How fast does the Qlife Electric Mountain Bike go?

The manufacturer lists up to 25 mph, with a promotional claim of 1000W peak power. Real speed depends on rider weight, terrain and assist level, and most riders will cruise well below that.

What range can I expect from the 48V 7.8Ah battery?

The listed figure is up to 40 miles, but that assumes light assist and favorable conditions. Expect noticeably less range on hills, in cold weather or with heavy throttle-style use.

Is it good for commuting?

It works for short commutes on pavement and paths, but it has no rack, fenders or rear light. The steel frame is heavy, so carrying it up stairs is a chore.

Does it have a throttle or only pedal assist?

It uses a cadence sensor for pedal assist, so the motor helps while you pedal. There is no separate throttle described, so you cannot ride on motor power alone.

What size rider does it fit?

The step-over frame comes in a single general size with 26-inch wheels. Check the standover height and listed payload of 330 lb against your own measurements before buying.

You get the bike, its 48V battery, charger and LCD display, plus a front LED light. Expect to fit the front wheel, handlebars and pedals and to adjust the gears and brakes yourself.