Stupid Question -- Shifting
 

I'm not really a "hardcore" bike enthusiast like most people here, so my question is probably pretty stupid.

I have a 21-Speed mountain bike. I don't know all the terminology, but basically I have 3 "gears" on the left of the handle bar and 7 on the right.

Can someone tell me what the "order" of the gears is overall (i.e. I assume "1-1" is the easiest, and "3-7" is the hardest, but I'm not sure how it progresses in between. I find that I very rarely change the left, leaving it almost always in "2", and I basically use the right only. To get going I'm in 2 or 3, making my way to 7 when I'm really going fast. I only use 1 if I'm climbing a hill and I run out of steam. Also I find that some "gears" don't really work well, so I assume I'm not really supposed to use them (e.g. 3-1.)

What are other people doing? Also, is it hard on the bike if I jump from say 2-3 to 2-5 in one shot?

Tom

Just to reassure you, I think you are on the right track...

The gear combinations 3-1 or 1-7 will not be really efficient because of chain angle, but all your gears should be usable. If not, there is probably some adjustment needed.

Also, shifting more than one gear at a time like 2-3 to 2-5 is not a problem...

Basically there is no easy way to tell you which gears follow specifically behind others in a general way, it depends on your bike...

However, I completed a 61+ mile ride two weeks ago, and I can tell you that I got onto my largest chainwheel for only a couple of minutes of the 5 hour ride, and my small ring only during some climbs.

BTW -chainwheel is the term for the front.

Anyway, for us recreational riders, I think about 80% of our riding should be in the middle chain ring, and moving to the small one for climbing the big hills... and the large one for going down hills really fast...

To get the specifics of the gearing, count (or read) the number of teeth on each gear, and use a gear calculator like the one here: http://www.sheldonbrown.com/gears/

I like using "gear inches" because it is what I know... Basically a large number means a hard gear and a small number is an easy gear (like you would want for climbing a hill)

You will find that the gear ranges for the middle ring overlap the gear ranges for the small and large rings...

If you print out the gear chart that Sheldon's calculator creates and put it on your bike, you will have the ability to select the perfect gear... If you are riding in a particular gear and it is too hard to push, and the next gear down makes your legs flail around because it is geared too low, the chart can help you find a gear that is in between. The in between gear can usually be found by shifting the front and also shifting the rear one or two clicks. This double shifting will become somewhat natural with time.


One technique I use when I start the climb at the bottom of a hill that I know I will need a low gear on, I will shift to my small chainring and shift up two or three gears on my rear... This will keep me close to the gear I was using, but give me the ability to only need to shift the back during the climb. The back will almost always shift easier, so when climbing we get smoother shifts this way...

I hope you get comfortable with the shifting, and keep having fun!

The short answer is: There is no simple progression.

Don't make it too complicated. Think of your bike as having three different gear ranges corresponding to the three front sprockets: One for flat surfaces, one for uphills and one for downhills.

Not a dumb question(s) at all. Everyone starts somewhere.

A note on nomeclature/convention: gear combinations are normally refered to by number of teeth on the chainring and cog selected, front to rear. Such as 42-17 (front - back). In your convention, something like 2-4 (again, front-rear).

It is pretty common for recreational riders to spend most of their time in the center chain ring up front (40 & 42 are pretty typical sizes) unless they live in hilly areas. The "order" of gears is from lowest gear ratio (easiest to pedal) to highest gear ratio (hardest to pedal), usually in gear-inches. So it would go from something like 30-25 (low) to 52-13 (high).

Shifting a couple of cogs on the rear sprocket is not too much of an issue if you remember to ease up on the pedals while shifting. Mostly you want to be smooth in transition to minimize the stress on the drivetrain.

Some gear combinations do not work because of cross-chaining. This is where the physical angle between the front chainring selected and rear cog selected is so great that the chain starts rubbing against the derailleur and also against the teeth on the gears/cogs. This will lead to premature chain wear. This is usually at extreme gear selections like 52-25 or 30-13 (approximate since I do not know what your exact gearing is).

A great website for these type of questions is the Sheldon Brown website. Sheldon is the man.

Cheers.

-José

Me too, samag. I only use the small chain ring going uphill, and the large is for downhill, or really good tailwinds. Because we have more hills here than I have horsepower, my small chainring is 26teeth instead of the factory 30teeth. Also my cassette (the mess of gears in the rear) has a somewhat wider spacing between individual cogs. Wrong for many, but perfect for me.

Not a stupid question.

Some people get very involved in knowing all the right gear combinations, which one to use in which situation, power ratios, etc. Very technical, and not necessary.

I like to keep it simple.
I also have 3 front rings and 7 rear gears (cogs). I usually start in 3-6 or 3-7 ('cause that is the gearing I usually end with) and shift to a gear that is comfortable to pedal at 80 to 90 rpm (cadance or pedal turns). If I feel too much resistance, I shift the rear one gear easier. Too little resistance, I shift one gear harder. When I'm in the middle of the gears, usually 4 or 5, I shift to the middle ring in front. If I reach the bottom of the gears and still have too much resistance on a hill, I shift to the small ring and use the 1-1 combination. As the hill gets easier I reverse the process - 1-1 to 1-2 to 1-3 to 2-3 to 2-4 and so on.

I usually don't even look at the numbers any more. I just go with what feels right. Going from highest to lowest gear is done in just 8 shifts - 6 shifts for the gears and 2 for the rings.

Shifting 2 or 3 gears at a time is no problem. Trickier is shifting the front and rear at the same time. Do it wrong and your chain falls off.

I aim for a cadence of 75 - 90, and use the gears to control resistance. The speed is just whatever it is. Now, I know that's just a different way of saying what cc rider said.

I'm with Retro Grouch on this one, I always tell my guys to think in terms of "gear ranges" for the crank, and dialing things in more precisely with the rear.

I work at a university, and am constantly amazed at the numbers of kiddies who come to school with modern 24-speed mountain bikes-and don't shift. You'll frequently see them get off on the rather mild hills we have on campus and walk.

I'll second the comment that there are no stupid questions.

As for the gearing, this is how I would explain it to new cyclists back when I worked at bike shops:

Here's the complex answer; you have three chainrings up front and seven in the rear for a combination of 27 gears controlled be the front and rear derailleurs, which can be shifted by these two levers.

Here's the simple answer; you have two kinds of gears: low gears and high gears.

Low gears are for low speed riding, like riding up a hill, riding into a headwind, or just slowly putzing around. They consist of the small and middle chainring up fron, and the bigger cogs in the rear.

High gears are for high speed riding, like riding down a hill, riding with a tailwind, or just putzing around while riding real fast. They consist of the middle and big chainring up front and the small cogs in the rear.

As far as shifting goes, you just don't want to "cross gear", meaning that you don't want to be in, say, the small chainring up front and the small cog in the rear. And likewise, you don't want to be in the big chainring up front and the big cog in the back. If you do that, the chain will be at an extreme angle. Instead of smoothley coming into contact with the teeth on the sprockets, it will be grinding into them and subsequently tearing off of them, and the rear derailleur will actually be forced into twisting sideways, and that's not good. You'll hear grinding and crunching, and that means find another gear, fast.

Otherwise, shifting and finding the right gears, especially on a mountain bike where riding conditions cna change rapidlly and frequentlly, shifitng into the right gear becomes a matter of feel, and over time, is something that comes naturaly, an innate sense unique to cyclists.