General Cycling Discussion - How do bike gearings work?

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ShadowGray
05-02-08, 06:46 AM
Ok, so I finally got my bike (no more bugging you guys :D). It's a Jamis 18spd Ukiah.. feels pretty good.
Now, I just wanted to know how the bike gearings work? Current it's set on 1 in the front and 6 in the rear, but when I drop the rear gears, it just seems to loosen up and make it near impossible to pedal. How exactly do they work?
twobikes
05-02-08, 06:58 AM
The numbers on the shifter can be confusing. My wife has problems with following them. I finally put labels on the shifters that say "hill" and "fast." Now she knows which way to move the indicator in her shifter window without thinking the whole thing through.
Basically, find a combination that allows you to pedal without making you breathe hard or straining your legs. Riding a bike will give you a workout, but it should also be fun and something you can sustain for as many hours as you wish without destroying yourself and your muscles. When pedalling becomes more difficult, switch to an easier gear to keep the effort about the same. Naturally, you will be going more slowly. When the pedalling becomes too easy, switch gears again to keep the effort about the same. You will now be going faster.
In general, learn to assess the situation a bit ahead and make your shift before the hill starts to rise, etc. Shift to an easier pedalling combination as you approach a stop sign or red light. It makes starting out again easier.
A smaller gear ring in the front means easier hill climbing. A smaller gear ring in the back means more speed, but harder hill climbing.
I always shift to the smallest sprockets front and back when storing the bike. It relaxes the tension on the springs and keeps them from weakening. Some say this is no problem, anyway.
Congrats on the bike, that's a good beginner bike (I ride a Jamis myself).
For these really basic questions you should check Sheldon Brown's site first:
http://sheldonbrown.com/beginners/index.html
He's explained it a lot better than most people could.
Congrats on the bike, that's a good beginner bike (I ride a Jamis myself).
For these really basic questions you should check Sheldon Brown's site first:
http://sheldonbrown.com/beginners/index.html
He's explained it a lot better than most people could.
Wow He does explain how to work the gears. very well.
deraltekluge
05-02-08, 09:04 AM
Ok, so I finally got my bike (no more bugging you guys :D). It's a Jamis 18spd Ukiah.. feels pretty good.
Now, I just wanted to know how the bike gearings work? Current it's set on 1 in the front and 6 in the rear, but when I drop the rear gears, it just seems to loosen up and make it near impossible to pedal. How exactly do they work?What does that mean, "loosen up"? If your gears are numbered normally, you probably shouldn't be using that setting. Generally, you shouldn't use smallest front with smallest rear, or largest front with largest rear.
Usually, in the front the smallest gear is called 1, and the largest is called 3. In the rear, the largest is 1, and the smallest is N (6 in your case).
So, if you're using 1-6, you've got the chain making its most extreme angle, from the nearest-to-the frame front gear to the farthest-from-the-wheel rear gear.
You should probably begin by using the middle gear (2), in the front. Do most of your shifting with the rear gears.
Remember, the higher the number the faster/harder the gear.
Hobartlemagne
05-02-08, 10:12 AM
I finally put labels on the shifters that say "hill" and "fast."
I've always thought that was the perfect explanation for a beginner.
Retro Grouch
05-02-08, 11:13 AM
Eighteen gears - I assume that means that you have 3 in front and 6 in back.
Think of your bike as having 3 different gear ranges - one for flatland, one for uphill and one for downhill.
For 90% of your riding, the flat 90%, put your chain on the middle front sprocket and forget about it. Use the rear shifter to match your gear to your speed. If your feet seem to be spinning too fast, pick a higher number. If it feels too hard to pedal, pick a lower number.
As you approach an "Oh my God" uphill, shift your chain onto the little sprocket in front. That'll make it a lot easier to pedal up the hill, but you won't go very fast. You can fine tune your gear with the rear shifter if you need to.
Save the big front sprocket for downhills and the twice a year that you have a tailwind.
That's all that you really need to know.
Bill Kapaun
05-02-08, 12:19 PM
Start off in 2-1 or 2-2 for normal flat land riding. Work your way up with the right shifter to 2-6.
If you need an even faster gear after 2-6, shift to 3-5.
You might even be OK starting in 3-1 and just staying in the big ring.
GlassWolf
05-02-08, 01:35 PM
Eighteen gears - I assume that means that you have 3 in front and 6 in back..
6x3 or 9x2. I'd think a 9 speed cassette, double crank is far more common than a 6 speed freewheel, triple crank.
6x3 or 9x2. I'd think a 9 speed cassette, double crank is far more common than a 6 speed freewheel, triple crank.
