Surface 604 Quad Rear Hub Motor

Surface 604 Quad Battery

Surface 604 Quad Sram X5 Drivetrain

Performance Review: SURFACE604 QUAD

Acceleration / Speed

The Surface604 Quad felt very smooth, and stable when accelerating. It also accelerated fast enough to get back up to speed within a matter of seconds. The Quad maintained its speed quite well too, and it never felt like it was overworking itself to keep moving.

One of the big factors that make the Quad so smooth is its torque sensor, because of it we always had the right amount of power whether we were on flat ground, or going up a steep hill.

Shifting / Gear Range

The Surface604 Quad comes with the SRAM X5 9spd drivetrain and shifter, which felt great! The shifting was quick, smooth, and crisp which we really appreciated especially when offroad. Because of the snappy shifting we were able to hold our speed up hills, and around corners without having to worry about shifting in time to do so.

Having 9 gears to choose from was also very convenient and made the Quad that much more versatile and capable. The less you have to focus on shifting the more fun you’ll have, and we really felt that when riding the Quad.


100MM Travel Suntour XCM 32 Fork

Maxxis Rekon 27.5+ Tires

Handling (Cornering, slow speeds, etc…)

We tested the Quad on every type of terrain we could find, from singletrack, to gravel, to slickrock, to paved trail, and the Quad handled it all, and really shined once off road.

The Quad handled like a regular hardtail mountain bike with a little bit more weight on the rear end because of the rear hub motor. The motor placement kept the rear tire stuck to the ground, which helped a lot with traction on corners. Because of the motors power and the 9 speed gear range we were able to climb the steepest of hills, and keep our speed regardless of the terrain we were on.

The torque sensor also gave us the right amount of power and engagement the second we needed it which helped out loads with the steep climbs, and managed technically challenging terrain that we experienced from time to time when riding our local light trails.

The Maxxis Rekon 2.8 inch tires kept us stuck to the ground, and prowled over rocks and dirt with ease, and the 100mm Suntour XCM 32 Suspension Fork helped us stay in control, and comfortable when things got tough.

Because of mountain bike geometry, 100mm of suspension, and 2.8 inch wide tires, the Quad handles great, especially if you’re looking to do all terrain biking.

Overall, we think you’ll find that the Quad handles nicely on a wide variety of trails – from paved city paths, to light off-road single track. We were even able to ride some pretty technical rocky sections, even though this bike isn’t designed for and won’t perform as well on rocky or rooty technical trails.


The Surface604 Quad is really comfortable, especially for being a mountain bike. We attribute a lot of the comfort to the Velo Saddle, and the leather lock on grips Surface604 equipped this bike with.

These are the two biggest contact points on the bike aside from the pedals, and because of this we really value comfort at these points. After plenty of miles on the Quad all our riders agreed that the saddle is a great median between being comfortable, and still being performance oriented for off-road riding. We felt the grips were comfortable, but weren’t quite performance oriented enough for the style of bike the Quad is.

The 100mm SunTour XCM 32 suspension fork also helped us out with comfort, it smoothed out chatter in the trail and allowed us to ride farther because of reduced fatigue. In short, the SunTour XCM 32 helped us stay fresher, for longer, leading to more time spent hitting the trails.


Mountain Bike Geometry

Range Test: Surface604 Quad

We already had a good idea of how far the Quad would get on max pedal assist from our recent review of its brother, the Shred. The Shred has the exact same 500w motor, and 14ah battery as the Quad . They also both possess the same tire width and wheel size.

Given how similar the bikes are, we decided to range test the Shred using power assist level 5 (i.e. use the highest assist level) and then range test the Quad using power assist level 1 (i.e. use the lowest assist level).

On our max power range test, we ended up getting 36.73 miles over 2 hours and 16 minutes, with an average speed of 16.1. I did this test, and weigh right around 170 lbs, and climbed 1,340 ft in elevation.

For our minimum power range test, Josh (5’11 and 125 lbs) ended up riding 63.74 miles over 4 hrs and 24 minutes, climbing 3,144 ft.

In summary, we ended up getting between 36-63 miles, which easily backs up Surface604’s stated claim that the Quad can travel up to 45 miles on a single charge.


Surface604 Quad Range Test

Specs/Features: Electrical Components


The Quad comes with a Bafang 500w rear hub motor that’s designed to be vibration free. Combine that with Surface604’s torque sensor, and controller and you’ve got yourself a smooth consistent motor setup that feels like a mid drive motor when it comes to engagement.

