Zhè liàng zìxíngchē de lúnfú shì bùxiùgāng zuò de.
This bicycle's spokes are made of stainless steel.
Tips
memory
轮 (lún, wheel) + 辐 (fú, spoke). The same 辐 also appears in 辐射 (fúshè, radiation) - same image: lines spreading out from a central hub. Once you see the spoke, radiation makes sense too.