Replacement parts are where mistakes get expensive. Each category explains how to identify what you have (voltage, connector, size, mount) before you buy. If your bike is misbehaving and you are not sure which part is at fault, start with an E-Bike Assessment instead of guessing.
Staff picks
Best for: Replacing a dead Hailong-style downtube pack on a 48V bike · Conversion kits using a Hailong mounting plate · Riders who want a known seller with a warranty process rather than a no-name listing
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Best for: Replacing a lost or dead 48V charger with a barrel-plug battery · Keeping a second charger at work or in the garage · Budget bikes whose maker no longer sells the original
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Best for: Replacing a dead controller on a KT-based conversion kit · Upgrading a noisy square wave controller to sine wave · Pairing with a KT LCD display
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Best for: KT controller kits that need a replacement display · Tinkerers who want access to controller parameters · Riders who value readability over looks
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Best for: Converting a rigid or hardtail bike with a standard 68–73 mm threaded bottom bracket · Hilly commutes where a hub motor struggles · Riders who want gear-assisted climbing rather than raw throttle power
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Best for: Replacing a dead thumb throttle on a Julet-connector kit · Riders who prefer a thumb paddle to a twist grip · Bikes running KT and similar controllers with waterproof harnesses
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Best for: E-bikes with Tektro HD-E350, HD-M275/M285/M290 style calipers and Aries/Novela mechanicals · Riders who want the OEM pad shape without guessing · Replacing worn resin pads at the first squeal
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Best for: Folding fat e-bikes (Lectric XP, Heybike, Engwe and similar 20x4 bikes) · Mostly paved riding with some trail · Riders replacing a worn stock 20x4 tire
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84 products
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A 20x4 tube is the single most common flat-repair purchase for folding fat e-bikes, and generic listings from brands like Kenda, CST, Sunlite and a dozen house brands are all essentially the same butyl tube. Buy by size and valve: 20 x 4.0 (often printed as 20x3.5-4.0 or 20x4.0-4.5), Schrader valve unless your rim is drilled for Presta, and a valve length that clears your rim. Keep two spares; on these bikes the rear wheel is a chore to remove and you do not want to do it twice for a patch that does not hold.
Best for: Folding fat e-bikes on 20x4 tires · Anyone who wants a couple of spares in the garage · Replacing a tube damaged by a pinch flat
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This is the single most common replacement charger for 48V e-bikes: 54.6V output, 2 amps, a 5.5 mm x 2.1 mm DC barrel plug, and a fan-cooled brick that takes most of a night to fill a mid-size pack. Because the listings are generic, the product you are really buying is a spec sheet: 54.6V DC output (for 13-series lithium-ion packs), 2A, correct plug, and a red/green status light. Bring your old charger's label to the listing and match the output voltage and plug exactly; a 48V label on the box is not enough.
Best for: Replacing a lost or dead 48V charger with a barrel-plug battery · Keeping a second charger at work or in the garage · Budget bikes whose maker no longer sells the original
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The BBS02B is the mid-drive kit that turned thousands of ordinary bikes into e-bikes. It replaces the bottom bracket with a motor unit that drives the chainring, so it uses your gears and climbs far better than a hub motor of the same wattage. Kits bundle the motor, a chainring, cranks, display, throttle, brake sensors or cutoff levers, and a speed sensor; the battery is sold separately. Installation is a weekend job with a few special tools. It is not quiet under hard load and it is hard on chains, but it is the most proven budget mid-drive there is.
Best for: Converting a rigid or hardtail bike with a standard 68–73 mm threaded bottom bracket · Hilly commutes where a hub motor struggles · Riders who want gear-assisted climbing rather than raw throttle power
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The Ergon GP1 is the ergonomic grip that most riders with numb hands end up with. Its wing-shaped platform spreads pressure across the palm instead of concentrating it on the ulnar nerve, and a lock-on clamp keeps it from rotating. On an upright e-bike it is a big comfort gain. It is sold in regular and large sizes and in a few versions for twist shifters and twist throttles that use a shorter grip on one side; pick the version that matches what is on your right bar. Fit it angled slightly downward and adjust until your wrist feels neutral.
