The two primary differences are in the track and the cable drums. When a standard-lift garage door is closed, the top roller rests at the bottom of the curved portion of the track, or just below it. High-lift garage doors have a longer straight portion of track between the top roller and the curved portion of track (as pictured on left). Vertical lift garage doors do not have any curved portions of track. Instead, the garage door opens straight up and at a slight angle backwards. The track is angled back slightly to let the door close as a wedge, as mentioned on our homepage.
Because the high-lift and vertical-lift garage doors open differently, these systems need different cable drums. Vertical-lift cable drums are not flat like standard-lift cable drums. Instead, the cable continually winds closer to the shaft on the drum as the garage door opens. High-lift cable drums are essentially a mixture of the vertical-lift and standard-lift cable drums. The first few times that the cable wraps around the drum, it moves closer to the shaft like a vertical-lift drum. At a certain point, however, the drum levels out and the cable continues to wrap around the drum at a constant distance from the shaft like a standard-lift drum.
Most standard-lift cable drums have a very small portion of high-lift on the outside edge. This was added to cable drums once it was realized that the torsion springs must support the entire weight of the garage door until the top rollers reach the horizontal portion of track. Although most people are inclined to think that some of the weight will be transferred to the curved portion of track, this was not consistent with the what was practically observed. This raised portion of the standard-lift cable drums allows the garage door to open without the torsion springs losing extra lift in the first portion of the door's travel.
If you are interested in converting from a standard-lift door to a high-lift garage door, see our High-Lift Conversion tutorial. If you have a residential door and you want to convert to a high-lift system, see our High-Lift Inquiry page after gathering the measurements listed in the tutorial to get a quote for a custom conversion kit.
IMPORTANT NOTE REGARDING LOCAL PICKUPS: DDM is considered a life-sustaining company because we are an internet retail company that provides essential products. Due to the recent outbreak of Coronavirus, however, we are changing our local order pickup policy at our West Chicago location. To pick up an order you will need to order first. The quickest way is to order in advance through our online shopping cart. There you can select the local pickup option. Or, you can call 630-293-1337 for assistance, to confirm availability of parts, and to place your order. Once ordered, your parts will be available for pickup in the lobby of our north side front entrance. Longer items will be picked up on the south side loading dock. Please honor the six foot social distancing rule. Thank you for your patience and understanding as we all navigate this challenge together. More information is available on our blog titled DDM Adjusts to the COVID-19 Coronavirus. In the same article you will also find documentation and an answer to the question: "Is a garage door repair company a life sustaining business?"