Fifty Plus (50+) - Understanding gears

Okay, I have to confess I simply and completely don't understand bicycle gears. I know only enough to shift up or down when the going gets harder or easier. That's it. I also now realize that I rarely shift the left shifter. It's always on the so-called toughest ring. As I write this from my hotel I can't even remember if that's the big ring or the small ring! See? I am clueless!

Can someone explain the numbers to me in such a way that a 12 year old could understand -- or give me a link where there is such an explanation? And -- is there a difference between my basic MTB gearing and a road bike (or hybrid, for that matter) gearing? Of course there must be, but howso?

Now you can see why I didn't go into any profession that involves numbers. My eyes just glaze over.

So -- bicycle gearing for dummies -- anyone care to help me out here?

If it weren't so late Gary we could have a nice confusing crash course, but I'll let one of the East Coast early risers do it. In the meantime, at least let me correct your "My eyes glaze over" to the more correct "My EYE glazes over". GoodNight all!!.

** First you wanted to be a "Fred", now you want to go and be a "Gearhead". Jeez Gary, and I'm just getting used to you being a Pirate. Go to bed so you can be fresh for all the numbers on this thread tomorrow.

:beer:

No numbers, Gary, just some principles. These have come from years of friction shifting with downtube shifters. Indexed shifters make things a little easier (most of the time!)
The front gears (chainwheel or crank) are sort of opposite to the back gears (freewheel), depending on how you look at them. The easier gears to push are the smaller rings on the front (inner ones), bigger ones on the back(inner ones too!).
You want to avoid combinations that make the chain go (looking from a vertical perspective) from inside to outside or visa versa, it puts a lot of side tension on the chain and derailleurs. For example, avoid having the chain on the big ring on the front and the biggest ring on the back. You can usually get the same gearing and be a lot more efficient by using the middle or smaller ring on the front and and intermediate ring on the back.
Shifting the front derailleur is usually more difficult than shifting the back so people tend to use the rear derailleurs more. I tend to stay in the biggest front ring on my road bike unless I'm getting into a lot of uphills, and on my mountain bike I usually keep it in the middle ring when I'm on the trails.
Another principle is down shift before you absolutely have to - It keeps you spinning better and puts a lot less strain on the shifting system

Hope this helps!!

Greg

The best advice or gearo-phobes is to leave the chain in the middle ring up front. That will give you adaquate range usng the rear cogs and avoid the issue of cross chaining.

When you feel ready to advance (or your hills get too steel), flip to the small chainring (uphill) or big ring (downhill).
You will find a lot of overlap between the 3 gear ranges. In practice, the 2 outer rings are only used with a few of the rear cogs. You generally get a better chainline using the duplicate gear on the middle ring.

Lots more info here (http://sheldonbrown.com/beginners/index.html)

Gary - knock yourself out..
http://www.panix.com/~jbarrm/cycal/cycal.30f.html

I was going to pose this question but since DG asked. I'll try it here, I just don't know if we'll get good answers in this subforum.

I understand Gear Inches. Gary just think of them as a way of measuring both how far you will travel each revolution of your cranks and what speed you'll be traveling. Lower numbers mean you are going slower but it takes less effort to keep going. Higher numbers mean you are going faster and it takes more power. So if you're finding your cadence/revolution speed is dropping and you have to push too hard, then it's time to switch to a lower numbered GI gear. When you're helicoptering and legs are going too fast with little resistance, it's time to switch to a higher numbered gear.

The other variable is the % change when you switch gears. The panic site is super for showing the % changes between gears. Changes under 4% are usually not a big enough change. Changes over 13% are usually too big [ unless at the very bottom of the scale. ]. Gear inches of 20 or 22 are considered ideal by loaded touring riders. Lower than that is not useful. Gear inches higher than 110 are of limited value as usely only need them on downhills.

Ok, all that is preliminary. I really don't understand torque. I've noticed that 2 similar GI results will feel much different. I can take a middle front chainring and and a the lowest rear cog and go up hills at about 10 mph. But when that gets too hard and I switch to the lower front chain ring to get up a steeper section, or just give out, then my speed will drop to 8 or 9, if that, mph. When the hill's slope eases up, I expected to find I could stay in the low front gear ring and shift up the rear cassette to higher gears so I could go faster. But for some reason it doesn't work. The gear inches of low chainring and middle chainring will be similiar, but I can't go as fast up hills with the low chainring. It is only after I switch back to the middle ring, that I recover my speeds.

Long post, but there is more to understanding gears than gear inches. I don't know what else there is. I suspect it's a physics torque issue, but this is just a guess.

Consider the imaginary plane down the center of the bike. No matter which you're talking about - chainring or cassette gear, further away from the plane equals a higher gear.

