I have a 1978 R100/7 that was originally equiped with a Luftmeister fairing long since removed. The front end has a rather harsh jarring effect. I am thinking this bike was equipped with a heavier duty spring? I had another person tell me his 78 R100 does the same thing. Now, If I buy Progressive springs, will that smooth out the jarring or should I look for an old OEM pair to install from say, a /6?