What props size work good for the hog bipe?he has a 60 os AX engine.

Something is wrong here?

There's a 55AX, 61 FX, 75AX Where or when did the 60 AX come about?

Ok it's probably the 61 FX, it's not mine im just asking for someone.

Not familiar with an OS 60AX but as a general .60 size prop for a bipe I'd start with a 12x7.

I have an ASP .61 on an Uproar 60. A 12x6 prop works great on it.

I have the OS .61fx currently, and they recommend using a 12x6-8, and 13x6-7

OS tends to recommend props intended to keep noise down. Apparently noise control is a big issue in Japan.
My opinion, worth the price being paid for it, is that a lot of the props they recommend are too big.

I've used an APC 13x4W on a TT61Pro (on a trainer) and liked that conmbination. One of our club members tried this prop on a Kyosho Flip 3D, with a 61FX, and hated it.

In the end you just have to pick a prop and try it. If it performs the way you like, keep using it. If it doesn't, try a different one. Fortunately the 11 to 13 inch props likely to be used on a .61 are fairly cheap. I'd hate to do a lot of experimenting with big props.

Props are a personal thing

"If it performs the way you like, keep using it. If it doesn't, try a different one."

Ok, mabe we will start out with a 12x6 and see how that goes.I guess I could use the same on my regular astro hog.

the 12 X 6 works well on the regular Astro Hog also