Surface 604 Colt Review

This review was provided for free, but Surface 604 did provide a temporary demo bike and accessories for me to test. My goal is to be transparent and unbiased with you, this video and writeup are not meant to be an endorsement of S604 products. I welcome your corrections, additions, and feedback in the comments below, and the Surface 604 electric bike forums.

Observations:

• In case you were wondering, the Surface 604 Colt and Rook are basically the same ebike (using most of the same components, battery, and motor systems). The Colt is built around a stiff high-step frame, and the Rook is built around a more approachable step-thru frame… which actually weighs more. Both models come in two frame sizes, but the Colt only comes in one color (black).
• Surface 604 dates all the way back to 2013. I was lucky enough to review their first product, the Element Electric Fat Bike! S604 products are designed to be affordable, but capable on a wide variety of terrain and conditions. Their designers frequently choose parts that are above average in terms of quality and reliability because they come from the mountain bike world. Surface 604 is based in British Columbia, Canada. Their name denotes the 604 phone area code for the Vancouver region, which is home to city, beach, and mountain conditions. The brand is sold in the US and Canada.
• The big differences that I noticed going from 2021 to 2022 versions of the Colt and Rook models include refined lights (headlight is mounted to the stem vs. suspension arch), a custom relaxed swept-back handlebar, and updated comfort saddle. The battery pack still comes in two capacities (672 watt hours or 960wh) for extended rides, and the rear light still activates blinking mode when the brake levers are pulled. Continued highlights include the hollow spindle bottom bracket, TMM4 torque sensor, 180mm hydraulic disc brakes with motor inhibitors, and powerful 45nm 750 watt geared hub motor. I tested the medium/large Colt and small/medium Rook for these reviews. Both are shown in the video above.

Pros:

