# AST 5100 coilovers

- Source: https://racingcarnetwork.com/wiki/ast-5100-coilovers/
- Publisher: Racing Car Network (racingcarnetwork.com), the race car marketplace
- Type: part · Brand: AST
- Discipline: parts
- Era: 2000s
- Last updated: 2026-07-06

The AST 5100 is the track world's serviceable damper: the Dutch house's single-adjustable coilover line (5200/5300 siblings adding ways) built rebuildable and revalvable — motorsport suspension philosophy sold at club prices.

## Specifications

| Spec | Value |
|---|---|
| Type | Monotube coilovers, rebuildable |
| Range | 5100 (1-way) / 5200 (2-way) / 5300 (3-way) |
| Adjustment | Rebound-focus (5100), + compression above |
| Application | Club race, endurance, time attack, track |
| Ecosystem | Custom valving, camber plates, ERS springs |
| Servicing | Factory + authorised rebuild agents |
| Years | 2008–present |
| Class | Serviceable club-motorsport suspension |

## History

AST Suspension — the Dutch damper manufacturer sharing lineage with the Moton motorsport brand — built the 5000-series to bring genuine motorsport architecture to the club market: the 5100 line's single-adjustable monotubes (rebound-focused adjustment), the 5200's double- and 5300's triple-adjustable siblings above it, all engineered around the properties street-brand coilovers skip — full rebuildability, custom valving per order, spring-platform and camber-plate ecosystems, and service support treating dampers as maintained instruments rather than sealed consumables.

Adoption tracked the serious end of track culture: club racers and endurance teams (the BMW and Porsche communities especially), time-attack builds and track-day devotees graduating from mass-market kits — buyers whose deciding question ('can it be revalved and rebuilt?') AST answered structurally.

The used market rewards exactly that philosophy: a used 5100 set's value is its service currency (AST and agents rebuild with records), valving specification against intended use, and corrosion state — with the rebuild path converting tired-but-honest sets into effectively fresh dampers at known cost, the economics sealed units can't offer.

## Palmarès

Under club endurance and sprint champions across European and American BMW/Porsche racing communities, time-attack class machinery and track-championship builds — the record of the rebuildable-damper philosophy at the grassroots sharp end.

## What to check before you buy

Service currency defines value: AST units carry rebuild histories (factory or authorised agents) — a set with recent service records and valving sheets prices as equipment, an unknown set prices as cores plus the rebuild you'll immediately fund. Verify model identity (5100 single versus 5200/5300 multi-adjustable — the adjustment ladder is the price ladder), fitment part numbers for your chassis, shaft condition and corrosion (northern-climate road use kills threads and bodies). Spring rates and camber plates included matter — completeness saves real money. The rebuild path is the safety net: honest cores at low prices are rational buys.

## Did you know

- AST's Moton lineage puts genuine motorsport valving knowledge inside the club catalogue — the 5100 descends from endurance-racing engineering, not marketing.
- The revalve-and-rebuild philosophy means AST dampers age like engines, not like consumer electronics — service history is the odometer.
- BMW club racing's AST ubiquity became self-reinforcing: shared valving knowledge across the paddock is a setup library no sealed-damper brand can match.

## Related entries

- Reiger rally suspension — https://racingcarnetwork.com/wiki/reiger-rally-suspension/
- Eibach race springs (ERS) — https://racingcarnetwork.com/wiki/eibach-race-springs/
- Bilstein MDS dampers — https://racingcarnetwork.com/wiki/bilstein-mds-dampers/
- AP Racing Pro 5000R brakes — https://racingcarnetwork.com/wiki/ap-racing-pro-5000r/