2023 Surface 604 Shred Review


Technical Specs & Ratings





Class 2, Class 3


Front Suspension



Hydraulic Disc



672 Wh

960 Wh

63 lbs / 28.60 kgs





Front Suspension


SR Suntour XCM 32 Spring Suspension, 110 mm Travel, Compression Adjust with Lockout, Preload Adjust, 32 mm Steel Stanchions, 110 mm Hub Spacing, 15 mm Thru Axle with 6 mm Hex Bolts

Double Wall, Aluminum Alloy, 35.5 mm Outer Width, 36 Hole, Black | Spokes: Stainless Steel, 13 Gauge Front and 12 Gauge Rear, Black with Adjustable Nipples, Front Bub 1-Piece Forged CNC with 2 Sealed Bearings, Cro-Mo Axle and Alloy Quick Release

CST Patrol, 27.5" x 2.8" (71-584), 20 to 35 PSI, 1.4 to 2.4 BAR, 140 to 240 KPa


SAMOX Tapered with Sealed Bearings, Tapered 1-1/8" to 1-1/2"

UNO, Aluminum Alloy, 40° Angle, 90 mm Length, 20 mm Tapered Base Spacer, One 10 mm Spacer, One 5 mm Spacer

PROMAX Aluminum Alloy, 30mm Rise With 9° Backsweep, 720mm Length

Velo, Flat Rubber, Locking, Black

Alloy, Forged Head, Dual Bolt


Selle Royal Essenza Plus Gel, Adjustable up to 9 Degrees

Wellgo Aluminum Alloy Platform with Fixed Pins

Hydraulic Disc

Tektro E500 Hydraulic Disc with 180mm Rotors that are 2.35mm Thick, Dual-Piston Calipers with Resin Composite Pads, Three-Finger Tektro Levers with Adjustable Reach and Motor Inhibitors


BÜCHEL SHINY 120 LED Headlight Mounted to Stem, Pre-Wired To Connect to Rear Stop Light

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)

9 lbs (4.08 kg)

17.5 in (44.45 cm)19.5 in (49.53 cm)

Medium / Large: 19.5" Seat Tube Length, 23.75" Reach, 27.5" Stand Over Height, 33.75" Minimum Saddle Height, 28" Width, 74" Length. Standover Height: Small-Medium: 28.5” (724mm) and Medium-Large: 30” (762mm), Recommended Rider Height: For Riders: S/M 5’2” - 5’7”, M/L 5’8” - 6’6” Frame Sizes: S/M - 17.5", M/L - 19.5"

Satin Black with Gloss Black Accents

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

Rear Rack Mounts, Fender Mounts, Bottle Cage Mount Below Downtube

KMC 9-Speed Chain, Flick Bell Near Right Grip, Integrated Büchel Shiny 120 E-Bike LED Headlight (120 LUX, Custom Stem Mount), Rear Mount Adjustable Kickstand, 5 Volt 1 Amp USB Type A Charging Port on Side of Battery Pack, Optional Wren Air Suspension (Inverted Design, 36mm Black Annodized Alloy Stanchions, Carbon Fiber Stanchion Shields, Lockout Adjust, Rebound Adjust, Air Compression and Air Progression Adjustability), Optional SR Suntour NCX Suspension Post, Optional 20 Amp Hour Battery Upgrade

Locking Removable Semi-Integrated Downtube Battery Pack (Reention Dorado), 1.4lb 2 Amp Charger, Optional 4 Amp Fast Charger

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)(Unlockable for 45kmh 28mph)

Video Reviews

Written Reviews

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 Surface 604 products. I welcome your corrections, additions, and feedback in the comments below, and the Surface 604 electric bike forums.


