The main paved bike path through San Jose runs along the Guadalupe River and connects several parks and neighborhoods. Expect a flat, easy ride of 10-20 miles round-trip depending on how far you go. The path is mostly smooth, shared with joggers, families, and the occasional e-bike commuter. You'll see a mix of urban edges, some greenery, and a surprising number of birds and turtles near the water. It's not a dramatic scenic ride but it's genuinely pleasant on a clear day and a low-stress way to get outside without dealing with car traffic.
Best time is spring or fall. Summers get hot and the path has almost no shade, so aim for early morning if you visit June through September. Winter can be nice but check the forecast; the trail floods quickly after heavy rain. Expect to pay around $25-45 for a half-day bike rental including helmet and lock. Guided group rides add $60-90 per person if you want navigation and stops explained.
Pick the northern section toward Alviso if you want fewer people and a bit more nature feel. Skip trying to combine it with downtown sightseeing in one go; the path doesn't connect cleanly and you'll waste time on busy streets. Bring your own water and snacks; options along the trail are limited.