If you want to know the math, it's (C*W)/F, where C is Chainring Teeth, W is the actual wheel diameter, and F is the freehub cassette teeth. From the formula, you can see that a bigger wheel or a bigger chainring will give you a bigger number result, which equals a higher gear. So if you want to go fast down a big hill, simply use a bigger wheel! ;) As a learning aid, you can make a chart showing the gear-inches for each gear combination you have, and tape it to your top tube.

Small ring up front, big cassette in back = go up hills easily

Big ring up front, small cassette in back = go fast on level ground!

Mtn bikes have gears arranged for steep, slow hills, road bikes for faster riding. They are different.

with a 28'' wheel racing bike and a frequence 60:

If you have 42 / 26 , it means 12.8 km/h
If you have 45 / 15 , it means 24.1 km/h
If you have 52 / 14 , it means 29.9 km/h



with a 26'' wheel Mountainbike and a frequence 60:

If you have 42 / 26 , it means 11.9 km/h
If you have 45 / 15 , it means 22.0 km/h
If you have 52 / 14 , it means 27.8 km/h


1 km/h = 0.55 mph


(I think I calculated right, but excuse any faults :p )
marmotte

Wow! You sure got a lot of meat to chew on there, Gary. Excellent answers from our little community. Now my .02. One thing I've noticed, and learned the hard way when it comes to shifiting; It's best to shift the chain ring before you run out of rear cog. In other words, if you are climbing and you need to downshift numerous times, when you are 2 or 3 gears out from your largest cog and you know you'll need to continue to downshift, now shift to a smaller chain ring, don't wait until you've arrived at the largest cog. As you guys probably know, my stoker/wife and I ride a tandem a lot. It can be easier to throw a chain on a tandem because the frame can flex more. I've found that if I shift my chain ring one or two cogs "early," I never have a problem throwing my chain. Doing this also puts less cross pressure on the chain which is a good thing. I hope I've made myself clear on this... OHB

It may be a bit misleading to quote a speed for a certain gear. Note that in the above example pedalling cadence is constant .
In real world cycling, the constant is your power output. You may be able to sprint a little but basically, your sustainable power output is fixed.
For cruising, your cadence should be fairly rapid (>80rpm) and your pedalling force quite low. Sprints and climbs require higher force.
Gearing matches your power, your desired pedalling cadence and the various drag forces on the bike. Any speed is a resultant outcome. If you are riding into a headwind you dont go as fast.

More than you EVER wanted to know about gears, gearing and why.

Ken Kifer's Bicycle Pages.

The late Ken Kifer was run over by a car. These pages were written by him before the fatal accident and are retained in his memory. Ken was a good friend to all cyclists and he is now going over the top of the worst climbs in the big ring.


http://www.kenkifer.com/bikepages/touring/gears.htm

Gary, now I'm all rested and the others have done the details. So much for the cognitive.....now go for the tactile sense of what gears mean and do. Do some shifting on your rides-- change chain rings, go up and down the cogs, drop it into a small cog and come off your saddle for a few yards. Your legs will teach you about gears. Hills would be good to demonstrate their usefulness, but short little sprints in higher (smaller cog & bigger chainring) gears will help. So will hummingbird spinning in low gears. (Strange how those silly, easy, go-nowhere gears become serious, even not-so-easy on climbs. Try a "harder" gear with the wind behind you. Before your memorized gear chart really seems understandable, your legs will tell you which cogs mean what level of effort. Most riders have a "home cog" on the flats with no wind, then one with wind, and so on. My flat, not much wind cruiser is in the low/mid 70's. My first few miles "warm up/cool down" gear in the upper 50's, and so on.

Maybe a tactile, personal knowledge of gears should precede just the sterile numbers...later they'll really mean something.

LOL, then you can start fooling with gear charts, pondering compact vs. triple, which cassette, which chainrings should you upgrade to, learn to resent redundancy, etc.

GrannyGear, Awesome post! Experiential learning! Let your body (legs mostly I guess) tell you what gears to be in. That can change as well as some days the legs are jelly-like, some few days like steel, and most days somewhere in between.

madli (hopefully not grinding the gears mentally and otherwise!)

Gary,

Here's a real nice gear calculator program that you can download for free.

http://www.kinetics-online.co.uk/K_Gear.exe

Once you know the gear inches for a particular gear on your bike, just take that times 3.141 (pi) and you will then know how far your bike will travel for one revolution of your pedals.

Less distance per turn of the pedals is easier and slower.

More distance per turn of the pedals is harder and faster.

Rik

If you're serious about learning gears get a bike computer with a cadence meter (like a Cateye Astrale). Ride in gears that allow you to maintain a cadence of 80 to 100 rpm, and don't cross-chain. Good advice above about riding on the middle chainring until you have a better idea what you are doing.