Best for: Riders with numb or tingling hands · Upright commuter and cruiser e-bikes · Replacing slippery stock grips
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The Kenda Krusade is one of the most common 20x4 tires on folding fat e-bikes, which makes it both a like-for-like replacement and an easy place to start when the stock tire wears out. It is a street-leaning tread with a shallow center and small side knobs, so it rolls quietly on pavement and still grips on packed gravel. Kenda sells versions with a puncture-resistant layer; look for that on the listing if flats are your problem. It is a wire-bead tire, so it will not fold for storage, and it is heavy like every 4-inch tire.
Best for: Folding fat e-bikes (Lectric XP, Heybike, Engwe and similar 20x4 bikes) · Mostly paved riding with some trail · Riders replacing a worn stock 20x4 tire
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KT (Kunteng) controllers are the de facto standard in the conversion-kit world, and the 22A sine wave unit is the one most people end up with for a 500W–750W hub motor. Sine wave drive is quieter than square wave and smoother off the line. KT controllers talk a specific serial protocol to KT displays (LCD3, LCD8H and friends), so if you already have a KT display this is the natural match; if you have a different display, plan to replace both. Connectors are typically the Julet/Higo waterproof style, which makes wiring tidy but ties you to matching plugs.
Best for: Replacing a dead controller on a KT-based conversion kit · Upgrading a noisy square wave controller to sine wave · Pairing with a KT LCD display
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The KT-LCD3 is the display most conversion-kit riders learn on. It is a monochrome LCD with a separate three-button pad, a deep settings menu (P and C parameters) and the ability to set wheel size, speed limit, assist levels and current limits on KT controllers. It is not pretty, but it is legible in sun and the parameter menu is documented all over the internet. If your bike has a KT controller and a dead or cracked display, an LCD3 is the cheapest functional replacement; the LCD8H is the same protocol in a more modern package.
Best for: KT controller kits that need a replacement display · Tinkerers who want access to controller parameters · Riders who value readability over looks
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Most rear hub-motor e-bikes use a thread-on freewheel rather than a cassette, and the 7-speed Shimano MF-TZ500 (successor to the TZ-31) is the one that comes on a huge share of them. It screws onto the motor's threaded boss and comes off with a standard Shimano freewheel remover. The 14-28 range is conservative: fine for flat commuting and assisted riding, limiting if you want to pedal fast downhill. When the freewheel starts skipping or the pawls stick, replacing it is a cheap twenty-minute job if you have the tool.
Best for: 7-speed hub-motor e-bikes with a thread-on freewheel · Fixing a skipping or sticky freewheel · Like-for-like replacements
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The Suntour NCX is the suspension seatpost most commonly recommended for e-bikes with rigid frames, and for good reason: its parallelogram linkage moves the saddle down and back rather than straight down, which feels far more natural than the telescoping posts that came before it. It has a preload adjuster, a standard two-bolt saddle clamp, and comes in 27.2, 30.9 and 31.6 mm diameters at 350 mm length. On a heavy e-bike ridden over rough pavement it takes the edge off hits in a way a padded saddle cannot. Measure your post diameter carefully before ordering.
Best for: Rigid-frame commuter and fat-tire e-bikes · Riders with back discomfort on rough roads · Anyone replacing a rigid post who wants a real upgrade
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If a budget or mid-priced e-bike has Tektro brakes, there is a good chance it takes the E10.11 pad: it fits many Tektro hydraulic calipers as well as the common Aries and Novela mechanical calipers. Tektro sells the E10.11 in resin/organic compound, and aftermarket makers offer semi-metallic and sintered versions in the same shape. Resin is quiet and bites quickly; metallic lasts longer on a heavy e-bike but can be noisier. Confirm the pad shape by checking the part number stamped on your old pads or by matching the outline before ordering.
