Surface 604 Twist Review

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Surface 604 Reviews
Surface 604 Twist Review

A folding fat tire electric bike with approachable step-thru frame. Low stand over height and low minimum saddle position. Two colors including satin black and satin grey. Large color LCD with USB port for charging electronics, powerful geared hub motor, clean wires and decals, quality 10-speed SRAM X5 drivetrain.
Good weight distribution with the battery pack low and center on the frame. The charging port and locking cylinder are high on the main tube, making them easier to access. The sturdy integrated rear rack, wide fenders, lights, and reflective tires make it safe and flexible in a wide range of conditions.
Free shipping and in-person availability through 90+ dealers. Powerful hydraulic disc brakes with motor inhibitor and brake light blinking mode. Torque sensing pedal assist is responsive and natural, trigger throttle overrides assist. Optional fast charger, trunk bag, pannier bags, suspension seat post, and more.
Kickstand mount is fairly close to left crank arm, and could get kicked while pedaling. Torque sensor may surge or activate unintentionally on rough terrain. Weighs 59lbs due to large motor, fenders, lights, and integrated rack. No mechanism to keep the bike folded, such as a magnet or strap, and no derailleur guard.

Make:

Surface 604

Model:

Twist

Price:

$2399

Body Position:

Upright

Suggested Use:

Neighborhood, Urban, Commuting, Trail

Electric Bike Class:

Throttle on Demand (Class 2), Speed Pedelec (Class 3)

Learn more about Ebike classes

Warranty:

1 Year Comprehensive, 3 Year Frame

Availability:

United States, Canada

Model Year:

2023

Motor Brand:

Bafang RMG060.500.DC

Motor Type:

Rear-Mounted Geared Hub

Learn more about Ebike motors

Motor Nominal Output:

500 watts

Motor Peak Output:

750 watts

Motor Torque:

80 Newton meters

Battery Brand:

Samsung 18650 3,500mAh, Reention Casing

Battery Voltage:

48 volts

Battery Amp Hours:

14 ah

Battery Watt Hours:

672 wh

Battery Chemistry:

Lithium-ion

Charge Time:

5 hours

Estimated Min Range:

30 miles (48 km)

Estimated Max Range:

60 miles (97 km)

Display Type:

Surface 604 Branded, Fixed, Adjustable Angle, 3.5" Color, Backlit LCD, USB Type A Charging Port on Bottom

Readouts:

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

Display Accessories:

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)

Drive Mode:

Torque Sensing Pedal Assist, Trigger Throttle

Top Speed:

20 mph (32 kph)

Total Weight:

59 lbs (26.76 kg)

Battery Weight:

8.2 lbs (3.72 kg)

Motor Weight:

8 lbs (3.63 kg)

Frame Material:

6061 Aluminum Alloy

Frame Sizes:

17.5 in (44.45 cm)

Geometry Measurements:

17.75" Seat Tube Length, 24" Simulated Top Tube Length, 18.5" Reach, 16.5" Stand Over Height, 32" Minimum Saddle Height, 26.75" Width, 45.5" Wheelbase, 70" Length

Frame Types:

Step-Thru

Frame Colors:

Satin Black, Satin Grey

Frame Fork Details:

Rigid Aluminum Alloy, 135mm Hub Spacing, 9mm Axle with Quick Release Skewer

Frame Rear Details:

175mm Hub Spacing, 12mm Threaded Axle with Keyed 10mm Flats, 18mm Nuts

Attachment Points:

Rear Rack, Fender Bosses, Bottle Bosses on Seat Tube

Gearing Details:

10Speed 1x11 Shimano RD-RX817 GRX Di2 Derailleur, Shimano CS-M8000 11-42 Tooth Cassette

Shifter Details:

SRAM X5 Triggers on Right (One-Way High, Three-Shift Low)

Cranks:

Samox, Forged Aluminum Alloy, 170mm Length Crank Arms, Sealed Cartridge Bearings, Hollow Axle, 44 Tooth Steel Chainring with Aluminum Alloy Guard

Pedals:

Wellgo K79 F265 Aluminum Alloy Platform with Integrated Pins, Folding, Black

Headset:

Integrated, Open Bearings, Quill, Straight 1-1/8"

Stem:

Aluminum Alloy, Folding, 12° Forward Angle, 31.8mm Clamp

Handlebar:

Aluminum Alloy, 660mm Length, Low-Rise, 6° Backsweep, 30mm Rise

Brake Details:

