One bike have V brakes. The rear brake is under the chainstays. I call v brakes maybe had other name. First time i see brake like that. The owner of the bike say this brakes even is working no stop the bike. I wonder if i can use regular v brakes under the chainstays any ideas?

I doubt it will work.

Without seeing your bike I'd be willing to bet the brake under the chain stay is a U-brake. If that's the case, the mounting studs will be in the wrong place to install a linear pull (V-brake).

I would have to see pics of the current setup.

Like this U-brake ?

You need to follow the instructions to the letter to have them work correctly. They are very effective when properly set up and maintained.

Just watch your knuckles while working on these brakes, those rings have sharp teeth. Also take care with chain lubing, it's easy to transfer lube to the pads. Andy.

U brake. No big deal to work on.

Let's see this bike.

Adjusting Cantilever "U-Brake" Bicycle Brakes

V brake won't work, U brake and roller brakes have different mounts than canti/ V brakes.

You see the U above, this is a roller:



Here's the difference in mounting them:





V brake/ Canti:

Can you simplify your question? I'm having trouble sifting through all the data you've provided.

Canti and V brake mounts are below the rim. Roller and U brake mounts are above the rim. It's that simple.

if you are unsure of your abilities I am too.. use a Bike Shop. pay someone who is capable.