After many visits we found that the adventorous way we were looking to reach the Central Jungle without riding by the main highway was by a gravel road with very low transit, almost none.
So to get to this place, you can go by car to Ricran village, then taking the detour to the highpass of Tambillo and start the ride down to the Jungle.
We started from 4600m at Tambillo distrit, straight down to Monobamba at 2000m approx. riding down crossing many altitudes and climates. And as usual in these places weather is always an enigma. You can get cold, web, rainy, misty at the top and you can continue wet  all the way down or reach a sunny and very hot day.
After Monobamba, the downhill turns not as fast, from this village we must ride and pedal to reach Vitoc, the entrance to San Ramon city, the main city at the entrance of Chanchamayo valley, known in the country as the Selva Central.
For your records the ride takes around 6 hours dropping nearly than 4000m by gravel road, anyway if you are tough a brave you can can start pedaling from Ricran and climb a 1,000 mt for a couple or three hours before the downhill ride.