inner diameter in the middle: ?
inner diameter in the middle: 23mm Right side radiator to engine: length: ~21 cm inner diameter: 19mm outer diameter: 25-26mm The reason for one of them to have a slightly smaller diameter in the middle than the others is because it wouldn’t fit otherwise. The hose is just barely in contact with the engine side. However if they are flexible (the OEM is not very flexible), I don’t see any reason why it wouldn’t be OK to bend it a bit.