Bike Child Seats — Front, Rear & Frame-Mount Buying Guide

Child carriers are regulated by the child's age, weight, and ability to hold their head up — not by frame size. Front-mount seats (Thule Yepp Mini, iBert Safe-T-Seat) typically fit children from 9 months (when neck strength supports a helmet) up to ~33 lb / 15 kg, and mount on the head tube or steerer with a bracket; they shine for visibility and conversation but limit your knee clearance. Rear-mount seats (Thule Yepp Maxi, Hamax Caress, Burley Dash) carry 9 months up to ~48.5 lb / 22 kg and bolt either to a rack (most common, requires a Class 26 or MIK-rated rear rack) or directly to the seat tube via a frame bracket. Mid-mount/saddle-area seats (Mac Ride, Kids Ride Shotgun) sit between the rider's arms and need 60 mm+ of exposed top tube and a 31.6/34.9 mm seat-tube clamp area — they don't fit most full-suspension MTBs or compact-geometry road frames. Always verify ebike compatibility: many seats are rated only up to 25 km/h pedelec speeds and are not approved for Class 3 (28 mph) ebikes.

• Age and weight rating: 9 months is the universal floor (helmet + neck strength). Front seats top out at ~15 kg / 33 lb; rear seats at ~22 kg / 48.5 lb. Don't extrapolate — manufacturers test to those limits.
• Mounting system: rear-rack seats need a rated rack (MIK, Racktime, or 'Class 26' load rating ≥ 25 kg). Seat-tube clamp seats need a round, unobstructed seat tube — not aero, dropper-post, or kinked tube profiles. Front-mount seats need a 1 1/8" steerer with enough exposed length above the headset.
• Ebike rating: confirm the seat is approved for Class 1/2 (20 mph) or Class 3 (28 mph) explicitly. EU pedelec ratings (EN 14344) cover up to 25 km/h only.
• 5-point harness vs 3-point: 5-point is the safety standard for any child under 4. Some economy seats use 3-point — fine for very short trips, not for daily commuting.
• Recline / sleep support: rear seats with adjustable recline (Hamax Caress, Yepp Maxi Easyfit with sleep roll) make the difference between a 30-minute trip and a meltdown when toddlers nap.
• Foot guards and adjustable stirrups: feet must be fully enclosed away from spokes — non-negotiable. Stirrups should adjust as the child grows; cheap fixed stirrups become useless at ~18 months.
• Helmet clearance: rear seats with a high backrest can collide with a child's helmet. Test-fit before buying or pick a seat with a notched, helmet-friendly headrest.