MTB Conversion For Lighter Commuting Just want some opinion. I have a MTB bike, but I want to make it lighter. So here are some of my thoughts currently on what I think I should change:


700c rims and tires
Cantilever brakes
Rigid fork 


The details of the bike are as below:


Disc brakes
26er wheels with road slick
Suspension fork


Additional details: 


Bike frame weighs 11kg with suspension fork without wheels
Current wheel set (rim and tire) weigh 2kg
7x3 speed 
Flat handlebar


Other related questions:


Should I change the gearing of the bike into that of a road (7x2 speed)?
Should the 700c rims able to withstand 10-11kg of frame? (note that the rider is 75kg)
The rear end of the bike does not seem to have a place to mount cantilever brakes, but has two small holes that can somewhat screw in something on each side the frame. What is it actually for? 


Thanks for sharing your opinion and information.
Its not a light bike, even by MTB standards, and will never be a great road bike as it will always be heavy. 

Start with the easy and relatively cheap stuff - tires and tubes. Dump excess rolling weight by getting light tires an even going tubeless. The next biggest bang for your $$$ will be replacing the fork. You should be able to pick up a second hand fork for next to nothing - just watch the geometry. If you do this, canti brakes on the front is likely worth doing. 

Replacing wheels is probably not worth the effort, you will shave off  a few hundred grams (admit-ably rolling weight), but it will cost big money.   

Look very hard at the costs of any proposals. My guess is that for what you are proposing, a cheaper option that will give you a better outcome would be to buy a second hand bike that does what you want, rather than trying to make your current bike into something it is not.  You may have access to cheap parts, but in that case you probably have access t cheap bikes.