Why is a mountain bike so difficult to ride on?! :(

The charity bike ride is next weekend. I borrowed a mountain bike from a sensei and he brought it to school sensei today. I tried riding on it and it feels so different!!! It's very difficult to control!!! so... now I am really scared!!! sigh... I have 1 week to get use to the bike. :(

I also need to transport the bike to Beppu which is a BIG problem. I need to beg the teachers to help me. Hopefully there is someone kind enough to help me with it. If not, I would have to buy a 5000 yen bag to bring it there.

I will go beg for help today. Wish me luck. (I really need it to survive the 3 days of biking.)

This is the bike I borrowed. What kind of bike is this?

I went out for a cycle today on this bike. It's not that difficult, I guess it's cycling on it for 3 days that will be difficult.