Hey there Realer. I noticed you're not far from me. Port Hope here. Anyhow, I have the 2010 SV291 and I have a clamp on bike rack that goes on the ladder at the back...and I also put two full size bicks in the back door. Hope this helps.
Realer, check this link, I posted some pics showing how I built a receiver hitch for the back of my trailer, I use a standard Thule bike rack that fits a 2" receiver, there is no additional weight on the bumper itself, rather spread throughout the frame with 2" angle iron. The pics are quite a ways down on the page.
Can anyone help me with finding a bike rack for the spare tire holder on the SV291? Or some other option if the rear bumper can't take the weight.
Don't do it! I did and before I got out of town I was dragging my bike on the freeway. The Tire rack assembly is not strong enough to support a bike. You can install a receiver hitch to the front of your vehicle and not have to worry about the bike that you can't see.