Its bugging me today. Call them Pro-Kit springs
. Then retailers will know what people are talking about.
I have Pro-kit springs and they are very nice. Difference is minimal over standard rideheight 10-15mm lowering max.
will lower a max of 20-25mm if all goes well on the RS.
Sportlines are a progressive rate spring. Pro-kit are mostly constant spring rates. Both in reality offer a similar ride so the saying of 'pros for go, sportline for show' should be laid to rest. I'll dig the spring rates for these out to confirm and will post details.