Hi Adithya,
Just saw this post, and your later one looking into costs of getting your bike up to Rohtang from Bangalore. Not sure if you've gotten some feedback already, here are my thoughts - based on my experiences cycling from Manali-Leh-Srinagar 3 summers ago, and also having trekked from Lamayuru - Padum and Darcha - Padum, although that was quite a few years ago.
2) LAMAYURU - PADUM ROAD? It also looks like there is a motorable road now from Lamayuru Gompa on the Leh-Kargil road South to Wanla. Then you have to trek further south till beyond Lingshed, and then you reach the Zanskar river valley, and it looks like the road has come up north from Padum till this point, beyond Zangla. When you get to Leh and Padum, ask how far the road between Lamayuru and Padum stretches, and how many km are still only walking trails. That will soon be another possibility to reach Padum by cycle without going all the way to Kargil from Leh.
3) GETTING TO MANALI: Take along lots of bungees - you should be able to lash your bike onto the top of any of the regular non-AC state buses, which will be cheaper than a Volvo, both for your ticket and the extra luggage charge.
4) TRY CYCLING UP TO MARHI FROM MANALI: Up to Marhi, you should be fine in terms of traffic. And yes, there was a lot of slush and traffic getting closer to Rohtang, but on a cycle you can actually get past most of the jams quicker. And its a good acclimatization climb.
5) IF GETTING A RIDE, JUST GO UP TILL ROHTANG: Most of the traffic stays on the southern side of Rohtang Pass. If you're not riding, then just get dropped at the top of the pass or a little before. Then enjoy the downhill ride all the way to the Chenab river, and more or less level riding till Khoksar. You could also ride from Manali to Marhi, spend a night there acclimatizing, then catch a ride from Marhi to Rohtang if the traffic is looking bad, and ride down to Khoksar.
6) LEAVE A DAY FOR PHUGTAL GOMPA: After crossing Shingo La, heading north, take a day to trek to Phugtal and back, well worth the side trip.
7) DONT TAKE A SUMO FROM KARGIL TO SRINAGAR, RIDE! I reached Srinagar from Kargil in 2 days. 1 day to Dras - tiring climb but you'll be quite fit at this point. Then a morning climb up to Zoji La, followed by a blissful 100 km descent in 3 hours all the way practically to the Srinagar bus station! Well worth the extra day.
8) SRINAGAR - DELHI: There are 24 hour state buses which will be the cheapest way to get back to Delhi.
9) TRY TO USE SAME AIRLINE: From Srinagar - Bangalore, or Bangalore - Leh, try to use the same airline. Then you can be sure your luggage will be booked through to the end point. Otherwise you may have to collect your bike box and recheck it for the 2nd leg, and go through the hassle of any extra baggage fees a second time. I've had good experiences with Jet airways the couple of times I've transported my cycle with them.
10) BIKE BOXES FIT INTO AMBASSADORS: Perhaps you can find an old Ambassador taxi and book him for taking you to the airport. The bike box snugly fits in the back seat, as I discovered in the city of Ambassador taxis - Kolkata! Specially if there are two of you, the airport bus will anyway be around 250-300 rupees each.
11) CYCLE GUIDE CONTACT IN MANALI: I highly recommend Rana, a nice laid-back local who has cycles for hire, and also organizes Manali-Leh and other rides. He has a guest house in Manali. He would be a good person to call and ask about the logistics of transporting your cycle from Manali to Rohtang, cost, latest road conditions, etc. His number is
9459829914.
Hope that's helpful. Please document and share the exact stretches from Darcha to Padum, and Padum-Lamayuru where there is a cycle-able road!