We were all really satisfied with the motor setup on the Quad, it really tied together the bike for us and gave us stellar performance. Because of the quick, consistent engagement the torque sensor provides we were able to maneuver through technical terrain noticeably better than we could using bikes with a cadence sensor. The torque sensor also allowed the motor to give the right amount of power needed which added to the overall performance of the bike.


The Quad is powered by a 48v 14ah Samsung Lithium Ion battery. This Samsung Lithium Ion battery is sleek, and low profile. It takes more than one glance at the Quad to tell if it’s even an electric bike because of how the battery fits into the frame, which definitely adds to the looks department of the Quad.

The battery holds its charge quite well, as we discovered in our range test where we nearly got 64 miles on a single charge while riding at the lowest level of pedal assist. For us, this inspires longer rides and riding at a higher assist level. It was great to know we had a solid, high quality battery below us.

Integrated Battery in Down Tube.

Powerful Rear Hub Motor

Front Head Light.

Pedal Assist

The Surface604 Quad comes with 5 total pedal assist levels, which is more than enough especially when paired with the 9 speed SRAM X5 drivetrain. We loved having a wide assortment of assistance levels on the Quad, and because of it we were always able to find the perfect difficulty and speed combo when riding.

We spent most of our time in assist levels 4 and 5 because of the speed and power they provide. With 45 total variations of gear/assist combos the Quad proved to be highly versatile and ready for anything, at any speed.


When it comes to ebike throttle there isn’t a lot of variation in design, however there is loads of variation in performance. While the push thumb throttle looks quite standard, it feels a lot smoother than a lot we have tested. This is likely because of the high end controller, and rear hub motor that Surface604 uses on the Quad.

The throttle was great for getting back up to speed, and accelerating from a stand still. It also came in handy on off road trails, as we were able to accelerate on parts of the trail that were difficult to pedal on.


The Quad comes with Surface604’s 3.5” Colored LCD Display. This display is not only visually appealing, but also gave us all the necessary information we needed when riding. The display allowed us to see our total miles, trip miles, current speed, and current wattage use which gave us a good idea of how the Quad was handling the ride. Thanks to the wattage meter, we were able to see which gears and pedal assist levels conserved the battery, and which ones drained it.



The Surface604 Quad comes with a Buchel Headlight that mounts to the stem. We honestly could have done without the light, as it’s not particularly bright or focused. With the Quad being a mountain bike, we don’t feel the light fits in with the rest of the bike.

The light feels more cruiser oriented to us, and if you plan on doing night rides we would suggest considering picking up some higher performance lights to emit your path.

If Surface604 decides to put lights on their future models, we would like to see a fork crown mounted light instead, as the lower light position will emit the path more, and be less distracting when riding.

Components & Accessories


The Surface604 Quad comes with Tektro Dorado Hydraulic Disc Brakes and 180mm rotors front and rear. If there is one component on the Quad that gets an A+ from our team here at Electric Bike Report, it would be these brakes.

These Dorado brakes performed as good as we could have asked for, as they were extremely responsive, powerful, and consistent. These brakes also provide a wide array of modulation when it comes to how hard you brake.

With the Quad being heavier and capable of higher speeds than a standard hardtail, quality brakes are critical to the overall performance of the bike, and Surface604 delivered with the Tektro Dorados.

Tektro Dorado Brakes

100MM Suntour XCM 32 Fork


The Quad comes stocked with a 100mm SunTour XCM 32 Spring fork, which from our experience is solid, but isn’t spectacular in any particular way. The XCM 32 helped smooth out chatter on trails and absorb impacts, but not quite as much as we would have liked to see.

We would have liked to see an air fork on the Quad, as air forks provide more adjustment and a softer more plush feeling, plus overall better performance than spring forks do. With the Quad being an upgrade from the Surface604 Shred, it only makes sense to have upgraded suspension too.

We think most riders will be just fine with the XCM 32 that comes on the Quad, but those who like to ride rugged terrain may feel the fork is lacking some performance.


The “X-Wing” Style 6061 Alloy frame is what really makes the Quad stand out in a crowd, in fact we wouldn’t be surprised if it’s why you clicked on this review in the first place! When we were testing the Quad we received plenty of questions and comments about the frame, wondering who made it was and how it felt. In short, the frame felt great.

The frame felt stiff and sturdy below us, and it also has standard mountain bike geometry. On top of that, the frame is relatively lightweight, and the welds are clean. Overall, the Quad’s frame performed just as good as it looked when riding.