Not on a mid-90s mountain bike.
kellyjdrummer
05-02-08, 02:09 PM
Another thing to remember, that can in some cases, make remembering easier.....the right side of the bike (sitting on it) is called 'outside,' and the left side (sitting on it) is called 'inside.' Your smallest rear cog is 'outside.' Your largest front ring is also 'outside.' Right is outside, left is inside.
This will help when you get around to installing your own derailleurs on the bike, if you ever do.
ShadowGray
05-02-08, 06:11 PM
I understand outside and inside, that's fine. It's just the high/low combos that get confusing... why is high and low switched on the front and back? Is there some good reason or is it just to make visualizing things difficult?
deraltekluge
05-02-08, 07:34 PM
I understand outside and inside, that's fine. It's just the high/low combos that get confusing... why is high and low switched on the front and back? Is there some good reason or is it just to make visualizing things difficult?High and low aren't switched. In the front, the large outside gear is high, and the small inside gear is low. In the rear, the small outside gear is high, and the large inside gear is low. In both cases, inside is low, outside is high.
Remember what I said about not using 1-6 and 3-1 combinations? It's called "cross-chaining" when you use those. The chain has to run from the innermost front gear to the outermost rear gear, or vice versa. It's inefficient and hard on the chain and the gears. To quote Sheldon Brown...
Try to avoid the gears that make the chain cross over at an extreme angle. These "criss-cross" gears are bad for the chain and sprockets. Especially bad is to combine the inside (small) front sprocket with the outside (small) rear sprocket. This noisy, inefficient gear causes the chain to wear out prematurely.
The way bikes are built, the chain runs more nearly in a straight line for both the highest and lowest of gearing combinations.
There's a lot of overlap in the gearing on a bike, so you really lose very little if you avoid the crossing situation...you still have the full range of gearing, from highest (large front, small rear) to lowest (small front, large rear).
BarracksSi
05-02-08, 09:56 PM
Firstly, don't worry about anything -- you're not going to break the bike as long as you're not stomping the pedals while shifting. You'll probably experience some chain rub in particular combinations (small front ring + small rear cog, for example), but that's no big deal, relatively speaking. So, you can do a lot of experimentation.
For a quick lesson in shifting, try this -- put the chain about in the middle of the rear cogs, and shift between the three front rings. BUT, and this is the key, try to keep your pedaling at the same tempo. What you'll find is, when the chain is on the big ring, you'll be putting more effort into each pedal stroke, but you'll go faster; when it's on the small ring, each stroke is easier, but you'll go slower.
Another idea: inside gears (both front AND rear) are for climbing, outside gears are for going really fast. Middle gears are for everything in between.
I like how Retro Grouch put it, too.
Retro Grouch
05-03-08, 07:27 AM
I understand outside and inside, that's fine. It's just the high/low combos that get confusing... why is high and low switched on the front and back? Is there some good reason or is it just to make visualizing things difficult?
Everything on a bicycle works together. That's one of the things that I love about them.
Look at how the tubes on your bike are angled. On the front the big chainrings have to be on the outside or they'd rub the chain stay tube. On the back the big cogs have to be on the inside or they'd rub.
I might get a little argument about this but I'm convinced that shifters work best when they use cable pull tension to pull the chain up onto a larger sprocket. That means the shifters have to work opposite one another, front and rear, to access easier hill climbing gears.
kellyjdrummer
05-03-08, 08:41 AM
Actually knowing what gear you are in is irrelevant. If you need to have leverage, shift to what you know is easier. If you need to just cruise on flat ground, shift to what you know is relaxing.
It's exactly like a car.
I do it this way.....front rings: Big is for flat....middle is for grass, gravel, light dirt.....small is for mud, trail riding, and anything I think will be hard to pedal through, disregarding inclined surfaces for small.
I've done lots of road riding and almost never used the small ring, and almost never used the two inside cogs. My resting cog was always the third from the inside and big ring.
Don't even pay attention to the little windows on the levers, or whatever indication they use. I never do. They don't offer me anything that will change the physics of reality.
;):)
wahoonc
05-03-08, 09:00 AM
Now I KNOW why I like IGH hubs...you only have to shift up or down...:eek::p (It is what got my wife back into cycling) I do ride multi geared bikes, done it without thinking for years.
Aaron:)
chinarider
05-03-08, 11:33 AM
I understand outside and inside, that's fine. It's just the high/low combos that get confusing... why is high and low switched on the front and back? Is there some good reason or is it just to make visualizing things difficult?
I think I know what you mean. The largest ring in front is highest but the smallest cog in back is highest. But if you understand the function, it makes sense. In front, the pedals are directly turning the rings. So it takes more power to turn the biggest one (more distance moved). In back, the cog turns the wheel. Now, the smallest cog requires more power because you are using less distance (i.e. the circumference of the cog) to move the wheel (as compared to the bigger cogs). Don't know if I explained that clearly; perhaps someone else can do it better.
