Brompton Electric C Line Explore folding bike review

The Brompton Electric C-Line Explore is built on the venerable Brompton design, which has remained pretty much the same since its introduction in the late 1970s. It's a design that's lasted because it gets so many things right, from ease of folding to ride comfort and cargo-hauling practicality.

The Brompton is still the most compact practical folding bike, and the Electric C-Line Explore adds an electrifying twist in a front-hub-drive motor. The result is an incredibly compact folder that will get you up most inclines you might face, and makes a great solution for someone who wants to incorporate a bicycle into a multimodal commute.

The Electric C-Line Explore adds motorized power to the venerable Brompton folding bike, and the result is a practical e-bike that makes a ton of sense for urban and multimodal commuters and errand-runners.

The best thing about the Brompton Electric C-Line Explore is that it doesn't make too many compromises on the time-tested Brompton design. It preserves the ultra-compact fold (something that's hard to achieve with the Swytch or many of the other motor retrofit kits that have been on the market). Just as the traditional Brompton is the smallest-folding, most compact practical bike, the Electric C-Line Explore is the smallest-folding really practical e-bike, collapsing into a package even smaller than some electric scooters.

There simply isn't another off-the-shelf folding electric bike out there that you can really stow away in a closet or under a desk, take onto a crowded bus, or put into the overhead luggage rack on a train by yourself. You could convert an existing Brompton with a Swytch kit, but that's more work and sacrifices some of the compactness.

Given the high price of electric bikes from traditional bicycle manufacturers, folders are great because by and large they are sold in a single size and can accommodate a wide range of riders. It's a lot easier for a household to justify a roughly $4,000 purchase if it can be shared between a couple or among family members. And the Brompton really delivers on that — it fits a huge range of adults, and for those over 6 feet tall, you can get an extended seatpost.

The C-Line does offer limited handlebar choices (there's no "low" flat bar available, just your choice of mid- or high-rise bar) compared to the standard Brompton lineup, but the Brompton design favors a relaxed, upright position and we don't really consider this a drawback. Those who are very tall who want a low, stretched-out position may not be well-served — but a Brompton may not be the best choice in that case anyway.

The Electric C-Line Explore is pretty much perfect for multimodal bike commuters, especially those who want to ride through the warmer months without working up too much of a sweat. While it's more expensive, its tiny folded footprint makes it a superior choice even over lightweight commuter bikes like the Velotric Thunder 1, since it's so easy to wrangle the Brompton onto a bus or train or into the trunk of a taxi should weather or the length of your commute demand.

It may not be a speedy ride, but a Brompton isn't really meant as a go-fast bike (well, outside of the Brompton World Championship) and the gentle assist is great for those who are riding in dress clothes and aren't looking to push the pace.

The most polarizing feature of the Electric C-Line Explore is the redesigned luggage block. The electric version uses a totally rethought block that tidily incorporates the battery connector, and the mounting action is much as before. Since the electric Brompton design places the battery within the bag, this is fantastic for quickly breaking down the bike to jump on a bus or lug into the office — you end up with the folded bike in one hand, your bag and battery in the other. The downside (more on this below) is that it limits you to using the new line of electric-specific Brompton luggage.

While the Electric C-Line Explore is motorized, it doesn't supply the sort of boost that’ll make you feel like you’re a pro cyclist. The 250-watt front hub drive provides a mannered, gentle boost, meant to give you some extra oomph uphill. It's also limited to 25 kph (roughly), or 15.5 mph (in keeping with European standards), so if you’re a reasonably strong cyclist on flat terrain you may not find yourself using the motor much past getting started at a stop sign. Luckily the overall package isn't terribly heavy, so it behaves much like a standard Brompton at speed.

Controlling the motor is more difficult than it is with other e-bikes, and more difficult than it needs to be, really. The Brompton Electric C-Line Explore doesn't have a handlebar-mount controller or display, so out of the box there's no way to switch between assist levels (there are three) while you’re riding. You can only switch from the top of the battery unit, so you’ll have to choose one before you get started and stick to it. In a flat area this might make sense, but it's a bit limiting on rolling terrain.

You can connect your phone and manage everything from the companion app, but that requires picking up a handlebar mount and being comfortable strapping your phone to the bars. This is certainly a more and more common solution, and understandable give that a well-thought-out app is going to provide access to more features than any bike computer. But a minimal control pod is going to be a better solution for the majority of riders who just want self-contained simplicity — which is, after all, Brompton's stock in trade.

In the area where we tested regularly — a neighborhood with rolling hills featuring grades up to 12% — we just left it on the middle or high setting and found we mostly had enough oomph, but missed the ability to tailor the motor's response to our needs. You can get around this by using the Brompton mobile app, but we really think a bike at this price shouldn't make you mount a phone to the bars to access basic functions.

Compared to a standard Brompton, the Electric C-Line isn't — at least it isn't yet — a great cargo carrier. Despite their small size, their low center of gravity and the front-mounted luggage block make traditional Bromptons capable of carrying surprisingly large loads. Nothing along the lines of a cargo bike like the Tern HSD S+, mind you, but a properly equipped standard Brompton can easily handle a weeks’ worth of groceries in a single trip. A huge range of bags fit the original Brompton luggage block, clicking in smoothly and securely and out just as quickly whenever you need to fold the bike.

But that isn't the case yet for the Electric C-Line. Even the biggest currently available bag, the City Bag, is really sized more for commuting than load-hauling. It will comfortably fit a laptop, a rain jacket and lunch, but the space for the battery takes up a large portion of the volume, making it hard to carry larger loads. If you want to be prepared to do some grocery shopping on the way home from work, you’ll want to have a backpack or messenger bag with you too, or perhaps keep a collapsible daypack tucked away in the City Bag. For now, it doesn't offer anywhere near the hauling capacity of a more traditional utility bike like the Co-op Cycles Generation e1.1.

But any way you slice it, that's more limiting than the regular Brompton's capacious carrier. We do expect that Brompton and third parties will step in to provide more bags to fit the redesigned block down the line as the Electric C-Line concept develops, but right now luggage is a weak point in the range.

The most impressive thing about the Brompton Electric C-Line is that it manages to pack a capable electric assist into the existing design without compromising the tiny fold — an impressive achievement that makes the Brompton a great choice for multimodal commuters or errand-runners who need to use public transportation part of the time. And it's small and light enough that you can tuck it under your desk once you arrive at the office. The design could use a little more refinement (more cargo carrying options and a better interface), but we think the Electric C-Line is a superior electric folder that does a great job of extending the Brompton idea into the e-bike era.