Ktm Duke 640 Review

Used Buyer Review

The Duke 640 is one of those bikes that rewards experienced riders and absolutely punishes beginners. That LC4 single is a proper thumper — 625cc of raw, vibey, characterful engine that'll rattle your fillings loose at idle and then launch you forward with surprising aggression once the revs climb. Nothing else feels quite like it. Just know what you're buying into. Used examples are a minefield. KTM's quality control from this era was genuinely patchy, so pre-purchase inspection isn't optional — it's mandatory. Check the frame for cracks near the headstock, inspect the subframe welds, and start the engine cold. A healthy LC4 fires without drama. Oil consumption is normal; excessive smoking isn't. Most problems trace back to deferred maintenance from owners who bought the hype and couldn't afford the upkeep. Get a good one and it's genuinely thrilling — light, flickable, and sonically intoxicating in a way modern singles never are. Pay a mechanic £100 for a proper inspection first. Non-negotiable.