# Touring - Does gear ratio really matter?

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View Full Version : Does gear ratio really matter?

cooleric1234
04-06-07, 11:27 AM
I apologize if this has been discussed, but hopefully I can add some insight. I'm looking at buying a touring bike, and I've been investigating all the usual suspects in the price range (Fuji Touring, Jamis Aurora, Trek 520, Cannondale T800, Bianchi Volpe). I keep hearing how most touring bikes don't have low enough gearing, so I thought I'd investigate. Let's take two examples. The Cannondale T800 seems to have the lowest gearing, with a ratio of 26 in the front to 34 in the back. The Jamis Aurora has a ratio of 30/32. Now, this is the calculation for speed:

Speed = Gear Ratio * Cadence [rpm] * Wheel Circumference [in] * Conversion of inches/min to mph

Assuming a cadence of 80 (I'm a beginner, not sure what my cadence is but it's probably not the oft quoted 90) this gives bottom speeds of 4.8 mph for the Cannondale and 5.9 mph for the Jamis. Now, I know this is for the case when climbing a hill with a load, but does the 1 mph make that much of a difference? I have panniers on my hybrid bike now and when climbing a hill I can't travel in a straight line going that slow (I'm sure the longer wheel base of a touring bike would help though). Is this an overstated problem? Does it really not matter that much as long as the ratios are within about 20% of each other? Any input would be appreciated.

By the way, I know that I can ask them to swap out the crankset when buying the bike, I'm trying to minimize costs. Also, sorry if some of my terminology is wrong, I'm still learning.

nun
04-06-07, 12:30 PM
I think a good rule of thumb is to have a top gear around 100" and a bottom gear of 20".
Most of the time you're going to be in the 60" to 80" range so get your best chainline
set for where you ride most often. you might look at a combo like 48-36-24 with a
12-34 cassette.

cyccommute
04-06-07, 01:04 PM
I apologize if this has been discussed, but hopefully I can add some insight. I'm looking at buying a touring bike, and I've been investigating all the usual suspects in the price range (Fuji Touring, Jamis Aurora, Trek 520, Cannondale T800, Bianchi Volpe). I keep hearing how most touring bikes don't have low enough gearing, so I thought I'd investigate. Let's take two examples. The Cannondale T800 seems to have the lowest gearing, with a ratio of 26 in the front to 34 in the back. The Jamis Aurora has a ratio of 30/32. Now, this is the calculation for speed:

Speed = Gear Ratio * Cadence [rpm] * Wheel Circumference [in] * Conversion of inches/min to mph

Assuming a cadence of 80 (I'm a beginner, not sure what my cadence is but it's probably not the oft quoted 90) this gives bottom speeds of 4.8 mph for the Cannondale and 5.9 mph for the Jamis. Now, I know this is for the case when climbing a hill with a load, but does the 1 mph make that much of a difference? I have panniers on my hybrid bike now and when climbing a hill I can't travel in a straight line going that slow (I'm sure the longer wheel base of a touring bike would help though). Is this an overstated problem? Does it really not matter that much as long as the ratios are within about 20% of each other? Any input would be appreciated.

By the way, I know that I can ask them to swap out the crankset when buying the bike, I'm trying to minimize costs. Also, sorry if some of my terminology is wrong, I'm still learning.

You are only thinking in terms of speed but that's not the primary usage of gears on the bike. It's more about power than about speed. Here's (http://users.frii.com/katana/biketext.html) a pretty good dissertation on the subject.

The upshot is that lower gears allow you to put more power into the cranks at a lower speed than higher gears. When you are trying to lift 300+ lbs up a hill, the more power you can put into the crank the better. Too high a gear and too tall a hill and you are going to be pushing the bike rather then pedaling. Trust me, pedaling - even at walking speed - beats the heck out of walking:)

Riding in a straight line at incredibly slow speeds isn't really that hard and is simply a matter of training. I regularly ride mountain bikes and loaded touring bikes at less than 4 mph...sometimes for longer than I should.

Lolly Pop
04-06-07, 01:07 PM
I don't think the speed perspective is a good one. I think gear inches is better. I agree with nun -- around 20" is good. I had 26 x 28 and switched to 22 x 34 and it made a huge improvement in my comfort on hills. I would say get as low a gear (22 or 24 on the front) and a 34 on the back, if you can get it stock.

Lolly Pop
04-06-07, 01:08 PM
Like cycocommute, I often do about 4 mph on hills and agree, it's far better than walking!

Roughstuff
04-06-07, 01:29 PM
Long live GRANNY GEARS! My knees are so bad (they suffered alot of damage from malaria and the malaria medication after my world tour)...I often lurch a bit when I walk on stairs...but I can bike all day.

roughstuff

NoReg
04-06-07, 01:34 PM
I'm not sure peddling always beats walking, but in NA it's kinda regarded as a failure if ever you have to dismount. Touring is treated kinda like trials riding where points are deducted for touching the ground.

