Synergy Kahuna Review

Synergy Kahuna Electric Bike Review
Synergy Kahuna
Synergy Kahuna Adjustable Length Kickstand Rear Swing Arm With Rack Mounts
Synergy Kahuna Internal Lithium Ion Battery 48v 14ah
Synergy Kahuna Handlebar Phone Mount Grips
Synergy Kahuna Bigstone Lcd Display For Ebikes
Synergy Kahuna Twist Shifter Tektro Hydraulic Disc Brake Levers With Motor Inhibitors
Synergy Kahuna Unbranded Suspension Fork With Compression Lockout And Preload
Synergy Kahuna Blaze Lite Hl3001 Ebike Headlight Dual Beam
Synergy Kahuna Wellgo F265 Folding Aluminum Alloy Platform Pedals
Synergy Kahuna 160mm Tektro Hydraulic Disc Brake Rotors
Synergy Kahuna Bottom Bracket Sealed Cadence Sensor And Support Arm
Synergy Kahuna 7 Speed Shimano Altus Drivetrain 14 28 Tooth Freewheel
Synergy Kahuna Generic Rear Suspension Shock Absorber
Synergy Kahuna Folding Fat Tire Full Suspension Ebike
Synergy Kahuna D Power Electric Bicycle Charger
Synergy Kahuna 2 Amp Portable Ebike Charger
Synergy Kahuna Stock Folding Black
Synergy Kahuna Electric Bike Review
Synergy Kahuna
Synergy Kahuna Adjustable Length Kickstand Rear Swing Arm With Rack Mounts
Synergy Kahuna Internal Lithium Ion Battery 48v 14ah
Synergy Kahuna Handlebar Phone Mount Grips
Synergy Kahuna Bigstone Lcd Display For Ebikes
Synergy Kahuna Twist Shifter Tektro Hydraulic Disc Brake Levers With Motor Inhibitors
Synergy Kahuna Unbranded Suspension Fork With Compression Lockout And Preload
Synergy Kahuna Blaze Lite Hl3001 Ebike Headlight Dual Beam
Synergy Kahuna Wellgo F265 Folding Aluminum Alloy Platform Pedals
Synergy Kahuna 160mm Tektro Hydraulic Disc Brake Rotors
Synergy Kahuna Bottom Bracket Sealed Cadence Sensor And Support Arm
Synergy Kahuna 7 Speed Shimano Altus Drivetrain 14 28 Tooth Freewheel
Synergy Kahuna Generic Rear Suspension Shock Absorber
Synergy Kahuna Folding Fat Tire Full Suspension Ebike
Synergy Kahuna D Power Electric Bicycle Charger
Synergy Kahuna 2 Amp Portable Ebike Charger
Synergy Kahuna Stock Folding Black

Summary

  • A full suspension folding fat tire electric bike, available in three timeless colors (dark blue, black, white). Powerful 750 watt Bafang geared hub motor feels very zippy and capable. Hydraulic disc brakes require less hand effort and offer adjustable-reach levers. Both brake levers also have motor inhibitors for safer stopping
  • Bright dual-beam headlight keeps you seen from multiple angles. No reflective paint or tire stripes here, but the white frame increases rider visibility. Optional $120 rear rack comes with a light mounted at the Back. They include a decent phone mount for free, Synergy also sells aluminum alloy and plastic fenders for $100 or rack fender combo for $150
  • Sturdy and large folding aluminum alloy pedals from Wellgo, great kickstand placement (with adjustable length), decent Shimano Altus derailleur, limited 14-28 tooth freewheel and slightly large 54 tooth chainring makes starting and climbing a bit slow and difficult
  • They key must be inserted and left in the frame in order to power the bike on... and the locking core is below the main tube, making it difficult to see and reach. Noticed some delay in starting and stopping using pedal assist, even though the cadence sensor hardware looked pretty nice (compact sealed design at bottom bracket), no torque arm or derailleur guard

Video Review

Introduction

Make:

Synergy

Model:

Kahuna

Price:

$1,899 ($2,499 CAD, Free Shipping in Contiguous US and Canada)

Body Position:

Upright

Suggested Use:

Travel, Neighborhood, Trail, Sand and Snow

Electric Bike Class:

Throttle on Demand (Class 2)
Learn more about Ebike classes

Warranty:

