I bought an old ST 400 at a fleamarket and it looks like the rear wheel is off center because it is closer to one chainstay near the crankbox. Is this normal for this frame? Sorry for a stupid question but I am quite perplexed by this frame. If it is straight I could use modern 130 mm rear wheels and I have an old Record Normal reach brakeset that allows me to use 700 cc wheels instead of the 27" set it was made for.