All BMW rear shocks and some fronts, can be rebuilt.  The trick is re-charging them with nitrogen. To do this I drill and tap a 5 mm hole for a small nitrogen valve into the body of the shock. You can see a nitrogen valve installed on the shocks in two of these photo’s.

One model doesn’t have enough space for the valve. On these bikes you will need to drill a hole or cut a notch and mark the top rear of the shock. Be sure to paint the work site to prevent rust.

Most but not all the front shocks can be rebuilt.  The close up photo of the black spring and chrome shaft shows the cap on the body of a rebuild-able front shock.  If the body is welded to the cap or if it’s bent over the cap, we are out of luck.

$290 each to rebuild.

The stock springs are weak and over pre-loaded for most riders.  Stronger springs will keep you in the upper/faster moving part of the suspensions travel more of the time.  Less pre-load will mean less wiggle after turns and bumps because there will be less stored energy.

Front springs are $125 + $40 for a spacer.  Rear springs are $125 or $135, about half of them will need a $40 spacer.

The valving in the stock Showa shocks is good.  The valving in the stock WP shocks is weak.  Re-valving adds $100 to the rebuild price.  A Showa should get a stronger spring with less pre-load.  A WP should get a re-valve.

ESA Shocks
The same as normal shocks except: You must back off the pre-load and damping before un-plugging the shock from the bike. Set everything to the soft/weak setting. Showa ESA shocks have weak springs but good valving. Most WP ESA shocks have strong springs but bad valving.  Sacahs ESA shocks are not cost or time effective to rebuild.