Commenting on Davids signing, Ryan said: "Quinton is an influential signing. We wanted someone to work alongside our existing locks, and by that we mean being different types of players.
"Quinton is the opposite kind of second row to Alex Brown, and alongside the other guys in that position in the squad, they complement each other. We now have more options throughout the season, for different times of the year and for different games."
Davids has signed a one-year contract with the option to extend for both parties for two more years.
"One of the key issues about signing Quinton is that he was prepared to prove himself. There's a longer-term deal on the table for him if he can show what he's worth. We want people to be driven by performance, and I'm delighted that he's got that attitude," added Ryan.
In addition to Davids, Club stalwart Mark Cornwell has signed a new one-year contract, and Ryan said: "Mark Cornwell's new contract is a significant one. He gives us options, and our second row options are now complete with Quinton Davids, Alex Brown, Adam Eustace, Jonathan Pendlebury and Mark Cornwell. We saw that area as something we wanted to build on, and we've done that."
Joining the two second row players is young wing James Bailey. The 21 year-old England sevens international has also signed a new one-year contract.
Commenting on Bailey, Ryan said: "We felt that his performances in the last few weeks of the season deserved the contract. He's certainly worth another 12 months of development and investment. With Bryan coming in there will be some new ideas and views and that offers James an opportunity to continue going forward."
Looking ahead to the make-up of the first team squad Ryan said: "We're not drawing a line under any more new players, but as we've said before we were always going to be restricted in terms of timings and the windows of opportunity that you have to work within.
"If there are opportunities over the next 12 months, then we'll look at them, but we won't be shipping players in and out. That's an important fact to state. Player recruitment is about enhancing what you have.