Best mid drive electric bike conversion kits in 2025 bring stronger hill-climbing power, better efficiency, and a more natural pedal feel than most hub motor kits. This guide reviews leading options such as Bafang BBS02, Bafang BBSHD, Tongsheng TSDZ2B, ToSeven DM02, and CYC Photon, comparing power, torque, ride feel, and ideal use cases. With these mid drive electric bike conversion kits laid out side by side, it’s easy to match the right system to different ebikes, terrains, and budgets.
Table: Top Mid Drive Conversion Kits at a glance
| Kit / Brand | Rated Power | Max Torque (approx.) | Best For |
| Bafang BBS02 750W | 750 W, 48/52 V | ~120 Nm | All-round commuting & light off-road |
| Bafang BBSHD 1000W | 1000 W, 48/52 V | up to 160 Nm | Heavy riders, cargo, steep hills |
| Tongsheng TSDZ2B | 250–500 W (up to 750 W versions) | ~80–90 Nm | Natural feel, legal-ish builds, touring |
| ToSeven DM02 | 250–500 W, 36/48 V | 90 Nm | Value torque-sensor kit, mixed terrain |
| CYC Photon Gen 2 | 750 W, 36–72 V | 130 Nm | Enthusiasts, high-performance buil |
1. Bafang BBS02 750W – best overall mid drive conversion kit
Why it’s on the list
The Bafang BBS02 750W is the classic answer when people ask for the “best all-round mid drive electric bike conversion kit.” It’s rated at 750 W, runs on 48–52 V batteries, and many dealers report peak output well above 1000 W with around 120 Nm of torque, which is plenty for most commuters and trail riders.
Highlights
- 750 W mid drive with integrated controller
- Designed for threaded bottom brackets (typically 68–73 mm)
- Works well on hardtail MTBs, hybrids, and many commuting bikes
- Huge community support, tons of guides, and spare parts
Pros
- Great balance of price, power, and availability
- Easy to find complete electric bike conversion kits with battery
- Massive user base and tutorials help beginners succeed
Cons
- Uses a cadence sensor, not torque, so assist feels more “moped-like”
- Not the lightest kit, and chain/drivetrain wear can be higher at full power
If you want a mid drive electric bicycle conversion kit that “just works” for daily riding, the BBS02 is still hard to beat in 2025.
2. Bafang BBSHD 1000W – best for power and steep hills
Why it’s on the list
The Bafang BBSHD 1000W is the big brother of the BBS02. It’s rated at 1000 W, with many sellers quoting up to 1600 W peak and 160 Nm torque, making it one of the strongest mainstream mid drive ebike conversion kits on the market.
Highlights
- 1000 W mid drive, 48/52 V compatible
- Built with heavier internals and better cooling than BBS02
- Offered in multiple bottom bracket widths, including fat-bike options
Pros
- Incredible climbing ability for cargo bikes, heavy riders, or off-road use
- Strong reliability reputation when set up and cooled correctly
- Widely supported by DIY shops, forums, and YouTube channels
Cons
- Heavier and bulkier than the BBS02
- Easy to exceed local e-bike power/speed limits if you don’t restrict it
- Overkill for flat-land commuters who just want light assist
If your priority is maximum power rather than minimal weight, and you understand the legal side in your region, the BBSHD is the king of “hot-rod” mid drive conversion kits.
3. Tongsheng TSDZ2B – best natural pedal feel (torque sensor)
Why it’s on the list
The Tongsheng TSDZ2B is the go-to option if you want a mid drive electric bike conversion kit with torque sensor and a more “factory e-bike” feel. Instead of just detecting crank rotation, it measures your pedaling force to give smooth, proportional assistance.
Many variants are available (250–500 W, and higher-power versions with open firmware), and it’s often highlighted as a top mid-drive kit in independent buyer guides for its balance of weight, efficiency, and climbing performance.
Highlights
- Torque + cadence sensing for natural assistance
- Commonly sold in 36 V and 48 V versions around 250–500 W
- Open Source Firmware (OSF) options give advanced tuning and customization
Pros
- Pedal feel is more like a premium OEM mid-drive e-bike
- Excellent for long rides, touring, and riders who want to keep “cycling” feel
- Very efficient at moderate assist levels
Cons
- A bit more sensitive to poor installation (e.g., sensor alignment)
- Some versions run hotter or wear more quickly if heavily over-volted
- Typically sold without a battery, so you must source it separately
If your main goal is a mid drive ebike conversion kit that feels like your legs just got stronger instead of riding a throttle-heavy moped, the TSDZ2B is a strong pick.
4. ToSeven DM02 – best value modern torque-sensor mid drive
Why it’s on the list
The ToSeven DM02 is a newer kid on the block compared with Bafang and Tongsheng, but it’s fast becoming a favorite among DIY builders who want modern, quiet, torque-sensor performance at a fair price.
Retailers list the DM02 with 250–500 W rated power, up to 90 Nm torque, and both torque and cadence sensors, designed to fit roughly 95% of standard bike frames.
