# Bike Gears 101



## mallettk (Apr 25, 2012)

Hey,

So i'm a little confused when it comes on to gearing and switching gears. I have a triple crankset on my bike and I was told that I will spend the majority of my rides in the middle chain ring. I was also told while using the middle chain ring, I will be able to utilize all the rear sprockets (I believe that's the proper name). Now if I decide to switch to the biggest ring (the one furthest away from me) in the front, I will only be able to utilize the 2 or 3 sprockets on the opposite side in the back (the ring thats closest to me) and vice versa. If I'm on the smallest ring in the front (the ring that's closest to me) I'm only able to utilize 2 or 3 sprockets on the opposite side in the back as well (furthest away from me).

Hopefully this post made sense hahah! But is this right or is that completely off the mark? Is there a best practice or underline rule when it comes onto using/switching gears? I just got a new bike and I want to be able to maximize the life of my components. It would suck to run into drive train problems a week or 2 from now just because I wasn't shifting correctly. 

Thanks a lot in advance!


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## AndrwSwitch (May 28, 2009)

You're reversing it.

You can use almost all of your cogs when you're in the middle ring.

When you're in the largest ring, you should avoid using the largest cogs. Which is fine, those gear ratios are redundant anyway.

When you're in the smallest ring, you should avoid using the smallest cogs.

I don't think too much about it, to be honest. I spend most of a solo ride in the 39t ring. I get in the 50 for a descent or if I'm doing intervals, and I use the 30 for sustained climbing. I shift the rear derailleur so that I have the cadence I want. If you feel like you're always at one end of the cassette when you're in the 39, you might get a little better use out of your gears with a different cassette. But since the bike is new, don't worry about it until you've been riding a while longer - the initial gain in how much power you can develop on your bike should be pretty quick as you get comfortable and efficient on it. When it comes time for your new bike tuneup, if you're not really using your gears, talk about it with your shop. Also keep in mind that I've given you some guidelines, not rules.

It'll take you longer than 2 weeks to trash your drivetrain even if you're doing it wrong. Unless you put an abrasive compound in your chain, anyway... Try to keep it clean, and relube as needed. I wipe mine with a dry rag after every ride, but I only relube if it's starting to get noisy. I'll probably get flamed for this, people have a lot of different views and strong emotional attachments to them.


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## PJ352 (Dec 5, 2007)

mallettk said:


> Hey,
> 
> So i'm a little confused when it comes on to gearing and switching gears. I have a triple crankset on my bike and I was told that I will spend the majority of my rides in the middle chain ring. I was also told while using the middle chain ring, I will be able to utilize all the rear sprockets (I believe that's the proper name). Now if I decide to switch to the biggest ring (the one furthest away from me) in the front, I will only be able to utilize the 2 or 3 sprockets on the opposite side in the back (the ring thats closest to me) and vice versa. If I'm on the smallest ring in the front (the ring that's closest to me) I'm only able to utilize 2 or 3 sprockets on the opposite side in the back as well (furthest away from me).
> 
> ...


If I'm reading this correctly, you've got it partly backwards. When in the middle chainring, you should be able to utilize all of the cogs, but I'd recommend using the inner and outermost cogs, sparingly (for short periods of time). 

When in the inner ring, you should be able to utilize all but the two smallest cogs and when in the outer ring, all but the two largest. This isn't cast in stone and how much of a variance allowed depends on a number of factors, but the bottom line is you want to avoid cross chaining (EX: crossing from inner front to outer rear/ from outer front to inner rear) for any length of time, because doing so can prematurely wear drivetrain components.


Another example: If I'm facing a shortish climb that I know I can crest in the outer ring and inner cog (at a 'decent' cadence), I'll cross chain rather than shift to the inner ring and down the 3-4 cogs necessary to maintain cadence.


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## Husker24 (Apr 18, 2012)

I think you have the information backwards and it seems a little too restrictive.
I ride a compact double (2 front chainrings) and from what I understand it is only not recommended to ride with your setup "cross-chained". So never ride big front to big in back and also never ride small in front to small in back. If you look down at your chain in those situations then the chain is at the largest angle it can be and creates more wear on the drivetrain.
I would just avoid the cross-chaining gear combinations and have fun on the bike !


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## JCavilia (Sep 12, 2005)

I don't have much to add, as Andrw and PJ have as usual explained things well. But I'd make a general point in response to this:


> I just got a new bike and I want to be able to maximize the life of my components. It would suck to run into drive train problems a week or 2 from now just because I wasn't shifting correctly.


That's the wrong way to be thinking about using this equipment. Your components will probably last longer than you want to keep this bike, even if you misuse them. You should be thinking about learning to ride in a way that maximizes speed, and efficiency, and especially fun. Parts will wear out, some faster than others, and when they do you replace them. It should be a very minor consideration. You can't replace the moments when the enjoyment of the ride was interrupted by your worry about whether doing something wrong might shorten your cassette life from 3 years to 2, or whatever.

In any event, the only real restriction is the cross-chaining mentioned by others, and it's not a rigid rule. 