• My favorite upgrade for the Colt and Rook models is headlight placement! Not only does S604 use a high quality light with side windows, making it visible from more angles, but they also placed it up high on the stem vs. down on the suspension fork arch where it used to be. The rear light is also very good because it uses two LEDs, and flashes when the brake levers are pulled.
• I appreciate the adjustable spring suspension fork here, offering lockout and preload to perform on different surfaces and support different loads. Surface 604 specced a taller 27.5″ tire that lowers the attack angle for comfort, and they used wider 2.4″ for improved stability and vibration dampening. When you combine the fork with the tires and add in the name brand Selle Royal saddle, you end up with a very comfortable hybrid bike.
• The handlebar has been refined a bit since the last generation and now sweeps back more. This pairs nicely with the adjustable angle stem, which is quite long. I feel like these bikes fit a very wide range of people because of the two sizes, adjustable stem, and the new handlebar. They’re almost setup as a blend of city and cruiser, which I prefer for everyday riding.
• The bikes look beautiful, and all of the supporting hardware matches! Notice the black hubs, spokes, rims, and posts. The black frame ties it all together and matches the battery cover, chain cover etc. I also appreciate how the wires and power cables are mostly hidden because they are internally routed through the frame.
• The sense of control and response is above average here, because the bike uses a torque sensor vs. cadence. The downside is that it can require more pedal pressure to get full power output and occasionally activate due to chain bounce.
• I love the large color LCD display panel used here! The 3.5″ screen is positioned high, so it’s easy to read, and includes brightness adjustability in the settings menu (hold + and – to access this menu). They configured it to stay bright even when the lights are activated, since many people like to ride with lights on during the day for added safety. I love that there’s a precise battery percentage readout, that the display has a full sized USB type A port at the base, and that you can adjust how many levels of assist are offered (0-3, 5, or 9) and even adjust the top speed.
• I appreciate the kickstand choice here, because it offers adjustable length. It’s mounted using a standard 40mm bolt spacing, which makes it easy to replace or swap out. They positioned it far enough back that it won’t cause pedal lock when backing the bike up while deployed, and it should support the weight of a loaded rear rack.
• I appreciate that Surface 604 has a higher weight rating for these ebikes at 300lbs total (up to 50lbs on the rear rack). That means heavier riders can enjoy the bikes and still feel safe. Part of what makes this possible is the thicker 13 gauge spokes and 36 spoke setup here vs. 32 or 28 spokes on many other electric bikes.
• The high-step Colt frame is fairly approachable, because they sloped the top tube. I find these frames easy to lift, and they are also lighter than the step-thru Rook. I appreciate that they added bottle cage bosses below the downtube in case you want to mount a folding lock, mini pump, or water bottle (even though it wouldn’t be that easy to reach). Perhaps you could use velcro straps to add a bottle cage below the top tube or maybe a triangle bag. The battery comes out to the side vs. straight up, so the center of the frame is fairly open to add-on accessories.
• Given the larger heavier wheel and tire combination here, I was impressed by the motor power and torque. Surface 604 reps told me that the motor can produce up to 45 newton meters of torque and peak out well above 500 watts. My experience riding was quite satisfying, and I think part of this has to do with the torque sensor. Keep in mind that I’m 5’9″ tall and weigh about 135lbs (61kg).
• This ebike has powerful hydraulic disc brakes with large 180mm rotors. This provides a strong mechanical advantage and cooling benefits. Both brake levers also send a signal to cut motor power, for added safety and efficiency. I appreciate that the brake levers offer adjustable reach to work well with different sized hands, it’s an added bonus for petite riders given the two frame size options.
• This ebike is a hybrid, meaning that it blends city and mountain components. You can see that with the suspension fork, hydraulic disc brakes, and hollow spindle. The larger aluminum pedals gave me a sense of confidence when pedaling and standing while riding off curbs and down steps.
• I love that the company offers two battery pack sizes! The standard 672 watt hour is already above average, in terms of capacity. If you want to go even higher, the 960 watt hour pack is a great option and only adds a few pounds. Both packs also have a USB port built into the right side, so you can use them as spare power banks when stored off of the bike!
• My understanding is that many of the Surface 604 bikes now use the same Reention Dorado battery interface, so the pack can be shared between friends or family members… even going back a couple of generations! This is a more open battery standard, which means you can have the batteries repacked or purchase from generic suppliers someday if S604 changes their design or stops selling them.
• In addition to the full length fenders, this ebike also comes with a plastic chain cover to keep your right pant leg or dress end from getting greasy and snagged on the chain and chainring. The cover has a reflective section as well, which adds to the visual footprint created by the reflective tires and side-visible lights.
• Surface 604 has some cool optional accessories including a sturdy Ergotec handlebar mirror for spotting traffic, a suspension seat post from SR Suntour, and some saddle bag panniers that are guaranteed to fit the bike. I’m a big fan of the comfortable suspension seat post, and it’s nice to know that it’s guaranteed to fit if you buy from them.
• There’s an emphasis on ease of use and modular repairs with these ebikes. For example, the controller uses standard XT60 connectors and is much easier to reach for diagnostics and repairs than some of the older ones. Notice the quick disconnect for the motor, headlight, display, brake motor inhibitors, and trigger throttle. The controller produces 25 amps of power output, which creates a zippy powerful feel. Many cheaper ebikes use 18 amp controllers.
• The company has been around since 2013 and earned my trust. I feel like they produce a quality product and offer good support. I try to communicate this whenever I have covered multiple generations of products.

