One factor to consider is how long you expect your retirement to be. The longer that time period, the higher your allocation to stocks should be. For a standard 30 year retirement, cFiresim suggests you should have at least 70% in stocks and 30% in bonds. There isn't much difference in the SWR throughout the 70/30 to 100/0 range. If you're looking at a 50 year retirement, according to cFiresim you should be at least 80/20.
There is also the camp that favors a "rising equity glidepath," wherein you reduce the equity portion of your allocation during the decade or so leading up to retirement and the decade or so following retirement, then begin to ratchet it back up to provide more growth once you're past the danger zone for sequence of return risk. My recollection from reading those studies (it's been a while) is that the benefit is marginal at best.
The other factor to consider, which you've already identified, is your personal risk tolerance. If you just can't bear the thought of seeing your nest egg decline by 30% or more, you may want to back off your allocation to stocks, even though history suggests such a change in your asset allocation would be sub-optimal over the long run.