Critical Cycles - Harper Single-Speed / Fixie Matte Black / 43cm / xs, Critical Cycles - 3

Harper Single-Speed / Fixie

$ 329.99 $ 199.99
Sage Green
Matte Black
White and Black
Graphite and Orange
Sky Blue
Suggested Height:
5'2" - 5'6"
Suggested Height:
5'6" - 5'9"
Suggested Height:
5'9" - 6'0"
Suggested Height:
4'9" - 5'2"
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The Harper single-speed fixed-gear is the next generation of commuter bike. It’s built around a tig-welded steel frame and fork and top shelf componentry and is equipped with front and rear brakes. The hand-built track frame has bar-spin clearance, a flat top tube, no toe overlap, and horizontal dropouts. This is a bike designed for you and your city street adventures.



The Harper Single-Speed / Fixed-Gear comes standard with a flip-flop hub. This means you can choose how you ride, whether it’s single-speed with a freewheel or fixed gear. The Harper SS comes with the freewheel single-speed side installed. A freewheel allows you to cruise without pedaling, as you would on a traditional bicycle.

You can also ride fixed with an easy switcheroo. All you need to do is remove the rear wheel, flip it around, and then remount it. With a fixed cog, the movements of your bike directly correlate to your pedaling. The faster and harder you ride, the faster and harder you’ll go. The motion of the rear wheel relies on the motion of your feet. But remember, riding fixed is a choice you can make or reject.


A single-speed / fixed-gear bicycle is simple, lightweight, and requires almost no maintenance. There are fewer parts that make up this kind of bike, which means there are fewer parts to potentially damage. Riding fixed is also an efficient workout because you’re always in motion and, therefore, always exercising. When you ride fixed, you are most at one with your bicycle. It doesn’t move unless you move with it. One of the best parts about having a flip-flop hub on a bike is that you can choose which way you want to ride anytime. Riding fixed is a choice you can always say no to.


Riser handlebars encourage a relaxed, upright riding position. This posture is more comfortable and ultimately better for your back.


The Harper single-speed / fixie is designed for longevity. The high-tensile strength steel diamond frame is hand-built and tig-welded for the commuter’s lifestyle. Rest assured you’ll be riding on your Critical Cycles frame for a long, long time.


Your safety is very important to us. We’ve equipped the Harper SS with dual braking. You’ll have more control over your commute and your stopping with a front and a rear braking system. The rims have machined braking surfaces for safer stopping.


We wouldn’t say we’re control freaks exactly, but we do like to be in control of our rides. That’s why we put so much effort into making every part of our bikes the best it can be. VP freestyle pedals and KMC chain are long-lasting and hard-wearing while the 30mm Deep-V rims and thick, stable Wanda tires make for a softer ride.


*All of our bikes have a weight limit of 220 lbs.

*Due to differences in screen resolutions, please note that colors may differ slightly.

Hand-built steel track frame
Bar spin clearance & no toe overlap
Horizontal drop-outs
30mm Super Deep-V Double Wall Rims with Braking Surface
Flip Flop Hub with Single-Speed 16T Freewheel & Fixed-Gear 16T Cog
Wanda City Tires 700x23C
KMC 1/8”
1 1/8" Threaded
Promax Alloy 25.4mm clamp size diameter
25.4mm Riser Handlebars
Kraton Rubber Track Grips
Front & Rear Promax Brakes with 22.2mm brake lever clamp diameter
Bottom Bracket
NECO 68x110 Cartridge Sealed
9/16” Plastic Pedals
Critical Cycles Pista Saddle
All the tools you need to build and maintain your own bicycle including three metric Allen wrenches and a flat wrench.


Shipping on all orders over $65 heading anywhere within the contiguous U.S. is free. Shipping on orders under $65 will cost a flat rate of $7.98. You can also choose to have signature required when your products are delivered for an additional $5.98.

We try really hard to ship all orders within 1 business day, but sometimes we're backed up. Most orders will go out within 3 business. Your order will be delivered within 1-5 business days.

We ship most of our orders out through FedEx. Keep this in mind when you're choosing a shipping method. If you don't request a signature and you're not home when FedEx arrives, it is left up to the driver's discretion to leave the package or not. Sometimes we send smaller orders out through USPS.

Check out more information about our shipping policies here.

Returns Policy

Great news! We offer a 30 day return policy! Returns are accepted for the full product credit if received at our warehouse within 30 days of the date of purchase in the original packaging that is still in retail condition.

Please bear in mind that our refunds do not include reimbursement of shipping fees.

Check out more information regarding our return policy here.

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