SSA,
There is no room for caste system in sikhism. Many will say that they have experianced it in many sikhs then only things I will say that those who believe in caste system cannot be called sikhs. For real sikhs caste system does not exists
Reference:: Sikh Philosophy Network http://www.sikhphilosophy.net/sikh-youth/14462-caste-system-in-sikhism.html
Roopsidhu