Believe it or not, until recently, I had never ridden a folding bike. Its not that I was actively steering clear of folding bikes; Ive just never had a reason to ride one or I didnt realize I had a reason. But I know they are not only popular, but convenient in many ways. And the Brompton C-Line proved to be exactly that.(Photos / Ron Frazelle)The folding bike world is full of passionate riders, just like every other segment of cycling. I mean, the Brompton Mafia is a thing. Its a group of rabid Brompton users/lovers effortlessly flying all over the world with their bicycles. And its pretty rad. The Sea Otter Classic Brompton race with Jordan wishing he practiced unfolding the bike moreThe Sea Otter Classic even holds a Le Mans-style Brompton race every year. Its really fun, irreverent, and quite the spectacle. In fact, our Racing Tech Editor, Jordan, competed in the Sea Otter Brompton race this year and podiumed, cause thats what Jordan does doesnt matter the bike. Fun times!!I Got to Take it to MADEAnywho, the opportunity to ride one arose this year, right before the MADE Show. I usually attend only two bike industry shows a year: the Sea Otter Classic and the MADE Show. I usually drive to both of these shows. Sea Otter is in Monterey, California, and only a 5-6-hour drive for me. And MADE is in Portland, Oregon, and is usually a 2-day drive for me 3 days if I dont want to kill myself.But for this years MADE Show, I decided I wanted to fly up to Portland. Zach, my Editor-in-Chief, and I booked our hotel for the show, and it ended up being very close to the venue.The Tern case and the Brompton case (forefront) at Portland airport.Getting in the rental car to make the short drive to the venue seemed wasteful and silly. And walking sucks, most of the time. So, Zach decided to bring his Tern BYB folder to ride to and from the show, and suggested I try to find a way to do something similar.I wanted to bring my Wilde Rambler SL, but I didnt have a proper travel case for it. And a bike that is made to easily handle navigating a crowded airport and flying with it sounded much easier. Plus, I wanted to try a folding bike, period. So, Zach suggested reaching out to Brompton, as weve never reviewed one of their bikes on the site before.So I did. Folding and Flying with the BromptonI received the 16 wheeled Brompton C Line 4-speed a few days before leaving for Portland. I also received the B&W Fold On Case. This hard-shell, suitcase-type case is the perfect size to check at the airport. And the bike fits effortlessly in that case.The case is not cheap at $269.99 on the Brompton site. If thats out of your budget, I will say there are a bunch of Brompton riders who will bring their Bromptons folded, out of a case, onto the plane as carry-ons. They just stow them in the airplanes overhead compartment (though you should definitely confirm the airline allows this before trying it). Just two folding bikes, ready to roll.I opted for the hard case, just for convenience. I packed the C Line into the case, paid the regular checked bag price, and away we went. Zero issues. Not one. Case size comparison Brompton vs. TernRecovering it from baggage claim was just as easy. The case rolled well through the airport and was easy to wield and maneuver through the crowds though one major difference between the Brompton case and the Tern is that it has two wheels instead of four. The Tern case was easier to wheel through the airport, but the Brompton case will likely be more durable. The handle also extends to a good length and is easy to manipulate up or down.Tern (left) with its 20 wheels vs 16 on BromptonThe Brompton C-Line weighs a claimed 26.1lbs. When packed in the case, it pushed the weight to a little under 44lbs. When folded, I found the included rolling rack a game changer. It made it a breeze to roll the folded and partially folded C-Line around. The rack also functions as a kickstand, it folds up to rest almost as quickly as you could kick a kickstand. Roller rackRiding the Brompton C-Line 4-SpeedBrompton C-Line in PortlandOverall, I enjoyed riding the C-Line 4-Speed. I will admit that there was a smidgen of a learning curve riding on 16 wheels. I think I wouldve preferred riding a bike with 20 wheels, like Zachs Tern. Rear suspensionBut after a very short time, I got used to its quick, albeit slightly twitchy, handling. The bike is long, so thats where, as a rider, you find your stability. I will say that I did not care for the tall gearing. Any hills? Get the 12 