It's 3600+ miles between Halifax and Vancouver on the TransCanada - more biking back roads - - maybe 4000, like 400 miles per week, every week. 10 weeks from the end of July puts you in Vancouver in the middle of October. Late September and early October can be beautiful, but you can also have early snowstorms. They can come as early as Labor Day. You can usually wait a few days and glorious weather returns, but your schedule is awfully tight. Then you get into early fall rains on the Washington/Oregon coasts by late October.
October is incredible south around San Fran and south of there. Same goes for Sept on the Oregon coast. I would urge you to consider hitting Banff no later than Sept 1.
That will put you into Victoria by mid-Sept and into San Fran by early/mid-Oct.
Best - J