I bought a pair of "Heavy Duty" Springs from a company in I think it was Darlaston/Black country Area, West Midlands, For the life of me I cant remember the name, But they are a Rover dealers for spares, The Springs were of a thicker Dia and stiffer than standard, They have worked well on my Tourer for a number of years now. Maybe some one on here will know the name of the company