Hi All,

I'm in the UK and restoring a much loved but neglected Peugeot Aquitaine (c. 1991) that is a 'sentimental attachment' veteran of Land's End to John O'Groats (eight days) amongst other long charity rides. I have a couple of other newer bikes (nothing too flash, and I'm in the market for a new carbon bike: I have not ventured there yet) but my sadly neglected Aquitaine is being slowly bought back to life, retiring to a less stressful life as a permanent feature on a turbo trainer (for the moment: it could rise again if I can figure out relaxing the brakes, which look prehistoric, and unavailable.....). I'm replacing the chain rings and find that they are BCD 72mm, 50T and 40T (StrongLight) rings. I can't find anything like that as current: are my measurements likely to be out? I've replaced the rear cassette with a new Shimano 7 speed: what should I be using on the chain rings, given the 72mm BCD measurement. I'm pretty certain it is not as much as 74mm I'd rather not have to replace the whole shaft do the pedals too.

I realise that this might seem strange if the bike is to be put out to pasture on a turbo trainer, but if I can replace the brakes, the old dear may yet see the tarmac again. Restoring full shifting capacity increases the chances that I'll try to achieve that.

So, yeah, there you go. Excuse that my introduction is immediately demanding of your expertise.... and that almost inevitably this is being submitted to the wrong forum section. Thanks to the moderators for reallocation, if appropriate.

Dornfield (aka Brian)