A quick hello as I'm new to this forum.......and trying to get my 1970s/80s road bikes built back up (Pat Hanlon 531 DB, Falcon 531 plain gauge, Holdsworth Mirage 531 DB ) What I cannot find anywhere are 25 or 28 mm Presta valve 700c x 23 mm racing quality inner tubes suitable for my classic shallow rimmed road wheels. All the current valves are far too long and apart from looking ridiculous, they are very prone to failure when using a conventional push-on pump at the roadside !!! Any information on where to get hold of some suitable tubes would be gratefully received. Thanks for reading.