Cycco is right about the gears. Another way to look at it is that your body has a certain output. For greatest efficiency you maintain the same cadence with the same force on your pedals at all times. The gear range is what allows you to do that though the terrain and wind force vary. Of course one can move out of the comfort zone, but then your endurance gets a greater test.

Gear range isn't the only thing though. The spacing of the steps bewteen gears also affects your ability to operate at peak efficiency. So conceivably a person could be better off to power up a little, pick up a little fitness and operate a tighter sproket, than stay a little soft, and drop so far into the lowest bail out gear that they loose forward momentum and fall off the bike. Sometimes it feels like just sitting and spining doesn't get the job done as the bike just keeps getting slower and you run out of gears or fall off. I enjoy riding my loaded bike through areas where there is a good racing comunity, and watching how they deal with the hills. No, I'm not getting out of the saddle, but sometimes I do have to take it up a notch.

You shouldn't have to swap out the cranks, just the chainring and/or sprocket. If the other stuff on the bike won't handle the swap, then it's not a real touring bike. I'm not sure every touring bike needs the absolute lowest gears and widest range known to man, however, 30/32 is not the ballpark for most.

One thing that really surprised me when checking blogs that had feet climbed per day info, was how close the numbers were, coming across Canada. I just assumed the average day was way worse coming through the rockies than in "flat" southern ontario. But in most cases the days are right around 700-900. I'm not suggesting the mountains don't have killer hills, depending on route, but I was expecting to see 5 fold differeces, not maybe 20%. The longest climb I did out east was about 40 miles, non-stop, at a shallow grade. Often the flat areas have roads dropping up and down over rivers that are so steep they come close to stopping unfamilliar cars. Other than thoses washes, the only other places I came to a complete stop were in flat pottato country, from wind. So one may need the low gears almost anywhere.

Roughstuff
04-06-07, 01:40 PM
I'm not sure peddling always beats walking, but in NA it's kinda regarded as a failure if ever you have to dismount. Touring is treated kinda like trials riding where points are deducted for touching the ground.

It probably does 99% of the time. Walking is more wear and tear on the legs/knees; ya are always smashing your knee against the pedal while ya walk the bike; it is awkward to push something that is off to one side or the other; and you tend to lean on the handlebars, which is awkward. don't worry about someone viewing it as a failure...who cares what someone else thinks? *I* Am the one touring, not them.

roughstuff

nun
04-06-07, 01:59 PM
Gear range isn't the only thing though. The spacing of the steps bewteen gears also affects your ability to operate at peak efficiency. So conceivably a person could be better off to power up a little, pick up a little fitness and operate a tighter sproket, than stay a little soft, and drop so far into the lowest bail out gear that they loose forward momentum and fall off the bike.

I've found this to be very true. When you ride fixed or singlespeed you have no option but to "power up" and it really helps my multiple gear riding. I now find myself doing hills I would have shifted down on, before I road singlespeed, in my usual 67" cruising gear by simply accelerating

NoReg
04-06-07, 02:39 PM
"It probably does 99% of the time. Walking is more wear and tear on the legs/knees"

I totally agree, and with a modern bike it's probably less than 1% of the hills that are worth walking.

The only thing is that when I run out of gears, and I'm on a serious hill, and maybe there are some potholes, a soft shoulder that is hard to tell from the hard, big trucks are going by, I'm weaving a little more than usual, there is a great view I can't look over at, and my heart is ready to explode... Sometimes it feels like walking would be easier. I rarely do because I won't improve my fitness if I pack it in, but on a scale of "lower probability of a heart attack", or "stop and smell the roses", walking would win.

Lolly Pop
04-06-07, 04:46 PM
I was on a hill so steep last fall that when I got off the bike (my derailleur rubbed the spokes when I went for my lowest gear and the chain got caught) it was impossible to get going again, so I had to walk it.

Looking back, I should have coasted back down and started again!

cooleric1234
04-06-07, 05:57 PM

n4zou
04-06-07, 06:28 PM
It probably does 99% of the time. Walking is more wear and tear on the legs/knees; ya are always smashing your knee against the pedal while ya walk the bike; it is awkward to push something that is off to one side or the other; and you tend to lean on the handlebars, which is awkward. don't worry about someone viewing it as a failure...who cares what someone else thinks? *I* Am the one touring, not them.

