Best E-Bike Conversion Kits 2026: Turn Any Bike Electric
An e-bike conversion kit lets you electrify a bike you already own and love — for $300-700 total instead of $1,200+ for a new e-bike. We compared the best mid-drive and hub motor conversion kits from Bafang, Swytch, Tongsheng, and more.
In This Guide
- Bafang BBS02B 750W Mid-Drive E-Bike Conversion Kit — Best Mid-Drive
- Swytch Universal E-Bike Conversion Kit — Best Plug-and-Play
- Bafang BBS01B 250W/350W Mid-Drive Kit — Best Budget Mid-Drive
- Tongsheng TSDZ2 Mid-Drive Torque Sensing Kit — Best Torque Sensing
- Leisger MD100 E-Bike Conversion Kit with Battery — Best Value Complete Kit
- Rad Power Bikes E-Bike Conversion Accessories — Best for Specific Bikes
- E-Bike Conversion Kit Buying Guide
- FAQ
1. Bafang BBS02B 750W Mid-Drive E-Bike Conversion Kit
The Bafang BBS02B is the gold standard for DIY e-bike conversions. As a mid-drive motor, it mounts at the bottom bracket of virtually any bike with a 68-73mm threaded bottom bracket shell, replacing the standard crankset. The 750W (peak 1,000W) motor uses the bike's existing gearing for efficient climbing — a significant advantage over hub motors on hilly terrain. The 8-fun display shows speed, battery level, assist level, and trip data. Battery is sold separately, and the kit typically pairs with a 48V 13-17Ah shark-pack battery for 30-50 miles of range. At around $300-400 for the motor kit (battery separate), the total conversion costs $500-700 — far less than a comparable e-bike purchase.
Pros
- Mid-drive efficiency — uses existing bike gearing
- Mounts to any 68-73mm threaded bottom bracket
- 750W (1,000W peak) motor
- DIY conversion — keep your existing bike
Cons
- Motor only — battery sold separately (~$150-250)
- Installation requires mechanical skill
- Mid-drive requires more maintenance than hub
2. Swytch Universal E-Bike Conversion Kit
Swytch's universal kit is the best option for riders who want a plug-and-play conversion without technical installation complexity. The front hub motor replaces the front wheel and the compact battery clips onto the handlebar in a single lightweight pack. The entire kit installs in 60 minutes with basic tools. The 250W (EU legal) or 500W motor provides assist up to 15.5 mph (EU) or 20 mph (US versions). Range is 30-50 miles depending on battery size selected. At around $649-799 depending on battery capacity, it's more expensive than a raw Bafang kit but provides a significantly simpler installation and a compact, removable battery design.
Pros
- Complete kit including battery and motor
- 60-minute installation — no technical skill needed
- Removable battery pack — charge anywhere
- Works with almost any bike type
Cons
- ~$649-799 — higher than raw kit pricing
- Front hub motor less efficient on climbs than mid-drive
- 250-500W — less power than Bafang options
3. Bafang BBS01B 250W/350W Mid-Drive Kit
The Bafang BBS01B is the entry-point in the Bafang mid-drive line — same proven motor architecture at a lower power output (250W or 350W depending on region). For flat to moderate terrain, 250W of mid-drive power delivers smooth, natural-feeling assist that's more nuanced than a hub motor of equivalent wattage. EU compliant at 250W. The installation is identical to the BBS02B — 68-73mm threaded bottom bracket. Battery sold separately. At around $150-200 for the motor, plus $150-250 for a compatible battery, the total conversion lands at $300-450 — the most affordable legitimate mid-drive conversion available. For casual riders on flat terrain, the BBS01B is more bike than they'll ever outgrow.