1 Year Manufacture Defect

Availability:

United States, Canada

Model Year:

2020

Bicycle Details

Total Weight:

65.1 lbs (29.52 kg)

Battery Weight:

8.3 lbs (3.76 kg)

Motor Weight:

8.7 lbs (3.94 kg)

Frame Material:

6061 Aluminum Alloy

Frame Sizes:

17.25 in (43.81 cm)

Geometry Measurements:

17.25" Seat Tube Length, 24" Reach, 26.5" Stand Over Height, 33.25" Minimum Saddle Height, 25.5" Width, 69.25" Length, 47.25" Wheelbase, Folded: 40" Length, 22" Width, 30" Height

Frame Types:

Mid-Step, Folding

Frame Colors:

Matte Black, Matte White, Matte Blue

Frame Fork Details:

Kahuna Branded Coil Suspension, 60mm Travel, Compression Adjust with Lockout, Preload Adjust, 32mm Stanchions, 135mm Hub Spacing, 9mm Threaded Axle with 15mm Nuts

Frame Rear Details:

Single Joint Swing Arm with Unbranded Shock Absorber, 60mm Travel, 175mm Hub Spacing, 12mm Threaded Slotted Axle with 18mm Nuts

Attachment Points:

Fender Mounts, Rear Rack Mounts

Gearing Details:

7 Speed 1x7 Shimano MF-TZ500-7 14-28 Tooth Freewheel, Shimano Altus Derailleur

Shifter Details:

Shimano Trigger Shifter on Right (One-Way High, Three-Shift Low)

Cranks:

Forged Aluminum Alloy, 170mm Length, 54 Tooth Chainring with Aluminum Alloy Guard

Pedals:

Wellgo F265 Aluminum Alloy Folding Platform with Reflectors, CrMo Axle, Black

Headset:

Semi-Integrated, Sealed Cartridge, 1-1/8" Straight

Stem:

Aluminum Alloy, Folding, 250mm Base Height, Additional Telescoping Height: 0mm to 100mm, One 5mm Spacer, 31.8mm Clamp

Handlebar:

Aluminum Alloy, Low-Rise, 640mm Length

Brake Details:

Tektro Hydraulic Disc with 160mm Rotors, Dual Piston Calipers, Three-Finger Tektro Levers with Motor Inhibitors and Adjustable Reach

Grips:

Generic, Flat Rubber, Non-Locking

Saddle:

Chaunts, Vented, Active

Seat Post:

Aluminum Alloy, Single Bolt Clamp

Seat Post Length:

450 mm

Seat Post Diameter:

33.9 mm

Rims:

Aluminum Alloy, Double Wall, 10mm Outer Width, 36 Hole Front, 32 Hole Rear

Spokes:

Stainless Steel, 13 Gauge Front, 12 Gauge Rear, Black with Nipples

Tire Brand:

Kenda Gigas, 20" x 4" (98-406)

Wheel Sizes:

20 in (50.8cm)

Tire Details:

5 to 30 PSI, 0.4 to 2.1 BAR

Tube Details:

Schrader Valve

Accessories:

Rear-Mount Adjustable Kickstand, BLAZE-LITE HL3001 Integrated Front Light (Dual-Beam), Yolin Cell Phone Holder, Plastic Sticker Slap Guard, Optional Rear Rack with Integrated Light (25kg 55lb Max Weight, Light Plugs Into Extra Cable Near Seat Tube, $120), Optional Aluminum Alloy Fenders (109mm Width, $100), Discounted Rack and Fenders Package ($150)

Other:

Locking Removable Downtube-Integrated Battery Pack, D-Power 1.5lb 2 Amp Charger, 300lb Maximum Weight Rating, Adjustable Top Speed (12km/h - 32km/h), Adjustable Units, Adjustable Wheel Size

Electronic Details

Motor Brand:

Bafang

Motor Type:

Rear-Mounted Geared Hub
Learn more about Ebike motors

Motor Nominal Output:

750 watts

Motor Torque:

80 Newton meters

Battery Brand:

Samsung 18650

Battery Voltage:

48 volts

Battery Amp Hours:

14 ah

Battery Watt Hours:

672 wh

Battery Chemistry:

Lithium-ion

Charge Time:

6 hours

Estimated Min Range:

25 miles (40 km)

Estimated Max Range:

