Hi.

I got a hybrid male bike with 28" wheels.
It come with a standard backboard that can hold up to 25kg, rear rack is maby the right word, that hold 25kg for cargo or a small kid.

Recently someone adult sit back to it, the bike was not running but i want to ask what kind of thing can be broken if its to mutch pressure on it?

Wonder of the mounting part on the aluminum chassi/tube can be broken because of that?

Thanks for reply.

While riding, you can do all sorts of damage with an adult on the rack. Flats, rim damage, broken/bent axles. But mostly it's the rack itself that gets damaged. Stays bent, or the actual rack bent.
For an adult sitting on a stationary bike, I'd only worry about the rack itself.

If it isn't broken, then I wouldn't worry about it. That is a good point that in some places, it is common to ride double on bikes, including using the rear rack.

What could go wrong? Maybe bending the legs of the rack near the attachment points. Perhaps it would depend a bit on the design, and how effectively the rack could take a vertical load.

Some cargo bikes are designed to take 100+ pound loads on the racks.

The 50 pound Dutch Opa/ Oma (grand pa/ma) bikes and rear racks, that they carry their friends on are not your average bike.

Thanks for the reply. On rack it stands max load is 55 pound.
Yes what i was worried about that it could damage the alupipe/chassie but like you say most probably will the rack be bent/cracked first.
He sit on it while it was parked.

Yes, I think they are built like tanks.



Most racks have a safety factor built in. I would not be too concerned with an adult sitting on it while it is standing still. The person would still have some of their weight supported by their feet, which should be on the ground.