Speed VersionThere are two drivetrain options for the C Line, a 4-speed and 12-speed. Both versions use the same 11-18t four-speed cassette, but the 12-speed drivetrain adds an internally geared hub with three speeds. The 12-speed version also gets a smaller 50t chainring vs. the 54t on the 4-speed. Granted, the smaller wheels make a big difference when considering chainring sizes, but the easiest 54x18t combination on the 16 Brompton is roughly equivalent to a 36x20t on a 700c x 35mm tire. Hardly a climbing gear for casual rides. That means the 12-speed offers much more range: 402% vs. the C-Line 4-speeds 163%. I live in the mountains, and that 4-speed gearing up here is a no-go for me. Ive only ridden it a handful of times while home. It rides nicely, but climbing on it is no bueno. My options for review were limited with a short turn around time, but if I had to do it again, I would definitely choose the 12-speed version. The only real downside to the 12-speed version is that its 0.28lbs (127g) heavier and $200 more. Worth it. FitIm 61, and the bike felt comfy for me while not feeling cramped at all. Brompton does a stellar job of designing the bike to fit a wide variety of riders. You get your choice of low, mid, or high handlebars when ordering. This bike had the high bars, which kept the front end nice and comfortable even with the seat post extended almost to the max. The proprietary rear derailleur seemed to work fine. When paired with the shifter, they delivered reliable, snappy shifts.I liked Bromptons proprietary clamp system that is used to secure the steering mast and for the mid-frame break. Brompton C-Line 4-Speed Retail & DetailRetail: $1,950Weight: From 26.12 lbMain frame: Precision-drawn, heat-treated steel tubing with hand brazing and selected auto-brazed jointsRear frame: Hand brazed cold-formed micro-alloy steel tubingFolded size: 25.3 H x 23 W x 10.6 DFork: One-piece carbon fork and steerer with magnetic pedal holderPedals: Brompton folding left-hand and non-folding right-hand pedalsBottom bracket: Square taperDerailleur: Brompton Chain pusherTires: 16 x 35C Schwalbe Marathon Racer. A puncture-resistant tire with a reflective sidewallSpeed: 4-speedChainset: 6061 forged aluminium crank with 54T chainring and integrated chainguardRear cassette: 11-13-15-18 teethHeadset: Brompton headsetBrakes: Brompton Dual Pivot CalipersRear Wheel: Double-wall rim, 28 spoke, Brompton Wide ratio 2-speed internal gear hubFront Wheel: Double-wall rim, 28 spokes laced to a Brompton front hubFenders: IncludedRear Rack: IncludedRiding in PortlandAll in all, I found the Brompton C-Line a pleasure to bring along for the show. It rides well and packs down to an incredibly small and manageable package. And that is really the point here, right? I mean, sure, the bike rides fine, but man, does it fold down small. Perfect for flying, storing in small spaces, and bringing it along in a small car without the need for an elaborate and expensive bike rack. Itll just sit in a small truck, the backseat, or that spot on the floor between the front and back seat. The only bummer, and its a small one, is how much of the Brompton uses proprietary parts. Not all of the parts, but some pretty important parts. I get it; they have one of the smallest folding bikes on the market when folded, so some parts are going to need to be specialty/proprietary parts.And Brompton has a robust support system in place, so replacing and working on their proprietary parts when they break is not thatbig of a deal. But still, it would be great if you could use the parts that you really wanted when upgrading or repairing stuff. In ConclusionI would absolutely recommend this bike to anyone looking for an amazing folding bike that folds down in less than 20 seconds. Its easy AF to fly with, and a great, fun way to get around at your destination if you decide to fly with it. MADE Show parting shot.I cant keep the bike, and I am a little sad that I have to return it. I could really use a folding bike in my life. You know, something super easy to throw in a case and fly with, or toss it in the back of my Jeep to just bring along. No racks and locks needed; itll easily fit in the back. Well, as it turns out, after attending the MADE Show, Ive worked something out for another folding bike review/story, so stay tuned here for that tomfoolery. Its going to be pretty awesome. In the meantime, do yourself a favor and hit the link below to check out the Brompton folding bike world. US.Brompton.com