45 miles (72 km)

Display Type:

Bigstone C500B-LCD, Fixed, Adjustable-Angle, Backlit, Grayscale 3" LCD, Buttons: Power, Set, +, -, Lights: Tap Power Button, Walk Mode: Hold - Button, Settings: Hold Set

Readouts:

Efficiency Guide (Power, Normal, Eco), Current Speed (MPH or KMH), Assist Level (0-5), BMS (Battery Voltage), Battery Charge Level (5 Bars), Trip Distance, Trip Time, Odometer

Display Accessories:

5 Volt 1 Amp USB Type-A Charging Port Below Display

Drive Mode:

Cadence Sensing Pedal Assist, Twist Throttle (Sealed Cadence Sensor)

Top Speed:

20 mph (32 kph)


Written Review

To run the forums, host the website, and travel, I charge a universal service fee for my reviews. This in-depth review was sponsored by Synergy Electric Bikes. My goal is to be transparent and unbiased with you, this video and writeup are not meant to be an endorsement of Synergy products. I welcome your corrections, additions, and feedback in the comments below and the Synergy electric bike forums.

Observations:

  • Synergy is a brand that produces electric kick scooters and electric bikes. They fall under the North 49 brand which owns Vintage Iron Cycles (the shop in Vancouver where I filmed the bike). All of these brands are new to me, and it was a little confusing at first, but the bike performed well and used recognizable parts that I trust
  • I was told that Synergy offers a one year warranty against manufacture defects. If you buy from the Vintage Iron ebike shop (or one of their ~50 dealers) the bike will be fully assembled, otherwise they offer free shipping to the contiguous US and Canada but you’ll have to do some minor assembly yourself
  • What really stood out to me about this product is that it’s a full suspension folding fat bike… that’s a pretty unique offering that’s very rare. The rear suspension is kind of basic, and the frame is made longer to accommodate the rear swing arm, but it did reduce back and neck sensitivity for me while riding. Given the higher 300lb (136kg) max weight rating and long 450mm seat post, this would be a great electric bike for taller or bigger riders who want portability as well as full leg extension

Pros:

