Plymouth is a funny old place sometimes, the bonuses far outweigh the negatives but if there were a negative then, as a cyclist, it would be the Wrangy Loop.
Every cycling club has one of these rides, it's kind of the ideal ride for people with a massive lack of imagination. It's the equivalent of always eating the burger because you know it'll taste ok and you cannot be arsed to try anything on the menu. People that always ride the Wrangy Loop are not bad people, in fact every cyclist in Plymouth does this ride far too often, but we all kick ourselves after every time. We have now taken to pretending to ride to other places near the loop - but having to cut off early, or renaming the ride on Strava. The "Wrangy-shaming" peaked in 2019.
That said, if you don't live in Plymouth and have never experienced it, it's a really nice ride. This is why it gets so much use.
Distance : Just over 30miles
Surface: It's a road ride in Devon so reasonable
Traffic: Not too bad, better than you'd think even in summer.
Most likely to kill you: Milk Tanker, old lady in Honda Jazz, knob head training to win the Dartmoor Classic.
Below is a link to the route on my Strava, I'll give you the abridged version which is basically you head out of RnR (where every good ride starts and ends), head towards Plymstock, over Laira Bridge, pick up the Modbury Road and keep riding, once past Yealm Bridge you'll climb past the Mothecombe turn and then descend at the bottom of the descent swing left signed for Ugborough. Continue all the way up the valley (gentle climb) and at the top of the climb swing left again to climb further to Wrangaton. Then left towards home via Ivybridge (a lovely flat and fast road), onwards to Lee Mill taking the cycle path alongside the A38. At Lee Mill follow the cycle route signs to Plymouth arriving at Deep Lane which offers you either left and home via Plymstock or right and home via Plympton.
Of course the route can be ridden in reverse in the interests of variety (Cheese Burger instead of Plain Burger).
Bail Out Option: If you have run out of mojo or you need to get home for an Ikea trip then this ride quickly converts into the perfectly respectable Ermington loop, simply turn off (before the bridge) at the bottom of the valley into Ermington, follow the mini Pogio through to Ivybridge and then pick up the rest of the route, it's about 23 miles.