Classic J-Strap Bifold Barn Door Hardware Kit | 4-Door Biparting

Panel weight: Up to 62.5 lbs per panel. Four panels works out to 250 lbs across the system, though that's simply the per-panel rating multiplied out rather than a separate limit. For heavier panels, see our heavy duty 4-door biparting bifold, rated to 200 lbs per panel.

Maximum panel size: 24 in wide × 84 in tall per panel. For larger panels, heavy duty bifold supports up to 48 in × 108 in.

Panel thickness: 1-1/4 in to 1-3/8 in. For thicker panels, heavy duty bifold handles 1-3/8 in to 2-1/4 in.

Panel width: Sized on total panel width — all four panels combined — rather than the rough opening. See the sizing section below for formulas and worked examples.

Panel height: Opening height + 1 in. That leaves 5/8 to 1-1/4 in of floor clearance, adjustable at the wall-mounted pivots during installation — more adjustment than sliding hardware gives you, which is useful over uneven flooring or thick carpet.

Ceiling clearance above door: 5-1/2 in required between the top of the door panels and the ceiling.

Wall clearance — both sides: Biparting needs clearance on both sides of the opening. For a fully clear opening, 5 in of clear wall on each side — two panels stack to just 5 in of depth. A minimum of 1/2 in is required between each track end and any adjacent wall or trim on the pivot sides.

Room depth on both stack sides: When the panels fold open they swing perpendicular to the wall, so each folded stack reaches into the room by the panel width plus 1/2 in — roughly 18 in on a 60 in opening sized for a fully clear span. Biparting needs very little wall but real floor space on both sides. Check that nothing occupies either footprint.

Wall header: A 1×6 hardwood header board is the minimum for every installation — oak, maple, or poplar, not pine. It spreads the load, and it decouples the track's bolt spacing from your stud spacing, since the track's mounting holes rarely line up with studs. Extend it past the track to the next stud or structural support point on each side, and make sure it runs continuously across any track joint. Never mount to drywall alone. Ceiling mount is not compatible with bifold hardware, so a solid header is the only mounting route.

Trim beside the opening: Casing, baseboard, or other trim projecting up to 1/2 in is already handled — the kit ships spacers that stand the track off the wall, with nothing extra to buy. Beyond that, add the extra trim clearance spacer from the options above, which takes you to 1-3/8 in of projection with the full stack. The spacers combine rather than replace each other, so you can mix the 1 in, the two 1/2 in, and the 7/8 in to land as close as possible to the 1/2 in door-to-wall gap. More than 1-3/8 in? Email us before ordering.

Origin: Colorado — made to order by Goldberg Brothers in Littleton

Lead time: 10-15 business days

Finishes: All 17 Goldberg Brothers colors

Wheels: Delrin installed — an acetal polymer, quieter than steel-on-steel

Weight capacity: 62.5 lbs per panel — 250 lbs across four panels

Panel thickness: 1-1/4 in to 1-3/8 in

Maximum panel size: 24 in wide × 84 in tall

Track lengths: 48 in, 56 in, 60 in, 64 in, 72 in, 80 in, 84 in, 96 in

Track sections: Anything over 7 ft 6 in ships in multiple sections with joining plates included

Track centerline height: Door height + 1-5/8 in + your floor gap (5/8 to 1-1/4 in) — unlike sliding hardware, the bifold figure doesn't already include the floor gap

Ceiling clearance: 5-1/2 in above door panels

Door-to-wall clearance: 1/2 in

Floor gap: 5/8 to 1-1/4 in — adjustable at the pivots during installation

Pivot type: Wall-mounted sidewall pivot — two included, one per side

Pull handles: Two 4 in pull handles included, one per side

Trim clearance: Spacers included — clears trim projecting up to 1/2 in · extra 7/8 in spacer available as an option above, reaching 1-3/8 in with the full stack

Soft close: Not available for any bifold configuration

Ceiling mount: Not compatible with bifold hardware

Returns: The listed track lengths are stock sizes and return under the standard window — 25 days from delivery with pre-approval and a 25% restocking fee. Designer colors are custom orders and can't be returned, which leaves 8 of the 17 colors returnable. See our return policy

Warranty: Limited lifetime warranty against manufacturing defects. Hardware is sold as rustic-finished, so minor marks and patina are characteristic rather than defects.

For bifold sizing across all six configurations see our bifold measuring guide. For general pre-order measurements see our measuring guide.

A 4-door biparting kit is two complete 2-door sets — one for each side — plus the alignment plates that join the two center panels.