  • This is one of the few electric bikes I’ve seen with a hub motor that uses a torque sensor. That makes it a bit smoother, but also requires more effort when pedaling. It’s a good option for trail and mountain riding, when precision is important.
  • Surface 604 offers a bunch of great add-on accessories including custom fitted fenders, a rear rack with pannier hangers, pannier bags, trunk bags, and an optional suspension seat post with shim (adapts 30.4mm to 27.2mm). The most exciting optional upgrade is the inverted Wren air suspension fork because it’s lighter, smoother, and much more adjustable than the stock spring fork. Surface 604 put the SR Suntour NCX suspension post and Wren fork on the demo bike and it was fun to test them, though I always prefer to test stock builds and am basing my review on my feelings about the stock bike.
  • Official list of upgrades: 21700 Samsung Cells 48V20Ah Battery, Chain Guide, NCX Suspension Seat Post, Rear Rack, Rear LED Light, and Wren Inverted 110mm 4.82 lbs suspension fork
  • I love that they  have moved the headlight up onto the stem (center of the handlebar), because it makes you more visible, still points where you steer, but won't get bounced around as much as the older position on the suspension fork arch.


  • Building on prior generations of this same model, Surface 604 has added a narrow-wide chainring to reduce drops, increased battery capacity options, and expanded from S/M and M/L frame sizes to include a new XS (extra small) which is basically the S/M frame with 26″ wheels. This is a great option for petite riders and youth.
  • The stock 672 watt hour battery is above average, but their 960wh option only costs $300 and would be great for long distance rides, people who rely on the throttle frequently, or those who plan on carrying gear. The bike comes with a USB charging port below the display, a second port on the battery pack, has an integrated headlight, and is wired for a rear light (that comes with their rear rack option). This bike could easily transform into a commuter platform.
  • Outstanding headlight placement, not only is this a high quality light but it’s positioned high and points where you steer. The custom metal bracket ensures that the headlight does not collide with the large color LCD display panel. The cockpit is great, and the light actually illuminates the path vs. just helping you be seen.
  • Refined paint job is clean and mean looking. The main color is satin black with some glossy black logos for branding. It has a more premium feel in my opinion, and nearly every hardware part is black to match including hubs, spokes, rims, cranks, seat post, stem, handlebar, and suspension fork. The stock fork has silver stanchions vs. the black anodized stanchions on the optional Wren air fork upgrade.
  • The stem is 45-degrees vs. 7-degrees and the handlebar is a low-rise vs. flat as you’d see on most true cross country mountain bikes. These hardware decisions combine to offer a more upright “SUV” feel. I appreciate the comfort and hybrid feel here, especially for a hardtail that is setup with a headlight and rack mount. I also like that they included a kickstand and mounted it far enough back that it won’t cause pedal lock. Great decisions all around.
  • The bike is fairly comfortable thanks to its plus sized 2.8″ tires, Selle Royal gel saddle, and adjustable suspension fork. The stock fork offers 110mm of travel, has a preload clicker to “pre-load” the spring based on your weight, and also a lockout for improved efficiency on paved streets. The optional
  • I was impressed that they used Boost hub spacing and a 15mm thru-axle up front. The rear has a unique 138mm hub spacing that provides a bit sturdier bracing angle and fits the plus sized tires. The entire frame is custom.
  • The display is large and bright, the important readouts are easy to see, and the battery has a percentage readout that is much more precise than a basic five bar infographic. I also appreciate that it has an adjustable angle to reduce glare.
  • Trigger throttles seem like a good choice for electric mountain bikes because they are separate from the grips. I have noticed that sometimes I grip harder when I’m anxious or about to miss a stop or turn, and this can result in twisting a twist-throttle and going faster when I really wanted to stop or slow down.
  • The torque sensor is more responsive than a cadence sensor, and works well for technical terrain and off-road riding. I also found that it encourages active pedaling, which extends range.
  • The hub motor is extremely quiet, I kept listening during the ride test and tried to show this in the video. I was told that this is a higher quality hub motor from Bafang. It offered good power, even though it was fairly quiet. Their official website says eMTB Specific 500W (Peaks At 750W) Bafang brushless geared hub motor that peaks out at 65nm of torque, so it appears to be more powerful than some others and specced for climbing and off road. They also say the controller is 12 MOS 48V 500W 25 amp, which is above average.
  • Surface 604 used higher quality SRAM and Shimano parts, which tend to shift more reliably and weigh less. This particular ebike model has a 12-34 tooth cassette with 9 sprockets, so you get lots of pedal cadence choices, and a decently sized large ring (for climbing). Depending on inventory, I have seen past Shred models use Shimano Alivio 11-36 tooth, which is even wider range.
  • I appreciate that the battery lock and charge port are high up on the left side of the frame, that the battery can be charged on or off the bike, and that they offer a fast charger! These Reention Dorado battery designs have become fairly common, and seem to hold up over time. They aren’t as beautiful as a fully integrated pack, but they cost less and are modular and cross compatible with other bikes. Since the bike is black, the battery blends in.
  • The bike can be unlocked to go a bit faster for off-road use or commuting as a Class 3 speed pedelec. This follows the more open battery design standard and trigger throttle. I believe they are mostly using Bafang parts.
  • Given the higher potential top speed and heavier build of this ebike (especially with suspension seat post and rear rack options) the 180mm hydraulic disc brakes with adjustable reach levers and motor inhibitors are perfect. They purposefully use Tektro, which is a more trusted brand, and have composite brake pads that are designed to not squeal as much.
  • Surface 604 uses high quality sealed headset and bottom bracket bearings that are sealed against water. They will last longer and won’t creak as much.
  • I like the large, sturdy, Wellgo brand aluminum alloy platform pedals that Surface 604 chose here. They match the color and design, and provide a stable surface to ride from compared to plastic or alloy cages. They have large openings for mud or snow to push through vs. clumping and getting slick.
  • Both wheels are built with thicker spokes and 36 hole vs. 32 hole to add strength for the higher speeds, off-road use, and potential cargo.
  • The trigger throttle overrides all levels of assist with full power, so you can zip up hills or catch up to friends without having to click any extra buttons. This is my favorite configuration because it’s more empowering. You can also completely unplug the throttle if you wish, which could help the bike comply with Class 1 riding.
  • I like the optional inverted Wren air suspension because it offers more preload adjustability (air pressure) and has a second chamber at the base of the left side for progressive stiffness. It also has a lockout and rebound adjust on the right. The lower stanchions are black annodized aluminum alloy that look great, and there are carbon fiber shields to protect from damage. This is a special fork because it fits an 1-1/8″ steer post (the size needed for S604 Shred). If you buy the fork, I’m told that they will install the crown race and star bolt, so it’s easier to swap in. You will still get the SR Suntour spring fork with the bike if you order the Wren, but you need to swap them yourself.


