The 600cc inline-four sportsbike
Effectively extinct
In 1996 every Japanese factory had a 600cc inline-four sportsbike: Honda CBR600F (carbed), Yamaha YZF600R Thundercat, Suzuki GSX-R600, Kawasaki ZX-6R. By 2026 they are essentially gone — Yamaha R6 is track-only, Honda CBR600RR is grey-import only, GSX-R600 killed, ZX-6R limited to specific markets. Replaced by parallel-twin supersports (Aprilia RS660, Yamaha R7, Triumph Daytona 660).
Why R6 didn't kill it sooner
Different riders
The 1999 YZF-R6 was track-focused — high redline (15,500rpm), aggressive ergonomics, narrow powerband. The Thundercat had broader torque, more upright ergos, comfortable for distance. R6 buyers were trackday/canyon riders; Thundercat buyers were commuters and tourers. Yamaha kept both for 9 years because the customer bases didn't overlap.
Why it ended 2007
Euro 3 emissions
Euro 3 came in for new motorcycles 2006 and Yamaha didn't fund the carb-to-FI conversion + emissions update for the Thundercat. The R6 had already been EFI for years. Cheaper to drop the Thundercat than to keep it compliant. Same fate as Honda's CBR600F (parallel killed 2006).
Real cost trajectory
−40% real
£6,499 Thundercat in 1996 (£13,000 today) → R7 (closest 2026 successor) at £9,310. Significantly cheaper in real terms. Used market in 2026: Thundercat £1.5-3k for clean low-mile. Cheapest 100bhp inline-four Yamaha you can buy.
ライダーエイド数 (1996 → 2026)
0 → 4
Thundercat had nothing — analogue dials, no ABS, no FI, no electronics. R7 (2026 closest replacement) has ABS, fuel injection, optional quickshifter, LCD dash. R6 (track-only) has full IMU electronics. Modern entry-level supersport is far more capable but less character.
最安の入口
£1.5k
A clean Thundercat from 1996-2002. 100bhp inline-four, EXUP, comfortable enough for distance, fast enough for trackdays. The cheapest path to a competent 600cc Japanese sportsbike. Pay attention to EXUP servo (cables seize), reg/rec, choke cable, and front-end condition. Properly undervalued in 2026.
vs CBR600F (1995-2006) used
Similar money
Honda CBR600F (1995-2006) used market: £1.5-3k for clean. YZF600R Thundercat: £1.5-3k. Same money for similar bikes — both are 600cc inline-four sportsbikes with EXUP-style mid-range tricks, both bombproof if maintained. Honda has slightly stronger parts supply and dealer network for older bikes.
