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Rosco Platypus

Regular price $1,350.00 USD
Regular price Sale price $1,350.00 USD
Shipping calculated at checkout.


Good for: Shopping, commuting, day rides, touring, light trail use. NOT heavy trail use. Let’s call it “incidental” trail use. If you want a trail bike—a “hillibike,” as we call them—get a Gus, Susie, Clem, or Atlantis.

Sizes: 50cm (650B wheels), 55cm, 60cm (both 700c wheels).

Sizing: See the chart in the pictures. Here's a useful thing to know about sizing these: the minimum achievable saddle height with the provided Kalloy post and a Brooks saddle is the seattube length (50,55, and 60) plus 15. So someone with a 86cm PBH (75cm saddle height) could ride the 60cm if they wanna go big. You don't have to worry about standover, since they're step thrus. Call us if you have questions about that.

Braze-ons: Aplenty.

Tubing: The same SILVER CrMo tubes we put on our normal bikes.

Construction quality: Up to snuff with all of our bikes.

Graphics package: Top-notch, A+.

Paint quality: Same. The same guy paints them. Cream details where possible.

Colors: “AnaPurple.” It’s really close to the same purple Ana C (“purpleriv”) has on her custom; and a really nice green, which for now is “Rosco Green.”

Maximum tire with fenders: 45mm

Without: 55mm

Kickstand plate: Of course

Brakes: This frame is intended for use with V-Brakes

What's included?: A FSA Duron headset, Kalloy post and BB guide. No bottom brackets this time. 

So what’s odd about it?

When making some Platypus forks, the builder noticed a minor, cosmetic-only imperfection that we wouldn’t have caught, or made even the slightest stink about: The rack holes in the top of the fork crown are sometimes off-center by up to 2mm. It makes no difference to anything, and the fork maker shouldn’t have even mentioned it. But they did, they felt bad, and so they sold us the forks cheaper and rather than use them on a regular bike, we took advantage of the situation and designed a whole bike around them. The forks were slated for the Platypus, so we used Platypus geometry and clearances. We opted to keep the price down by tig-welding and using rings on the seat tube and head tube instead of lugs. The seat tube ring, made for our HHH tandem, accepts a 31.8mm seat tube (1/8th-inch bigger in diameter than our standard), so the Rosco has a fatter seat tube. It’s still skinny by modern standards.

This frame has as much Rivendell vibe and spirit, ride quality, and all-around smartness as any bike in our line. It is still considerably more detailed than a standard tig-welded frame with it’s head and seat tube reinforcement rings.

We have 70 total, 35 of each color divided by three frame sizes, for an average of 7.7 of each size/color variant. We expect them to sell out quickly. The closest “regular” model in our line is (as stated) the Platypus. The Platypus is coming again in the fall. It’s fully lugged, fancier, prettier for the lugs, costs more, but is zero better riding or more comfortable. Both are good deals.

If you’re on a budget and not snobby about lugs, get this one. If you don’t have any of our bikes, it’ll be the best-riding bike you own. If you have one or more of our bikes, it’ll be just as good as any of them.


Want a complete bike?

Having us build your frame is the easy, smart and low-risk way.

If you aren’t well-versed in bike parts and familiar with particulars and minor differences:

We encourage this route here. You tell us what handlebars, style of shifting and what type of riding you will do and we figure out the build. Keep in mind this still offers you far more input than a bike off the floor of any bike shop. This route saves you $300 off the build price.


A la carte builds:

Add this option to your order and work with us to pick your parts one-by-one. We’ll reach out to you about the build with a list of questions. Email communication works well, but don’t hesitate to call, either. You don’t have to know every single part you want, we will gladly help to fill in any gaps.

Whatever you decide, please have one selection from this section of the website added to your cart when you check out so we know how to sort the orders. We recommend adding it before the presale "goes live".

$50 to charity

We've added $50 to the retail price, and all of that from each frame sale will go to the Oglala Lakota Children’s Justice Center OLCJC, part of the Pine Ridge Reservation in South Dakota. The OCJC’s focus is on child sexual abuse, and the staff of two services the entire 6,000+ population. It is severely underfunded, and the $3,500 or so from Rosco sales will be a windfall.


Ever since our demand has increased, people tend to buy frames only to decide later whether they actually want it or not. It's an impulse we understand but it sometimes prevents someone who's absolutely sure they want one from getting a frame, and when people do cancel, we can't just re-stock it on the website because restocking just one frame alerts the 20 odd people who are on the back-in-stock email notification list, and the bummer cycle of missing out repeats itself. So we're implementing a 10% cancellation fee on these frames.



Frame shipping is automatically set at $87 within the lower 48 states.

This rate may be adjusted depending on the actual rate at the time of shipping. 


Bike orders will default to $250 to the lower 48. If your actual shipping price is more, we will reach out to you for an additional payment.