You could try to use a longer stem. Which puts more pressure over the bar and put more pressure on your bar.I have a similar issue with my S3 at 176cm, but I'm not sure if it's actually a problem. When I ride standing, my center of gravity is completely balanced over the pedals and I can grip the handlebars relatively loosely (I have long arms). This allows a very agile and playful driving style in most situations. At the same time, if I need extra pressure on the front wheel, I have to shift my center of gravity towards the handlebars, which causes an unsafe feeling in some situations. With a bigger bike I would probably have constant pressure on my arms and I don't know if that would necessarily be better.