Originally Posted by
Tamiya
those bikes are single chainring?
ive seen some kiddy bikes with 1X7 Shimano, the single chain ring has plastic guard on both sides & the chain runs in the channel between them
im still not decided whether they're there to guard/guide the chain or more to protect the kiddy shin away from the sharp spikey chainring
When you shift in the rear, a wave propagates on the chain up to the chainring that can cause a chain drop when the chainring is rotating. A front derailleur cage limits the lateral movement of the chain and so does a chainguard attached in a close vicinity of the chain. This is also the purpose of the chain guide on Bike Friday.