isinwheel U-Series Comparison: U1 vs U2 vs U3 vs U4 vs U5
Share
The isinwheel U-Series covers five folding and compact e-bikes — the U1, U2, U3, U4, and U5 — and at a glance, they can look nearly identical. They're not. Each one is built around a different priority: compact size, long range, fast charging, or rugged tires. Here's how to tell them apart.
Side-by-side specs
| Model | Motor | Range | Charge Time | Wheels | Standout Feature |
|---|---|---|---|---|---|
| U1 | 500W | 24.9 mi | 4–5 hr | 14" | Most compact — easiest to carry and store |
| U2 | 500W | 45 mi | 6 hr | 26" | Longest range, full-size cruiser wheels |
| U3 | 500W | 30 mi | 2–3 hr | 16" | Fastest charging in the lineup |
| U4 | 500W | 35 mi | 4–5 hr | 16" | Wider tires, more range than U3 |
| U5 | 500W | 30 mi | 3–4 hr | 20" | Fat tires, 48V battery, 3 color options |
U1: Built for tight spaces
The U1 has the smallest wheels in the lineup (14") and the lightest overall footprint, making it the easiest of the five to carry up stairs or fit in a small apartment or closet. Range tops out at 24.9 miles — plenty for daily errands or a short commute, but not the bike to reach for if you need serious distance.
U2: The long-range cruiser
The U2 breaks from the compact/folding format entirely — it uses full-size 26" wheels and a larger battery to deliver 45 miles of range, by far the most in the U-Series. Front shock absorption smooths out longer rides. If you want a folding bike, this isn't it; if you want distance and ride stability, it's the clear pick.
U3: Charge it and go
The U3's defining feature isn't range or power — it's charge time. A full charge takes just 2–3 hours, roughly half the time of most bikes in this lineup. That matters most for riders who fold and carry their bike as part of a multi-modal commute (car + bike, bus + bike) and only have a short window to top up the battery between trips.
U4: More range, wider tires
The U4 takes the U3's folding format and adds a bigger battery (35 miles of range, up from 30) and wider 2.15" tires for extra stability on uneven pavement or light gravel. The tradeoff is a longer charge time than the U3 — you're trading charging speed for range and stability.
U5: Fat tires and more power
The U5 stands apart with chunky 20"x2.6" fat tires — both a styling choice and a practical one, adding grip and cushioning on rougher surfaces without needing full suspension. It also runs on a 48V battery (versus 36V on the rest of the lineup) for punchier acceleration, and comes in three colors: white, black, and yellow.
Which U-Series model should you buy?
- Tightest storage space, shortest trips → U1
- Longest commute or weekend range, don't need to fold it → U2
- Multi-modal commute, need fast recharges between trips → U3
- Want U3's format but more range and stability → U4
- Want a distinctive look plus grip on rougher terrain → U5
All five share the same 500W motor and core folding-friendly design — the real decision comes down to which single tradeoff (size, range, charge speed, or terrain grip) matters most for how you'll actually ride.