If I want to carry bikes on my spare tire rack do I really need to get an aftermarket tire carrier and bumper (2009 jk)?
Thank you,

 

A safe alternative is a body mounted tire carrier built to handle some weight. Tons of companies producing options on this.

With a stock tire it would probably last a little while. My stock carrier cracked after a year with a 33" tire. Ride it till it cracks and replace it.

 

Your profile is not filled out, so we can't see what equipment you are working with. By the looks of your avatar, guessing you have larger tires. If you're still using the factory tire carrier, I personally would not add any additional weight to it. I wouldn't be worried about cracking the tire carrier, I'd be concerned with my tailgate and hinge. Unfortunately tire carriers aren't cheap....whether you go with a solid hinged tailgate model or upgrade your bumper. If this is all about carrying a bike along, why not just consider a receiver mounted bike rack for now? I have a Yakima doubledown and it works great.

 

I couldn't find a bike rack that would fit on the stock 32's. So if you have larger tires I would imagine the odds of finding one would be even less likely. Why not look into a hitch mounted bike rack?

 

There's always the hitch mounted option.

 

The stock carrier and gate is only rated for a minimal amount of weight. If you'd like the tailgate and carrier to last then you 'should' upgrade before it becomes an issue.

 

Thanks everyone. Yes I've got 32s. That answers my question. I've heard about the cracking tail gate wanted to be on the safe side. I didn't want to drop $300 for gear I didn't really need. Thanks again for everyones input.