Here's some reading you might enjoy, from a dear, departed and sorely missed master mechanic.
http://sheldonbrown.com/gears.html
http://sheldonbrown.com/gearing/index.html

Have fun, and welcome to the club.


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## tlg (May 11, 2011)

Here's a good video on shifting and cross chaining.





And another.
The Problems With Cross-Chaining - YouTube


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## mikeny278 (May 14, 2012)

What does 39t or 50 mean? 

On my first ride the chain fell off because I was shifting without slowing down my cadence while shifting, and was cross-chaining. Very helpful posts, thank you.


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## dpeters11 (Jan 30, 2011)

Number of teeth. You don't want to shift while the pedals are under pressure. You need to be pedaling, but lighten the pressure while doing it. Shift before you need to when approaching a hill. You don't want to change half way up if you can avoid it.


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## Naixed (Apr 10, 2012)

very helpful video, thanks for posting


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## GabooN85 (Mar 7, 2012)

I know of cross chaining and gear changing concepts but just a question after reading thought this thread.

I have a compact double 50/34 and an 8 speed 12-26 cassette.

I find I have been riding on the big chain ring up front. I live in a flat area, no real hills. I will pull away from a stop in the largest cassette in the back and on the large ring up front. Within a few strokes though I'm up to the second, third or fourth cassette in the back. I originally tried using the smaller chain ring as I tried to follow gearing advice, but since dropping to the small chain ring means moving to a smaller cassette right away, and then a gear or two later having to move over to the large chain ring anyway, it didn't really make sense to be switching small and large chainrings all the time.

So by using the large chainring almost exclusively, am I doing anything wrong? Having only 2 chainrings, cross chaining from large ring to large cassette isn't a huge stretch (as it would be on a 3 ring). Also having only 8 cassettes compared to 9 or 10, does this help alleviate this as well..

Basically, is it ok the way I am currently riding, or should I try to make use of both chain rings next time I go riding. I kinda figured that, if I were to encounter hills I would obviously use the small chain ring more, but exclusively riding flat terrain, those gears weren't needed.


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## AndrwSwitch (May 28, 2009)

I really like my 39t chainring for riding on my own in flat areas. That's the biggest criticism I have of the compact standard - I feel like, for me, the 50t is a bit bigger than I really want if I'm not drafting or doing speed work, and I end up a bit cross-chained in the 34. Honestly, I would have been fine doing speed work in my 39 today, but it ended up a bit more cross-chained than I liked - I was trying for a 39/13 or 50/17 ratio, to match(ish) my track bike.

On the bike I have with a 50/34 compact double, I've ended up generally staying in the 50t when I'm riding in the flats. I don't shift down much when I get to a stop. Sometimes not at all, sometimes one or two cogs. Depends on whether or not I'm out to ride hard, and if I'm just going to get to another stop sign in a moment, or if I'm getting back up to "cruising speed."

Anyway, your drivetrain's not going to explode or anything if you're cross-chained every now and then. It's more that you shouldn't make a habit of it.

If you're a high-cadence guy and you don't race or travel to places with descents, you might be happier with a smaller large ring. I put a 46t on my 'cross bike recently, and I'm quite happy with it on the road. I had a 48/14 max. on my commuter for a while, and I was perfectly happy with that. This is more something to file away for whenever you have to replace a chain ring - when that comes up, ask yourself if you ever use your 50/12, 50/13, etc., and consider making the biggest ratio you actually do you your maximum ratio with the new chainring size.

Basically, it's nice to have a chainring that I'm happy with most of the time in the flats, and if you have to change your small or big ring to have one that fits that well, you're not alone.

Sorry, long answer to a short question. But there you go.


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## GabooN85 (Mar 7, 2012)

Thanks that helps to know others are in similar situations. I don't tend to use the hardest of gears, done a few sprints that got up there but don't think I used the last gear.

This is my first full season so I'm relatively new so I will see how it goes as my speeds increase. After getting a Garmin Edge 500 recently, my average cadence seems to be right around 100.. I'll typically shift if it dips below 95-100, and shift if i reach about 110, depending on wind resistance etc. going on at the time.

Racing isn't really in my (near?) future. I'm starting my masters degree this September so I'll be in my current flat local (Windsor, Ontario) another 2 years minimum. Make a few trips a year to Oakville/Toronto area, plan to bring out my bike but hills shouldn't be a huge concern there either.


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## tlg (May 11, 2011)

GabooN85 said:


> So by using the large chainring almost exclusively, am I doing anything wrong?


Nope. If you live in a flat area, you'll hardly ever use your small chainring. 


> Also having only 8 cassettes compared to 9 or 10, does this help alleviate this as well.


No. 8, 9, & 10sp cassettes are all the same overall width. The cogs are just thinner and closer together as the number goes up. So when in the largest and smallest cogs of each, you'll have the same cross chain angle.


> Basically, is it ok the way I am currently riding, or should I try to make use of both chain rings next time I go riding.


If you're not having any shifting problems, there's nothing to really be concerned of. It's just going to add increased wear to your drivetrain. How much is impossible to say and really depends on how much you do it. Most likely it'll be a very negligible amount. 
Also, as you ride more and become stronger, you'll be able to not need your biggest cogs in the rear as much.

