YuanShi shaft hardness: what one Chinese badminton creator's testing rig actually tells you
YuanShi is not a scientific protocol — it's the handle of a Chinese badminton creator who measures rackets on a professional shaft-deflection machine and posts the numbers. Here is what they mean, what they don't, and how to use them when shopping.
Overview
Victor finally clicked: classic Hypersonic WES Whip Enhancement System 3.0 paired with alloy carbon fibre punch from DriveX 10M and Auraspeed 90K Metallic — stiff yet supple, soul injected. Is this pink Auraspeed 99 the 90K M attack plus Hypersonic speed blend people wanted? Front-line comparison below. Frame inherits 90K M's 76-hole large-face dynamic aero profile with alloy carbon fibre, TR+ toughened nano carbon tube, and Rebound Shield. 6.8 mm shaft: PBO carbon plus alloy carbon fibre plus WES 3.0 that defined Hypersonic and reshaped this racket's feel. On paper, besides slightly higher balance, WES 3.0, alloy shaft, and nano aerogel in the frame versus 90K M, Auraspeed 99 tracks 90K M closely. Hypersonic's setup is familiar: WES 3.0, small head, Free Core handle. Head-heavy feel: Auraspeed 99 > Auraspeed 90K Metallic > Auraspeed Hypersonic. 99 feels clearly head-heavy at first; 4U weight plus dynamic aero frame keeps swing speed acceptable. Hypersonic is lightest; 90K M sits middle. Frame stiffness: Auraspeed 99 ≥ Auraspeed 90K Metallic > Auraspeed Hypersonic. 90K M-like frame and alloy fibre — 99 and 90K M resist torque like rock. Great for net spins and pushes without over-bounce. Shaft stiffness: Auraspeed 90K Metallic ≥ Auraspeed 99 = Auraspeed Hypersonic. Higher balance on 99 shows more head swing on clears — easier momentum for big-arm players; intercepts and brush drops feel effortless. WES 3.0 lowers burst versus 90K M — you can whip harder more easily; overall rigidity softens slightly versus 90K M's clang; whip feels closer to Hypersonic's bright crack. Important: that is active threshold. Passive defence is another story — hard frame plus head weight on the same 6.8 mm shaft (even with TR+, Rebound Shield, and long-awaited WES 3.0) cancels much of the tech gain. Passive pickup still is not Hypersonic-nimble. Singles players often ignore line precision. Hypersonic chases burst and speed with damping — weaker for singles precision, last here. 99 has more pop and alloy recovery but lacks 90K M's unreasonable stiffness; on full smash without big shaft load, 99 gives the tightest line of the three. Front-court speed needs the 210 mm handle choked up. 99's balance is only slightly higher than 90K M — overall swing cost is small. Head feel on 99 comes from overall stiffness and micro-deformation on small hits — hard and lively, especially sharp on upper-court drives. Low drives suffer a little; sub-300 mm head weight is not catastrophic versus 90K M, but less agile than Hypersonic. Upper-court slice, hold, brush: all three stiff, clean, instant exit — no mush. Slightly head-heavier 99 adds a bit of hold — cross with less force, but short dwell makes friction and unload hard; net drops tend long and invite front-court punch. Some wonder why a "speed" Auraspeed feels more attack than speed — I almost do not call 99 a pure speed frame. On 90K M, big smash needs real skill — sharp downward angle and stiff feedback tax the arm after offence. WES 3.0 on 99 gives sharper violence than 90K M with milder negative feedback — second only to Hypersonic's Free Core comfort. 99 will not out-speed Hypersonic, but with higher head balance it beats 90K M on continuous downward pressure. Shaft burst feels Hypersonic-satisfying with a straighter hand feel. Fast hidden flick kills still favour Hypersonic swing. Large dynamic aero face plus high swing speed and long handle — doubles optimal. Like 90K M, 99 is not attack-only: passive drives and lifts stay stable; torque control places returns well. Hypersonic's small head is what I fear on defence.
First impressions
Many say Auraspeed 99 merges 90K M offence with Hypersonic speed. I play both often — Hypersonic is my recent main — so here is an honest side-by-side.
Drive threshold
Auraspeed 90K Metallic ≥ Auraspeed 99 > Auraspeed Hypersonic.
Shot precision
Auraspeed 90K Metallic > Auraspeed 99 > Auraspeed Hypersonic.
Flat drive and block
Auraspeed Hypersonic > Auraspeed 90K Metallic > Auraspeed 99.
Slice, hold, brush
Auraspeed 99 ≥ Auraspeed 90K Metallic > Auraspeed Hypersonic.
Absolute attack
Auraspeed 99 ≥ Auraspeed 90K Metallic > Auraspeed Hypersonic.
Defence and counter
Auraspeed 99 ≥ Auraspeed 90K Metallic > Auraspeed Hypersonic.
Recommendation
With WES 3.0, Auraspeed 99, Hypersonic, and Auraspeed 90K Metallic each have strengths. I see 99 as attack cap raised and threshold slightly lower versus 90K M — clearly an attack-leaning speed frame. It does not truly match Hypersonic pure speed; it borrows some burst. Overall it is a happier, easier 90K M. Recommended for rear-court doubles attackers who like pink.