Can't take a train? Cycle Instead!

Updated plan ... 

I tried to book a ScotRail trip from Pitlochry to Sterling, but learned that there are only 2 or 3 berths for bicycles on each train, and no more bicycle reservations are available on any train on the day I planned to travel. So, I will ride back from Pitlochry to Sterling in one day, and then on to Glasgow the next. 

Overnight in Sterling at the Scottish Youth Hostel (for which being young is not a requirement). Last time I stayed in a youth hostel while biking was on my 1979 cross country (USA) tour.

I thought taking the train would be as easy as this:

Cycling Tourists, 1950's

or this

Cyclists Special, a short film about cycle touring in the UK, 1955

Here's the updated itinerary:

Trip Day	Activity	Biking Miles
0	Fly from BOS to GLA	0
1	Bike to Callander from Gear Bikes Rental in Glasgow. Hotel in Callander	38
2	Loop - Callander to Loch Katrine. Hotel in Callander	48
3	Bike from Callander to Killin. Hotel in Killin.	25
4	Bike from Killin to Aberfeldy. Hotel in Aberfeldy	25
5	Bike from Aberfeldy to Pitlochry. Hotel in Pitlochry	16
6	Loop - Loch Tummel Circuit & River Garry to Blaire Castle, Hotel in Pitlochry	45
7	Loop - Whitefield Castle. Hotel in Pitlochry	33
8	Formal Trip over. Cycle to Stirling. Stay at the Sterling Youth Hostel.	77
9	Cycle to Glasgow via Tak-Ma-Doon Rd. Stay at SafeStay 27 Elmbank St, Glasgow	30
10	Day in Glascow , Fly GLA to Boston	?
11	Arrive Boston
		337