Bypass doors put two moving panels on one track, so either end of the opening can be the way in. A single slider moves one panel alongside a fixed panel, so the entry is always at the same end. Bypass suits wide tub openings. Single sliders suit bases where one end is the obvious entrance. Both are cut to size at the Lodi shop.
Neither style opens the full width. On a bypass, one panel slides behind the other, so the clear entry is a little under half the total width and you get to pick which half. On a single slider the moving panel parks over the fixed one, giving you slightly less than half at one end only. Across a standard tub that is plenty of room to step over the wall. In a narrow alcove, half of a small opening starts to feel tight, and a hinged door or a fixed walk in panel may serve you better.
Do that arithmetic before you fall for either style. Measure the full opening, halve it, then subtract the overlap where one panel passes the other along with the width of the track ends. What is left is the space you actually step through with a towel in one hand. Across a long tub the number stays generous. On a compact base it can fall below comfortable, and learning that from a tape measure beats learning it from the finished shower.
Bypass is the traditional tub answer in older North Jersey bathrooms because the opening is long, the tub deck runs the full width and entering from either end helps when you are bathing children or reaching the far corner to clean. Single sliders turn up more often on shower bases, and on tub openings where a window, the plumbing wall or a grab bar makes one end the natural entrance. Both ride on rollers, and both want a level curb and reasonably plumb walls to track smoothly year after year.
Rollers and track carry the daily load either way. A bypass has twice the rollers and a second panel path to keep clean, so soap film builds in two channels rather than one. A single slider concentrates that wear on one roller set and one bottom guide. Wipe the track dry, keep the weep holes open, and both keep gliding.
Track design has moved on since the aluminum channels sitting in most older bathrooms. Newer bottom rails shed water instead of holding it, and top hung rollers take the load off the sill entirely. If the reason you are replacing a slider is a corroded track with standing water in it, say so when you call, because that is a solvable problem rather than a reason to give up on sliding doors.
Most do. Bypass panels usually lift up and tilt free of the track so you can reach the back face and the channel behind them, and single sliders often lift the same way. Do it with a second set of hands, because tempered glass is heavier and more awkward than it looks, and rest the panel on a towel rather than the tub rim.
Yes, as long as the base is wide enough that half the opening still leaves a comfortable entry. On a narrow base the arithmetic turns against you and a hinged door or a fixed panel gives more room to step through. The curb also has to be level and the walls close enough to plumb for the track to sit true across the span.
Sliding hardware makes far more sense once you have worked it yourself. A free in-home measure records the opening, the curb and the wall condition, and the panels are then fabricated to those exact numbers at our Lodi shop.
