Why cant i put disc brake on my mountain bike?

i wanted to put disc brake on my mountain bike but the bike shop owner said that my bike cant.
can anyone name all the factor that may be the reason why i cant put disc brake?
example: brake lever? rim? fork? or other reason
thanks

Two key points;
1) The wheel hubs might not be disk compatible.
2) Your frame and or fork might not have the proper mounting boss' for the disk brake caliper.

I think that it would probably be the rim and the fork. I have a disc brake and the fork is slightly wider to accomodate the disc brake. You would probably have to get an entirely new whell assembly if you wanted to install one.
You probably do not have disc bosses on the fork, and maybe not on the frame located on the back left axle area.

I hope your MTB isnt an X-mart bike.
See this: http://www.superridescooter.com/dirt%20b...

See those two holes on the back of the fork where the brake is connected too? See if you have that.
Disk breaks are attached to your frame at the rear end of the bike and your fork or front shock in the front of your bike.The disk itself is attached to the wheel hubs. Some bike frames and a lot of wheel hubs are not disk break compatible. Sounds like this is the case with your bike. Hope this was helpful
Im a MTB enthusiast and I build my own bikes.

Tags

Kids Bike Schwinn Bike Cruiser Bike Road Bike Folding Bike Mountain Bike

Related information

Is anyone familiar with the ICO IC mountain bike?

Should i keep my luggege rack on my mountain bike?

Looking for relativly "cheap" mag wheel s for mountain bike?

How can I find out what year my mountain bike was made?

What does the sizing of a mountain bike refer to?

Can someone tell me the aprox. value of my mountain bike?

Whats the difference between a normal mountain bike and a bmx?

Where's a good place to mountain bike in Chicago?