Smart sardarji...bikes

A sardarji comes up to the Pakistan border on his bike. He’s got two large bags over his shoulders.
The guard Iqbal stops him and says, ‘What’s in the bags?’ ‘Sand,’ answered the Sardarji.
Iqbal says, ‘We’ll just see about that. Get off the bike.’
Iqbal’s guard takes the bags and rips them apart, he empties them out and finds nothing in them but sand. He detains the sardarji all night and has the sand analyzed, only to discover that there is nothing but pure sand in the bags. Iqbal releases the sardaji, puts the sand into new bags, lefts them onto the sardarji’s shoulders, and lets him cross the border.
A week later, the same thing happens. Iqbal asks, ‘What have you got?’ ‘Sand,’ says the Sardarji.
Iqbal does his thorough examination and discovers that the bags contain nothing but sand. He gives the sand back to the Sardar, and crosses the border on his bike. This sequence of events is repeated every day for three years.
Finally, the Sardarji doesn’t show up one day and the guard, Iqbal, meets him in a ‘Dhaba’ in Islamabad.
‘Hey, Buddy,’ says Iqbal, ‘I know you are smuggling something. It’s driving me crazy. It’s all I think about…I can’t sleep. Just between you and me, what are you smuggling?’
The Sardaji, sips his Lassi and says, ‘Bikes’