Attach the rear bicycle rack that comes with your Topeak BabySeat to your bicycle. Use the included Phillips-head screws to affix the bottom portion of the rack to the holes on each side of your bicycle frame located just above where your rear wheel fits into the frame. Screw the chrome extenders that stick out from the top of the rack to the holes on the seat stay portion of your frame, which extends down from the seatpost to the rear wheel.
Tighten the screws for the bike rack completely after you properly positioned the rack. Be certain that all holes on the frame line up with all holes on the rack. The rack must fit straight. Spin your rear wheel to make sure it does not rub the rear rack. While this is usually not an issue, it does not hurt to check.
Position the Topeak BabySeat onto the front rail of the rack. Standing behind the bike, attach the bottom, rear portion of the seat to the rail of the rack closest to the bike's saddle. Lower the seat down until you hear it click into position.
Push the red button, as noted in the Topeak BabySeat user guide, and slide the locking mechanism all the way back. Push the red button again and slide the lock back onto the rack. Make sure you hear a click and see the red button through the hole on the rack surface. This ensures that the seat has securely engaged the rack.
Fasten the T-strap, which comes through a slot at the bottom of your Topeak BabySeat, to the seatpost. Shorten the length of the strap so that it is taut when wrapped around the seatpost from the seat's bottom.