Brake system and straddle-type vehicle

A brake system (100) for a straddle-type vehicle (10) of a rear-wheel-drive type, the brake system comprising:

• a front-wheel brake mechanism (20) that brakes a front wheel (3) of the straddle-type vehicle (10);
• a rear-wheel brake mechanism (40) that brakes a rear wheel (4) of the straddle-type vehicle (10);
• and
• an operation element (11) that is operated by a rider of the straddle-type vehicle (10), wherein
• the front-wheel brake mechanism (20) includes a friction brake mechanism (21, 70) that generates a friction braking force only on the front wheel (3), and can generate the friction braking force in response to motion of the operation element (11),
• the rear-wheel brake mechanism (40) does not include a friction brake mechanism but includes a regenerative brake mechanism (5) that generates a regenerative braking force on the rear wheel (4), and
• the front-wheel brake mechanism (20) can further increase or reduce the friction braking force by the friction brake mechanism (21, 70) regardless of the motion of the operation element (11).