when you approach the lake, the road forks. Do NOT take the right fork that heads downward, take the left fork and follow it even if it looks worse. I had experienced this first hand.
Both FR4130 and FR4131 are now almost completely brush free due to road decommissioning work done by Forest Service contractors in 2014. Numerous 'tank traps' make the road unsuitable for mountain bikes. If you have any interest in climbing Big Bear, Liberty, or Fletcher, the next few years will be a great opportunity to do so.