Gearing on a bicycle is like gearing in your car, whether manual or automatic. A car's engine has an rpm range where it runs smoother and developes more power. Your body is the engine for your bike.

Al

with a 28'' wheel racing bike and a frequence 60:

If you have 42 / 26 , it means 12.8 km/h
If you have 45 / 15 , it means 24.1 km/h
If you have 52 / 14 , it means 29.9 km/h



with a 26'' wheel Mountainbike and a frequence 60:

If you have 42 / 26 , it means 11.9 km/h
If you have 45 / 15 , it means 22.0 km/h
If you have 52 / 14 , it means 27.8 km/h


1 km/h = 0.55 mph


(I think I calculated right, but excuse any faults :p )

marmotte

You scare me. According to your calculations I have just worn out my knee joints on a 26" wheel, 48/11 gearing and 44mph. No wonder it hurt.

Never bothered about the technicalities of gearing- but only one gear to be in- the one you are comfortable with and DON'T CROSSCHAIN.

GrannyGear, Awesome post! Experiential learning! Let your body (legs mostly I guess) tell you what gears to be in. That can change as well as some days the legs are jelly-like, some few days like steel, and most days somewhere in between.

madli (hopefully not grinding the gears mentally and otherwise!)


Agree with madli, great post GrannyGear. Keeping in mind that when I first started riding you could only get a five cog cluster in the rear. Then it was 6, then 7...8...9, and now (big drum roll)...10. I gave up trying to keep gear numbers in my head and just let my legs (and lungs) tell me when to shift. Before I'd get involved in endless discussion about duplicate gears and how to avoid them, if half-step plus granny was the way to go on a fully loaded tour, what my high gear in inches was and how fast I'd be going when I reached the spin limit with it. Not any more. I let my legs tell me what I need to know. If you get all of your gear numbers down for your current rig, you'll just have to do it again with the next one. Having said all of that, I know some folks have a greater ability to jump into and enjoy the details of this kind of thing. I say knock yourself out!

More than you EVER wanted to know about gears, gearing and why.

Ken Kifer's Bicycle Pages.

The late Ken Kifer was run over by a car. These pages were written by him before the fatal accident and are retained in his memory. Ken was a good friend to all cyclists and he is now going over the top of the worst climbs in the big ring.


http://www.kenkifer.com/bikepages/touring/gears.htm


Sorry to hear that, he was a good positive force for promoting cycling.

Being an engineer I just can't help but salivate with this kind of topic. It's some of the "technical" aspects of cycling that I've come to enjoy. I just love those formulas and numbers and equations.....

Here's the cliffs notes version that might be of help. The "numbers" on the gears or cogs are the number of teeth that a gear has on it. A typical set-up on a triple road bike these days is 3 chain rings on the front with the gears being a 52-42-30. The 52 being the largest chain ring. A typical set-up on a double road bike is a 53-39. A more recent addition to these two set-ups that is increasing in favor is a 50-34 double.

When the chain is in the largest gear in the front chain rings, it is hardest to pedal.

The rear gears are assembled together and called a cassette. Older bikes might only have 3-5 gears in the rear cassette. The newest arrangement is 10 speeds or gears in the rear cassette. Probably the most common rear gearing on road bikes today is either 8 or 9 speeds because 10 speeds have only been around 1-2 two years.


I know this is going to blow your mind but converse to the front chain ring, when the chain is in the largest gear in the rear cassette next to the spokes, that is the easiest gear to pedal. As you change gears from there, the chain will move outward and those gears get harder to pedal.

Thus if you have a double front chain ring and a 10 speed rear cassette-you have a total of 20 different gears.

I'm playing with my gears (both my front chainring and rear cassette) to try and optimize my gears. The advantage of a triple is that it provides a wide range of gears. The disadvantage is that there is some "duplication" (or at least close to it) where you don't really need or probably use all 30 gears. If you calculate the "gear inches" you can see where the crossover is between the chain rings.


With the terrain I ride I need both the high end gears (combinations hardest to pedal) and the very lowest gears (easiest to pedal), if that makes sense. Where I'm probably headed is towards a compact crank on the front chain ring and will probably go with a 50-34. I'll probably put a mountain bike rear derailleur and rear cassette gearing on it so I'll have some even easier gears for the mountain climbs. By doing that I'll lose a little on the high end but gain a little easier gear on the lower end and optimize the number of overall gears I have. That's not a combination that works for everyone but I think it will best suit my needs.

I hope this has not been too tough a subject for you especially since you're saddled with mono vision......I do hope you're feeling better.

