A suggested Bike on Bus Ride
Here is a trip that requires a little flexibility, but with SEPTA's Frontier Division now over 60% bike accessible it offers the best chance to take your bike on the bus to experience the Perkiomen Trial.
On a Saturday take your bike on the R6 or route 100 (the easier option) to the Norristown Transportation Center. Then take the 91 to Graterford and ride back to Norristown or Center City on the Perkiomen and Schuylkill River Trails.
The bike path crosses Graterford Road about a 1/4 mile before the prison entrance in an open field. Its a beautiful place to start a bike ride (really).
There are also more flexible options that offer shorter bike rides.
The 93 crosses the Perkiomen Trail near 3rd and Main in Collegeville.
The 99 meets the trail at Lower Perkiomen Park. (Egypt and New Mill Roads just before the 422 interchange)
Note: both the 93 and 99 run hourly 7 days a week. The 91 only runs on Saturdays leaving Norristown at 8:15, 10:15, 12:15 and 2:15
Of course there's no guarantee of a bike rack so you need to keep your options open. Just show up at Norristown and see which bus has a rack. If all else fails you can simply start your ride on the bike path.