Best for: E-bikes with Tektro HD-E350, HD-M275/M285/M290 style calipers and Aries/Novela mechanicals · Riders who want the OEM pad shape without guessing · Replacing worn resin pads at the first squeal
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Most modern kit bikes and a lot of budget production e-bikes use a hall-effect thumb throttle with a three-wire lead: power, ground and signal. When the throttle dies, a generic replacement with the same connector usually plugs straight in, which is why the 3-pin Julet (Higo-style) waterproof version is the best-selling type. Before buying, confirm that your throttle lead uses the small 3-pin waterproof round plug and note whether it is male or female; a photo of your old throttle next to the listing saves a return.
Best for: Replacing a dead thumb throttle on a Julet-connector kit · Riders who prefer a thumb paddle to a twist grip · Bikes running KT and similar controllers with waterproof harnesses
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Unit Pack Power (UPP) is one of the longest-running aftermarket battery sellers on Amazon, and this 48V 13Ah pack in the familiar Hailong bottle-style case is their bread-and-butter product. It is the pack people reach for when a Hailong-mount bike from a lesser-known brand has a dead battery and the manufacturer is no longer answering email. The case has a built-in key lock, a USB port on most versions, and a standard Hailong slide rail. The 13Ah capacity puts it in the middle of the range: enough for most commutes, not a long-range upgrade.
Best for: Replacing a dead Hailong-style downtube pack on a 48V bike · Conversion kits using a Hailong mounting plate · Riders who want a known seller with a warranty process rather than a no-name listing
Sold on Amazon
The 12-magnet cadence sensor is the standard pedal assist pickup on hub-motor kits: a magnet disc that slides onto the crank spindle and a small sensor bracket that mounts against the bottom bracket. Dual-hall versions sense pedaling direction, so assist stops when you back-pedal. Twelve magnets give faster response than the old 5- or 8-magnet discs. Most use a 3-wire lead with either a Julet waterproof plug or a small SM plug. Installation is the fiddly part: the crank usually has to come off, and on some bikes the disc needs to be the split type.
Best for: Replacing a broken or intermittent PAS disc on a kit bike · Upgrading a slow 5-magnet sensor to 12-magnet response · Builders who want assist to cut when back-pedaling
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Hub-motor wheels are laced with short, thick spokes — 13 gauge (2.3 mm) is the usual — because the big flange sits close to the rim and the wheel carries far more load than a normal bike wheel. When a spoke snaps, ordinary 14 gauge spokes from a bike shop are the wrong diameter for the motor flange holes and nipples. Generic 13g spoke packs come in several lengths; measuring an existing spoke from elbow to end is the only reliable way to order. A pack of 36 lets you replace one or re-lace the whole wheel.
Best for: Replacing broken spokes on a rear or front hub-motor wheel · Re-lacing a hub motor into a new rim · Keeping spares for a heavy e-bike
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The typical hub-motor e-bike has a single front chainring on a square-taper crankset, and when a crank arm strips or the chainring wears hooked, the replacement is a generic 170 mm alloy crankset with a 44T or 46T ring and a plastic chainguard. These are sold by many sellers and are functionally interchangeable. The important checks are square-taper bottom bracket (not Octalink or Hollowtech), crank length, and chainring size; keep the same tooth count to preserve your gearing. A square-taper crank puller is needed for removal.
Best for: Replacing a stripped crank arm or worn chainring on a hub-motor e-bike · Bikes with a square-taper bottom bracket · Budget repairs
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The front wheel on a fat folding e-bike is a plain bicycle wheel: no motor, a 6-bolt disc hub, and an 80 mm wide rim for a 4-inch tire. When one gets tacoed by a pothole, a generic replacement is the cheapest fix, and several sellers list 20-inch fat front wheels with an alloy double-wall rim and a quick-release or bolt-on hub. Check your fork's dropout spacing (100 mm and 135 mm both exist on these bikes) and hub type before ordering. Tire, tube and rotor are usually not included.