To really 'get' bike gearing, you have to come to a Zen awareness of the various ratios that are on YOUR bike. After many hours of deep meditation you will come to; Shift up when the pedaling gets too hard and shift down when it gets too easy. Then you will have it. Intellectual, engineering or mathematical understanding is an illusion born of overeducation and ego worship. Once you have the zen aspect down, all you have to do is ask your legs. They will 'know'. bk

I find the different approaches to "understanding gears" to be fascinating.

It reflects the varied personalities (somatypes?) of the folks here who ride bicycles, from the highly technical, engineering-type explanations of gear inches to the "If you want to pedal easier, shift small front and big back" to "listen to your legs" and the "Meditate yourself into gear shifting nirvana" to "All I care about is keeping a constant cadence!"

I'm not sure what DG is/was looking for, but he sure got a variety of answers! :D

Being an engineer I just can't help but salivate with this kind of topic. It's some of the "technical" aspects of cycling that I've come to enjoy. I just love those formulas and numbers and equations.....

I am an engineer too Gary but I take an entirely different approach. There are automatic shifts for bicycles out there. Get one and stop worrying.

I find the different approaches to "understanding gears" to be fascinating.

It reflects the varied personalities (somatypes?) of the folks here who ride bicycles, from the highly technical, engineering-type explanations of gear inches to the "If you want to pedal easier, shift small front and big back" to "listen to your legs" and the "Meditate yourself into gear shifting nirvana" to "All I care about is keeping a constant cadence!"

I'm not sure what DG is/was looking for, but he sure got a variety of answers! :D

Well, I just had the chance to read most of the responses to my initial question. I'm not sure I put it right, although all of these responses are appreciated. Some of them kind of got to what I was looking for, while others are just darn good advice.

I know to shift up or down when it's getting harder or easier. What I didn't understand was what the numbers mean, and how a mountain bike is configured differently from a road bike, for example. Does the MTB have lower gears overall, and the road bike have higher gears (for more speed)? I'm still not sure I understand that.

Secondly, I'm wondering if someone will comment on this: I hardly ever ever shift my front gears. I'm always on the fastest one, not the granny gear except in very rare instances on hills. On the back, I tend to ride on 6, 7, or 8 almost all the time, occasionally shifting down to 2-3 on hills. What does this mean, in terms of my fitness? Am I sort of outgrowing this bike's gearing? Should I switch to the middle gear up front for most of my rides? That's how I started nine months ago,but then I discovered I could go faster with the higher gear, and it quickly became the only one (in front) that I use.

What difference would I detect (if any) when i switch to a road bike? Even higher gears? Perhaps higher AND lower gears (and the MTB is somewhere in themiddle?)

Anyway, that's what I'm wondering and I'll also check out all those links. I want to get my brain around this one of these days!~

PS: My eye is healing pretty well. Still a bit sensitive to light, but not red anymore. I should be putting the contacts back in by Saturday. Thanks for the concern!

Does the MTB have lower gears overall, and the road bike have higher gears (for more speed)? I'm still not sure I understand that.

Yes. The mountain bike will have a lower "top speed" than a roadie, and will take you up steep climbs that you would fail on a roadie.

When I ride my mtn bike, I am almost always in the middle chain ring of my triple, and vary through all the cogs of my cassette. When I am descending, I shift to the large CR in front, and pedal like crazy to get going faster. Going up a very steep incline, I use the small CR in front.

I don't think it means anything regarding your fitness. You can get the same gear inches from the large CR as you can get from a middle chain ring. It just depends on the cog you choose in the rear. My LBS tells me he can tell I always ride in the middle CR on all of my bikes, roadie or mtn, by examining the wear on my CR's.

No, you are not outgrowing the gearing, unless your cadence is high - likely you just need to pedal faster.

Changing to a road bike. Because of the differences in construction and weight, the RB will feel more responsive. You will generally go faster for the same speed of pedaling.

I am glad your eye is getting better. Hope it heals all the way promptly!

I'd say yes you have outgrown your gears. Your lbs should be able to set you up with larger chainrings. Do not worry about the numbers, just take the bike in and show the mechanic the gear combination(s) your normally use. Road bikes tend to have higher gears because most roads are not as steep as some trails. Touring and mtn bikes would have lower gears, even a small third front chainring, to permit heavier loads, softer surfaces, and steeper hills.

Can someone explain the numbers to me in such a way that a 12 year old could understand

Having taught 12 year olds for many years maybe I can offer this: As the chain moves farther from the bike (on to the bigger chainrings on the front or the smaller cogs on the back)the pedaling becomes harder and the speed increases (assuming you keep pedalling at the same rate - cadence) So ......