Tektro Auriga Hydraulic Disc with 180mm Rotors, Dual-Piston Calipers, Three-Finger Tektro Levers with Motor Inhibitors and Brake Light Blink Activation and Adjustable Reach

Grips:

Stitched Faux Leather, Ergonomic, Black

Saddle:

Selle Royal Essenza Plus+

Seat Post:

Aluminum Alloy with Forged Single-Bolt Clamp

Seat Post Length:

300 mm

Seat Post Diameter:

30.4 mm

Rims:

6061 Aluminum Alloy, Single Wall, 80mm Outer Width, 36 Hole, Black

Spokes:

Stainless Steel, 13 Gauge, Black

Tire Brand:

CST Big Boat, 20" x 4.0" (98-406)

Wheel Sizes:

20 in (50.8cm)

Tire Details:

5 to 30 PSI, Reflective Sidewall Stripe

Tube Details:

Schrader Valve

Accessories:

Plastic Fenders (100mm Width), Flick Bell Near Right Grip, Integrated Shiny 120 LED Headlight (120 LUX), Integrated Büchel Tivoli 2-LED Rear Light (Blinks When Braking), Welded-On Rear Rack with Top Platform and Bungee Loops, Rear Mounted Adjustable Length Kickstand (40mm Tab)

Other:

Locking Removable Downtube-Integrated Battery Pack (Reention), 1.5lb 2 Amp Charger, Optional 4 Amp Fast Charger

This review was provided for free using a demo bike. 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:

This is the second generation Twist from Surface 604, and they updated a few things including: improved stem angle (more forward, matches the feel of small/medium sized Rook), no longer has an adjustable height stem, stiffer bottom bracket, sturdier chainring guard, 10-speed cassette vs. 9-speed, and strong seat tube that allows the saddle to go lower!
The company has been around since 2013, and has a good reputation for making fat tire and light trail bikes. What makes this particular folding fat bike unique and special are the two colors, super-low approachable frame, and powerful motor battery combination.
I consider this ebike “feature complete” which means it can be used in a variety of lighting and weather conditions, while also transporting cargo. It comes with fenders, integrated lights, and a sturdy rear rack. Components are nearly all above average.

Pros:

Extremely approachable ebike with low standover height. The step-thru design is low and also fairly long, so there’s plenty of room to mount and stand over the frame. This helps you stabilize the bike and feel comfortable… especially because the fat tires also improve stability side to side.
The fat tires provide many benefits including stability and comfort. I like the CST Big Boat model that Surface 604 chose because the hybrid tread is efficient and quiet, they even have reflective stripes to increase your visual footprint and safety.
High quality integrated lights are included. The rear light uses two LEDs and blinks when either brake lever is pulled! The headlight is bright, aimable, points where you steer, is not blocked by the fender, and has side cutouts to improve your visibility from many angles. Excellent choice!
The bike is fairly comfortable. They chose a name brand Selle Royal gel saddle and specced ergonomic grips. The fat tires offer a bit of shock absorption and vibration dampening, especially if you lower the pressure a bit. They are taller than non-fat 20″ tires and that lowers the attack angle for a smoother ride over cracks and small obstacles.
Electric bikes can get pretty heavy, especially with powerful motors, high capacity battery packs, fenders, lights, and integrated racks like this one has! The fact that they chose to skip a suspension fork actually makes the bike feel more steady and significantly reduces weight. I look at this as positive trade-off if you care about reduced weight… this model weighs just under 60lbs, while similar products are 5 to 10 pounds heavier.
I love the battery choice, because it mounts from the top! It’s fairly heavy at 8.2lbs, and it’s just easier to access and remove than ones that mount from the bottom of the frame tube or require you to fold the frame. The battery is positioned farther forward, so it balances out the hub motor pretty well.
I appreciate that the charging port and locking core for the battery pack are both high up on the frame vs. low near the crank arms, where the cable or key could get snagged.
I love that Surface 604 included bottle cage mounts on the seat tube! This is something that often gets skipped on ebikes due to battery positioning. They were very deliberate with the seat tube, having it flare out towards the bottom for improved stiffness and strength. I was told that this also allows the seat post to go down farther (without colliding with the bottle cage bosses) which lowers saddle height.
The price point is pretty good when you consider all of the parts, such as the 10-speed SRAM X5 drivetrain with cassette vs. freewheel and the wide 11-36 tooth spread. That’s an excellent range for this type of ebike! The battery capacity is above average, and the Bafang motor is high quality. Surface 604 offers free shipping, sells through some bike shops, and a has decent one year warranty.
The two color options look good, but it sounds like they discontinued pink (which was unique and kind of fun last generation). I appreciate the light grey one because it will be more visible at night and is kind of neutral.
Many electric bikes opt for cadence sensors because they are affordable and pretty consistent. Surface 604 tends to go with torque sensors to provide more instant power and a dynamic ride feel. It performed well for me, and even though it has some trade-offs with surging and requires more consistent pedal pressure, it’s something a lot of people appreciate because it feels more natural and responsive.
Both brake levers have motor inhibitors that cut power and activate the rear light in blinking mode. This is not a feature that all torque sensing ebikes include because motor cutoff is already near-instant when torque is reduced. They went above and beyond with this decision.
Hydraulic disc brakes are wonderful, because they require less hand effort and have more adjustable levers. These ones are very good because of the motor inhibitors and large 180mm rotors that cool faster and provide an excellent mechanical advantage over the small wheel size. Nice to have with the heavier bike and powerful planetary geared hub motor.
Great display panel because of the large size and color readout. You can adjust the angle to reduce glare, and there’s a full sized USB Type A port built into the bottom to power your portable electronics on the go! This checks all of my boxes, and also has some nice settings where you can adjust top speed (lower or higher).
I appreciate the trigger throttle, because it allows for instant help when starting, and overrides lower levels of assist so you can temporarily boost up hills or catch a friend. It’s setup exactly how I like, but you could easily unplug and remove it if you wanted to convert the bike to Class 1 or wanted to de-clutter the handlebar area and reduce the possibility of accidentally bumping it during starts or folding etc. I recommend always having the bike powered off before folding and unfolding.
Excellent pedal choice! They went with the large aluminum alloy Wellgo folding pedals vs. cheaper plastic ones that flex and aren’t as wide. They also specced a stiffer Sammox hollow spindle bottom bracket vs. squared tapered, and are using a sturdier chainring guard now!
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.
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.