I live in a fairly hilly area, and sometimes on short hills I'll stay in the large chainring and use my large cog. It's more convenient and I can accept it if my chain wears out a few hundred miles sooner.


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## D&MsDad (Jul 17, 2007)

I think you're overcomplicating this.

If pedalling is too hard, shift to easier gears in the back. If you run out of easier gears in the back, shift to an easier gear in the front. This will be a big jump, so be prepared to shift to harder gears in the back because pedalling might get too easy.

If pedalling is too easy, shift to harder gears in the back until you run out, then shift to a harder gear in front. This will be a big jump, so be prepared to shift to easier gears in the back because pedalling might get too hard.

Yes, you should probably avoid cross-chaining while grinding away for 20 min. on a climb, but as someone already mentioned occasional cross-chaining will not have much, if any, effect on drivetrain life. This is a finer point, and you should concentrate on this point only AFTER you are thoroughly comfortable with shifting in response to changes in terrain or when you want to change your level of effort.






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## PJ352 (Dec 5, 2007)

Re: GabooN85's post and responses, a couple of thoughts/ experiences...

8,9,10 speed cassettes use thinner cogs spaced closer together, but the cassettes vary in overall width. More info here:
http://sheldonbrown.com/cribsheet-spacing.shtml#overhang
Scroll down to cassette/ freewheel spacing.

And for those interested, some info re: ID/OD of bike chains.
http://en.wikibooks.org/wiki/Bicycles/Maintenance_and_Repair/Chains/Chain_sizes

Re: the cross chaining question, in GabooN85's scenario he's doing so for a short enough period that I see no detrimental effect. I do similar and generally 'cruise' in the 53/19 combo (which is very close in resultant chain line) and run Ultegra chains for up to 4k miles. As always, YMMV, but IMO/E _as long as the drivetrain is cleaned/ lubed_ frequently, there'll be no appreciable premature wear.


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## mallettk (Apr 25, 2012)

Thanks guys for all the help, it all makes sense to me now!!! : )


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## JCavilia (Sep 12, 2005)

GabooN85 said:


> . I will pull away from a stop in the largest cassette in the back and on the large ring up front. Within a few strokes though I'm up to the second, third or fourth cassette in the back.


This kind of jumped out at me, and I have another suggestion you might want to consider. You seem to be trying to shift in such a way that you will stay in your preferred cadence range as much of the time as possible. But that's not always necessary, and sometimes it means a lot of extra shifting. Even if you like to spin, it's okay to turn a much lower cadence briefly, especially when you need a lot of torque, such as when accelerating from a stop. The trick is you do those high-torque low-cadence efforts standing.

If you're finding you have to shift "within a few strokes," maybe you didn't need to downshift in the first place. Try leaving it in the 3d or 4th cog (we call them "cogs" - the "cassette" is the whole cluster of cogs), and just standing up when you leave the stop. In a few turns you'll be up to a speed where you can sit down and spin that gear.

If you're not comfortable pedaling standing, it's a useful skill to work on.


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## Doug B (Sep 11, 2009)

I cross chain a lot. Normally run on my 50t chainring. 8 thousand miles over 3.5 years on my cassette and you can barely notice the wear visually. I just changed the chain this spring. It was about three quarters of a link long. The front chain ring is showing a bit of wear. I have a new one sitting on the work bench but I'm too lazy to change it, as I am not having any shifting problems or skipping or anything wrong.
I wipe the chain about every hundred miles and re-lube then too. Relube if I hear noise too. Mi don't use fancy chain oils. I use marvel mystery oil and Quaker state synthetic oil, one drop on each pin. Remove the chain once a year for a good cleaning with kerosene and soak in oil.


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## Guest (May 16, 2012)

Graphical gear-calculator showing triple-crank, and usable gears
Setup with double crankset for comparison

Try playing around with that applet I showed. You can also see what speed you will end up at for different combinations of gears, and cadence (RPMs at the pedals)

The grayed-out gears on that plot indicate cross-chained combinations that may be a bad idea to use.


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## GabooN85 (Mar 7, 2012)

Thanks everyone. I probably overstated how often I start in the biggest cassette in the rear for simplicities sake. Especially recently, I have been just leaving it on a bit harder gear when hitting stop signs. I do tend to shift down when I stop, not ALWAYS to the furthest left. I just figured if I should be changing up the way I think about it, now was as good a time as any.

I do like to spin up, around 100 or so. That wasn't my intention with shifting down when stopping. It was more just easier to get going with a half spin, clip in (speed play) and then get going. Now I'm used to clipping in (a month or so?) and don't think of it as much.


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## GabooN85 (Mar 7, 2012)

PhotonFreak said:


> Graphical gear-calculator showing triple-crank, and usable gears
> Setup with double crankset for comparison
> 
> Try playing around with that applet I showed. You can also see what speed you will end up at for different combinations of gears, and cadence (RPMs at the pedals)
> ...


Cool link, thanks.


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