Seat Lowering Slider Rails, 58mm (2.3")

Price:
£319.00

In Stock

Brand: Jass.Performance
Product Code: 2668

Available Options

* Side: Right Left

Seat Back Raising Kit:

Seat Options: Trimming tool (+£12.00)

Tags: MK4

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Tags: MK4

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Jass Performance Seat Lowering Slider Rails, 58mm Extreme, for the Mazda MX-5 (ND), Fiat 124 Spider — compatible with OEM seats only.

The deepest seat drop available in a sliding rail solution for the ND. Designed for drivers above 193cm who need every millimetre of headroom the car can give. The seat drops 58mm, fore/aft sliding is retained, and the installation is bolt-on. The optional seat base trimming extends travel further — and if ever needed, the seat can be returned to stock.

For any driver above 193cm, a properly lowered seat is also a safety matter — not just comfort. Correct headroom restores proper engagement with road information, full use of the rear-view mirror, and a driving position that lets you react rather than manage the car around your height.

Key Specifications

Seat drop

58mm (2.3")

Recommended height

193cm+

Material

Steel

Seat compatibility

OEM only

Installation

Bolt-on, reversible

Fore/aft travel

60–125mm

What Sets These Apart

The deepest seat drop in a sliding solution for the ND. At 58mm, built for drivers above 193cm where a standard drop is not enough — proper headroom, correct sight lines, and a natural posture instead of one built around the car's limitations.
Fore/aft sliding retained. Unlike fixed adapters, the seat continues to slide after installation — you keep the ability to adjust your position.
Steel construction reinforced with the floor contour. No flex, no play, no movement under daily and track use.
Bolt-on installation, returnable to stock. The rails come off and the car goes back to standard at any point.
A complete system built around the drop. The Backrest Raising Kit, the Seat Trimming Template, and the 9mm Backrest Offset are all designed specifically for these rails — every additional millimetre a very tall driver needs is covered.

These products were developed by someone who needed them personally — at 197cm, the designer of this range has spent years refining every millimetre of the solution from the driver's seat. Every question answered here, every trade-off explained, every recommendation in the decision guide comes from that direct experience, combined with feedback from hundreds of customers across the UK, EU, and USA. You're not just getting a part — you're getting the accumulated knowledge of what actually works, from someone who still drives an ND daily at the height this was designed for.

Fits

Mazda MX-5 ND (all versions) — soft-top and RF. Standard OEM seats only. Also compatible with Fiat 124 Spider — soft-top and RF.

Technical Details

Seat drop: 58mm (2.3").
Headroom gain (soft-top): seat reference point to roof increases from 916mm to 974mm. The RF has 20mm less factory headroom; the drop is identical.
Fore/aft travel: 60mm standard. Trimming the non-structural lower part of the seat base extends rearward travel to 125mm — a Seat Trimming Template is available in the shop.
Side coded — order left for the driver's seat in USA, EU, etc.; right for UK, Japan, Australia, etc.
Sold as a kit per seat — order two kits to lower both seats.

Options to Consider

Backrest Raising Kit. When the seat is at maximum drop, the factory backrest shifts relative to a very tall driver's body — the headrest, side supports, speakers, and belt guides all move out of their intended alignment. The Backrest Raising Kit raises the backrest 50mm to restore the correct ergonomic position. Strongly recommended when using these rails at the lowest setting.

Seat Trimming Template. The template allows the non-structural lower part of the seat base to be trimmed, extending rearward travel from 60mm to 125mm — getting the seat further back than OEM range. Available in the shop.

Backrest Raising Kit with 9mm Base Offset (available on request only). For the tallest drivers who needs every last millimetre, this offset offsets the bottom of the backrest by a further 9mm to the rear. Not sold in the shop — contact us to order. With this offset the backrest sits in the rearmost position tight to the wall and provides additional leg room. It is not offered as direct option in the shop, as the backrest cannot engage in further forward position and suits a dedicated tall driver's car rather than a shared vehicle.