Cons:

The bike only comes in one frame size, and the stem is not adjustable, but you can raise and lower the seat height. The older Surface 604 Twist did have an adjustable stem, but it just wasn’t as stiff and sturdy feeling as this. I was told that they also extended the reach by changing the stem angle 12-degrees, so the bike will feel more like the small/medium sized Rook model they also sell.
Folding electric bikes can appear to be small and easy to lift, but they usually aren’t very light. The fat tires, high powered motor, and high capacity battery pack add significant weight to the Twist, in addition to fenders, lights, and integrated rear rack. I would definitely remove the 8.2lb battery before lifting. Perhaps they could use punched out rims on future models to further reduce weight?
The folding design of the bike works pretty well, but there are no mechanisms to keep it from coming unfolded such as a magnetic clasp (which don’t always work well) or rubber strap. I would use a towel between the frame to prevent chips and scratches, then connect the loose parts using bungee straps.
I love the reflective stripes and hybrid tread of the tires, but I wish they had a pressure rating range instead of just “inflate to 30 PSI”. In my own experience with similar tires, they usually say 5-30 PSI which allows for lower pressure to ride on sand and soft loamy terrain. I would also love some puncture protection on the tires, since fat bikes are good candidates for gravel and light trail riding.
No suspension fork or seat post suspension is included. It’s not such a big issue for people who ride on paved surfaces, but this is where knowing the tire pressure range would be helpful, lower pressure could greatly improve comfort.
The torque sensor works fairly well, and activates much faster than a cadence sensor. However, it can cause some surge feelings based on the uneven pressure of pedal downstrokes. It can also get activated if the chain bounces a lot while riding on rough terrain. I feel that it requires a bit of extra care when removing and re-attaching the rear wheel too, so things aren’t over-tightened. On the upside, this sensor plate might double as a torque arm because it adds more surface area for the axle to push against vs. just the alloy frame dropouts.
A couple of times, the heel of my left shoe caught on the kickstand while pedaling. It’s positioned fairly close to the bottom bracket and while it does not cause pedal lock, it’s just a little exposed and could get in the way for people with big feet or shoes.
The charger for this ebike is pretty basic and a bit slow for the high 672 watt hour capacity of the battery. It’s fairly compact, has a removable wall-side cord to reduce length, and it only weighs ~1.5lbs, but it only puts out 2 amps. Thankfully, they do sell an optional 4 amp fast charger if you’re willing to pay a bit extra.
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 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.
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 if you really go for it). Fortunately, the relaxed position of the riser handlebar means 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 paint could get chipped off 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 motor power cable enters on the right side of the bike, near the deraillur and shifter cable. This area is already a bit crowded, and the extra cable kind of sticks out and could get damaged if the bike tipped. This is especially relevant for a wide folding mode with no derailleur guard. Some motors now bring this power cable along the left side of the frame and have it tucked between the frame and disc brake rotor.
The torque sensor plate can be a little sensitive, if you’re pedaling while powering the bike on, it may impact the zero point and make pedal assist less sensitive for that session. I recommend not pedaling when you power the bike on. One upside of this design is that the torque plate acts as a torque arm to reduce wear and tear on the dropouts… which is relevant for a more powerful hub motor like this.

