Acerbis 21 liter tank
The stock tank is puny (13 liters) and the 21 liter capacity of the Acerbis tank gives the bike a decent range. This is a very nice tank and it fits well. The Acerbis part number is 15-84. It cost me $290 plus shipping and is available from Tom at Touratech USA.
Suspension Upgrade
When new, the stock NX suspension is mediocre at best. After 15+ years it is pretty much worn out and is hard to manage, especially off road. The NX bottomed out on jumps and the rear end did some nasty dancing on high speed whoops. So it was high time for a suspension upgrade. After a bit of research and assessing costs I decided to go with progressive springs up front and a Work Performance rear shock.
Installation: The front end was straight forward. I ordered the springs from Motorcycle Accessory Warehouse, pulled the forks, and replaced the springs, fork oil, and seals. The rear shock is a custom order job. I sent the stock shock to WP and they built a whole new unit. The spring is made by Hyperco and I requested 10% stiffer than stock. The turn-around was a couple weeks and the customer service was superb. Installation of the rear shock would have been easy except for one minor problem. The schraeder valve was too long and it bumped the air box. It's pretty close and WP recommended sending the shock back to install a low-profile BMW valve. That would have taken a couple weeks and I decided to take a different approach. I removed the air box, heated up the area where the valve was rubbing with a propane torch, and CAREFULLY reshaped that portion of the air box to allow more room. Following this 20-minute modification it fits perfectly and does not rub at all.
Results: Before the suspension updgrade the bike sagged pretty bad under my 210 pound load and I stood flat footed. Now my heels are off the ground and the ergonomics are a lot more comfortable. Off road it handles much better and I am under control most of the time. :)
Before:
After:
Progressive fork spings - Part # 11-1506. On sale at Motorcycle Accessory Warehouse as of 4/14/04 for $67.95 (uses the same springs as the DR650).
Works Performance rear shock/springs. DuraCross gas emulsion shock with single-rate spring and threaded preload. Specs: UltraX 13.5 SRS 221+. $497.74 (includes shipping and 10% cycle show discount). Be sure to ask for the low-profile BMW schraeder valve!