Here is a combination of climbs you might like. I rode on Saturday, but at least this time of year, you'll not want to spend too much time at any of the food/water stops (or if you do . . . bring lights)..
Five of us started at 8:00AM from Encanto Park in Duarte. We got on the SGRT very close to the park, then merged with Hwy 39 a mile or so later. We took Hwy 39 to the Crystal Lake turn-off and from there 2 miles to the Crystal Lake Café, where we had lunch.
After lunch we descended to East Fork. At this point, 2 of our riders took Hwy 39 back to the park, i.e. an out-and-back route. Three of us took East Fork to Camp Williams and after a short food/water stop rode Little GMR up to the GRR/GMR junction. At this point, 2 riders went down Big GMR and took Sierra Madre back to the start.
I took GRR over to Mt. Baldy Village, filled my bottles at the Lodge and rode back over GRR to GMR, then to Sierra Madre and back to the park. Total miles: 96.2 (not quite a century). Total climbing: 11,161 feet.
Strava:
Bike Ride Profile | Encanto to Crystal Lake Cafe, Camp Williams, GRR to Mt. Baldy Village, back GRR/GMR near Duarte | Times and Records | Strava
Garmin:
Garmin Connect
This route strings together several good climbs and I think you would like it.
Rick / OCRR