After the first 2008 World Cup race in Maribor arguments filled the interweb on what size the new Boxxer stanchions were. 34mm, 36mm and 40mm had been thrown out there. However, as usual on the internet, everyone was wrong. The new forks have stanchions (or the chassis as SRAM refer to them) of 35mm.

SRAM stated the reason for this change from the tried and true 32mm stanchions was to increase stiffness. Then why not go all the way to 40mm like the Fox 40? According to the Rock Shox product developers they didn’t want to make the fork “too stiff” as the impact from obstacles in the trail could deflect the front wheel offline and transfer additional hand feedback. So in the end 35mm stanchions were used as a happy medium between too flexy and too stiff.

The new fork also comes with the new mission control DH unit. This provides both high and low speed compression dampening and beginning and end stroke rebound adjustment.

I think this is a solid move away from the previous models motion control unit with low speed compression with a floodgate. The floodgate simply increased the force required to bypass the low speed compression allowing the high speed circuit to kick in. This is a good idea in principle but it didn’t transfer to the trail. For downhill you don’t want too much low speed compression as you want the fork to track really well over the small bumps. So out on the race track most riders ran little to no compression and floodgate.

The new low and high speed compression gives the user more ability to tune the performance of their fork. Small bump sensitivity and brake dive can be adjusted with the low speed compression and the forks ability to handle large hits can be tuned with the high speed compression. This gives riders the capacity to perfectly match the forks characteristics to their riding style.

Beginning and ending stroke rebound adjustment is also a nice touch. My main gripe with the previous Boxxer fork was that the rebound at the start of the stroke (when the fork is fully extended) was too fast for my liking. However, now users have the ability to vary this initial rebound. The beginning stroke rebound acts for approximately the first 20% of the travel and the ending stroke works for the last 80%. This split is dependant on the relationship between the amount of beginning and ending stroke rebound applied.

Added to all this is a bottom out adjuster on the World Cup model. As you’re probably aware the World Cup model has the solo air spring. Rock Shox have now added a volume adjuster for the air chamber allowing riders to firm up the ending ramp of the fork. Definitely a nice addition for people who love to have their suspension set up “just right”.

For those that have had issues with the Maxle front axle in the past it’s now time to rejoice. The Maxle has been redesigned for the new Boxxer. Many of the aluminium pieces that liked to strip out at the slightest provocation have now been replaced with nice, shiny titanium. Way stronger and no heavier, just what I like to hear.

So it’s an all round redesign for the new Boxxer fork. What I wanted to know was if all these improvements would work out in the real world?
 
Ride

I was pretty excited to get hold of the new World Cup Boxxer for the Queensland national. The Illinbah track mixes up some of the best sections any downhill course could offer. High speed wide open areas are linked by steep technical sections, including a rocky root infested forest section, the perfect place to test out a new fork. In addition I’ve ridden there many times before on my 2008 World Cup Boxxers. This gave me the chance to provide a direct comparison between new and old.

By far the biggest difference I felt over the old model was how much better the fork tracks. Within 20 seconds into my first run I could already feel how my front wheel was much more planted to the ground. My front didn’t skate around half as much as my old Boxxers. This was a direct testament to the larger, stiffer chassis. Although I also feel that the new dampening system leant a helping hand.

After a while I could tell that the forks were going through their travel fairly quickly. However seeing as I hadn’t set the forks up in the first place it was no surprise that I was running less than recommended pressures. Bumping up the pressure to 60psi fixed the problem straight away and didn’t effect the small bump compliance.

The remainder of the weekend was spent fine tuning the forks. However I never got a chance to play with the bottom out adjustment. They were working so well that I didn’t bother. Given more time I would have dropped pressure a little bit and wound the bottom out in to see if I could get the forks even more supple in the mid range.

The larger stanchions have also done wonders for the air pressure. My preferred pressure in the new Boxxer was half of that in the old fork. This should have a dramatic effect on the life of the air seals, a problem that has plagued many World Cup Boxxer owners in previous years.

The new Boxxer is a solid step forward for the Rock Shox family. With a complete redesign and new dampening system the new Boxxer firmly retains its mark as one of the best downhill forks available today. The one drawback I had over the weekend was that I had to give them back once I’d finished my race run, and it would be months before I could get my hands on a production set.