This review was provided for free, but Surface 604 shipped and assembled the bike through Rides N Motion to make it easier for me. My goal is to be transparent and unbiased with you, this video and writeup are not meant to be an endorsement of Surface 604 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 primary differences between the Surface 604 Big Sky and Sunny Day models are the frame style and size. The Big Sky is a high-step with a 19″ seat tube and the Sunny Day is a more approachable mid-step with a 17.5″ seat tube. They are painted differently too, but the motor, battery, and other components are all the same.
- 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 ocean, city, and mountain conditions. The brand is sold in the US and Canada, direct online and through 100+ dealers in the US and Canada.
Pros:
- This is one of the most affordable electric bikes from Surface 604. It’s stripped down a bit, but they still included a chain protector to keep your clothes from getting greasy and snagged, and mounting points to add fenders and a rear rack if you wish.
- I care about safety, so the light color paint with matching rims and some bright orange accents, the reflective puncture resistant tires, and the pre-wiring for adding lights are all great! They even include a little flick bell for friendly signaling.
- Purpose built frame keeps weight low on the frame, hides part of the battery pack, and also keeps wires mostly out of the way. Notice how they run through the frame, so they don’t clutter the look or get snagged. I love how they enter the downtube and almost look like they are going into the smaller tubing that bisects the mid triangle of the frame.
- Great hydraulic disc brakes from Tektro with motor inhibiting levers that cut power whenever they’re pulled. Surface 604 chose large 180mm rotors to gain a mechanical advantage and improve cooling. Note that the brakes also send a signal to blink the rear light if you get that as an option.
- For those who wish to ride farther, or those carrying more weight, or those who use the throttle and high speed modes a lot, the company sells two high capacity battery upgrades. The default pack is 12 amp hours, but there’s a 14ah and 20ah pack that significantly increase capacity. The batteries are also cross compatible with many of the other Surface 604 frames including the Sunny Day mid-step model.
- If the Big Sky seems a bit large, consider the smaller Sunny Day model that uses all of the same parts and has a slightly different paint job. That model is a mid-step that’s also a bit more approachable due to lower stand over height.
- Note the longer cruiser handlebar that was custom specced for this bike. It’s not as wide as some, which makes it easier to get through doorways and between cars in traffic. The handlebar and large comfort saddle work together to improve comfort, and you could swap the rigid 30.4mm seat post with a suspension post to further reduce vibration and shocks, but note that it will raise the minimum saddle height by a few inches.
- This is a little thing, but all of the support hardware matches. Notice the black hubs, spokes, posts, and bars. I can tell that the designer puts extra time and energy into the little details and has been creating ebikes for over a decade.
- The sense of control and response is above average here, because the bike uses a torque sensor vs. cadence. It measures how hard you push and responds dynamically. I find that this setup makes the bike feel more like an extension of your legs, and also extends range.
- I love the large color LCD display panel used here! The 3.5″ color LCD 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 set it up to stay bright even when the lights are activated, since many people like to ride with lights on during the day for added safety. However, you can manually adjust brightness down if you wish. I love that there’s a precise battery percentage readout, that the display has a full sized USB type A port built into 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 believe it can go up to 28mph if you wish. There’s even a password setting in the display, so you can restrict access.
- 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. They positioned it far enough back that it won’t cause pedal lock when backing the bike up, and it should support a loaded rear rack well if you add that option.
- Given the larger heavier tires 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 around 750 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 is another little thing, but I appreciate that it uses an oversized quick release clamp lever that is easier to adjust… especially if it’s really tight or cold outside.
- 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, and trigger throttle.
- 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… even though the Big Sky and Sunny Day are new for 2023, they carry over a lot of the trust from the Rook, Colt, and other S604 ebikes.
Cons:
- Some of the parts used on this model are cheaper than the others from Surface 604, to help keep costs low. Those include the square tapered spindle, steel chain cover that could rust if scratched, and generic hub motor, which seems to make a bit more zipping noise than others in the line.
- I was surprised that the bike weighs 55.5lbs considering that it doesn’t include fenders, a rear rack, or lights. I was expecting something in the mid to high 40’s to be honest. At least the weight is kept low and center on the frame for improved balance and handling. It will weigh more with the high capacity battery options and optional accessories.
- There’s only one color scheme for the Big Sky right now. I appreciate that it’s light and has bright accents, to be more visible in the early morning or night time.
- There are no bottle cage mounting points on this frame. You could add a cup holder on the handlebar, or a trunk bag with a bottle holster if you get a rear rack for it.
- The battery charger for this ebike is pretty basic, though it does look nice with the S604 logo sticker. It’s fairly compact, has a removable wall-side cord to reduce length, and only weighs about 1.5lbs, but it only puts out 2 amps. Thankfully, Surface 604 does sell an optional 4 amp fast charger that is ideal if you get the higher capacity batteries.
- The optional 20ah super high capacity battery pack spills out on the left side and is not symmetrical like the 12ah and 14ah packs. Functionally, the bike still handles well and I didn’t bump my left calf or anything, it just looks a bit odd to me from some angles.
- The charging port on the smaller packs is positioned low on the left side of the frame, near the path of the left crank arm, but thankfully not directly in its path. It requires a bit more effort to bend down and reach. If you pay more for the largest 20ah pack, the charging port is up high near the battery lock core on the left. Ideally, both the lock and charging port would be up high and on the right side of the bike to be easier to reach and less vulnerable to the crank arms.
- 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 paint could get chipped off if the chain is bouncing up and down a lot while riding off-road. Consider using a 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 means that they could get bent during shipping or if the bike tips over to the right. The demo bikes I rode had the cables pretty close to the frame so it didn’t seem like a major concern. Some newer designs put the power cable on the left side of the frame, tucked between the dropout and disc brake rotor, perhaps we will see that in the future.
- 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 rear dropout) can also be more sensitive to over-tightening the axle bolt and doing wheel maintenance. I guess it’s the trade-off for a more responsive system compared to a standard cadence sensor, which can be a lot less natural feeling.
- Another consideration for this torque sensor is that it calibrates when the bike is booting up. For this reason, it’s best not to pedal during this phase because it might impact how the sensor responds later. Basically, power the bike up without putting pressure on the pedals.
- The planetary geared hub motor used on this model is more generic, and it produced some extra zipping noise compared to other Surface 604 models. The rear axle didn’t have a torque arm, but the torque sensor and thicker frame seemed pretty sturdy. No quick release for the rear wheel due to the hub motor design.
- 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. I like the upgraded Shimano Deore and SRAM shifters that allow for high and low shifting using your thumb, because this allows the pointer finger to stay on the brake lever if you wish.
NW says
Is there a step thru, class 2 foldable full size bike. We are in our 60s and need throttle on occasion. Need to be able to lift and put in trunk.
Court says
Hi NW! Check out the RadExpand as a folding Class 2 electric bike. It’s a great bike for the price. I think Magnum also has several folding Class 2 models including the Pathfinder and Premium.