  • This is one of the only folding electric bikes I’ve ever seen with full suspension… let alone being a fat bike. It’s pretty comfortable by default but you could always lower the air pressure or adjust compression and preload on the front shock to really dial it in. Having rear suspension reduces knee pressure if you stand up vs. a suspension seat post which only reduces your torso, shoulders, neck, and arm pressure
  • The bike only comes in one frame size, but the extra long 450mm seat post, telescoping stem (with 100mm travel) make it pretty versatile. It’s a good option for taller riders because of the 300lb max weight rating and longer frame (due to rear suspension design)
  • Available in three good looking colors. Black is the most seamless because the hardware and cables are all black by default, so they don’t stand out. White will be the most visible from the side, increasing safety. Apparently blue is pretty popular, and creates variety in a world with so many black or white ebikes. This makes the bike fun for a his/hers setup or so friends can keep their bikes separate and unique. The satin paint leans a bit matte, but looks good and shouldn’t so too many finger prints
  • The battery and controller are both mounted inside the frame, so they’re well protected and the aesthetic of the bike is fairly clean and streamlined
  • I like that the Kahuna comes with a phone mount and has a full sized USB Type-A charging port built into the base of the display panel! This means you could easily use your phone for GPS directions while charging it
  • Considering it’s a full suspension ebike with fat tires, I was kind of surprised that the bike only weighs ~65lbs because similar competing products weigh more… however, some of them include a rack or fenders. If you do add fenders, the plastic ones will probably be lighter than aluminum alloy
  • I was excited to see that Synergy chose trigger shifters here, even with a twist throttle on the right! Usually, there isn’t enough room for this because throttle housings and cables limit mounting options for brakes and shifters. I like triggers because they are a bit quicker to shift with and don’t compromise my hand position while riding. There is room for improvement here however, because the high lever requires index finger action vs. a two-way trigger that could be pushed by the thumb or index finger
  • The headlight is pretty great! It has two powerful beams and a lens that shines out from the sides a little bit to help improve visibility. Even though the bike doesn’t come with a rear light unless you pay $120 for the rear rack, I love that the rear light also plugs into the main battery pack. This means you won’t need independent disposable cells and won’t have an extra step to turn either light off when you stop the bike
  • The full sized 20″ x 4″ fat tires provide stability, cushion, and they lower the attack angle of the wheels which improves comfort. The tread pattern wasn’t so knobby that it made a lot of noise on the concrete, but did provide good traction for my rides through dirt and sand
  • Despite being fairly large and heavy, the weight on this electric bicycle is positioned well and the frame didn’t feel flexy. Sometimes, suspension can add a feeling of flex and looseness to steering and handling, but that also wasn’t an issue for me here
  • The motor is very powerful and capable! Planetary geared hub motors work very well with throttles, they coast without producing any drag, and they start with a lot of torque compared to gearless hub motors. Since this ebike has smaller 20″ diameter wheels (probably closer to 24″ with the fat tires) the hub motor gets a mechanical advantage compared to a larger 26″ or 28″ wheel
  • Both of the frame folding points (at the center of the frame and on the stem) have a locking mechanism for safety when riding, this way, they won’t come completely unfolded if the clamp becomes loose
  • I love that the LCD display panel is fairly large, has adjustable backlight brightness, and offers a full size USB charging port built into the bottom (providing 5 volts and a full 1 amp of power). This is very convenient if you are using the included phone mount with your smartphone for GPS and need a bit of extra juice for your smartphone on long rides… the phone holder they chose worked very well for me during the test ride :)
  • I’m glad that the LCD display isn’t programmed with so many options here. I’ve seen this same hardware used on other ebikes that allow you to select the power level, and it’s just one more step that can create confusion. This one just has five levels of assist and the power level increases automatically as you go from 1-5
  • The display is large, easy to read, and has plenty of good readouts… though I wish it had 10 bars for the battery infographic or used a percentage vs. 5 bars. It’s not removable, but can be swiveled to reduce glare or add protection when folding the bike
  • Synergy chose a sealed cadence sensor that’s less likely to get blocked by mud or kicked out of position. It’s mounted around the crank spindle on the left side of the bike
  • The twist throttle design is excellent here, because it lets you override all five levels of assist with near-full power. This means that you can ride in assist 1 or 2 (which are still very powerful) and then override for speed or extra power on a hill climb without pushing any buttons, simply twisting the throttle
  • The kickstand is adjustable, has a wide platform at the bottom to keep it from sinking in to soft terrain, and it works well if you’re loading the bike with gear. Note that the kickstand is positioned far enough back that it won’t cause pedal lock when backing the bike out, or cause heel strikes when pedaling
  • Both wheels are built with thicker 13 and 12 gauge spokes for increased durability and weight capacity. I appreciate that Synergy chose to paint the spokes black on the Kahuna models to blend in with the rims and hubs. Note that the official max weight rating is a higher than average 300 pounds (~136 kilograms)
  • The bike comes with free shipping for most locations in the US and Canada, which is great! Sometimes, shipping is an additional $100+ cost, so it feels like there’s a lot of value with this product. The one year warranty seems decent as well, even though this is a fairly new company to me… they had a nice headquarters location with lots of bikes and a very friendly staff :)

Cons:

