A rectangular case that bolts to the down tube and slides off on a rail. The most widely used format, so mounting brackets, controllers and replacement shells are all easy to find.
Works well when- The widest choice — we mould 15 variants, the largest range we carry
- Fits frames that were never designed around an integrated pack
- Cable exit, charge port and mounting centres are selectable at order
Worth knowing- The pack sits outside the frame, so the bike reads as electric
- Length is capped by the down tube, which limits how far capacity can go before you have to change format
Best for: Conversions, commuters, and any frame where you want the battery removable
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A long, slim case that follows the down tube closely. Same mounting idea as Hailong, but stretched: the internal envelope is taller and longer for the same footprint on the frame.
Works well when- Where the high-capacity builds live — up to 104 cells in 18650
- The narrow profile leaves clearance on frames with a tight triangle
- 27 variants, so most length requirements are covered from stock tooling
Worth knowing- The extra length is the whole point, so it needs a long down tube
- On 21700 the ceiling is lower than the 18650 figure suggests — check both numbers
Best for: Touring, cargo and long-range commuter packs
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The battery lives inside the down tube or the frame body rather than bolting onto it. Nothing shows from the outside.
Works well when- The bike still looks like a bicycle — this is the reason brands choose it
- 28 variants, from 20-cell compact frames to 65-cell touring frames
- Aluminium sections available where the frame needs a structural member
Worth knowing- Fitment is measured against the frame, not against a bolt pattern, so it needs your drawing — this is the format where guessing costs the most
- Harder to service: the pack comes out of the frame, not off a rail
Best for: Brands designing a clean silhouette, and the assemblers supplying them
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The classic bolt-on down-tube mount, usually with a lockable top cover and a recessed anti-theft fit. The format most kit conversions end up using.
Works well when- Works on a frame that was built as a normal bicycle — no frame change needed
- 21 variants spanning 40 to 104 cells in 18650
- The format most often bought one or two pieces at a time, so MOQ 1 matters here
Worth knowing- Visually the most obviously 'an electric bike' of the six
- Mounting centres vary more between moulds than in the Hailong family — measure before you commit
Best for: Retrofit conversions, and replacing a cracked case on a bike already in service
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The pack rides over the back wheel instead of in the frame, which frees the entire frame triangle for other things.
Works well when- The largest envelopes we make — up to 104 cells in 18650, 78 in 21700
- Frees the down tube completely, useful on step-through and cargo frames
- Easy to lift off for charging, and easy to swap between bikes
Worth knowing- Weight sits high and behind the rider, which changes handling — a non-issue on a cargo bike, noticeable on a light road frame
- Adds length to the bike, which matters for storage and for tight doorways
Best for: Cargo, commuter and step-through builds; trikes
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Mounts where a water bottle cage would go. The smallest and least intrusive option, and the one that reads as an accessory rather than a component.
Works well when- The least visually intrusive of the six
- Two stock models: a 30-cell envelope in both formats, and a 40 / 52-cell 18650
- Often used as a second, range-extender pack alongside a main battery
Worth knowing- Small by design — a small range is all this format genuinely supports, so if you need more than about 52 cells a downtube or rack case will serve you better
- Bottle bosses were not designed to carry a battery; check the frame's limit
Best for: Minimal builds, folders, and range-extender second packs
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