MICHELIN M14S Bib Mousse 140/80-18 Enduro Soft (Rear)
The MICHELIN Bib Mousse M14S is a soft-compound rear foam insert for 140/80-18 enduro tyres, developed to replace the inner tube and eliminate punctures in off-road part of the Bib Mousse range, it benefits from an exceptional record in rally, enduro and motocross, including multiple Dakar victories and world titles.citeturn1search6
Key product highlights
- Soft enduro-specific compound: M14S is the soft variant in the 140/80-18 Bib Mousse family, tuned for enhanced traction, comfort and carcass compliance in technical enduro terrain.
- Puncture-free foam insert: Closed-cell foam ring used instead of a conventional inner tube, so it cannot lose air from pinch flats or punctures in normal off-road use.
- Rear 18" application: Dimensioned for rear tyres in size 140/80-18 and corresponding to the 18 UHD Large fitment category.citeturn1search5
- Pressure-equivalent feel: Designed to offer a riding feel roughly equivalent to about 0.9 bar (13 psi), while remaining lighter than an ultra heavy duty inner tube.citeturn1search15
- Optimised for MICHELIN enduro tyres: Specifically matched to selected MICHELIN 140/80-18 enduro tyres for a precise fit, consistent support and durable performance.citeturn0search12
- Off-road competition focus: Intended for cross-country, enduro, rally and motocross use where reliability and grip on varied terrain are critical.citeturn1search6
- Non-road-approved design: For off-road use only; when fitted, the tyre is no longer approved for use on public roads.citeturn1search6
Technical details
| Manufacturer | MICHELIN |
| Product type | Off-road foam mousse insert (inner tube replacement) |
| Model | Bib Mousse M14S Enduro Soft |
| SKU / Reference | 074167 |
| Tyre position | Rear |
| Nominal tyre size | 140/80-18 |
| Rim diameter | 18 inch |
| UHD tube equivalence | 18 UHD Large category |
| Compound characteristic | Soft (Enduro Soft) for higher deformation and grip |
| equivalent | About 0.9 bar (13 psi) riding feel (Bib Mousse family value) |
| Intended use | Off-road enduro, hard enduro, rally stages, off-road training |
| Road approval | Not approved for use on public roads (off-road only) |
Recommended MICHELIN tyre pairing (rear 140/80-18)
The MICHELIN Bib Mousse M14S is dimensioned to fit selected MICHELIN rear off-road tyres in size 140/ following combinations are specified in MICHELIN technical documentation for this reference:citeturn0search12
| Tyre line | Tyre dimension | Bib Mousse model |
| MICHELIN Enduro Medium | 140/80-18 | M14S |
| MICHELIN Enduro Medium 2 | 140/80-18 | M14S |
Performance and benefits in use
- Defect prevention: Foam construction removes the risk of classic punctures and pinch flats that affect tube-type setups in sharp rocks, roots or impact landings.
- Consistent low-pressure feel: Maintains a stable, low "virtual" pressure over time, supporting traction and comfort without the need for air-pressure checks.
- Enhanced grip on technical terrain: Soft mousse behaviour allows the tyre carcass to conform to rocks, roots and ruts, increasing the contact patch and mechanical grip.
- Controlled deformation at speed: Despite its softness, the M14S is engineered to support the tyre at race pace, limiting squirm and preserving directional stability.
- Reduced unsprung weight versus UHD tubes: Lighter than many ultra heavy duty tubes of equivalent application, contributing to suspension response and wheel behaviour.citeturn1search15
Typical applications
- Classic enduro special tests on mixed surfaces (loam, hardpack, stones).
- Hard enduro and extreme enduro sections with slow, highly technical climbs and obstacle crossings.
- Rocky and root-infested forest trails where conventional tubes are exposed to frequent impacts.
- Off-road rally stages and long-distance off-road rides that require high reliability against punctures.
- Regular off-road training where consistent feel and reduced maintenance of tyre pressure are desirable.
Design and installation characteristics
- Engineered to be installed inside compatible MICHELIN 140/80-18 enduro tyres in place of an inner tube.
- Designed to be used with MICHELIN Bib Mousse Gel during mounting to reduce friction and heat build-up and to support mousse longevity.
- Profile and dimensions tailored to MICHELIN off-road carcass shapes for precise seating on the rim and uniform support across the tread.
- Supplied as a single rear mousse insert, ready to be combined with the appropriate MICHELIN enduro rear tyre.
