A good starting point is Zennor. The Tinners Arms and The Old Chapel Backpackers provide watering holes at the end of your circuit. The Tinners Arms does pub food and a modest selection of beers. The Old Chapel Backpackers cafe does pizzas, teas etc. as well as providing accommodation.
I recommend doing the route anti clockwise.The climb out of Zennor is steep so walking is a good option if you are not fit. This is probably the most strenous part of the ride. You are soon on the top of the moors of Penwith with views over the Atlantic and the English Channel.
Depending on the time available you can visit Mulfa Quoit on the top of Mulfa Hill. If you enter New Mill at the bottom of Try Valley you know you missed the left turn to Chysauster. The iron age village of Chysauster is a must. One of the best preserved stone hut complex’s in Cornwall and under the care of English Heritage. Joining the Penzance to St Ives road you are rewarded at the top of the hill with great views of St Michael’s Mount, the north coast up to St Agnes beacon, Carn Brea at Redruth, Godolphin Hill with sections of the Lizard peninsula off to it’s right.
First left at Nancledra gets you back on to quiet country lanes. The last section of the ride is along the St Ives to Zennor road with its lovely coastal views and bronze age field landscape.
Time permitting a quick cycle strait up the valley from Zennor and a walk over the carn on your left brings you to Zennor Quoit.