HARD OUT.......... EASY IN

Try your best to spin the cranks at about the same rate all the time. Count it or get a cadence computer - SOMEWHERE in the 65 - 75 strokes per minute works for me when touring.
It has always been explained to me that the "numbers" when referring to gear inches are what the diameter (or circumference or radius or well .... something!) of the front wheel of the old "Penny Farthing" was - you know, that one with the huge front wheel and the tiny back one. Seems they bore the same relationship to the size of the English penny and farthing. Lots of good advice about "feel". Depends on age, muscles, pain threshold, the old knees, and rhythm. Just be careful not to spin too slowly - wrecks the knees quickly.

Gary,

Try this web page: http://sheldonbrown.com/gears/

Plug in your wheel size and cadence information, add the various front chain ring teeth and the assorted gear sizes and check out the results.

I think it will be almost self-explanitory at that point. At least it was for a hillbilly, like me.

Glad to hear you are feeling better.
Bink

[QUOTE=Digital Gee]
Secondly, I'm wondering if someone will comment on this: I hardly ever ever shift my front gears. I'm always on the fastest one, not the granny gear except in very rare instances on hills. On the back, I tend to ride on 6, 7, or 8 almost all the time, occasionally shifting down to 2-3 on hills. What does this mean, in terms of my fitness? Am I sort of outgrowing this bike's gearing? Should I switch to the middle gear up front for most of my rides? That's how I started nine months ago,but then I discovered I could go faster with the higher gear, and it quickly became the only one (in front) that I use.

What difference would I detect (if any) when i switch to a road bike? Even higher gears? Perhaps higher AND lower gears (and the MTB is somewhere in themiddle?)
QUOTE]

Mountain Bikes are generally geared differently than Road Bikes. In general, Mountain Bikes are geared more for climbing and rougher terrain and road bikes are designed more around speed. The largest gear on the front on the a mountain bike is a little smaller than the largest chain ring on a road bike.

If you're able to climb hills and stay in your largest chainring in the front and from the amount of time it sounds like you're in it my guess is it's probably a little smaller than the typical large chainring on a road bike. In general, the easiest gears on a mountain bike are a little easier than the easiest on a road bike. That is why I mentioned I was probably going to reconfigure the gearing on my road bike and put some mountain bike rear gear equipment on it to come up with even easier gears for some of the road climbs.

If you get a road bike, I'd be really surprised if you do a lot of climbing in the large chainring. If you get a triple I suspect you'd do most of the climbing in either the middle or the small chainring.
If you're climbing in the large chain ring now you're doing pretty darn good and must certainly be getting the legs in better shape.

I rarely/hardly ever ride in "1 or 2" when in the big chainring. I'll always shift to the middle chainring and then be in 3-4-5 in the middle chainring. This is easier on the legs, knees and less strain overall as it's probably a little higher cadence.

When you switch to a road bike your top end speed should be higher because of the gears and aerodynamics. I think you've overall average speed will go up around 10 per cent based on my personal experience making the same change. While you will have the same gearing for the hills on a road bike as a mountain bike, I think you will climb a little faster because the road bike should be lighter.

Well, I just had the chance to read most of the responses to my initial question.

Gary, you may have to take many reading settings until you eye heals. You need to spend some time on the links already given.

#1 Read at least 3 times, http://www.kenkifer.com/bikepages/touring/gears.htm

#2 After that, then this link will be your new found joy http://www.panix.com/~jbarrm/cycal/cycal.30f.html
as it is one of the few sites that will help you determine what both how many real gear you have and how well they will work for you.

I'll give you some examples, but you've got to work with me, ok.
We'll start looking at the cassettes and then going to the typical bikes. It gets too confusing if you jump directly to X-speed bikes.


Cassettes range from a "far range" mtn cassette to a "close range" road cassette. Let's look at 3 of them.
Mtn cassette
Go to panic site, use 30 for chainring teeth. Remember we're skipping the other front chainrings.
Use 11-12-14-16-18-21-28-32 for a 9speed 11:32 cassettes
Enter 27 inches for wheel size, click on button. Print out page.

Moderate cassette
Use 12-13-14-15-17-19-21-24-27 for 9speed 12:27 cassette. Use 26 for front chainring.
Click on button and print out page.

Road Racing cassette
Use 11-12-13-14-15-17-19-21-23 for 9speed 11:23 cassette. Use 39 for front chainring.
Click on button and print out page.

Got the 3 pages in front of you. Ok, let's discuss them.
Mtn cassette, 11-32 and 30. Look at column 3 and column 4.
Range is wide 25 inches to 74 inches, [49 inch difference] but the price of getting that wide range of speeds without shifting is seen in column 4. Look at the percentage change with gear changes: 13%, 14% and 17%. The only reason I know this is important is I used to deliver papers on an old Schwinn Varsity for 4 years. I hated sifting between the 3rd fastest gear and the 2nd fastest gear because shifting both hurt my thighs too much and make me lose sooo much speed because I had to push too hard. Last year I looked up the specs on the old schwinn and it had GI % change of 17% at that change. So I vowed, never again or I'll give up biking.

