uppercuts on hvy bag

I want to be able to pratice combinations on my heavy bag that include uppercuts. Any innovative ideas on how to "tweak" a heavy bag to provide some sort of "lip" for uppercuts? I remember seeing some bags in a video, that looked like they had a small diameter inner tube inflated on them horizontally, but never could figure out what they did or how they did it.
Would appreciate any ideas you have. Thanks.

RevGear makes a great uppercut attachment for heavy bags.


Thanks. That looks real promising. Have you used one?
I know what hugojkd means: Ringside had a "strap on" uppercut attachment that was all over the place. Would be great to find something a lot more "fixed".
Anybody else have any experience w/this Revgear product?

On my bag, which is not a RevGear bag, it was just a tad loose but I was ablt to fit it so that it doesn't really slide.

I like this bag for uppercuts and hooks.

But, we have these at the gym.

Thanks, guys.
You've given me good info.
I think I'll save up for the Revgear attachment.

Yeah, Thailand seems to have some crazy tough foam...

We have the ringside one in the picture above at the gym and it is great.

My old boxing gym just used the standard heavy bag without any fancy attachments. The trainers would have us step in behind our punches and basically push the bag back so our uppercuts were into an angled bag.

A favorite inside drill they like to use was to have you step in with your forehead pushing on the bag, you step in far enough so your centerline was directly below the anchor point of the bag. Never let the bag get back to a vertical position. Work your hooks and uppercuts on it for a round. It did a great job of teaching you to maintain pressure on the inside (this was pure boxing not MT or KB).

Their take on uppercuts was they were a VERY close range punch. If you were close enough to uppercut, you were too close for anything else but a very short hook. They basically had us in contact distance for all uppercuts.

It's worked well for me keeping with those drills.