  • The Shimano Alivio derailleur shifts well, but the high gear shifter lever requires the index finger on the right hand vs. the thumb (which is used to press the low gear lever). I point this out because I prefer to use my thumb for all shifting and dedicate my pointer and middle fingers to braking.
  • Minor consideration, the steer post is straight 1-1/8″ vs. tapered which limits the options for upgrading the suspension fork. The included SR Suntour XCM 32 is a decent spring suspension and their $799 Wren air fork upgrade is a very good option.
  • Weighing in at ~57.1 lbs (for the 19.5″ frame with the smaller 14 amp hour battery), this ebike is a bit heavy for a hardtail. I think the weight is due to using a spring fork, thru-axle with Boost hub spacing up front, plus sized tires, and the more powerful hub motor.
  • The bike does not come with a slap guard. I’d probably use a piece of clear box tape or purpose made sticker slap guard to protect the black paint. Deep chips could expose the silver aluminum alloy and spoil the look.
  • There’s a little bit of crowding at the right rear dropout because the shifter cable and motor power cable both connect here, try not to let these cables get snagged or bent (like if the bike tips over). There’s no derailleur guard or other protective hardware in place, which could also help during shipping. Just be careful with the derailleur when unboxing.
  • I like how large the display is, but considering the mountain bike application… it could be exposed to falls and more scratches than a pure city bike. I guess I’m pointing this out because most of the super high-end eMTB models appear to be going with super small displays or integrate them into the top tube.
  • If you pay extra for the high capacity 20 amp hour battery pack, you will notice that it spills out to the left of the downtube a bit. It’s not symmetrical like the standard 14 amp hour pack because it has longer 21700 cells inside vs. 18650 cells.

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