Moderate cassette, 12-27.
Range is moderate 26 inches to 58 inches, [32 inch difference]. So you lose 14 inches of range where you are going to have to shift the front gears to get a different speed. But look at col 4. Instead of 7 double digit changes, there are only 5 and the changes dropped from 17% to 14% for the worst. So you lose ability to go more speeds on the cassettes, but you gain the ability to shift gears more easily without changing your cadence as much.

Race cassette, 11-23
Range is narrow, 45 inches to 95 inches [50 inch difference].
Look where the low starts, at 46 inches. You'ld better have a lot of muscles for hill climbing at that moderate gear. Why do they do it? They have the muscles and are more interested in column 4. Only 3 changes are double digit, and those are the lower ones that don't matter as much. Their worst change is a nice 13% change. They can keep their spinning about the same speed as they change gears to handle changes in elevation.

Ok, still there, or do you need an eye drop refresh? I know it's hard to read a lot but almost finished.

Now let's talk about some typical bikes:
Mtn bike, Trek 4500. Cassette 11-32 [11.12.14.16.18.21.24.28.32 if you want to run the numbers ]
But look at chainrings: 24.34.42 Not just mtn bikers use this but this is also considered ideal by touring bikers who carry some loads.
Range: 20 inches to 103 inches. 3 double digit gear changes. 6 junk gears where they are duplicates. 2 of high % changes are in the granny range and don't matter as much. But the shift from 3rd highest to 2nd highest is a rough 13%.

2004 Giant OCR, Cassette the same, but average chainrings: 30.42.52. Since using the same cassette, the changes between gears is the same. The trade off is you lose 2 low end gears for steep hills and gain 2 high end gears for downhills.

Trek Madone/equidox etc. Cassette 11-23 [11.12.13.14.15.17.19.21.23 to run the numbers]
Range: 46 to 130 inches. This is the double most racers use and they mock us mere mortals who use gears so we can keep on riding. So they throw away 12 lower gears of the mountain bike. They add 3 higher gears and the ability to keep shifts smoother.

Now if anyone is still awake and still able to read, if someone could return the favor and explain a part of gearing I don't understand.
I have a 26.42.54 triple and 12-27 cassette. Print out the numbers. Gear inches of 54.00 is returned for both gears #10 and gears #11. But in riding, when I switch from the middle ring 42 to the low ring 26 and have the same gear inches by changing the rear cassette at the same time., I lose between 1 and 1.5 mph at the same cadence. Huh??????

Did this help at all, or was it too complicated?

You guys are amazing. I'm really blown away at the generosity of everyone who's taken the time to 'splain all this. HiYo, that was incredible. I don't want to forget to mention anyone, so please -- know that I appreciate ALL the responses!

I'm not sure I fully understand, BUT I see some light at the end of the tunnel. You know how sometimes things have to kind of go round in circles in your head, and then all of the sudden, a light goes on, and you realize it's the fridge, because you went downstairs for a snack?

Wait...that's not it at all.

What I'm trying to say is it's starting to make sense. I must re-read all this a few times, but then I think I'll get it.

I don't know how to thank you all enough! :)

You're welcome. It took me months and months to reach some understanding.

You scare me. According to your calculations I have just worn out my knee joints on a 26" wheel, 48/11 gearing and 44mph. No wonder it hurt.

Never bothered about the technicalities of gearing- but only one gear to be in- the one you are comfortable with and DON'T CROSSCHAIN.

I made a mistake: 1 american mile is 1.6 km, thus 1 km/h is 0.625 mph. Therefore 26'' with cadence 60 and 48/11 gearing is about 32 km/h or 20 mph

What's interesting about the panic site, is you can set wheel sizes, results in english or metric values and after get to page I was talking about above, there is another button that will show you the speed in mph/kph at different cadences in each gear.

I made a mistake: 1 american mile is 1.6 km, thus 1 km/h is 0.625 mph. Therefore 26'' with cadence 60 and 48/11 gearing is about 32 km/h or 20 mph


Thats pleased me a bit, but still puts me at 125 cadence at 44mph. and I reckon that must be about my limit when still pulling hard on the flat.
That is another point with regard to gearing. Your cadence is governed by what you are used to. When I first started biking- I had relatively high gearing for offroad and this meant that My cadence was also low.Probably built up muscle but I did suffer the day after with quad muscles that ached. Now have a lower gearing and cadence is pretty high. Normally around the 90 mark and once we get into the rhythm of riding it is probably up around 100. Rarely find a muscle ache, but occasionally run out of lungs uphill. If I ever have to sit in and grind up the long hills with a cadence of less than 70- then I start to feel those quad's again. Suppose it is what you get used to, but whatever gearing is set on the bike- that is what you get used to.