Best for: Replacing a bent front wheel on a 20x4 fat folder · Riders who want a spare front wheel for a second tire setup · Budget repairs
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Heavy, fast e-bikes benefit from big rotors, and 203 mm is the size many fat-tire and cargo bikes ship with or upgrade to. Generic stainless 203 mm 6-bolt rotors from brands like Tektro, Jagwire and a dozen unbranded sellers are widely sold; the useful ones are stamped from one piece of stainless, rated for metallic pads, and come with six bolts. Going up to 203 mm from a smaller rotor requires a caliper adapter and a frame or fork rated for it, so this is a like-for-like replacement for most buyers rather than an upgrade.
Best for: Replacing a warped 203 mm rotor on a fat-tire or cargo e-bike · Riders using sintered pads who need a metallic-rated rotor · Heavy riders who want maximum heat capacity
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Fat folding e-bikes throw an impressive rooster tail, and many ship without fenders or with flimsy ones that crack. Generic 20x4 fender sets are wide plastic or alloy mudguards with stays sized for 20-inch wheels and roughly 4-inch tires, sold as a front and rear pair. Fit varies because fork crown and frame bridge designs differ between brands; sets made for a specific model (Lectric, Heybike, etc.) fit better than universal ones. Expect to bend stays and drill a hole or two. Measure your tire width and check the fender is at least 4.5 inches wide.
Best for: 20x4 fat folders that came without fenders · Replacing cracked stock fenders · Rainy-season commuters
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This is the replacement rear wheel for a mid-drive conversion or a front-hub e-bike with a 26-inch wheel, where the rear is a plain non-motor wheel with a thread-on freewheel hub. It is not a replacement for a rear hub-motor wheel. Generic alloy double-wall wheels with a 6-bolt disc hub and 135 mm spacing are widely sold and cheap; the better ones have sealed bearings and come trued. Check whether your bike takes a thread-on freewheel or a cassette freehub, because the two are not interchangeable and many budget listings are freewheel-only.
Best for: Mid-drive or front-hub e-bikes with a plain 26-inch rear wheel · Replacing a cracked rim or badly bent wheel · Budget conversions
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Full-size fat e-bikes on 26x4 tires need fenders at least 4.5 inches wide, and the sets sold for them are wide alloy or plastic guards with adjustable stays and, usually, a bracket for a rack tail light. Universal sets fit most rigid and hardtail fat bikes with eyelets, but suspension forks and frames without eyelets need clamp-style stays or a model-specific set. Alloy fenders rattle less and survive better than plastic. Installation takes an hour the first time; take the time to set stays so the fender does not rub the tire under load.
Best for: 26x4 fat e-bikes ridden in rain or mud · Commuters who want full coverage rather than clip-on guards · Replacing worn or bent OEM fenders
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The 26x4 tube is the full-size fat-bike counterpart to the 20x4 folder tube, and it is what most 26-inch fat e-bikes run. Generic butyl tubes in 26 x 3.5–4.5 (or 4.0–4.9) are widely sold; the branded ones from Kenda, Sunlite and CST are not meaningfully different from house brands. Schrader is the common valve on these bikes. Because a 4-inch tube holds a lot of air at low pressure, pinch flats from running too soft are the usual cause of death, so check pressure weekly and carry a spare on long rides.
Best for: 26x4 fat-tire e-bikes · Spares for the trail bag or garage · Riders replacing a pinch-flatted tube
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Many budget 36V e-bikes and conversion kits use an unbranded Hailong-case battery, and when one dies the replacement is usually another unbranded Hailong-case battery. The listings all look alike, so the job is to match four things: 36V nominal (42V fully charged), the correct Hailong case generation, the discharge connector on your cradle, and a BMS that can feed your controller. A 10Ah pack is a modest capacity, suited to 250W–500W bikes that see neighborhood and short-commute duty. Choose a listing that states the BMS amp rating and ships with a charger.