Installation

Bolt-on installation, but more involved than the 48mm version. Achieving full fore/aft travel may require trimming the non-structural lower part of the seat base — tolerances are tight and careful test fitting is needed. If you are not confident with this kind of hands-on work, professional installation is recommended.

We work with experienced MX-5 specialists for fitting and seat trimming:

UK: AutolinkUK, TheMX5Restorer
USA: Red Hen Racing (St. Cloud, MN)
Netherlands: DeCabrioHoeve

Select your side and any optional kits above. Same-day shipping from EU and UK.

Frequently Asked Questions

Is the front of the seat lowered as well, or just the rear?

Both front and rear are lowered. The rear drops 58mm, the front drops approximately 15mm as part of the rail geometry. Removing the height adjustment rack drops the front a further 15–22mm on top of that — a free, reversible modification that extends the benefit further.

Why 193cm and not lower — can a shorter driver use these?

The 58mm drop creates a steeper rake angle than the 48mm version. That angle works well for drivers with proportionally long legs — it opens up diagonal headroom while keeping pedal reach comfortable. Below 193cm, most drivers find the rake too aggressive and the knees uncomfortably high. The 48mm rails with the Fine Drop Adjustment Kit are the better solution for drivers between 177–193cm. That said, it is common when sharing the car with a partner to use a bolster seat — this compensates well for the rake difference and makes the car comfortable for a shorter driver without changing the setup.

Why are these not Recaro compatible?

The Recaro seat base does not allow the drop that the 58mm extreme rails produce. For Recaro seats, the 48mm sliding rails are the correct solution — they are compatible with both OEM and Recaro seats.

I have a heavier build — which option should I choose?

With sliding rails, the raised front of the seat can prevent you from using the full drop at the rear. The fixed adapters sit flatter and make better use of the available drop, so they are the better choice for a heavier body.

Should I choose the 58mm rails or the fixed adapters?

The 58mm rails suit very tall drivers above 193cm with proportional or long legs who want to retain fore/aft adjustability. The fixed adapters produce a flatter rake angle — better for drivers with shorter legs, heavier builds, or helmet use. If you are fitting with a helmet, the fixed adapters are the correct choice regardless of height.

What is the fore/aft travel limitation?

Without modification, fore/aft travel is 60mm. Trimming the non-structural lower part of the seat base extends rearward travel to 125mm — A trimming template is available to order. For most very tall drivers, the rearmost positions are the useful ones anyway.

Do I need the Backrest Raising Kit?

Strongly recommended when using the 58mm rails in the lowest positions. At maximum drop, the factory backrest geometry misaligns the headrest, side supports, belt routing, and speakers relative to a very tall driver's body. The Backrest Raising Kit corrects all of this by raising the rear of the seat 50mm to restore the intended ergonomics.

Can I do the installation myself?

If you're coming from the NA/NB world or have done any DIY on an NC, you'll be perfectly fine. If removing the seat, detaching the battery, disconnecting the airbag connector, and pulling the seat plastic trim sounds like too much — find a nearby garage. It's a straightforward job, just not one to rush.

How difficult is it to remove the seat once the rails are installed?

Exactly as easy as removing the OEM seat — 4 bolts and a connector. Nothing changes.

The available headroom with these rails is 974mm and I need an additional 20mm to fit at 200cm — what can I do?

The additional space is achievable through a combination of measures that work alongside the seat drop — detaching the backrest tensioners, removing the height adjustment rack, de-foaming the side bolsters, and adjusting the seat position. These are covered in full on the seat lowering techniques page.

I'm in the USA — will the rails clear the belt tensioner trim?

The belt tensioner trim will collide with the seat trim at the lowest position. The common fix is to remove the tensioner trim or replace it with a piece of black carpet. This is a US-market issue — no equivalent trim exists on European cars.