Pros
- Most affordable mid-drive conversion kit
- Same architecture as BBS02B — proven design
- EU-compliant 250W option available
- Natural pedal feel from mid-drive placement
Cons
- Lower power limits steep hill performance
- Battery sold separately
- 250W insufficient for heavy loads or steep grades
4. Tongsheng TSDZ2 Mid-Drive Torque Sensing Kit
The Tongsheng TSDZ2 is the mid-drive conversion kit preferred by riders who want the most natural pedal-assist feel. Where most kits use cadence sensors (counting pedal revolutions), the TSDZ2 uses a torque sensor — it measures how hard you're pushing on the pedals and provides proportional assist. The result is an e-bike that feels like a performance-enhanced bicycle rather than a motorized one. Available in 250W, 350W, and 500W versions. Compatible with most mid-drive mounting standards. Battery sold separately. At around $250-350 for the motor, it's priced above Bafang entry options but below the premium conversion kits from established brands.
Pros
- Torque sensor — most natural pedal feel
- Available in 250W, 350W, 500W
- More sophisticated assist response than cadence sensors
- ~$250-350 — competitive mid-drive pricing
Cons
- Battery sold separately
- Installation requires mechanical confidence
- Fewer replacement parts available vs Bafang
5. Leisger MD100 E-Bike Conversion Kit with Battery
The Leisger MD100 is notable because it's sold as a complete kit — motor, battery, display, and all hardware included — at a price that undercuts most competitors for the complete package. The 350W front hub motor converts most 26-inch or 700c bikes. The 36V 10.4Ah battery provides 25-35 miles of range. The 7-speed assist system provides some ride customization. At around $279-349 for the complete kit (including battery), the Leisger is the best value for riders who want a one-box conversion without sourcing components separately. The tradeoff vs. Bafang: hub motor (less efficient on hills) and lower-quality component sourcing.
Pros
- Complete kit including battery — no separate sourcing
- ~$279-349 — lowest all-in price here
- 25-35 mile range adequate for most commuters
- Compatible with most 26-inch and 700c bikes
Cons
- Front hub motor — less efficient on hills
- Lower component quality vs. Bafang
- 25-mile range limits longer rides
6. Rad Power Bikes E-Bike Conversion Accessories
Rad Power Bikes doesn't sell a standalone conversion kit, but their accessory ecosystem for existing RadRover and RadMission bikes deserves mention for existing owners. The extended-range battery (adds 50-80% more range), upgraded display with turn-by-turn navigation, and cargo rack systems expand a base RadRover 6 significantly. For riders who already own a Rad bike and want more capability without buying a new bike, the upgrade accessories deliver real value. The extended range battery at $349 is considerably cheaper than buying a new bike, and it essentially doubles your riding range. For existing Rad owners, this is the upgrade path worth considering.
Pros
- Direct fit for existing Rad Power Bikes
- Extended battery adds 50-80% range to existing bike
- Official Rad accessory — warranty preserved
- Cost-effective vs. buying a new bike
Cons
- Only for existing Rad Power Bikes
- Not a true conversion kit for non-Rad bikes
- Accessory battery pricing ($349) adds up
Frequently Asked Questions
Is converting a bike to electric worth it vs. buying an e-bike?
Converting makes sense if you have a quality bike you already love, want to retain a specific frame geometry, or want to keep the investment under $600-700. If you're starting from scratch and don't have a bike to convert, a purpose-built e-bike (Rad Power, Aventon, Lectric) at $1,200-1,700 typically delivers better integration, warranty, and long-term support than a DIY conversion.
Can I install an e-bike conversion kit myself?
Front hub motor kits (Swytch, Leisger) can be installed by most mechanically confident cyclists with basic bike tools in 1-2 hours. Mid-drive conversions (Bafang BBS02B) require removing the bottom bracket, properly torquing the motor, and routing cables — doable for confident home mechanics with 3-4 hours and the right tools. If you're not comfortable with bottom bracket removal, have a local bike shop handle installation.
Will converting my bike void its warranty?
Adding a conversion kit to a non-warranty bike is irrelevant. For bikes still under warranty: yes, most frame warranties exclude damage from motor conversions, and conversion motors void most warranties. If your bike is out of warranty or never had one, this isn't a concern. Always check your specific frame manufacturer's warranty terms before converting.
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