Add the black friday bundle for $99, continue to the checkout and payment screens. At some point you'll see an option to add a 3 wheel bundle for $59. Add the 3 wheel bundle and back out to the main page, go back into your cart and you can delete the black friday bundle but you'll have to pay $6.95 shipping now. I was unable to get the bundle quantity to change and keep the discounted price.
My back's been hurting and I thought these looked interesting enough to try.