2023 Surface 604 Quad Review


Technical Specs & Ratings





Class 2, Class 3


Front Suspension



Hydraulic Disc



672 Wh

960 Wh

61 lbs / 27.69 kgs





Front Suspension


SR Suntour XCM 32 Spring Suspension, 100 mm Travel, Compression Adjust with Lockout, Preload Adjust, 100 mm Hub Spacing, 32 mm Steel Stanchions, 15 mm Thru-Axle with 6 mm Hex Bolt

Double Wall, 6061 Aluminum Alloy, 35 mm Outer Width, 36 Hole, Black | Spokes: Stainless Steel, 12 Gauge Back, 13 Gauge Front, Black

Maxxis Rekon+, 27.5" x 2.80" (71-584), 17 to 35 PSI, 1.2 to 2.5 BAR, Skinwall Brown Sidewalls, 3C, MaxxTerra, Reinforced Silkshield EXO Protection, Tubeless Ready


Surface 604 Branded, Integrated, Sealed Cartridge, Straight 1-1/8"

Ergotec 6+, Aluminum Alloy, 0° Rise, 50 mm Length, Base Height, 15 mm Tapered Spacer, Two 10 mm Spacers, One 5 mm Spacer, 31.8 mm Clamp Diameter

Aluminum Alloy, 40 mm Low-Rise, 20 mm Backsweep, 720 mm Width

Stitched Faux Leather, Ergonomic, Black, Locking

Aluminum Alloy with Forged Single-Bolt Clamp, 4 mm Hex Bolt for Seat Clamp (30.4 mm to 27.2 mm Shim and SR Suntour NCX Suspension Seatpost Shown on Demo Bike)


Velo, Active, Brown

Aluminum Alloy Platform, Wide with Integrated Pins, Gold with Silver Accents (They May Switch to Black)

Hydraulic Disc

Tektro Dorado Hydraulic Disc with 180 mm Rotors, Dual-Piston Calipers, Three-Finger Tektro Levers with Motor Inhibitors and Adjustable Reach

More Details

Urban, Trail, Mountain

United States, Canada

1 Year Comprehensive, 3 Year Frame

7.7 lbs (3.49 kg) (672wh Battery, 10lb for 960wh Battery)

7.7 lbs (3.49 kg)

17.5 in (44.45 cm)19.5 in (49.53 cm)

Medium-Large Frame: 19.5" Seat Tube Length, 24.5" Simulated Top Tube Length, 17" Reach, 29.75" Stand Over Height, 34" Minimum Saddle Height, 42" Maximum Saddle Height, 28.75" Width, 75" Length, 46.75" Wheelbase

Brushed Aluminum Alloy with Glossy Silver Labeling and Black and Gold Accents

138mm Hub Spacing, 12mm Threaded Axle with Keyed 10mm Flats, 18mm Nuts

Rear Rack, Fender Bosses, Bottle Bosses Below Downtube

5 Volt 1 Amp USB Type A Charging Port at Top Right Side of Battery, Flick Bell Near Right Grip, Integrated Büchel Shiny 120 E-Bike LED Headlight (120 LUX), Rear Mounted Adjustable Kickstand (40mm Tab), Optional Rear Rack with Integrated Büchel 2-LED Rear Light, Optional SR Suntour Suspension Seatpost, Optional Ergotec Handlebar Mirror, Optional Leather Panniers, Optional Aluminum Alloy Fenders

Locking Removable Semi-Integrated Downtube Battery Pack, VG Sports Gold Colored Chain, 1.4lb 54.6 Volt 2 Amp Charger, 20 Amp Motor Controller, 300lb Total Weight Rating

Independent Button Pad near Left Grip, Buttons: +, -, Information, Lights, On/Off, (Hold - for Walk Mode, Hold + and - for Settings Menu, Settings Password 1212, Speed Limit Password 0510)

Battery Percentage, Current Speed (With Infographic), Power Meter, Trip Distance, Odometer, Max Speed, Avg Speed, Trip Time, Assist Level (0-5)

Torque Sensing Pedal Assist, Trigger Throttle (Measures Pedal Torque at Rear Dropout)

20 mph (32 kph)(Can Unlock ~26mph Top Speed)

Video Reviews

Written Reviews

This review was provided for free, but Surface 604 did provide a temporary demo bike and accessories 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.