Observations:

This is the second generation Twist from Surface 604, and they updated a few things including: improved stem angle (more forward, matches the feel of small/medium sized Rook), no longer has an adjustable height stem, stiffer bottom bracket, sturdier chainring guard, 10-speed cassette vs. 9-speed, and strong seat tube that allows the saddle to go lower!
The company has been around since 2013, and has a good reputation for making fat tire and light trail bikes. What makes this particular folding fat bike unique and special are the two colors, super-low approachable frame, and powerful motor battery combination.
I consider this ebike “feature complete” which means it can be used in a variety of lighting and weather conditions, while also transporting cargo. It comes with fenders, integrated lights, and a sturdy rear rack. Components are nearly all above average.

Pros:

Extremely approachable ebike with low standover height. The step-thru design is low and also fairly long, so there’s plenty of room to mount and stand over the frame. This helps you stabilize the bike and feel comfortable… especially because the fat tires also improve stability side to side.
The fat tires provide many benefits including stability and comfort. I like the CST Big Boat model that Surface 604 chose because the hybrid tread is efficient and quiet, they even have reflective stripes to increase your visual footprint and safety.
High quality integrated lights are included. The rear light uses two LEDs and blinks when either brake lever is pulled! The headlight is bright, aimable, points where you steer, is not blocked by the fender, and has side cutouts to improve your visibility from many angles. Excellent choice!
The bike is fairly comfortable. They chose a name brand Selle Royal gel saddle and specced ergonomic grips. The fat tires offer a bit of shock absorption and vibration dampening, especially if you lower the pressure a bit. They are taller than non-fat 20″ tires and that lowers the attack angle for a smoother ride over cracks and small obstacles.
Electric bikes can get pretty heavy, especially with powerful motors, high capacity battery packs, fenders, lights, and integrated racks like this one has! The fact that they chose to skip a suspension fork actually makes the bike feel more steady and significantly reduces weight. I look at this as positive trade-off if you care about reduced weight… this model weighs just under 60lbs, while similar products are 5 to 10 pounds heavier.
I love the battery choice, because it mounts from the top! It’s fairly heavy at 8.2lbs, and it’s just easier to access and remove than ones that mount from the bottom of the frame tube or require you to fold the frame. The battery is positioned farther forward, so it balances out the hub motor pretty well.
I appreciate that the charging port and locking core for the battery pack are both high up on the frame vs. low near the crank arms, where the cable or key could get snagged.
I love that Surface 604 included bottle cage mounts on the seat tube! This is something that often gets skipped on ebikes due to battery positioning. They were very deliberate with the seat tube, having it flare out towards the bottom for improved stiffness and strength. I was told that this also allows the seat post to go down farther (without colliding with the bottle cage bosses) which lowers saddle height.
The price point is pretty good when you consider all of the parts, such as the 10-speed SRAM X5 drivetrain with cassette vs. freewheel and the wide 11-36 tooth spread. That’s an excellent range for this type of ebike! The battery capacity is above average, and the Bafang motor is high quality. Surface 604 offers free shipping, sells through some bike shops, and a has decent one year warranty.
The two color options look good, but it sounds like they discontinued pink (which was unique and kind of fun last generation). I appreciate the light grey one because it will be more visible at night and is kind of neutral.
Many electric bikes opt for cadence sensors because they are affordable and pretty consistent. Surface 604 tends to go with torque sensors to provide more instant power and a dynamic ride feel. It performed well for me, and even though it has some trade-offs with surging and requires more consistent pedal pressure, it’s something a lot of people appreciate because it feels more natural and responsive.
Both brake levers have motor inhibitors that cut power and activate the rear light in blinking mode. This is not a feature that all torque sensing ebikes include because motor cutoff is already near-instant when torque is reduced. They went above and beyond with this decision.
Hydraulic disc brakes are wonderful, because they require less hand effort and have more adjustable levers. These ones are very good because of the motor inhibitors and large 180mm rotors that cool faster and provide an excellent mechanical advantage over the small wheel size. Nice to have with the heavier bike and powerful planetary geared hub motor.
Great display panel because of the large size and color readout. You can adjust the angle to reduce glare, and there’s a full sized USB Type A port built into the bottom to power your portable electronics on the go! This checks all of my boxes, and also has some nice settings where you can adjust top speed (lower or higher).
I appreciate the trigger throttle, because it allows for instant help when starting, and overrides lower levels of assist so you can temporarily boost up hills or catch a friend. It’s setup exactly how I like, but you could easily unplug and remove it if you wanted to convert the bike to Class 1 or wanted to de-clutter the handlebar area and reduce the possibility of accidentally bumping it during starts or folding etc. I recommend always having the bike powered off before folding and unfolding.
Excellent pedal choice! They went with the large aluminum alloy Wellgo folding pedals vs. cheaper plastic ones that flex and aren’t as wide. They also specced a stiffer Sammox hollow spindle bottom bracket vs. squared tapered, and are using a sturdier chainring guard now!
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.
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.

