Wilbers Zero Friction 6.0-8.3 N/mm Progressive Fork Springs '85-'95 with RS/RT Fairing

BMW only produced one fork spring rate for these applications regardless if the bike had a heavy RT fairing or no fairing at all. Wilbers takes fork performance to a higher level by offering two different spring kits, one for Monolever bikes with fairings and one for bikes without fairings. This kit is 6.0 N/mm - 8.3 N/mm for 1985-on Monolever bikes with fairings. (See part number 600-0097-03 for the 5.0 N/mm - 7.5 N/mm springs for Monolever bikes without fairings).

Wilbers Zero Friction Progressive Fork Springs have some advantages over linear fork springs due to their two stage design. The first stage for this application is 6.0 N/mm which is firmer than stock as needed for models with fairings and it increases in rate as it compresses, up to 8.3 N/mm, to provide better chassis control during weight transfer such as when riding down a steep decline or under heavy braking, while still providing good compliance over the small bumps. 

No preload spacers are required, Wilbers springs are cut to length to provide the correct preload. 

Remove the old springs and drain the oil, compress the fork fully (bottomed out) with springs removed and add fresh 10 wt oil to the proper oil height (air chamber). Yes you can just pour in the correct amount of cc's per the manual, but the professional way is to add oil until the oil height is 140mm below the top of the fork tube with the fork fully bottomed which sets your air chamber correctly. This air space acts as an air spring as the fork compresses, especially towards the end of stroke so this setting is important to the performance of your fork. 

On the end of the Wilbers box is a label with the words "Luftkammer" and a number. Luftkammer is German for Air Chamber. This can be measured with a tape measure and flashlight or more conveniently with our fork oil level tool. 

Fork oil and fork oil level measuring tool sold seperately, see below.