I just got a pair of a-arms with 8 hemi joints and I am wondering if after a dayof trail riding how much dirt and sand are going to get in these things and how long they will last. I am planning on doing hair scrambles and XC racing.

 

They work good but dont lube them with grease or anything tacky. Use dry non dust collecting lubes. If you grease them they will wear out quickly. They are great for dirt free environments like winter /ice racing . There are companies out there that make rubber boots that go over the joints to keep the dirt out. Ive got a set on my tie rods and they work good. Check ebay for those.