Surface 604 Quad Frame

Sram X5 Drivetrain

Velo Saddle


The Quad comes with the SRAM X5 9 Speed Drivetrain, and a unique gold paint job that fits nicely with the rest of the bike. It also has a 38 tooth chainring to keep things moving. The X5 shifter is crisp, consistent, and it performed just as we’d hope it would. Surface604 made the right choice when it comes to the drivetrain in our eyes.

9 total gears gave us a wide range with plenty of variation in difficulty. We had a gear for steep hill climbs, straight aways, and everywhere in between the two. And no, this isn’t a SRAM XX1 Eagle Drivetrain, although it looks like it!

Grips and saddle

The leather grips, and Velo Saddle both add to the looks of the bike, and are quite comfortable. When riding off road, the leather grips felt a bit slick when holding on to them and we believe a tackier, more rubber based grip may benefit the performance of the Quad overall.

As far as the saddle goes, it’s plenty soft to ride on for hours at a time, and it’s also pretty good looking! We think most riders will be just fine with these components, and they are both easy to replace if that doesn’t end up being the case.


Surface604 has put Promax aluminium handlebars on the Quad, these bars have 60mm of rise with 9 degrees of back sweep and are 720mm wide. The rise was great for riding in an upright, yet performance oriented position. Our test riders that prefer mountain biking all would have liked a wider bar for stability and control, but agreed that it wasn’t too thin to be an issue. Riders who aren’t used to modern mountain bikes will likely be just fine with the 720mm width.


Surface604 has selected Gold Wellgo Platform Pedals for the Quad. These pedals match the color scheme of the rest of the bike nicely. These pedals have shown to be quite sturdy, and can withstand large pedal strikes too, the Wellgo Platform Pedals were grippy enough to keep our feet on the pedals through chatter and rough sections of the trail, which was definitely appreciated. Not only are these pedals good looking, they are also high quality in their build, and performance.


The Quad’s kickstand is a heavy duty aluminum kickstand, that they’ve placed far enough back on the chainstay that you’re still able to pedal with the kickstand down (not that we would recommend that). This kickstand tucks up next to the chainstay nicely and is sturdy enough to stay in place when up, and down.


One of our favorite features of the Surface604 Quad was definitely the Maxxis Rekon Tires (27.5 x 2.8) . These tires have a wide, blocky tread pattern that’s perfect for off road riding. We were able to climb extremely steep and loose hills without sliding out, and were able to corner with more speed and traction than we are used to.

Because of the 2.8 inch width we noticed improved balance and control at low speeds, and increased stability at high speeds – The Rekon’s 2.8 inch width felt like a happy median of rolling speeds, and traction.

The tan sidewalls of the Rekon tires was also a nice touch, as it fits the scheme of the Quad perfectly.

Maxxis Tires

2.8″ Wide Tires

Summary Review / Where to Buy

The Surface604 Quad proved itself worthy on all the light to intermediate trails we rode it on, and showed that it was well engineered by the team at Surface604. We really liked having the torque sensor hooked up to the vibration free rear hub motor. The motor was quick to engage and consistent in feeling, and performance. This setup also was great at flattening hills, we got one of our fastest hill climb test time on the Quad.

The Quad always seemed to know how much power to give us when riding, and because of this we were able to tackle moderate technical off road terrain far better than we could have on a cadence/speed sensor bike. The Quads ability to mediate power output also allowed the bike to hold on to battery life for far longer than we were expecting.

You can purchase the Surface604 Quad directly from the manufacturer’s website, or use their dealer locator tool to find one near you.

We were very impressed with the maximum range of the Quad’s 48v battery. Knowing the Quad can get over 60 miles on a charge was definitely confidence inspiring to us, and we did some crazy voyages because of it.

The whole Electric Bike Report team agreed that the Quad felt just as good as it looked, and that the bike is a great value for the price you pay. With a quality frame, motor, sensor, tires, and more it’s hard not to love what the Quad has to offer. It’s unique, and can hang with the competition.

If you want to progress your riding, and knowledge of the area you live, a bike like the Quad is a great option. Those looking to adventure, and tackle off road trails and roads will surely like what the Quad offers. Surface604 has put lots of time, and engineering into the Quad, and we were able to see and feel. All in all, The Surface604 Quad proved to be a great adventure bike, and we enjoyed the unique experience the Quad offered us.



Reader Interactions


  1. I own a 2021 Quad, the best, awesome, can’t say enough. Never worry about climbing up or dropping down any terrain. I am 59 yrs old and will ride forever now.

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