Understanding gears on TREK 1.1

Not sure where the difficulty is. Is he able to change gears at all while riding? Please explain a little better what you need.

For a beginner, just have him make sure that he is in a gear that he can sustain a quick cadence. You go up a hill, shift to an easier gear, starting from a stop, start in a low gear, and when you hit your cadence, shift up, etc. Different schools of thought on optimal cadence, but 90ish should suffice for the simplicity of this post.

Your gear will be determined by 2 things.

1 - Your chain ring - These are the big 'gears' located by your feet and traditionally controlled by your left-hand shifter. The larger the chain ring, the more your wheel will spin with each pedal stroke. A smaller chain ring will spin more easily, but you won't go as fast - good for going up hills.

2 - Your cog - These are the smaller 'gears' located on the rear wheel and controlled by your right-hand shifter. The smaller the cog, the more your wheel will spin with each pedal stroke.

Biggest Chain Ring + Smallest Cog = Going very fast on flats or down hill.
Smallest Chain Ring + Largest Cog = Going slowly, but more easily up steep hills.

Try not to cross-chain. This is when you are in your largest chain ring and largest cog, or smallest chain ring and smallest cog. It causes the chain to work at a more severe angle. Practice riding in an open parking lot to get used to the shifting. The more you ride, the more natural it will feel.

Oh, and congratulate your teen. This is their first step into a big 'ol world of awesome!

Thanks for your help. The biggest problem is with getting to the gear he is looking for more than understanding the way it works. No numbers to work with on gears just arrows. Knowing when to use the entire brake lever and when to use just the bottom lever. Understanding the difference between what the left and right levers do. Understand it is probably easy but my son is a awesome kid but he struggles with some learning issues. He can do it just needs alite more guidance to get started.

Go to youtube and search "How to shift a road bike". There's a number of them...some better than others. If your son watches a few of them, he'll be more than ready to practice on his own.

Gotchya. Aside from the crossover stuff that was mentioned above what gear you are in doesn't really matter. What matters most is perceived exertion and ability to maintain a fast cadence.

If he was doing short races where fast shifts were necessary it would be kinda like driving, you always have to anticipate the next shift. For a Tri, race and a beginner, no less, the point is just to be comfortable with the gear he is in. If he's having to mash on the pedals, shift to an easier gear. If he's spinning like a kid down a mountain on a bigwheel, then shift to something harder.

It took some getting used to with the gears for me. My mountain bike had the numbers and the road bike didn't It drove me nuts! The funny thing is that I'm much better about being in a proper gear on my mtn bike now that I don't even really care what number the shifters say!

So, when do you shift the front, versus the rear? Meh, there's a proper answer for that, but it isn't going to matter until he is more comfortable with the bike anyway. Heck, I bet 95% of what he needs is with it in the middle gear in the front and just using the rear to change gears. (Exceptions would be big hills down or up!)

When my son started riding a couple years ago we just kept it simple by using the left shifter to put the chain on the big spocket and we left it there.

Then just taught him how to shift the back to get the gears he wanted. If you ride in a hilly area he will need the front shifted to the small sprocket instead.

with the front set:

1. always use the right shifter which shifts the rear derailer which is the gears on the rear wheel
2. push the big lever over to shift to a big gear (pedaling gets easier but you go slower)
3. push the small lever over to go to a small gear (pedaling gets harder but you go faster)

I think figuring out how to shift the back to start is easier for them to learn. Once he has that down without a problem then he can worry about the front.

When my son started riding a couple years ago we just kept it simple by using the left shifter to put the chain on the big spocket and we left it there.

Then just taught him how to shift the back to get the gears he wanted. If you ride in a hilly area he will need the front shifted to the small sprocket instead.

with the front set:

1. always use the right shifter which shifts the rear derailer which is the gears on the rear wheel
2. push the big lever over to shift to a big gear (pedaling gets easier but you go slower)
3. push the small lever over to go to a small gear (pedaling gets harder but you go faster)

I think figuring out how to shift the back to start is easier for them to learn. Once he has that down without a problem then he can worry about the front.

Thanks a lot for the help. I think I understand enough to get him headed in the right direction.

These explanations are good- but a lot of it is just riding for a while until you "get it". FWIW,when I'm not on a bike I could not tell you which shifter controls the front, and what motion shifts up or down, without really thinking about it, but I have no problem when I'm riding.
I'd suggest going somewhere flat and just shifting through the gears, to get a feel for when it gets harder and when it gets easier. It's more about muscle memory than conscious thought about what lever controls what.
Also I think it's really cool that he saved up for a bike and that you're helping him learn about it.