mander

different skid patches
more teeth=longer wear
different virtual chainstay length for magic gear
arguably even-even combos wear longer (says Sheldon)

Karsten of course gear inches are useful. It shouldn't really need explanation. What a silly thing to start a thread about.

Ken Cox

If a rider knows his gear inches, and wants to go up a little in effort and speed, or down a little in effort for more controllability, he can look at a gear inch chart and see the cheapest and easiest combination for the result he wants.

I ride a 53 X 19 for 73 inches.

What would I need to do to go to 75 inches?

77 inches?

If I have reference point, or a known starting point, I can make informed choices at how to go where I want.

I don't see that as an obsession but as simple information for making cost effective choices.

SD Fixed

You get oil.

That was over a 4 year period.

SD Fixed

See, this was a my previous understanding. But, in order to maintain speed and keep ahead, I simply bumped 46 to 48. 48, higher, thus harder, but resultant, faster.

I must be dense. I mean, it's like a pebble, a stone, and a brick. You through the pebble, it might hurt someone. Take a stone and throw it, it's gonna leave a mark. But a brick, that's going to be brain damage.

So, you could take physics into it, and explain the whole thing about mass and velocity, and impact and transfer of energy.

But, really. If you need a pebble, you use a pebble. If you need a brick, you use a brick.

Seems like people work to hard to caculate what they are doing and.. don't really enjoy what they are doing.

Or maybe it's a hobby.

I just don't get it. Must be something wrong with me.

Hocam

A bike with a 35mm tire is geared higher than the same one with a 23mm tire.

trons

dutret had it with post 2, i don't see what is so hard to get here

Ken Cox

It might seem that way to William in his imagination, but I thoroughly enjoy what I do, and understanding it only adds to the enjoyment.
It also adds to the performance.
I have gained a lot of effieciency and speed from constant refinement, and constant refinement has come from constant study.


People who want to excel at something, or enjoy it to the max, study it.
They don't study it out of some duty or anal obsession, but out of fascination with the subject.

I look at charts of chainrings and cogs and the resulting gear inches and think about things like riding through the Cascade Mountains and what gear combination would let me do that comfortably.
I study the known to gain insight into the unknown.

If you like airplanes you study airplanes and all the silly numbers associated with flight.

If you like women, you study women, often in great detail.

Some people who really, really like fixed gear bikes talk about goofy things like gear inches and the fine, maybe even nonexistent differences between cranksets.

Clearly not William's cup of tea.

I can live with that.

Can William live with it?

Yoshi

But let's say that you ride a bike geared at 48x16. Someone rolls up with a bike geared at 48x16. Are you pushing the same gear? If the person's wheels are a different diameter than no, your gearing is different. And what about that guy riding 39x13? Is it immediately obvious that he's riding the same gearing, assuming that you both have the same size wheels/tires?

Gear inches make comparisons easier. Instead of saying "I ride a 47x16 with 700x23C tires" I can say "I ride 77 gear inches." You tell me which is easier.

SD Fixed

Must be a San Diego thing, cause all I see here fixed is 700cc tires.

SD Fixed

This post (Mine) is about half poking fun at gear inch geeks, and half wondering the appeal is out of an honest desire to understand why people talk it up so much.

SD Fixed

By simple use.

SD Fixed

Uh, lack of knowledge about geek inches never stopped me from riding.

Are gear inch calculators the virtual gun of the keyboard cowboys?

the pope

If people didn't know your history on this board, this would have been blasted as a troll post in about thirty seconds. I can sense the scrunched up eyebrows in the responses.

SD Fixed

What history is that?



So many new folks, I'm pretty much new myself.

illzkla

which is easier...

knowing that someone with ratio 46x16 is basically the same as 52x18

or

knowing that someone pushing 75.6 gear inches is basically the same as 75.9 gear inches




it should speak for itself.


edit: i didnt read any of this thread

mander

OK Karsten, I will answer your (fairly dumb) question. There are many reasons why gear inches is a useful measurement.

1. If you want to gear up or down a certain amount, often adding or subtracting a teeth from your existing setup (the bonehead method) can have undesirable consequences. It may throw off skid patches, etc.

2. What if you want bigger rings for better wear, but about the same development as your current gear?

3. For different people to be able to meaningfully discuss gearing, a universalizable standard is needed. Gain ratios are a tiny bit better, but crank length makes so little difference that you can get along without it.