BarracksSi
05-03-08, 09:32 PM
I think I know what you mean. The largest ring in front is highest but the smallest cog in back is highest. But if you understand the function, it makes sense. In front, the pedals are directly turning the rings. So it takes more power to turn the biggest one (more distance moved). In back, the cog turns the wheel. Now, the smallest cog requires more power because you are using less distance (i.e. the circumference of the cog) to move the wheel (as compared to the bigger cogs). Don't know if I explained that clearly; perhaps someone else can do it better.
It's like levers, basically (that's really what gears are anyway). Big in front & small in back is like putting the fulcrum at the far end, away from you, right next to the load that you're lifting. Small front/big back is like moving the fulcrum closer.
chinarider
05-03-08, 10:06 PM
It's like levers, basically (that's really what gears are anyway). Big in front & small in back is like putting the fulcrum at the far end from you, right next to the load that you're lifting. Small front/big back is like moving the fulcrum closer.
Actually, I think this is backwards. When the fulcrum is next to the load and far from you, the load is easier thus corresponding to small front/big back. But I think the concept is right. For a given number of chain links, the biggest back cog moves the bike less distance than the smaller ones corresponding to the fulcrum next to the load lifting the load less than when it is further away. And the smallest front ring moves fewer chainlinks per pedal rotation than the bigger ones corresponding to the fact that when the fulcrum is far away from you & next to the load, pulling down on the lever a given distance moves the load less than pulling it that distance when the fulcrum is closer to you. But then again, I may be wrong. I'm no Archimedes.
BarracksSi
05-03-08, 10:24 PM
Actually, I think this is backwards.
Whoops, you're right, I had it backwards... ;)
BarracksSi
05-04-08, 06:11 AM
Oh, I figured out the right way to think about the lever idea -- at least in terms of just the back wheel.
Picture the hub as the fulcrum, the tire as the "load", the spokes as the "load side", and the cogs as the "near end" that you'd be pushing on. Better yet, imagine pushing on one particular tooth of the cog to move the opposite side of the wheel.
Using the small cog is like pushing on the lever right next to the fulcrum, requiring higher effort while yielding greater speed. Etc.
chinarider
05-04-08, 10:58 AM
Oh, I figured out the right way to think about the lever idea -- at least in terms of just the back wheel.
Picture the hub as the fulcrum, the tire as the "load", the spokes as the "load side", and the cogs as the "near end" that you'd be pushing on. Better yet, imagine pushing on one particular tooth of the cog to move the opposite side of the wheel.
Using the small cog is like pushing on the lever right next to the fulcrum, requiring higher effort while yielding greater speed. Etc.
I think its simplier to consider that it is the chain that moves the bike & the relationship of the ring or cog to movement of the chain: The bigger the front ring, the further the chain goes on 1 rotation of the ring, but the bigger the rear cog, the more chain movement is required for 1 rotation of the cog (and thus for the same effort the bike is moving less distance).
ShadowGray
05-04-08, 12:28 PM
lol wow you guys get detailed.
I think the first few posts got it good... 3rd gear for easy conditions, 2nd for normal, 3rd for hard and uphill. On rear, lower number = lighter, higher number = more force.
Am I getting this right?
Bill Kapaun
05-04-08, 01:15 PM
Just ride the *** thing! You could have it figured out by now.
kellyjdrummer
05-04-08, 02:30 PM
'Being a new guy to this forum, but a vet to forums from Photoshop to biking, I may step on toes with this, but it is starting to sound like the OP is playing you all. Bikes are not hard to 'get.'
ShadowGray
05-04-08, 02:55 PM
lol... I've gotten most of the hang of it now. I just need that first few posts which basically described "hill and flat"... and I'm still in that kind of mindset now.
BarracksSi
05-04-08, 04:39 PM
'Being a new guy to this forum, but a vet to forums from Photoshop to biking, I may step on toes with this, but it is starting to sound like the OP is playing you all. Bikes are not hard to 'get.'
Sure, probably, but sometimes it's kinda fun to see if this stuff can be broken down Barney-style for anyone to understand. :D
kellyjdrummer
05-04-08, 04:46 PM
Sure, probably, but sometimes it's kinda fun to see if this stuff can be broken down Barney-style for anyone to understand. :D
Certainly you are right, but at 15 yo I was on a bike I could barely get on top of and dealt with it. It IS NOT science.
BarracksSi
05-04-08, 05:07 PM
Certainly you are right, but at 15 yo I was on a bike I could barely get on top of and dealt with it. It IS NOT science.
Yeah, true. I think I was also adjusting the shifters on mine when I was 12. They were friction SunTour thumb levers on a wide-bar "ATB" -- gotta love fine-tuning the trim on the fly without worrying about such things as "indexing". :D
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