What was the VMO of the L1011?
375 knots
Mmo M.90
Pilots that fly lighter (smaller) jet transport aircraft normally have a somewhat difficult time understanding the concept of very heavy weight models (especially those designed for higher cruise speeds, in the past) and the necessity of faster than what might otherwise seem prudent climb speeds...compared with the lighter/smaller/slower cruisers that they normally fly.
In other words, B737 and A320 aircraft, they are not.
The L1011 was designed for a normal enroute cruise speed of M.86, and a LRC speed of M.84, and if at heavier weights, a slower than optimum climb speed was attempted, the time to climb would be longer.
Guaranteed.