The former member of the Crusty Demons spent Sunday night in Dunedin Hospital after crashing while attempting a back flip manoeuvre that morning.
He had been discharged from hospital on Monday but was taken back to Dunedin Hospital by ambulance yesterday after becoming ill on Monday night.
Smith was assessed in the Emergency Department yesterday and was in a stable condition in a general ward last night.
The Auckland-based motocross rider had been staging the first South Island Big Air Boot Camp at the weekend, teaching riders on a special motocross track complete with free-riding jumps and freestyle ramps, on farmland near Alexandra.