  • Surface 604 dates all the way back to 2013. I was lucky enough to review their first product, the Element electric fat bike, in 2014. S604 products are designed to be affordable, but capable on a wide variety of terrain. Their designers frequently choose components that are a step up in terms of durability and quality because they come from the mountain bike background in Vancouver Canada, where it rains a lot. 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.
  • The Quad is names after quadangle BMX bikes that were popular in the 1980’s. You can tell that the designer (Jason, who is awesome) had a lot of fun with this model! The brushed aluminum alloy with silver and gold accents is so sweet. This ebike is like an SUV in my opinion, it’s capable but still comfortable with a more upright geometry. The bike is almost exactly the same as the S604 Shred model, just built around a different frame with different tires.
  • Standard features include: Adjustable Kickstand, Water Bottle Bosses, LED Headlight, Optional upgrades include: 21700 Samsung Cells 48V20Ah Battery, Chain Guide, NCX Suspension Seat Post, Metal Fenders, Rear Rack, Rear Led Light.


  • Very unique style and look, in my opinion it is done perfectly! The bike only comes in one color scheme, but the brushed aluminum alloy, silver and gold accents, and all-black components just look amazing. The gold chain is almost like a gold necklace and the muted branding is on point. If you don’t love this look, consider the Surface 604 Shred which is basically the same bike.
  • Available in two frame sizes for improved fit and function. Considering the price point here, which is slightly above the value mark for products that use the same motor and battery setup, I appreciate the extra frame size options, sealed bearings, hollow spindle, and 15mm thru-axle.
  • Even though I consider the geometry and body position to be more SUV than true cross country, the bike uses quality parts and could handle off-road. You could always swap the stem and handlebar to make it more aggressive and the puncture resistant tires would do great.
  • Surface 604 has been around since 2013 and built a solid reputation. They sell online direct, as well as through a network of independent bicycle dealers that can help with assembly and support. They have earned my trust.
  • I love that the design team included a bottle cage mount on the bottom of the downtube, even though it’s difficult to reach. This may be used for a mini pump, folding lock, or bottle cage. Same goes for the fender bosses and rear rack bosses. Surface 604 sells a bunch of accessories that are guaranteed to fit and look great, you can see the fenders on my demo model.
  • If you opt for a rear cargo rack, I believe it’s rated to 50lbs and compatible with most child seats. It also works with their integrated light that connects directly to the controller and runs off of the main rechargeable ebike battery! This is awesome, because by default, the bike only comes with a headlight.
  • The headlight they chose is quite bright, and has side windows to improve your visual footprint. Normally, headlights are mounted lower down on the suspension arch which isn’t as safe and may vibrate more because that position is not suspended. S604 made a custom light bracket that mounts to the stem and it works great… points where you steer and the beam won’t get cut off by the fender or front tire.
  • There are two battery options with this ebike, and the default 672 is above average! For a bit more money, you can upgrade to 960 watt hours to extend range (great if you plan to use the throttle frequently). I love that both battery packs have a built-in USB port for charging accessories, even if the battery is not on the bike. There is a second USB Type A port built into the base of the display, so you don’t have to run wires all over the bike if you add more lights or want to charge your phone… this is all great considering the extra energy the bike batteries both have.
  • My understanding is that many of the Surface 604 bikes now use the same Reention Dorado battery interface, so the battery pack can be shared! This is a more open battery standard, which means you can have the batteries repacked or purchase them from generic suppliers someday if S604 changes their design or goes out of business.
