Bendy buses on 851 are they full day starters or all split on
weekdays?
Out of the total number of 8 bendy buses of 851, 6 of them
crossover to Service 856 and 969 respectively, 3 to each service
during Weekdays AM Peak. That's why you don't get to see lots of
bendy buses on 851, almost all are OCs and Citaros or O405s. One of
the 2 bendy buses operates between SMB79J and SMB96J, around 6am
plus travelling to Yishun Bus Interchange in the MORNING ONLY, in
the afternoon won't be seen, in the evening operates after
SMB73A.
They will begin to reappearly slowly in the afternoon, and are
most easily observed during PM peak hours.
Take note that the shift of bendy buses is usually fixed,
however the buses alternates shifts every single week.