4. Say you need a magic gear, and you want it to be well suited to your commute.

5. Maybe you want a setup with all prime numbers, and you want it to be suited to your commute.

6. Maybe you want a setup with all odd numbers, and you want it to be suited to your commute.

7. Maybe you want a setup with all even numbers, and you want it to be suited to your commute.

I could go on; there are all kinds of conceivable situations where calculating gear inches is useful. Knowledge is power. I am bewildered that you do not seem to understand this.

Ken Cox

William pretends to not understand because he likes the attention he gets from belittling the interests of others.

Kinda sad.

What has happened to this forum?

I moderate other forums and I have, in the past, preferred this forum to any other.

I liked the way people wrote here (some great, unpretentious, natural writing here) and their zeal for fixed gear bikes.

I've noticed a number of people who I really admired, like absentr, have disappeared.

Gone away.

Well, maybe this forum has run its course.

Like I said, kinda sad.

Does anyone here remember when I fell on my bike, broke all those ribs and collapsed my lung?

The doctors punched a hole in my chest and put a tube in it to suck my lung back into shape.

I had tubes and wires going all over the place.

I asked for a computer and they gave me one, and I came here while the hospital, almost a living thing itself, sucked at my chest through a tube.
I couldn't hear the suction machine behind the walls going pocketa-pocketa-pocketa, but I could feel it inside me.

I felt so connected, to the hospital, the plumbing, tubing and wiring, and, through the internet, to friends on this forum.

Kind of a universal cosmic thing, y'know?

People hundreds and thousands of miles, even continents away, talked to me real time through the internet while the hospital suctioned out the air between the outside of my lung and the inside of my chest wall.

Not that I felt afraid or alone.

I just couldn't quite understand how I could get hurt so bad by something I loved so much.

I remember absentr took a bad fall that same month, during a race, and got hurt a lot worse than I did.

He recovered and built a bike with pink Phil hubs.

Didn't he?

Anybody remember that?

Well, the pendulum swings first one way and then the other.

Maybe this forum will swing back in a better direction.

doofo

way to kill a perfectly petty argument ken!

moe sizlack

Read: Copyright infringement.

San Rensho 

Anybody who seriously rides the road or the track is very sensitive to gearing. Gear inches is a way to quantify and experiment with gearing, to find the best gear for you and for different situations.

Now you seem to be of the mindset that "I don't need no stinking gear inches to know whether I'm riding fast or slow, I go by how it feels" but eventually riders will get to the point where a 48/14 is too big because it "feels" too big and a 48/15 is too small because it feels too spinny. Only one tooth difference, right? Well the gear inches are 92 and 86 respectively. A huge difference in gear.

To get a slightly bigger gear, you have to go to a gear chart (or much easier, just calculate it) to find the right CR/cog combination.

53/18 doesn't mean a whole lot to me because I don't have gear charts memorized. But I know that a 92 inch gear, no matter what CR/cog combination achieves that, is way too big for me now.

Hocam

Don't make me quote myself. I get angry when I have to quote myself, and you wouldn't like me when I'm angry.

h_curtis

Dude, that is awesome. I can't remember the show, was it "land of the lost"?

Yoshi

As has been pointed out many times, 23C tires will give you a different gear inch than a 20C or 25C or whatever tire. And I'm sure even in San Diego people are riding with different tire widths. Not to mention I have some really short friends who ride 650C wheels.

But even ignoring the usefulness of gear inches with respect to different wheel sizes, it is still useful for comparison. To give you an example I was recently in a roller race. There is a UCI gear limit to how large a gear you can use while roller racing. That limit is 7.69 development meters (the European equivalent to gear inches). Since you seem to be suggesting that gear inches (and by congruence, development meters) are somewhat pointless, why did the UCI specify the gear limit in development meters instead of gear ratios? Well the problem is that there are dozens of combinations of gear ratios and tire widths that will get you to the limit. To list them would be a lot harder and more confusing that simply saying, "No gear over 7.69 development meters." and let the riders do the calculations themselves (actually the officials mark off 7.69 meters on the floor and roll out your bike).

To give you an example, the following gear ratios and tire sizes will give you 7.69 (or at least, as close as possible) development meters:

for 700x23C tires:
53x15, 51x14, 47x13, 39x11
for 700x20C tires:
48x13, 53x14

Ken Cox

That pretty well explains it, doesn't it?

cphfxt

Ok you go use those 2 gears and switch between them on one bike and tell me if you can notice the difference (wait incl) .. If you say you can -I say bah.. Not because of anything other than I would not believe it.. Simple too..