I have struggled with my Fox 36 for the last year. Long story short, but the air spring is wildy inconsistent. The issue is wide known and Fox no long uses this style of air spring, however several manufacturers offer fixes. MRP, Vorsprung and a few one-man shops try to address this with various approaches. After talking with Craig at Avalanche he brought up that he too offers a solution to address this and that I should give it a try before spending money on a new chassis. The 2015-2017 Fox NA air spring uses a transfer rod to equalize the positive and negative air springs at full extension. A small dimple in this rod does the equalizing. As the rod travels through the air piston an o-ring and 2 washers seal the transfer rod shaft and separate the two chambers. Craig suggest that there is not enough squish on the o-ring to provide consistent equalization and thus results in a build up of pressure in the negative chamber. This pulls the fork down in its travel upsetting the geometry of the bike. As a result the rider tends to adjust the fork (via spring pressure and damper clickers) to compensate for a poor preforming fork. As you can imagine this quickly spirals out of control and results in real frustration. I found my fork to preform incredible one-day and horribly the next. As a result my confidence takes a hit and I struggle. I feel like it really effected me during the spring DH race at Windrock and the EWS qualifier.
I implemented Craig’s fix and rode last Friday. But before I could focus on getting the fork feeling good I also struggled on tire pressure. I know my Silca pump reads too high and as a result I have fought flats and cut tires for a long time. I purchased an analog gauge specifically for bikes and turns out it read too low. So in Friday, when I thought I was running 30psi I was running closer to 40psi. Well, with Windrock under some of the toughest conditions it was a recipe for struggling. I crashed twice and again my confidence was shattered. I just could trust anything I was doing and trying to put my tires where I wanted was a real gamble.
I went home Friday evening kind of lost and wondering where to go next. So Saturday morning I delayed a trip to the cabin to reset a few things and headed back to Windrock to wash the bad taste out of my mouth. I set my fork sag to 22%, rear to 23%, adjusted my clickers to a rocky setting (19 compression, 15 rebound), and tires to the thumb test. I would guess they were in the 25psi. Which is risk, but I taking steps to mitigate this. I also swapped to some brand new Maxxis DH MaxxGrip rubber. Wow, what a difference!. The bike was much more planted and that translated to confidence. I was able to go deeper, brake later, and increase the risk. The real trick will be can I get the same performance next weekend.