If you bought say a single stock for $10000. $5000 on Margin and $5000 in unsettled cash. Same day you want to sell of the margin amount of shares. Is this considered a free ride or is this ok since you only sold the margin's amount of shares?
I'm not 100% sure, but I don't think it would be considered a free ride. The idea of a free ride is that you are engaging in a transaction when you do not actually have the money available to cover it, since the broker is technically giving you a 3 day loan whenever you purchase your stock (3 day rule to settle.)
However, if you are using a margin account, and you have enough credit available, then you are not actually using unsettled assets, but rather an additional line of credit which was granted to you. You would just need to make sure that your total transactions are less than your purchasing power.
That's my take on it anyway. I hope that helps, and hopefully someone can confirm or reject what I have said.
There is no free ride at most brokers. You will likely be charged a margin fee for that trade even though you only held the margin shares for part of one day. The margin fee would be the annual margin interest rate calculated down to a one day holding period,so it would be smaller. Check your broker's policies but most work like this.