Best for: Replacing a worn-out 36V Hailong pack on a budget commuter or folding bike · 36V 250W–500W conversion kits with a Hailong cradle · Riders who only need 15–25 miles of assisted range
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Most 36V e-bikes and scooters charge through a 42V output brick with a DC barrel plug, and this is the generic replacement for that brick. The important number is 42V on the output label (10-series lithium-ion), with 2A being the standard rate. Plugs are the confusing part: 36V bikes use 5.5x2.1 and 5.5x2.5 mm barrels most often, and some use a 3-pin XLR or a proprietary plug instead. Look at your battery's charge port and your old charger before ordering, and prefer a listing that shows the plug diameter clearly.
Best for: Replacing the charger on a 36V folding or commuter e-bike · 36V conversion kit batteries with a barrel charge port · A spare for the office
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A small geared front hub is the simplest conversion there is: drop the wheel in the fork, mount a battery and controller, and you have an assisted bike without touching the drivetrain. The 350W geared units are light, freewheel without drag, and climb moderately well thanks to internal reduction gears. Listings are generic, so match wheel size, fork dropout width (usually 100 mm), and make sure the kit includes a torque arm or buy one; front dropouts on aluminum and suspension forks do not tolerate motor torque well without one.
Best for: Light assist on a commuter or hybrid with a steel or rigid fork · Riders who want to keep the rear drivetrain stock · Budget conversions
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Quick finders
Find a charger by battery voltage
The charger must match the pack: 36V → 42.0V, 48V → 54.6V, 52V → 58.8V output.
Find a controller by voltage
Controllers and displays are usually paired — confirm the protocol.
Find a tire by size
Size is printed on the sidewall (e.g. 20×4.0, 26×4.0, 27.5×2.4, 700×38c).
Find a tube by size
Match the tire size and the valve type (Schrader vs Presta).
Brake pads by brake type
Pad shape depends on the caliper model — check yours before ordering.
By connector / plug
XT60, Anderson, Julet/Higo, DC barrel, XLR…
Browse
Grouped the way a shop is organized. Each category page has buying notes, compatibility tips and its own filters.
Replacement and spare lithium packs — match voltage, mount and connector.
Replacement chargers — voltage, amperage and plug type must match your pack.
The brain between battery, motor, throttle and display.
LCD/LED displays and replacement screens matched to your controller protocol.
Replacement hub and mid-drive motors and conversion kits.
Front and rear geared/direct-drive hub motors and wheel kits.
Chainrings, kits and service parts for mid-drive systems.
Main cables and extension harnesses for display, throttle and brake sensors.
XT60/XT90, Anderson, Julet/Higo waterproof connectors and battery discharge plugs.
Screens and protective covers for common display models.
Disc pads in the right shape and compound for heavier, faster e-bikes.
160/180/203 mm rotors — check mount type (6-bolt vs Centerlock).
Mechanical and hydraulic levers, including e-bike levers with motor cut-off sensors.
Calipers, hoses, olives, bleed kits and mineral oil / DOT fluid.
E-bike rated tires with puncture protection in the common 20×4, 26×4, 27.5 and 700c sizes.
Schrader/Presta tubes, thorn-resistant and sealant-filled options.
Sealant, valves, rim tape and plugs for tubeless setups.
Replacement wheels and rims, including motor-compatible dropout widths.
Spokes sized for hub-motor flanges and heavy e-bike loads.
7–12 speed cassettes; freehub standard must match your wheel.
Thread-on freewheels common on hub-motor e-bikes (often 7-speed).
E-bike rated chains with stronger plates; match your speed count.
Rear derailleurs, hangers and shifters for common e-bike drivetrains.
Cranks, chainrings and bottom brackets — including PAS-compatible options.
Flat, wide-platform and folding pedals with grip for commuting.
Headlights and taillights — battery-powered or wired to the main pack.
Full-coverage and fat-tire fenders sized to your wheel and tire width.
Front and rear rack hardware for commuter and cargo setups.
Heavy-duty single and double-leg stands rated for e-bike weight.
Wide comfort saddles, suspension seats and replacement covers.
Suspension and rigid posts — check diameter (27.2, 30.9, 31.6 mm).
Riser, swept-back and adjustable stems for a more upright fit.
Ergonomic and lock-on grips for numb-hand relief.