roughstuff
I like to get off the bike occasionally and walk it. Some places I go are simply too dangerous to ride the bike across.
http://img171.imageshack.us/img171/1351/94bridgejy7.jpg
A few months back some one posted photos of Chinese bicycles and I noticed most of them has an accessory bar and grip clamped to the seat post so instead of holding the seat and the handlebar you took hold of the seat post mounted grip and the handlebar moving you away from the bike about 6". This gets you away from the pedal and the rear left side pannier. I made one myself and stuck it on and you would be surprised at how much better walking the bike is. Here is the photo that got me to try one.
http://www.thirdwave-websites.com/bike/seat-hand-bar.jpg
Here is the link to a web site with other interesting pictures of Chinese bikes and a small explanation of that extra bar and grip.
http://www.thirdwave-websites.com/bike/beijing-bikes.cfm

edtrek
04-07-07, 10:25 PM
[QUOTE=n4zou**A few months back some one posted photos of Chinese bicycles and I noticed most of them has an accessory bar and grip.... [/QUOTE]

Hey, that was me! Cool. Do you have a photo of what you built? Thanks, Ed

ronjon10
04-07-07, 11:24 PM
Also depends on how strong you are. When I was on tour, my lowest gear was 30 front, 34 rear. Early on the tour, I had to stop and walk quite a bit. I would've had to do that even if it was a 26 - 34 combo, but I would've made it further. By the end, I rarely used the 34 ring.

tacomee
04-08-07, 01:00 AM
Very true ronjon10,

Gearing is a personal matter-- everybody uses a little different.

But a low of 20-25 gear inches and a high of 95-105 seems to work for most people.

I'd ask the shop to swap out the small 30 tooth chainring for a 26. That's the low coast solution.

lighthorse
04-09-07, 04:36 PM
Cooler,
After reading all of the posts here I think that you can get some information from each. RonJon comes closer to my thoughts. My tour across the Southern Tier was my first tour of any kind (age 58, and a real novice at bicycling at the time). I was loaded with two panniers on a road bike with a stock Ultegra Crankset: 52/40/30, and I put on a 12-27 cassette. I did not feel out of place on the hills that I encountered with that set up (30/27 low gear). I did end up walking about 200 yards total on two different hills. In fact I often stop riding and just walk around to use some different muscles and a different body position. I do not consider walking an unnatural act. We all spend most of our time in the middle of the cassette and I personally want the spacing on my cassette to be as close as I can get it. The definition of "adequate lowest gear" is just too subjective and depends too much on the person riding, and the terrain to be ridden.

For my next cross country tour (Florida to Oregon) I am set up with a 48/36/26 crankset. After a couple of thousand miles I definitely like this crankset. I never used the 52 ring when loaded unless I was headed down a mountain, and then I normally just like to coast, relax and take in the scenery. Now I often use the 48 ring on the level with a tailwind. The bike came with a 11-32 cassette and I have changed that out for a 13-30 cassette. This setup feels good for me. Again, it is a very personal choice based on your conditioning, the terrain you will be traversing, and the way you like to ride.

gregw
04-11-07, 06:45 PM
Hmmmm....... Does gear ratio really matter? No!

Oh wait, I mean Yes!!

cooleric1234
04-11-07, 07:28 PM
Hmmmm....... Does gear ratio really matter? No!

Oh wait, I mean Yes!!

All right, smart aleck, if you read my post you would know my question was a little bit more in depth than that. Just for that I demand you answer the following questions:

What is the ground speed velocity of a laden touring bike?

gregw
04-11-07, 09:41 PM
All right, smart aleck, if you read my post you would know my question was a little bit more in depth than that. Just for that I demand you answer the following questions:

What is your name? ..........Smart Aleck, but then you knew that.[/B]

What is your favorite color? .........[B]7

What is the ground speed velocity of a laden touring bike? ..........Depends on the gear ratio, Oh wait a minute, no it doesn't.

:)

gregw
04-11-07, 10:08 PM
All right, smart aleck, if you read my post you would know my question was a little bit more in depth than that. Just for that I demand you answer the following questions:

What is your name? ..........Smart Aleck, but then you knew that.[/B]

What is your favorite color? .........[B]7

What is the ground speed velocity of a laden touring bike? ..........Depends on the gear ratio, Oh wait a minute, no it doesn't.

:)
Sorry for not having any Holy Grail references, Oh wait a minute, no not sorry, sorry.:)

cooleric1234
04-11-07, 10:18 PM
You are now cast into the Gorge of Eternal Uphill Climbs (as opposed to the downhill climbs). You'll wish you'd paid more attention to my gear ratio question now.

Revtor
04-17-07, 07:51 PM
Think of the toughest hill you've ever chugged up, and then think about getting up it one mile per hour faster. Even a lowly one mile per hour difference adds alot more effort. 28/32 at least. 26/34 is better. you won't use it that often, but when you need it and have it you'll be glad you do! And yeah, riding even at a snails pace beats pushing a 65lb bike up that steep hill for sure.

Go low, go slow, enjoy your trip.
~Steve

DukeArcher
04-17-07, 08:47 PM
A lot of people complain about the gears on the Trek 520 to be too high, but I've been training for my upcoming tour, a lot of huge hills fully loaded, and I can't see any problem.