Which is better for a 13-year-old?

The Gpower fits the 8-14 age range and its 25 in seat and 55 lb weight suit a young rider. A tall or heavy 13-year-old is better served by the B200RSV, which is rated 13+ and carries up to 200 lb.

Can an adult ride the Gpower?

Only if they weigh under 165 lb and fit the 5'1" to 5'9" height range. Most adults will feel cramped and underpowered on a 50cc bike, so the B200RSV is the better fit.

The B200RSV has the heavier frame and larger engine built for adult loads, so it should hold up better to hard use. The Gpower is a light kids' bike and its 90-day-class components wear faster under heavy riders.

Is the B200RSV worth stepping up to?

Yes if you need more speed, more torque, or a bike that fits an adult. You give up light weight and easy transport, since it weighs 154 lb.

Do both have disc brakes?

Yes. Both list front and rear disc brakes, so stopping hardware is not the deciding factor. Suspension and engine size are.

Which is easier to start?

Both use a recoil pull start. The Gpower has the edge for beginners because it needs no fuel mixing, while the B200RSV's larger engine takes a firmer pull.

B200RSV Mini Bike vs GPOWER 50cc Dirt Bike

The B200RSV is a full-size adult mini bike: 196cc, roughly 30 mph, hydraulic front suspension, and a 200 lb load limit. The Gpower is a small kids' dirt bike: 50cc, 25 mph, 55 lb, and a 165 lb limit. Buy the B200RSV for teens and adults who want real torque and a sturdier frame. Buy the Gpower for a younger or lighter rider who needs a light, easy-to-handle starter bike.

Choose the B200RSV if you are a teen or adult who wants a bigger, torquier bike that can handle trails and heavier riders.
Choose the Gpower if the rider is a kid or smaller teen who needs a light, low, easy-to-start first dirt bike.

Prices

B200RSV Mini Bike: $38.00 at Schumann (checked today)
GPOWER 50cc Dirt Bike: $229.99 at Amazon (checked today)
Difference: the B200RSV Mini Bike is $191.99 cheaper than the GPOWER 50cc Dirt Bike today