The old fashioned method, before the new pension freedoms, was based on buying an annuity on the day you retired. Because this was a fixed date, you couldn’t risk a crash just before you retired, so you were gradually moved into bonds and cash in the 10 years prior.
Now, if you plan to use drawdown, you need to build 3 years supply of fixed income/cash, which will allow you to ride out the maximum expected length of stock market crashes without having to sell equities/funds whilst they are down.
The potential growth of an equity portfolio whilst retired is massive compared to bonds. So even low risk investments are a risk in themselves…..