How Many Metres of Gear Rack Do I Need for a Sliding Gate?
Short answer: buy gear rack for the full length of the gate leaf, not just the opening, and round up to the next whole metre. Our GR-12M 12 mm GI gear rack comes in 1 metre pieces at ₹1,399 per metre with 3 studs per piece, so a 4.2 metre gate needs 5 pieces (₹6,995) and a 6 metre gate needs 6 pieces (₹8,394). Prices are our live website prices, include GST, and delivery across India is free.
Why does the rack need to run the whole gate?
A sliding gate motor does not pull the gate with a chain or a belt. It turns a small toothed wheel, the pinion, and the pinion pushes against a toothed strip, the gear rack, that is bolted along the side of the gate. The motor stays fixed on its base plate beside the opening. The gate, with its rack, moves past it.
That means the pinion has to stay engaged with the rack from the moment the gate is fully closed until it is fully open. If the rack ends too early, the pinion runs off the end and the gate stops short, or worse, drops off the teeth and jams. A gate leaf in India is usually a little longer than the opening, so it overlaps the pillar on both sides. Running the rack along the full leaf length covers the whole travel with a margin at each end. It is the simple, safe rule that most installers follow.
How to measure your gate for gear rack
- Measure the gate leaf, not the opening. Take the tape along the bottom rail of the gate itself, from one end to the other. If the opening is 4 metres and the leaf is 4.3 metres, the number you want is 4.3.
- Check how far the gate travels. Slide it by hand from fully closed to fully open and note the distance. The rack must cover this travel plus a little at each end so the pinion never leaves the teeth. On a normal gate the full leaf length already does this.
- Decide where the motor sits. The motor goes on the side the gate slides towards, close to the pillar, on a firm base. The rack is fixed on the inside face of the gate at the height of the pinion. Your fabricator can add a flat strip on the gate if the frame has no straight face for the rack.
- Convert to metres. Many fabricators measure in feet. One foot is 0.3048 metres, so a 14 ft gate is about 4.27 metres.
- Round up to the next whole metre. GR-12M is sold in 1 metre pieces. 4.27 metres becomes 5 pieces. Never round down; a short rack is the one mistake you cannot fix without buying again.
- Cut the last piece if needed. Any extra beyond the end of the gate can be cut off by your fabricator with a grinder. Leave the rack flush with the gate ends.
If you would rather not do the maths, the Gate Builder asks for your gate weight and length and works out the motor and the rack in whole metres for you.
Gear rack quantity and cost by gate length
| Gate leaf length | About in feet | GR-12M pieces | Rack cost |
|---|---|---|---|
| Up to 3 m | up to 9.8 ft | 3 | ₹4,197 |
| 3.1 to 4 m | 10.2 to 13.1 ft | 4 | ₹5,596 |
| 4.1 to 5 m | 13.5 to 16.4 ft | 5 | ₹6,995 |
| 5.1 to 6 m | 16.7 to 19.7 ft | 6 | ₹8,394 |
| 6.1 to 7 m | 20 to 23 ft | 7 | ₹9,793 |
| 7.1 to 8 m | 23.3 to 26.2 ft | 8 | ₹11,192 |
| 9.1 to 10 m | 29.9 to 32.8 ft | 10 | ₹13,990 |
Each piece of the GR-12M gear rack is 1 metre of 12 mm galvanised iron with 3 studs included. For a long gate, WhatsApp us before ordering so we can confirm we have enough pieces ready to ship together.
Should I buy rack separately or take a kit with rails?
Our SGM-370 and SGM-550 kits come with gear rails already in the box, from 3 rails (about 10 ft total) to 8 rails (about 26 ft total), plus an obstacle sensor, a siren lamp and 2 remotes. The rail lengths are the approximate totals stated on each listing. The GR-12M listing notes that rail supplied with a motor is generally 8 mm, while GR-12M is 12 mm. If you want the heavier 12 mm rack, buy a motor without rail and add GR-12M by the metre.
| Option | Rack | What else is included | Price |
|---|---|---|---|
| SGM-370 kit, 3 rails | approx. 10 ft | 600 kg motor, obstacle sensor, siren lamp, 2 remotes | ₹31,500 |
| SGM-370 kit, 5 rails | approx. 16.3 ft | Same | ₹34,500 |
| SGM-370 kit, 6 rails | approx. 20 ft | Same | ₹35,950 |
| SGM-550 kit, 6 rails | approx. 20 ft | 1200 kg motor, obstacle sensor, siren lamp, 2 remotes | ₹38,500 |
| SGM-370 with single beam sensor, no rack | none, add GR-12M | 600 kg motor, obstacle sensor, 2 remotes | ₹23,500 |
| GR-12M gear rack | 12 mm GI, 1 m | 3 studs per piece | ₹1,399 per metre |
| NB-SGM nut bolt pack | spare fixings | Pack of 3 steel nut bolts with corrosion-resistant coating | ₹399 |
Worked example: a 5 metre gate
Say your gate leaf measures exactly 5 metres (about 16.4 ft) and weighs around 500 kg. The 600 kg SGM-370 is the right motor.
- Separate parts: SGM-370 with single beam sensor (₹23,500) + 5 x GR-12M (₹6,995) = ₹30,495. Add an SF-2T warning light (₹850) to match the kit and the total is ₹31,345, with 12 mm rack.
- Kit: the 5-rail kit gives about 16.3 ft, which is just short of 16.4 ft. Do not take it. Take the 6-rail kit (about 20 ft) at ₹35,950 and cut the extra.
This is the most common trap: a gate that is "about 16 feet" is often a few centimetres over. Measure, convert, and round up.
Fitting tips that save trouble later
- Keep the rack level and straight along the whole run. A rack that rises or dips makes the pinion bind in one spot and slip in another.
- Leave a small gap between pinion and rack. The gate's weight should sit on its wheels, not on the motor. Follow the gap shown in the motor's manual.
- Line up the teeth at every joint. Hold a short offcut of rack across the joint so the tooth spacing stays even, then tighten the studs.
- Fix the rack before setting limit switches. The limit positions are set on the finished gate.
For motor sizing by weight and the full price list, read the sliding gate motor price guide and the sliding gate motor buying guide. Browse all parts in gate motor accessories and sliding gate motors.
FAQ
Is gear rack included with a sliding gate motor?
Not with our motor-only listings such as the SGM-370, SGM-550, SGM-750 and SGM-1200. Buy GR-12M rack at ₹1,399 per metre, or choose an SGM-370 or SGM-550 kit that includes rails.
Do I need gear rack for the opening width or the full gate?
The full gate leaf. The pinion must stay engaged from fully closed to fully open, and running the rack along the whole leaf covers that travel with a margin at each end.
How many studs come with each metre of gear rack?
Each 1 metre GR-12M piece comes with 3 studs. Spare fixings are sold as the NB-SGM pack of 3 nut bolts at ₹399.
What is the difference between 8 mm and 12 mm gear rack?
The number is the rack thickness. The GR-12M listing says rail supplied with a motor is generally 8 mm; GR-12M is a heavier 12 mm galvanised iron rack for buyers who want a stronger rail.
Can gear rack be cut to length?
Yes. The last piece can be cut with a grinder so the rack ends flush with the gate. That is why you always round up to the next whole metre.
How much gear rack do I need for a 15 ft gate?
15 ft is about 4.57 metres, so you need 5 metres of rack. Five GR-12M pieces cost ₹6,995.
Prices are NavKar Systems website prices on 27 October 2026, inclusive of GST, and may change.
