Hi there, have just been out to the garage and measured my shox, and they are 320mm between centres. Your query hit a nerve with me because I purchased a pair of replacements of very similar design without checking the length!!!! When fitted, the extra length meant that the rear axle nut fouled the silencer, so instead of calling it a day I managed to re-jig the silencer mounting, (Pillock!). When all this was accomplished everything looked ok until I realised that the rear wheel was only just off the ground when on the stand, and when the bike was taken off the stand it fouled the lower run of the rear chain! Removed, returned to seller for prompt refund, and took my time and eventually found a pattern pair that are a perfect match in size, looks, and capability. Do not fit any that are a different length!!!!!! Regards, Michael.