  • I like the physical design of the cadence sensor, because it’s compact and sealed, but the configuration seemed a bit delayed… it took a moment for the motor to kick in when I pedaled and another moment to stop when I ceased pedaling. Good thing both brake levers have motor inhibitor switches built-in for safer stopping
  • With such big tires, heavy rims, and a powerful 750 watt hub motor, I feel that the bike could benefit from a torque arm on the rear axle. As it stands, the flat portions of the rear axle and torque washers seem to do a good job, but it wouldn’t add much weight to have a full torque arm. As an end user, make sure the rear portion of the bike is setup correctly and the bolts are sufficiently tight so you don’t end up with rocking and have the steel axle chew into the aluminum alloy dropouts. I’ve had this happen when I fixed a flat tire or did some derailleur/freewheel maintenance and didn’t do a great job tightening things up afterwards
  • I suspect that a good portion of sales for this product will be made online-direct, even though Synergy claims to have over 50 dealers (which is awesome!) so it would have been nice to see a derailleur guard to protect the derailleur cable, derailleur, and motor power cable during shipping and during use… especially when folded. They could also include a velcro strap, rubber band system, or magnets to keep the bike folded securely since rattling can chip the paint (velcro strap is probably the cheapest and most effective with such a large frame, consider an aftermarket bungee cord with plastic hooks that won’t scratch the paint for your own solution)
  • You definitely pay a premium for the full-suspension setup and hydraulic disc brakes here, and the price continues to rise if you want fenders and a rear rack ($150 if purchased together or $100 individually). I noticed that the rear fender connects near the bottom bracket and up at the seat stays, but then extends pretty far without any support… it made me wonder if it rattles or would clink against the optional rear rack if you got it (since the rack surrounds the fender pretty close)
  • This bike has a bit more exposed wiring, and the wires are not internally routed. Visually, it’s a negative, but physically it’s less vulnerable given the folding frame design
  • I love that the bike has a good quality headlight with bright beams that can be seen from the sides, but there’s no rear light unless you buy the rack (at least it’s wired in though! There’s a little connector cable near the seat tube). I didn’t see any reflective paint or stickers on the frame, no reflective stripes on the tires, and the tires didn’t seem to have puncture protection… so consider using Slime or some tire liners
  • In order to power on the display, you first have to insert the key below the main tube and twist to “on” which requires some bending down and fiddling. It’s not as convenient as a side-mounted locking core, and I wish you could remove the key so it could be kept on a keychain
  • Basic 2 amp battery charger means it takes longer to refill the bike than a 3 amp or 4 amp charger, but it’s fairly lightweight and I’ve seen D-Power before, so it should be cheap to replace or get an extra if needed (one at home, one at work for example)
  • With a limited freewheel offering 14 to 28 tooth (vs. 11 to 32+) and a very large 54 tooth chainring, this ebike can be slower and more difficult to start from standstill or climb with, even in the lowest gear
  • You have to fold the bike in order to reach the battery for removal and independent charging. I feel like many people will just leave it in the frame and plug in near the folding joint… but keep the battery in a cool dry location if possible because extreme heat will degrade the cells and extreme cold will limit your range temporarily
  • The main folding joint on the downtube is pretty wide. That makes it sturdy, but also creates the potential for banging a knee or thigh (which happened to my girlfriend once on a similar ebike, leaving a bruise)
  • Keep an eye on the front cables when the stem is fully extended, if you stretch them out too far it can impact steering or unplug the wires. Same thing goes for folding the bike, try not to pinch the cables and make sure the stem is all the way down to achieve the most compact size
  • The display is large and easy to read but not removable, so it could take extra weather wear and possibly get scratched at a bike rack. I appreciate that the bike can be completely disabled by turning the key to the locked-off position when parking at racks, so nobody can tamper with it.
  • I love that you can enter into the display settings area and adjust units by holding the set button (press set again to navigate through four menus there including speed adjust), but I wish there was more feedback about range and remaining battery capacity, it only shows five bars which relay 20% steps vs. 10 bars or a full 100% readout
  • Minor considerations here, the headlight is mounted to the lower portion of the suspension fork and will bounce up and down when you ride over bumpy terrain. This would not happen if it was mounted to the stem or handlebars… and it would be much higher and more visible there as well (but possibly prone to damage when folding/transporting).
  • The clear plastic slap guard on my demo unit was peeling at the edges and didn’t quite protect the right chainstay. I think it would be nice if they included a bell with the bike, even a simple one :)
  • I didn’t see a mounting point for adding a bottle cage on the frame. You could always get the optional rear rack and use a trunk bag with a bottle holster… I can see why maybe they skipped bottle mounts, since the frame tubing is almost horizontal, and the bottle could drip, but they can also be used for folding locks and other accessories, so it’s still missed a little
  • Minor consideration here, the weight of the bike could be decreased and the comfort plushness of the tires increased if they used punched out rims. This is something I’ve seen on a few other fat tire ebikes, and it would also save material, so I like to point it out as a possible future upgrade they could do

Useful Resources:

Comments (4) YouTube Comments

Mendovan Villar
1 month ago

Nice and beautiful, I want one!

  Reply
Court
1 month ago

Hey Mendovan, I agree with you… and it’s comfortable and capable off-road. Nice combination ;)

  Reply
Віктор Ігорович
1 month ago

A set of technical solutions for the frame, battery placement and folding hinge – bravo to the designer!👍💪👏

  Reply
Court
1 month ago

Yeah, I agree that it’s a nice design. Thanks for your comment :)

  Reply

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