• Pre-punched track (1), in your selected length — supplied in multiple sections with joining plates on lengths over 7 ft 6 in
• Fixed J-strap hangers (2) · Loose J-strap hangers (2) — one fixed and one loose per side
• 1-3/4 in carriage bolts (12) · keps nuts (12) — eight for the hangers, four for the pull handles
• 3/4 in hex bolts (2) · 1-1/4 in hex bolts (2) · 3/8 in spacers (2) · flange nuts (4)
• Hinges (8 — 6 used for panels 7 ft tall or under, all 8 for taller panels) · 5/8 in hinge screws (32)
• Sidewall pivot assemblies (2) — wall-mounted, one per side
• Door bottom plates (2) · 3/4 in steel washers (2)
• Track stops (4) · rubber bumper bands (2) · clear bumper pads (12) · felt strips (2)
• 5 in hex lag bolts (6) · nylon fender washers (6) · 1-5/8 in wood screws (8)
• 1 in spacers (6) · 1/2 in spacers (12)
• 4-door alignment plates (2) · 1-5/8 in wood screws (4)
• 4 in pull handles (2), one per side

The fixed hanger on each side attaches to the pivot-side panel. The loose hanger attaches to the center-facing panel and travels freely along the track as the doors fold open. The alignment plates attach to the bottom of the two center panels, holding them flush against each other for a clean center seam when closed — arrange those panels edge to edge, either touching or with a gap up to 1/8 in.

Trim clearance spacers are included. One 1 in spacer per lag bolt sets the baseline standoff; adding the 1/2 in spacers clears casing, base, or other trim projecting up to 1/2 in. Nothing extra to select.

Fastener finish: clear zinc with Raw Steel, Silver Metallic, and PC Chrome; black oxide with Matte Black Texture, Bronze Texture, Black, and Arch Bronze; powder coated to match on the remaining ten colors — Jacob's Gold, Rustic Brown, Regal Red, Rocket White, Blue Ribbon, Flint Gray Texture, Dark Gray Texture, White Bronze Texture, Silver Vein, and Copper Vein. The J-strap is face-mounted, so the bolt heads sit on the panel faces and are visible once installed, along with the lag bolts securing the track to the wall. On the seven finishes that don't ship matched, the touch-up paint option lets you paint them.

A latch and flush pull are not included — add them before ordering to avoid a second shipment. Soft close is not compatible with bifold hardware.

This kit includes two 4 in pull handles and trim clearance spacers for trim up to 1/2 in. A latch and flush pull are not included:

• Latch: Keeps the door closed deliberately — browse our latches collection
• Flush pull: For the wall-facing side if the doors are operated from both sides — browse our flush pulls collection
• Extra trim clearance spacer: Only if your casing or baseboard projects more than 1/2 in — your kit already covers anything up to that. Adds a 7/8 in spacer, reaching 1-3/8 in of projection. Select it in the options above
• Touch-up paint: For painting the visible bolt heads on finishes that don't ship matched — select it in the options above

4-door biparting sizing is based on total panel width — all four panels combined — not the rough opening. The track length you select equals your total panel width. For a full walkthrough of all six configurations see our bifold measuring guide.

Minimum coverage (doors close over the opening with a small overlap on each side):

Total panel width = opening + 4 in · Each panel = (opening + 4 in) ÷ 4

Example: 60 in opening → total = 64 in → each panel = 16 in

Fully clear opening (recommended — the track overlaps the wall by at least 5 in on each side, so the stacked panels sit entirely clear):

Total panel width = opening + 10 in · Each panel = (opening + 10 in) ÷ 4

Example: 60 in opening → total = 70 in → each panel = 17.5 in, round up to 18 in

Because biparting splits symmetrically from the center, the installation looks balanced when open without the extra planning a symmetrical one-way setup needs.

The track lengths listed in the options above are stock sizes, 48 in through 96 in. They ship as ordered and return under the standard 25-day window. Note that 96 in of track is four 24 in panels, which is this kit's maximum panel width — if your calculation runs past 96 in total, you're into heavy duty bifold or an 8-door configuration rather than a longer track. The 96 in length ships in multiple sections with joining plates included, and your header board needs to run continuously across the joint.

For a length outside those options, email us at info@thebarndoorhardwarestore.com — priced the same as the next standard size, but a track cut to order is a custom order and can't be returned, so confirm your measurement first.

Goldberg Brothers hardware uses sealed bearings that run dry. Do not lubricate the track or rollers. Silicone spray, WD-40, and white lithium grease all attract dust, build up in the channel, and make the doors harder to fold, not easier. If the panels start to drag or squeak, the cause is almost always debris in the track or a pivot that needs adjusting — wipe the track channel with a dry cloth and check that the hardware is still tight. On a bifold, also check the hinge screws, since folding puts repeated load on them.