Hiboy KS4 Pro Electric Scooter

There are two modes: Drive tops out at 13 mph and Sport at 19 mph, and the Hiboy app adds a lock, cruise control and a choice of zero-start or kick-start. Hiboy sells it in the US only and describes no faster setting. Its 19 mph top speed fits New York's e-scooter definition (VTL §114-e: no more than 20 mph and under 100 lb) and is above California's 15 mph limit (Vehicle Code §22411), so California riders must keep to 15 mph or below; Drive mode does that. Scooters are not e-bikes, so the US e-bike classes do not apply. California also requires a driver's license or instruction permit (§21235) and a helmet under 18. New Jersey's legal e-scooter must be under 19 mph, and Hiboy lists 19 mph (its manual's 30 km/h is about 18.6 mph), so the KS4 Pro sits right on that line; Pennsylvania does not allow e-scooters on public roads at all.

Hiboy claims 25 miles and publishes how it got there: a 165 lb load at a steady 11.4 mph on flat ground at 77°F with no wind. We estimate full-speed range by dividing battery capacity by 22 to 27 watt-hours per mile, a band taken from published full-speed tests and adjusted to a 175 to 180 lb rider. For 417.6 Wh that is about 15 to 19 miles a charge, the same as the S2 Pro, which takes the same replacement battery. Riding in Drive mode adds some. This is an estimate from the spec sheet; we have not ridden the KS4 Pro. Charging takes 4 to 6 hours on the 42 V, 2 A charger.

Both wheels are 10-inch honeycomb tires: solid, airless and puncture-proof, but firmer than air-filled tires. Suspension is two preload-adjustable shocks at the rear only; the front fork is rigid. The Amazon listing's "adjustable dual shock absorption system" reads as if both ends are sprung, and the manual shows they are not, so expect a firmer front end than a scooter with a suspension fork, such as the NIU KQi 300P. One lever works a rear disc brake and a front electronic regenerative brake together. The rating is IPX4, splash resistance only, and the manual says not to ride through water deeper than 0.78 in. Climbing is listed three ways: 15° on the spec table and FAQ, a 15% grade in the description, and "approx. 15" in a manual column marked in percent. A 15° slope is about a 27% grade, so the units matter; we use 15%. It folds to 45.3 x 18.9 x 20.7 in. Weight is 40.6 lb in Hiboy's table, FAQ and manual; the Amazon listing says 38.5 lb.

Hiboy publishes the paperwork, as it does for the S2 Pro and the S2. The UL badge on the product page links to UL LLC certificates of compliance: UL 2272 certificate UL-US-2402077-1 (report reference E535405-20240201) for the scooter's electrical system, and UL 2271 certificate UL-US-2348387-0 for the battery pack. The Amazon listing also names UL LLC as the test lab. We could not check the numbers in UL's own directory, which needs a login, so we report them as Hiboy's published documents. New York City has required UL 2272 for e-scooters sold there since September 16, 2023 (Local Law 39), and California's SB 1271 has required UL 2272 battery testing for motorized scooters sold there since January 1, 2026. No CPSC recall found for the Hiboy KS4 Pro as of October 2026.

One ownership caveat: on October 21, 2026 Hiboy's own store showed the shared S2 Pro and KS4 Pro battery, the front wheel with motor and the KS4 Pro controller and handle as sold out. The charger, forks, fender, disc brakes and the KS4 Pro dashboard were in stock. If you plan to keep a scooter for years, check that the battery is back before you buy.

• Hiboy S2 Pro ($422.95 as of Oct 22, 11:10 AM EDT, subject to change, against $399.98 (as of Oct 22, 11:10 AM EDT, subject to change) for the KS4 Pro): the same motor wheel, battery, brakes and tires with narrower 16.5-inch bars and 0.9 lb less weight by the manuals. Choose on price and on whether you want the wider grip. Our KS4 Pro vs S2 Pro comparison goes line by line.
• NIU KQi 300P ($749 as of Oct 22, 11:10 AM EDT, subject to change): the step up for rough streets and rain. It has a hydraulic front fork, 10.5-inch tubeless air tires, disc brakes at both ends, IP55, a 486.7 Wh battery and a 265 lb limit, at about 5 lb more weight.
• Segway Max G2 ($699.99 as of Oct 22, 11:10 AM EDT, subject to change): more battery (551 Wh), suspension at both ends, IPX5 and a 265 lb limit, at 53.5 lb.

Buy the KS4 Pro if your round trip is up to about 15 miles on reasonable pavement, you weigh under 220 lb with your bag, you want tires that never go flat, and you care about published UL certificates, which matter for a New York City building or a California purchase. Buy it over the S2 Pro when it is the cheaper of the two, or when you want the wider bars. Skip it if your streets are broken up (solid tires and a rigid front transmit a lot), if you ride in regular rain (IPX4), if you weigh more than 220 lb, or if you carry the scooter up stairs every day at 40.6 lb.