  • Normally, I love to see tires with reflective stripes on the sides… especially on ebikes that are meant for urban environments (which I feel like this kind of is). Given the light brown sidewalls, silver frame, and great headlight, I feel like this one offers a great visual footprint and is pretty safe in that sense… so the cross country tires (which normally don’t have reflective stripes) are fine.
  • Pretty good suspension fork here, I love that it offers lockout and preload adjust to “pre load” the spring for heaver riders. The sturdy 15mm thru-axle is a big upgrade from 9mm axles that use quick release, and the wider 110mm Boost hub spacing improves spoke bracing angle and strength. The front wheel has 13mm spokes and the rear appears to be 12mm which is even thicker. The wheels are super sturdy and use 36 spokes, so they should be capable of handling heavier riders and heavier trails.
  • Good weight distribution with the battery pack low and center. The spring fork weighs a bit and balances out the rear hub motor. High-step diamond frames tend to be sturdier and stiffer than mixte mid-step or step-thru, so the bike should perform without flex or failure with 300lbs of total weight onboard.
  • The LCD display is large and fairly easy to read, it offers adjustable angle to reduce glare and has the USB port in the bottom. I appreciate that the button pad for it has a dedicated lights on/off button and info button. You can get into the settings fairly easily by holding + and – simultaneously and S604 has codes that let you unlock higher speeds if you wish. Both the button pad and trigger throttle are fairly easy to reach and intuitive to operate.
  • I was told that the bike comes with a shim adapter that converts the 30.4mm seat post to 27.2mm which is more standard, to make it easier for you to swap to a suspension post if you wish! The demo bike I got already had their optional SR Suntour NCX suspension post installed, and it’s a great way to reduce back, shoulder, and neck sensitivity if you do plan on going off-road.
  • Speaking of off-road, not only are the chain and cassette upgraded (with a wide 11 to 36 tooth cassette painted gold) but the chainring uses a narrow-wide tooth pattern that grabs the chain more securely so you don’t drop it when riding on bumpy sections of trail. It’s a clean lightweight way to improve the drivetrain vs. a full guide.
  • I already mentioned this briefly, but since the bike weighs a bit more and has a powerful motor, I love that they chose larger 180mm hydraulic disc brakes because the larger diameter improves stopping power due to mechanical advantage, and they usually cool faster too. The brake calipers are standard dual piston, but the pistons appeared to be larger than average, and the brake levers were definitely large 3 or 4 finger with balled ends for safety (like motorcycles have).
  • 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.
  • The large 27.5″ x 2.8″ plus sized tires offer a larger contact patch that improves grip, float, and stability. It’s a popular size for ebikes because the additional weight and drag are more than offset by the motor. These tires come tubeless ready if you wish to set the rims up, they are puncture resistant, and have the stylish brown sidewall. The larger overall diameter is close to 29″ which offers a lower attack angle for easier rides over rough terrain.
  • The hub motor is fairly quiet considering the higher 65 newton meters of peak torque output. It’s rated at 500 watts nominal, but probably peaks out around 750 peak. The torque sensor design is very responsive to start, and more natural for mountain biking than a cadence sensor in my opinion, they say it is rated at 65nm of torque.
  • This is a minor thing, but the brake levers both offer adjustable reach for improved fit, and I suspect that they activate the rear light if you get that as an option with the rack (at least this is the case for their city models like the Surface 604 Rook and Colt).
  • Lots of changes from previous generations for easier maintenance and repairs, for example, the controller has been changed to use standard XT60 connectors and is much easier to reach for diagnostics and repairs when necessary. Notice the quick disconnect for the motor, headlight, display, brake motor inhibitors, and trigger throttle. The controller has also been upgraded to produce 20 amps of power output for that zippy powerful ride feel. Many cheaper ebikes use 18 amp controllers.


