Brakes: Cantilever Rear Rack mounts and front and rear fork eyelets

Tubing: (the most highly stressed tubes are heat-treated, tubes that don't are not) Lugs: Long Shen Dropouts: Liow Ko Top Tube: True Temper .9-.6-.9, 28.6 (1-1/8") Down Tube: True Temper Heat Treated .9-.6-.9, 31.8 (1-1.4") Seat Tube: True Temper .9-.6 Heat Treated Head Tube: True Temper .9 Steerer: True Temper Seat Stays: True Temper 16 mm diameter x .8 mm thickness Chain Stays: Starlight Heat Treated Fork Blades: True Temper 1.1mm tapering to .6 mm

 

Geometry