Cons:

The bike only comes in one frame size, and the stem is not adjustable, but you can raise and lower the seat height. The older Surface 604 Twist did have an adjustable stem, but it just wasn’t as stiff and sturdy feeling as this. I was told that they also extended the reach by changing the stem angle 12-degrees, so the bike will feel more like the small/medium sized Rook model they also sell.
Folding electric bikes can appear to be small and easy to lift, but they usually aren’t very light. The fat tires, high powered motor, and high capacity battery pack add significant weight to the Twist, in addition to fenders, lights, and integrated rear rack. I would definitely remove the 8.2lb battery before lifting. Perhaps they could use punched out rims on future models to further reduce weight?
The folding design of the bike works pretty well, but there are no mechanisms to keep it from coming unfolded such as a magnetic clasp (which don’t always work well) or rubber strap. I would use a towel between the frame to prevent chips and scratches, then connect the loose parts using bungee straps.
I love the reflective stripes and hybrid tread of the tires, but I wish they had a pressure rating range instead of just “inflate to 30 PSI”. In my own experience with similar tires, they usually say 5-30 PSI which allows for lower pressure to ride on sand and soft loamy terrain. I would also love some puncture protection on the tires, since fat bikes are good candidates for gravel and light trail riding.
No suspension fork or seat post suspension is included. It’s not such a big issue for people who ride on paved surfaces, but this is where knowing the tire pressure range would be helpful, lower pressure could greatly improve comfort.
The torque sensor works fairly well, and activates much faster than a cadence sensor. However, it can cause some surge feelings based on the uneven pressure of pedal downstrokes. It can also get activated if the chain bounces a lot while riding on rough terrain. I feel that it requires a bit of extra care when removing and re-attaching the rear wheel too, so things aren’t over-tightened. On the upside, this sensor plate might double as a torque arm because it adds more surface area for the axle to push against vs. just the alloy frame dropouts.
A couple of times, the heel of my left shoe caught on the kickstand while pedaling. It’s positioned fairly close to the bottom bracket and while it does not cause pedal lock, it’s just a little exposed and could get in the way for people with big feet or shoes.
The charger for this ebike is pretty basic and a bit slow for the high 672 watt hour capacity of the battery. It’s fairly compact, has a removable wall-side cord to reduce length, and it only weighs ~1.5lbs, but it only puts out 2 amps. Thankfully, they do sell an optional 4 amp fast charger if you’re willing to pay a bit extra.
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 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.
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 if you really go for it). Fortunately, the relaxed position of the riser handlebar means 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 paint could get chipped off 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 motor power cable enters on the right side of the bike, near the deraillur and shifter cable. This area is already a bit crowded, and the extra cable kind of sticks out and could get damaged if the bike tipped. This is especially relevant for a wide folding mode with no derailleur guard. Some motors now bring this power cable along the left side of the frame and have it tucked between the frame and disc brake rotor.
The torque sensor plate can be a little sensitive, if you’re pedaling while powering the bike on, it may impact the zero point and make pedal assist less sensitive for that session. I recommend not pedaling when you power the bike on. One upside of this design is that the torque plate acts as a torque arm to reduce wear and tear on the dropouts… which is relevant for a more powerful hub motor like this.