  • The Quad I looked at was first generation, which always gives me a bit of pause… but since it’s using the same hardware as the very proven Shred model, and S604 has been in business designing and selling bikes so long, it felt more trustworthy than some other newcomer models.
  • Since this is technically a high-step frame, it’s less approachable than many of the newer mixte mid-step or step-thru models. That means you’ll need extra hip and leg flexibility to mount and ride, especially if you add a rear rack. It’s stiff, sturdy, and off-road capable, just higher to standover and a bit wider due to the triple tubes of the quadangle (look at photos looking down onto the frame to see what I mean).
  • Weighing in at 57.4lbs for the medium-large frame with the standard size battery and no fenders or seat post suspension… this is a heavier than average ebike. Normally hardtail ebike models with this battery and motor configuration are closer to 54lbs, but I suspect the boost hub spacing, additional and thicker spokes, plus sized tires, spring suspension, and quadangle frame add the additional 3+lbs. It will weigh even more with the fenders, rack, and optional suspension seatpost. Good thing the 7.7lb battery pack is relatively easy to remove, so the bike is easier to lift onto car racks etc.
  • Minor consideration, but the seat post clamp and wheels all use hex bolts (6mm and 4mm respectively) which is great to deter theft, but makes maintenance and adjustments slower and requires that you bring a multi-tool.
  • The saddle is definitely more active than comfort, but it felt GREAT to me. I’m only bringing this up because the bike is a bit more of an SUV in my opinion, than a BMX or cross country ebike. More upright geometry, shorter stem, low-rise handlebar. Maybe the saddle felt great to me because I normally ride firm active saddles and it had a suspension seatpost setup.
  • The battery locking cylinder and charge port are both on the non-drivetrain side of the bike, which is more vulnerable since it leans that way when on kickstand. The charge port is low, and exposes the charging cable to the left crank arm. You have to bend down to plug it in, and the bike leans towards you. I’d prefer both of these to be high on the right side of the bike for easy access and reduced snag potential.
  • The charger for this ebike is pretty basic, though I do appreciate the branding they did. It’s fairly compact, has a removable wall-side cord to reduce length, and it only weighs ~1.4lbs, but it only puts out 2 amps. This makes it slower than some of the 3 and 4 amp chargers I’ve seen from other companies, which is especially relevant if you get the upgraded 20 amp hour battery (960 watt hour) because it could take 7+ hours for a full charge. I’ve also heard that the barrel style charger plugs can ark easier or crack the plug socket if bumped.
  • Considering that many customers will probably order the Surface 604 Quad online vs. in a shop, I was surprised that it didn’t have a derailleur guard? This can reduce damage in shipping and if the bike tips. It protects the derailleur and the motor power cable from snags and is common on many ebikes with the same drive system design. There’s also no slap guard to protect the frame from grease and chips… but it’s brushed aluminum alloy, so won’t rust and won’t really show chips, so maybe not a big deal :)
  • The display panel is not removable, and may take damage when parked at bike racks. it’s all meant to be fairly water resistant though, which is great if you ride this as a commuter. The throttle is on the left side vs. right, which I feel is more intuitive to people who grew up riding mopeds, motorcycles, jet skis etc. but that’s because the trigger shifters for the gears are on the right and they didn’t want to compromise the sturdy grips with a twist throttle (sometimes less safe when actually riding off-road on bumpy terrain than a trigger).
  • As great as the torque sensor at the rear dropout is for starting and responding naturally, it didn’t seem to cutoff as quickly as a multi-sensor and may even activate unexpectedly when going off drops or large bumps due to chain tension changes. You can see me talk about this and demonstrate in the video review above. To overcome this issue, just pull either brake lever slightly whenever you wish to cut power to the motor.
  • The fork they chose is pretty decent and kind of unique, because it’s a 15mm thru-axle with boost but because it’s using a straight 1-1/8″ steer tube vs. tapered 1-1/8″ to 1-1/2″ you may struggle to replace or upgrade it with an air fork to reduce weight and add tuning options like rebound, you might have limited options.
  • If you opt for the upgraded 48 volt 20 amp hour 960 watt hour battery pack, you will notice that it spills out to the left side a bit and is not perfectly centered on the frame. This bugs me a bit aesthetically and may slightly impact the balance of the frame.
  • While the quadangle frame looks cool and is sturdy and stiff, it does not leave enough room for a bottle cage mount on the seat tube and may be difficult to hang on some car and bus racks, or to shoulder and carry.
  • Due to supply chain challenges, this ebike 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. Furthermore, the fenders may be plastic SKS which are durable and light but noisier than the aluminum alloy ones.
  • The control pad is mounted behind the trigger throttle on the left, and I found that it took a bit more flexibility and effort to reach in this configuration, you could always change the order, but then the throttle would be tricky to reach, you could also try to put the throttle on the right portion of the handlebar but then it will interfere with the trigger shifters, maybe a future throttle mount will be narrower so the buttons can move closer…

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