CycleOps Riser Block for Indoor Bicycle Trainers
The CycleOps Riser Block's unique three level design, let's you pick a height for your front tire that will make your trainer riding time more comfortable and productive.  You'll train harder and longer, because you'll be riding a more natural position.  Virtually indestrucible, the injection-molded Riser blocks stabilizes your bike for a worry free in any rear mounted trainer.