Originally Posted by
Norel
I bought a Norco hybrid at the beginning of the season, It has 21 speeds. After using the bike all summer long, i found out that i was using mainly the middle sprocket. I am now thinking of taking off the smaller and bigger sprocket, is that possible?
For your information, they're usually called chainwheels or chainrings, not sprockets.
And whether they're removable or not, it depends. On cheap cranksets the chainrings can be riveted in place, where slightly more expensive cranksets have bolted-on chainrings. Bolted, removal is easy. Riveted, it takes some more serious tools and determination.
Do note that removing the smallest will require pulling the crankarm off, unless you wish to cut it off. Pulling the crankarm usually require the use of a crank puller tool, but is somewhat dependent on which crank and bottom bracket you have.
Originally Posted by
Norel
Taking off the front derailer (since it would be useless with one sprocket) and the two sprockets woulk possibly make the bicycle a bit lighter
True, but not by a lot. All in all it's a fair bit of tinkering for not much actual benefit, maybe 2 lbs or so. Not that much as seem as a fraction of the whole bike weight.
Originally Posted by
Norel
Will i have to change anything related to the crankset or other parts?
Depends on your riding style and your expectations.
Running one ring and no derailer
might cause the bike to throw its chain every now and them.
If that becomes a problem you might want to either reinstall the derailer and lock it in place by the limit screws, or get one of those chain devices used by DH MTBers.
Oh, and there's that chain ring bolt length thing that's already been pointed out.