Incidentally- although we have lower gearing than the road bikes- we rarely use the highest gear of 48/11- even on the road.And we don't often reach 44mph either. What we have found though is that we can stay with the good club riders on the flat- we lose them on the downhills but stop pedalling at 35mph. We do lose out on the uphills, untill it gets severe, but that is because some of the road bikes do not have a low enough gear for those steep hills, and the age/strength of their legs.

Gearing has universal truths for those with memories. When I was a kid with my balloon Schwinn I had one trusty gear (with free coasting option) for hills and flats and everything. When a young friend came to possess a hand-me-down "English bike" with a 3 speed gizmo trigger thing on the bars I was confounded with the infinite possibilities of this new-to-me technology. In later life when I rediscovered biking on a shiny new sure enough "chromoly main frame" Univega with, gulp!, 5 speeds, I was ready for the Alps. Bring 'em on. I soon discovered something called an Ultra-spaced freewheel-- and now I had the ultimate 6 speeds...how could I use or remember them all?! Soon enough there was an incredible Dura Ace gruppo with an outrageous 7 speeds being touted in "Bicycling" mag..............and so on you guess the rest.

Flash to last summer. (btw, I was then at 9 speeds.) Stopped at a rest stop on an organized ride, started talking to a lean and mean 60'ish guy riding an immaculate Rivendell custom fixie. Just finished a rolling, hilly 60 miles on his one-gear and had to getmoving so he wouldn't miss dinner. He said he'd just thrown in the towel on multi-speeds and was having a ball.

Sometimes I long for my old Schwinn (maybe not at the foot our local 3 mile grade)....start the whole evolutionary gearing thing all over again....fit myself to the terrain rather than the reverse. But most of the time, I'm looking at a 10 speed upgrade. :rolleyes:

I would say most road riding (on "road" geared bikes) is done in the largest chain ring (front gears are called chain rings) till you get to a good incline then you might shift to the middle or (for really big hills) the small chain ring. So if you spend most of your time on the big chain ring, that is normal.
Most shifting is done on the gears (also called: sprockets) they are in the rear.
Bigger chain rings and smaller gears make the bike go faster for equal revoloutions of the pedals.
MBT bikes have small chain rings and bigger gears because that gives you more torque for terain that is harder to pedal over. MBT bikes also have smaller dia. wheels (but that will just confuse you).
Put tape over the numbers on your shifters, thinking about those numbers is pointless, as someone else suggested "feel" it, don't "think" it.

I still have indexed thumb shifters on my MTB (only hit dirt occasionally), and when I'm on the trail I'm slamming gears so often, watching for obstructions and thinking "Whoa, sh*t!" that I seldom know which cog I'm in...strictly seat of pants, couldn't care less, and feeling purely like a kid. On the road, my usual venue, I can tell by the position of the dt or bar-end lever where I'm at and I think of gears as my "trusty 74", "bail-out 42", "beat that Rottweiller 94". Knowing the gear inches is a universal way of communicating with other riders and, ultimately, a way of labeling your own effort vs. conditions........as in "feeling good so I went up Cemetary Hill in my 55". Keeping in mind, my cruising 74 is somebody else's warm-up gear. Gears are still relative to our own, unique effort/fitness levels.

I think I'm the one who started the "feel" consideration of gears and I meant it. As riding experience grows however, its good to have a reference for chainring/cog combinations...and gear inches seem a useful way.

So let me ask a simple question, even though I thought i understood, obviously it's still kind of like my high school physics class -- it makes sense until i try to 'splain it to someone else.

My bike has 42/34/24 chainrings, and 11-32 in the rear. If I moved to a bike that was 54-42-30 in the front, same in the rear, same tire size, etc. would the new bike be:

A. Faster
B: Easier to climb hills
C: Both
D: Neither

A. Faster
B: Easier to climb hills
C: Both
D: Neither

A yes B no

So let me ask a simple question, even though I thought i understood, obviously it's still kind of like my high school physics class -- it makes sense until i try to 'splain it to someone else.

My bike has 42/34/24 chainrings, and 11-32 in the rear. If I moved to a bike that was 54-42-30 in the front, same in the rear, same tire size, etc. would the new bike be:

A. Faster
B: Easier to climb hills
C: Both
D: Neither

A. Your "top end" speed should be higher because you have "harder gears" you can use when you're moving faster (greater than 25 mph). I have not run the numbers on cadence but I doubt you can spin a 42/11 fast enough to go faster than you could with a little harder gear in the 52. BTW-the most common Triple setup is 52-42-30 on road bikes.
B. No (assuming the new bike was the same weight) -the 24 (granny) on the existing bike is much easier to spin than the 30. Having said that, I think you can manage most hills using the 30 in the front and a 32 in the rear. If you can reduce overall weight both with the bike and person you'll see noticeable difference and can easily manage the 30/32.