Highlights
- 250–500 W mid drive with torque + cadence sensing
- Compatible with a wide voltage range (often 36–48 V, some listings mention up to 52–60 V)
- Designed to integrate neatly on commuter, hybrid, and MTB frames
Pros
- Very smooth, quiet power delivery
- Strong low-speed torque for hills without going into BBSHD overkill territory
- Good option if you want a more modern design than older mid drives
Cons
- Smaller community and fewer years in the field versus Bafang
- Fewer plug-and-play battery bundles compared to big legacy brands
If you’re shopping in 2025 and want something more up-to-date than the classic Bafang units but still reasonably priced, the ToSeven DM02 mid drive conversion kit is worth putting on your shortlist.
5. CYC Photon Gen 2 – best high-performance enthusiast kit
Why it’s on the list
The CYC Photon Gen 2 is aimed at enthusiasts who want high performance and wide tuning options rather than just a basic commuter build. The official spec lists 750 W rated power, 1200 W peak, 130 Nm torque, and compatibility with 36–72 V systems, which is a huge voltage range compared to most other kits.
Highlights
- Compact but powerful mid drive conversion kit
- High torque with advanced controller and thermal management
- Sold as a complete motor kit; you choose the battery to match your voltage goals
Pros
- Very flexible: can be built as a tame commuter or a powerful trail machine
- Strong hill-climbing and acceleration thanks to 130 Nm torque
- Backed by detailed documentation and dealer network
Cons
- More expensive than mainstream options like Bafang and Tongsheng
- Setup and tuning can be more involved for beginners
- Often overkill if you just need casual city assist
If you’re a tinkerer or performance-oriented rider who wants a mid drive electric bike conversion kit that can grow with your skills, the Photon Gen 2 is one of the most capable systems in 2025.
Which mid drive kit should you choose?
Very roughly:
- Mostly flat commuting, balanced budget & power → Bafang BBS02 750W
- Steep hills, heavy rider, cargo, or off-road → Bafang BBSHD 1000W
- You care about natural pedal feel & efficiency → Tongsheng TSDZ2B
- You want a modern, quiet torque-sensor kit at good value → ToSeven DM02
- You want high-performance and advanced tuning → CYC Photon Gen 2
Always double-check bottom bracket size, local e-bike power/speed laws, and battery compatibility before ordering any mid drive electric bike conversion kit.
Key features to look for in the best mid drive electric bike conversion kits
When you compare mid drive electric bike conversion kits this year, don’t just look at watts. Pay attention to:
1. Power and voltage
- Common options: 500W, 750W, 1000W mid drive ebike conversion kit
- Voltage: 36V, 48V, 52V systems
Higher voltage usually delivers better efficiency and stronger performance, especially at higher speeds or with heavier riders.
2. Pedal assist style
- Torque-sensor mid drive kits: Respond to how hard you pedal. Smooth, natural, “bike-like” feel.
- Cadence-sensor mid drive kits: Respond to whether you’re pedaling at all. Simpler and often cheaper.
For premium feel and better range, many riders now prefer torque-sensor mid drive electric bike conversion kits.
3. Battery options
Some kits are “motor-only,” others are complete electric bike conversion kits with battery. Look for:
- Capacity (Wh): 500–900 Wh is common for daily commuting and weekend rides
- Mounting style: downtube, bottle cage mount, or rear rack
- Certified cells and a good BMS (battery management system)
4. Compatibility with your frame
Check:
- Bottom bracket type (BSA/68–73mm is most common)
- Chainline and crank clearance
- Chainstay shape (especially on full-suspension or fat bikes)
If you ride a mountain bike or gravel bike, a compact mid drive ebike conversion kit that keeps good ground clearance is key.
5. Reliability, support, and warranty
The best mid drive ebike conversion kits for adults in 2025 come from brands that:
- Offer a clear warranty on motor and electronics
- Provide install guides and exploded diagrams
- Have responsive email or chat support
- Keep spare parts in stock (displays, sensors, harnesses)
Who are mid drive conversion kits best for?
Mid drive kits are ideal if you:
- Live in a hilly area and need strong climbing power
- Carry kids, cargo, or tow a trailer
- Ride off-road or on mixed terrain
- Want a more sporty, natural-feeling e-bike
- Already own a quality bike and don’t want to buy a whole new one
If you’re just cruising flat bike paths at low speed and want the simplest setup, a basic hub-motor electric bike conversion kit may be enough. But if you want your converted bike to feel like a premium mid drive e-MTB or commuter, a mid drive is where you should look.
Installation tips for mid drive electric bike conversion kits
Installing a DIY mid drive electric bike conversion kit isn’t rocket science, but it’s more involved than a simple front hub kit. A few practical tips:
- Measure your bottom bracket before ordering. Make sure the kit matches your shell width and type.
- Prepare the right tools: crank puller, bottom bracket tool, torque wrench, cable ties, and cutters.
- Mock up cable routing before you zip-tie everything. Keep wires away from moving parts and sharp edges.
- Set up your display and assist levels for your actual riding. Don’t just leave it on max; lower assist can extend battery life.
- If you’re not confident in removing your crankset and bottom bracket, ask a local bike shop to handle that part while you take care of the electrical connections.
Final thoughts
In 2025, mid drive electric bike conversion kits are still one of the smartest upgrades if you already own a solid bike and want better climbing power, range, and ride feel than most cheap hub kits can offer. Focus on compatibility, power, battery quality, and support, and you’ll end up with a converted bike that rides like a high-end e-bike.
