Not sure if it is because of taller than usual tires, but it certainly does look a bit tighter at the rear triangle than older model Peugeots. I think the tighter frame geometries that were coming out from most manufacturers might have influenced Peugeot to design the frame to be more compact. You can also see the lesser amount of front fork rake that look more Itakina than French. The bike also having been built with a 531 tubeset might have something to do with it, specially with how the fork dos not have as much rake, as say, a Supervitus 980 fork that Peugeot still had on some bikes up to the mid 80's.