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.
Source information was checked on 29 September 2026. The editorial update date above does not mean prices, availability or retailer terms were checked again. Confirm those details with the retailer before buying.
AI Summary
- Separate movement designed into a multi-direction armrest from a loose fixing or failed mechanism.
- Do not add glue, shims or excessive screw force before checking the warranty; unauthorised modification is excluded by Sihoo’s policy. Source 3
- Keep a video, order number and exact model details when asking for a replacement part.
Decision table
| Situation | Practical choice |
|---|---|
| Arm moves only along normal adjustment paths | Check its intended positions and resistance. |
| Arm drops, rattles or detaches | Stop using it and send the seller a clear fault video. |
What to do
Film the armrest unloaded, under a light hand pressure and during ordinary desk work. Compare left and right. Tom’s Guide reviewer Anthony Spadafora reported that his C300 armrests held their height but were easy to knock sideways. That personal observation is useful when describing normal movement; it is not evidence of a defect in every unit. Avoid an unverified DIY "friction fix" inside the joint. Source 4 Source 1
Record the fault without altering the mechanism
Use a short video with the seat empty. Show each armrest at the same setting, the direction of an ordinary light push, and whether either arm drops in height, rattles or separates from its mounting. Note the exact variant because the C300 and C300 Pro have different armrest designs. Tom's Guide's C300 review reported easy sideways movement on its sample while height remained stable; that is a single reviewer's observation, not a tolerance specification for every chair.
If the movement is limited to the designed adjustment paths and both arms behave alike, check the manual before treating it as a fault. If an arm drops, detaches or has clearly asymmetric play, stop leaning on it and send the seller the recording, model details and proof of purchase. Avoid glue, wedges and overtightening: the UK warranty terms exclude unauthorised modification, and no manufacturer-approved friction repair was verified.
Frequently asked questions
Does all movement indicate a fault?
No. Check the movements the selected version is designed to allow.
Can I add my own friction pad?
Ask the manufacturer first; alteration may affect a claim.
Can a fault be reported after 30 days?
Potential manufacturing-defect claims are governed by the applicable warranty and legal rights. Source 3
What evidence does support need?
Order proof, model identification and a short, repeatable fault video.
Sources and citation notes
Specifications and policies are attributed to their original publishers. Named hands-on reviews are attributed to the reviewer and tested version. The decision advice is editorial synthesis, not a clinical, laboratory or transaction result. Check version-specific details and current terms before buying.
- [1] SIHOO UK Doro C300 specification
- [2] SIHOO UK C300 Pro specification
- [3] SIHOO UK refund, return and warranty policy
- [4] Tom's Guide, Anthony Spadafora, hands-on C300 review (2023)
Sources were checked on 29 September 2026.
Related Sihoo UK guides
- Sihoo chair squeaks: a safe way to locate the noise
- Rollerblade castors on a Sihoo chair: is an 11 mm stem enough?
Note: This article is for reference only.