Where's My Bike's Serial Number?
You'll need it to register, to check a bike before buying, or to report a theft — here's where to actually find it.
Check the bottom bracket first
On the vast majority of regular bikes, the serial number is stamped into the underside of the bottom bracket shell — the part the pedal cranks pass through. You'll usually need to tilt or flip the bike to see it clearly; a phone torch and a rag to wipe off grime both help.
Check the headtube and rear dropout next
If it's not on the bottom bracket, check the headtube (where the front fork meets the frame) and the rear dropouts (where the rear wheel's axle sits) — some brands stamp it in one of these spots instead.
For e-bikes, check the battery and motor too
E-bikes typically carry their own separate serial numbers on the battery pack casing and the motor unit, in addition to the frame serial. SpokeID has dedicated fields for all three and the checker matches against every one, so record the lot. There is a full walkthrough of exactly where each of the three sits at /ebike-serial-numbers.
Can't find it? Use what you have
If the serial has been scratched off, or you genuinely can't locate one, register with whatever you do have — a receipt, a purchase confirmation email, or clear photos of the bike. A partial record with photos and a timestamp of ownership is still far better than nothing.