junebu8680@aol.

I am new to cycling and just purchase a diamondback road bike. It is one of the lower end models. I got it home and went for a ride. When I pushed down on the shifter it moved the chain to the smallest front crank(?) and smallest back crank(?). This bike has Shimano 150 STI Dual control shifters. There are two little gray levers to push down with your thumb, one on each handle bar. I know the left operates the front and the right operates the back. But no matter what I push the chain doesn't move. I can't figure out how to get the shifter to move the chain to a diffrent crank. Is there something wrong. I know I am missing something easy, can anyone help?

Al1943

The front sprokets are called chainrings, the rear sprokets are called cassette cogs. The cranks are what the pedals are attached to.
To shift to the larger chainrings shove the left brake lever toward the front wheel. To shift to larger cogs push the right brake lever toward the rear wheel. Avoid "cross-chaining", small to small, large to large. Avoid chainrub on the front derailleur, trim it side to side with the left shifter.
Enjoy,

Al

DevLaVaca

These shift with two mechanisms. Pushing the thumb lever moves the chain to the smaller chainring and smaller cog. To move to a larger one, you will have to push the entire brake lever towards the centerline of your bike. They will swing from the top. Looking at your handlebars from the front, they should look something like this: |T| . You want to swing the lever like this: \T|. You will also need to be pedalling while you do it.

Also, if you're in small/small right now, you may have managed to seize the rear derailleur (that's the arm assembly below the cassette (gears in back)). The derailleur has a spring in it to pull the chain taut, but small/small may give too much slack for it to handle. If this is the case, you'll need to get your fingers dirty and just pick up the chain and move it to the next-largest cog. You can get the grease and dirt off more easily with hand lotion, followed by soap, than with soap alone.


And welcome to cycling! Sheldon Brown, cycle guru, has a great webpage for beginners, and the first article is: Everything You Wanted To Know About Shifting Your Bicycle's Gears, But Were Afraid To Ask. Check it out here.

Mountain_Owl

I just posted a similar question in the Introductions thread. Thanks for the link, DevLaVaca! (Please also visit my Introduction thread to offer any insight.)