There is no evidence to suggest that babies are more likely to get nappy rash in cloth nappies than disposables. 

Some studies have found that babies with 100% cotton cloth nappies (cool and breathable) next to their skin are 5 times less likely to get nappy rash than those in disposable nappies^8,9 (which contain plastics, perfumes and chemical gels)!!

Changing your baby often, when we or soiled, whether in disposable or cloth nappies is a much better way to avoiding nappy rash.  Other factors which promote nappy rash include general health and nutrition.

If your baby does seem to be sensitive to cloth nappies - it is most likely to be the washing powder or process that will be the problem, not the nappies