Source
r/NoStupidQuestions•
deadrs

Can someone please explain bicycle gears to me?

I honestly feel so dumb and I’m reading through articles, asking friends for advice, and I’m just not getting it.

So, my bike has two front gears and 7 back gears. After riding for a few miles, I learned that you shouldn’t match big gears with small gears. I was riding with the biggest gear on the front, with a low gear on the back. Okay, lesson learned. Still a bit confused, but I’m getting there!

I was going up hill with the highest front gear and a low back gear, so how would I go about going uphill?

Let’s say I’m going from straight to uphill, my front gear is at 2(highest), my back gear is at like 5 or something. Before going uphill, do I change my front to the lowest gear, pedal a bit, then start changing my back gear to a lower gear?

I keep having to get off my bike and walk it uphill. I know it’s normal for a beginner, but I feel so fatigued after like a half mile ride and I think it’s because of what gears i’m in.

Please try to be as visual as possible. I feel hella dumb right now.

Posted Aug 24, 2019, 10:33 AM UTC · edited

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stereoroidcould be worse•

The big gear is on the right on the front and on the left at the back, so if you engage those the chain is at more of an angle away from straight. In general, this is a problem because it increases the wear and the chance of slippage or coming off. Your derailleur limits were set up with the chain straight too, plus straighter is a little more efficient.

Personally, if I come to a hill, I start dropping the rear gears, but if it becomes clear that won't be enough, then I switch the front gear. I do that before getting to the lowest (biggest) gear at the rear. Think of the gears as "rough" and "fine" settings: the front gear is the "rough" setting, where you set the range, then you fine-tune it with the rear gears. My bike has three front gears, so I treat them as three ranges: uphill range, general range, fast/downhill range.

As for walking uphill: the bike itself has a lot to do with it, I think. I bought a bike last year that is a lot better on hills than the bike I had years ago. The gears on that bike just didn't seem to go low enough.

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deadrsOP•

Since I only have two front gears, would it be bad if I drop the rear gears and leave the front at 2, like would that damage my chain/derailleur?

I’m so scared of damaging my bike while I’m getting used to shifting gears.

Thank you for replying!!

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stereoroidcould be worse•

I don't know what "2" means on your particular bike, but if that means big-big, that's what we're talking about here. You shouldn't have to worry that much, just try and avoid the extreme crossover situations (big-big, small-small).

I don't have experience with your exact 2x7 setup, but to avoid the extremes, I would think about roughly limiting my gear use like this:

  • front on low: rear on 1 (biggest) to 5.

  • front on high: rear on 3 to 7 (smallest).

That avoids the extreme crossovers e.g. if you have front on high, you come to a hill, you start dropping the rear ... if you get to 3 or 4 at the rear and it's still too hard, then it's time to drop the front and go in to "hill mode". You can then drop the rear further if you need to.

On YouTube videos such as this they call it "cross chaining". Exactly how bad it is depends on the bike. I have a 3x8 setup, so that would probably be worse there than on your 2x7.

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deadrsOP•

2 as in the biggest front gear.

What is considered a low gear with the back gear then? Let’s say I’m on the biggest front gear (2) and my back gear is at, say 5. Would that cause cross chaining, or is it only possible to cross chain if my front gear is on 2 and my back gear is on 7?

Thank you for your informative advice!!

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stereoroidcould be worse•

I don't really get what's not clear here. Think in terms of the angle of the chain, straighter is better for reasons related to wear. You can turn your bike over, play with the gears, look at the angles and get a feel for what's happening. There's no substitute for getting to know your own bike. ;-)

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ThereIsAThingForThat•

Okay, so your bike has a front gear (chainrings) and a back gear (sprockets)

The basic is that the smaller front gear you have, the easier it becomes to pedal, and the larger back gear you have, it becomes easier to pedal.

The reason why you don't want to do "chain crossing" (using the smallest chainring with the smallest sprocket, or the largest chainring with the largest sprocket) is that it can cause your chain to slip, as well as damage the chain over time.

If you're going up hill, you want to use low gears, which is a small chainring (front gear) with a large sprocket (back gear). In every bike I've ever seen, this means using setting 1 on the front gear and probably setting 1-2 on your back gear.

Basically, experiment. When you go uphill, start at gears 1-1, see how you fare. If it works out alright, go to gears 1-2, then 1-3 etc until you find your limit.

If you max out your back gear (so 1-7), you want to switch to 2-3 or something like that, to avoid chain crossing both from the 1-7 and 2-1 setup, and then just try out until you find the correct 2-whatever setup.

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deadrsOP•

Very informative, thank you so much!

Can you elaborate on the last paragraph, please?

When you say (1-7) and then switching to 2-3 does that mean 1/2= chainrings and 7/3=sprockets? How fast can I go down in gears, let’s say I maxed out my back gear to 7 and need to get it to 3, do I wait until I hear the chain move on the cassette(is that the right word?) until I shift down again?

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ThereIsAThingForThat•

When you say (1-7) and then switching to 2-3 does that mean 1/2= chainrings and 7/3=sprockets?

Going from the 1 on your front gear (which is likely on your left) to 2, and from 7 on your back gear (which is likely on your right) to 2 or 3, yes.

The reason why you want to do this is that it's likely that the setting of 1-7 is the same "difficulty" as the setting 2-2 or 2-3, but you avoid chain crossing and the additional maintenance it causes.

How fast can I go down in gears, let’s say I maxed out my back gear to 7 and need to get it to 3, do I wait until I hear the chain move on the cassette(is that the right word?) until I shift down again?

The cassette is specifically the back set of sprockets, but those are the ones you're going to shift most of the time (the front set is called the chainring(s)).

As for how much to shift at once... If you're on a flat, you can basically just go through several gears at once. If you're on a hard hill or mountainbiking, you might want to shift one gear at a time, but for regular rides just shifting several at once should be fine.

What you want to avoid is shifting both the front and the rear gear at the same time, since that can cause the chain to slip. So wait until either the back or front gear is shifted before you shift the other gear, although which one you do first depends a lot on the situation and is something you just learn through trial and error.

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