What you can do is to ride some hills in the middle chain ring (34) and see if you can easily manage hills in the gear next to the 34 in the rear (next to the easiest). This will give you a close approximation of what riding in the 30 on a new bike would be like.

Hope this helps!

It would be a big mistake to change the gearing on your bike without knowing your cadence. If you are riding mostly on the big ring it may simply mean that your cadence isn't high enough. A higher cadence is better for the "engine", especially the heart, lungs, and joints.
For mechanical reasons it's probably impractical, maybe impossible, to change your chainrings to 52-42-30. And that would be a huge change from what you now have. You probably could replace your 42 big ring with a 44 or 46 but if you go much larger you'll need a different front derailleur. Going from a 42 to a 46 would be a big change. If your goal is to go faster maybe you should consider a road bike already setup with your gears of choice.
BTW, the standard triple chainring set is gradually becoming 52-39-30, that's what the Shimano 10-speeds have.

Al

I'm a little late posting to this topic, but would like to share my setup and make a couple of comments. I know this thread is about gears, but another issue that needs to be considered is also the length of the crank. I have two bikes, a '73 Schwinn LeTour and a new Cannondale Cyclocross ('05 model). I had taken the Schwinn to my LBS a couple years ago. He rigged me up with a very large big chain ring (53) and an 11 small cog on the rear cassette.

The Schwinn has 27 inch tires, and, in combination with the large chain ring and small cog, it was one fast bike on level ground and especially on downhills. It was almost impossible to spin out. I also had it fitted with longer than normal crank arms.

For me, this combination proved most comfortable. I find that long crank arms are more comfortabel for me on uphill climbs. My mind tells me that this probably should not be so, but, in practice, my legs tend to fatigue less when I can push them through a larger circle on uphill climbs.

When I purchased the Cannondale, I asked them to duplicate the Schwinn setup which they did, but, for some reason, the bike just didn't seem as fast. It wouldn't coast as fast as the Schwinn, would spin out on downhills as my son leisurely pedaled past me on the Schwinn, and uphills were a struggle.

I recently took the bike to my favoriate LBS mechanic, and he fitted it with some extra long crank arms from a French company called TA Specialties along with one of their front chain ring setups. The new setup is as follows: Front - 63-51 and rear 34-11. For me personally, this setup is extremely comfortable. I was worried that having a 51 as the small front chain ring would make climbing hills impossible. But I have found that this is more than offset by the longer crank arms. Climbing hills is almost effortless. I suppose this is a personal thing, but, chugging around with those short crank arms would make hill climbing tedious for me, and having to coast or turn the pedals with no resistance during downhills seemed like a waste.

Now, there is no hill in my area that I can descend where I spin out. I've had this combination up to 50 MPH and can comfortably maintain my rhythm the whole way.

Also, while this is a bit off topic, the bearings in the new set up are independent on each side of the bottom bracket. The stock setup used a sort of cartridge that held the bearings. There's nothing wrong with that per se, but those bearings from day one did not turn as smoothly as either my Schwinn or the new TA setup (this mechanic has done extensive work to the cranks, bearings, and wheels on my Schwinn, also.

This was a good thread - very informative. I still haven't grasped all of the detail here - I'm one of those who pays attention to the terrain and makes anticipatory shifts to keep it feeling right. I also vary my approach during a ride. Sometimes, I'll stay on the large chainring during an uphill, slide back a bit on the saddle, let the arches of my feet ride the pedals, and concentrate on keeping a slow steady cadence that stretches my leg at the bottom of the travel. At other times, I'll approach a similar climb by shifting to a lower combination, keeping the balls of my feet on the pedals while spinning at a faster rate and involving more of my calf muscles (you've probably guessed that I don't use clips or clipless or whatever you call them). Both my bikes are fitted with high quality mountain bike pedals, and I ride in either tennis shoes or boat shoes. Back in the '70's, I used to have toe clips that were installed on the stock Schwinn pedals. I found those saw-toothed pedals uncomfortable back then, and, now, in my more mature years, refuse to be anything but comfortable on my bike.

Hope I haven't rambled on too much - but wanted to make the point about crank length because, from experience, I can say that it is also an important consideration.

(edit) I should also mention that one has to be careful with long crank arms. I learned early on to coast through corners - or the pedals will scrape the ground - could cause a nasty spill - so far for me, so good.

Caruso