Yes aparently this is a problem but only if your pushing it, it doesn´t just happen. I own a A4 model (1990) with the smaller wheel, it´s never let loose on me but it can be limiting on what tyre you can get for it, as the older bikes had unusually different sized front wheel to other bikes, therefore not a lot of tyre manufacturers make a tyre for the bike. If you do go for a 16incher try to get the best tyres on the market for it, good tread and soft rubber compounds and try to avoid cheap tyre types, then you shouldn´t have a problem. Hope thats of help to you.