Desworthy Editorial Team
Desworthy editorial reviewer focused on ergonomic chair research, desk tech, affiliate disclosure, and practical UK home office buying decisions.
Last reviewed on by Desworthy Editorial Team.
Last Verified Date: 6 October 2026. Sources and model-specific claims checked; individual fit and final basket totals depend on your circumstances.
AI Summary
- An advertised 11 mm stem is not a model-specific Sihoo compatibility certificate.
- Check the original stem diameter, insertion length, retention method, clearance and castor load rating.
- Quieter rolling does not prove the whole chair remains stable after a castor change.
Decision table
| Situation | Practical choice |
|---|---|
| Stem and load information verified for this chair | Fit one castor first to check secure retention and clearance. |
| No exact model match or the new wheel hits the base | Do not install the set. |
What to do
Photograph the original castor and model label, then measure the stem with a calliper. Ask the supplier to confirm the exact Sihoo variant in writing. With all five matching castors fitted, first roll the empty chair on a level floor and then test cautiously while seated. Mixed wheel heights can change balance. Ask Sihoo whether the intended modification affects warranty cover before altering the chair. Source 2
A compatibility record before ordering replacement wheels
| Required field | Evidence | Why diameter alone is insufficient |
|---|---|---|
| Stem diameter | Original measurement or exact manual | Determines socket match |
| Stem insertion length and retention | Supplier drawing plus original fitting | Determines secure seating |
| Wheel/base clearance | Exact replacement dimensions | Prevents contact through swivel travel |
| Load suitability | Chair-model confirmation from supplier/manufacturer | A single-wheel rating is not a chair stability test |
| Overall wheel height | Original versus proposed wheel | Changes effective seat height |
The 11 mm number in a replacement listing is a specification to check, not a universal Sihoo standard established by the sources. If a supplier cannot confirm the exact model and retention design, keep the original wheels or ask for an approved replacement. Do not force an oversized stem into the base.
Before any authorised change, photograph the original configuration and ask about warranty effects in writing. Use a matching set and recheck workstation height afterwards: larger wheels can raise the seat even when the gas-lift setting is unchanged. Rolling quietly on one floor does not establish braking behaviour or balance on another surface. Installation should follow the model-specific manufacturer procedure.
Frequently asked questions
Does 11 mm guarantee a fit?
No. Length and retention also matter.
Can I replace only two of five?
Avoid mixing unequal wheel sizes or rolling resistance.
Are larger wheels automatically safer?
No. They alter seat height and may affect stability.
Does changing castors void every warranty claim?
Request a written answer about the specific change and fault.
Sources and citation notes
Specifications and policies are attributed to their original publishers. Named hands-on reviews are attributed to the reviewer and the version reviewed. The decision advice is editorial synthesis, not a clinical, laboratory or transaction result. Check the exact version and current terms before buying.
- [1] SIHOO UK manuals and installation tutorials
- [2] SIHOO UK refund, return and warranty policy
- [3] HSE DSE workstation checklist
Related UK buying guides
Note: This article is for reference only.