^ The catalog specs aren't necessarily accurate for many lines of bikes, esp European ones, maybe especially French. Motobecane wasn't even sure what lugs they were using on the GR in 1974. But...the difference between '3 main tubes' and 'all' 531 is significant, so it would seem your GR is later than mine. Maybe yours is 75-76, mine 74-75. We can also compare SNs...not that that is necessarily more systematic!
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I never think I have hit hard, unless it rebounds.
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Last edited by Chicago Al; 05-05-12 at 03:31 PM.