Cons:

• I noticed that the price of this model went up by $200 compared to years past. It’s still a good value for an above average value hybrid, in my opinion. Most ebikes have gone up in price, but I love the multiple frame styles and battery sizes offered here.
• The charger for this ebike is pretty standard, but looks nice with the branding. It’s fairly compact, has a removable wall-side cord to reduce length, and only weighs ~1.4lbs. The downside is that it only puts out 2 amps, and the batteries can take longer to charge given their high capacities. Thankfully, S604 does sell an optional 4 amp fast charger now that is ideal if you get the optional 960wh battery pack… it just costs extra.
• I appreciate how battery weight is kept low and center on the frame, and partially integrated into the downtube, but I noticed that the upgraded pack spills out on the left side and is not symmetrical. Functionally, the bike still handles well and I didn’t bump my leg or anything, it just looks a bit odd.
• The charging port on the default sized 672wh battery pack is positioned low on the left side of the frame, directly in the path of the left crank arm. This could cause the cord to get snagged or the plug interface to crack if the crank arm catches it. If you pay more for the larger upgraded 960wh pack, the charging port is positioned up high near the battery lock core. Ideally, both the lock and charging port would be up high and on the right side of the bike to be less vulnerable and easier to reach.
• The rear rack is welded to the frame, which means it cannot be removed and adds weight to the overall build. The upside is that it won’t rattle loose over time, it’s color matched, and has the pannier hangers, bungee loops, flat slats on top, and is rated to 50lbs (22.6kg). This rack would probably work well with child seats like the Thule Yepp Nexxt Maxi, and is a sturdy mounting point for the included rear light. It would be nice if the rear fender also attached to this rack in the middle for added strength.
• The ergonomic grips are not locking, which means that if you bear down on them you can twist them forward and back (or even slip them off the ends of the handlebar if you really go for it). Fortunately, the relaxed position of the riser stem and handlebar mean that you won’t be bearing down on the grips the way you might with a mountain bike. Grips are pretty affordable to upgrade if you want locking, consider the Ergon GP1 for example.
• I was surprised to see that there was no slap guard sticker on the right chain stay. This is a minor annoyance, but it does mean that the black paint could get chipped off over time if the chain is bouncing up and down a lot while riding off-road. Consider using piece of clear box tape or aftermarket velcro slap guard like this if you plan to ride fast and on bumpy terrain.
• The rear derailleur and motor power cable are not protected by a derailleur guard, which mean that they could get bent during shipping, or if the bike were to tip over to the right. just be careful not to snag the wires, and consider using extra zip ties if your cable protrudes a lot. The demo bikes I rode had the cables pretty close to the frame, so it didn’t seem like a major concern.
• One drawback to torque sensing pedal assist is that the controller may think you’re pedaling when it’s really just the chain bouncing around. The strain plate (mounted on the inside of the right chain stay dropout area) can also be more sensitive to over-tightening the rear bolt and doing wheel maintenance. I guess it’s the trade-off for a more responsive system compared to a basic cadence sensor.
• Hub motors are zippy, work well with throttles, aren’t as hard on the drivetrain, and cost less than mid-drives. However, they usually do not allow for quick release axles (which is the case here) so only the front wheel has that feature. It just adds time and requires tools to work on the rear wheel and motor. Also, given the high power of this motor and no torque arm system, be sure that the rear bolts stay tight so the axle doesn’t rock back and forth and chew into the aluminum alloy frame over time.
• Due to supply chain uncertainty, this electric bicycle may come with a SRAM X5 or Shimano Alivio drivetrain and the shifters are slightly different… that’s not a huge deal to me, but you may care. The bike I tested used the Shimano Alivio but had a limited range 11 to 32 tooth cassette vs. 34 tooth in years past.
• The trigger shifter has a multi-shift low lever, but the high lever is just one way, so you have to use your pointer finger to activate it. I like the upgraded shifters that allow for high and low shifting using your thumb, because this allows the pointer finger to stay on the brake lever at all times if you wish.
• I like how wide the metal fenders are, and they didn’t rattle much when going off the curb or down the steps… but the front fender is connected to the lowers of the suspension fork with plastic cuffs vs. threaded eyelets. It’s just a bit less sturdy and clean, but the stays don’t stick out on the back, so it’s a decent solution.

Useful Resources:

• Surface 604 electric bike dealers.
• Official Surface 604 website.