bradtx

wheelinthai, I voted 27 GI or less, but on a bike I can use as a light touring bike, my granny is just under 32 GI. Partially because that granny worked when I was 20+ lb. heavier. There isn't much room for a 'reserve granny' on my bike, but 27 GI should do the trick.

Brad

bikenh

This is the smartest thing I've heard anyone on this message board ever say. You talk about physics and that is what counts.

To move an object up a hill at a certain speed is going to take a certain amount of force. The force will be the same amount of force no matter what gear you are in. If you are applying 250 watts to the pedals you will be getting 250 watts of force out of the bike going up the hill whether you are in a 53x16 or a 36x25. It will still be 250 watts. Unless you increase your uphill speed you won't make it up the hill any faster. If you continue to use same the amount of watts you will continue to use the same amount of watts and get up the hill just as fast as you did before. How fast you will climb will depend not on what gear you are riding in but rather how much power you are applying to the pedals.

Now on the exact opposite side of the equation you have the wear and tear on the knees versus the wear and tear on the knees. The wear and tear can come from two sources pressure and repetitive motion. Just like metal if you bend a piece of metal back and forth enough times it will break sooner or later. The same with any body part. You move the body part enough time, higher speed spinning going up a climb, you just create more wear and tear on the knee that will break down and cause you trouble in the long run(talk to the women who spend all their time on computers typing away and come down with carpal tunnel syndrome). This is just the same as riding a big gear will increase the amount of pressure applied to the knee and cause the wearing down of the knees. Either way you ride you are going to run in to problems in the long run. The only way to avoid the problem is to not use the knees, err not ride the bike.

Now the other thing you have to remember. The more gears you have on the bike, the heavier the bike is...the more weight you have to carry up all those hills. The more gears you use the more wear and tear you create on both the chain and the gears...the sooner you will have to replace them. The more gears you have on the bike, the more friction you have that makes you have to apply more pressure to the bike to get to the same speed than you would have to apply on a single speed bike. The more you can reduce the friction the easier the pedaling.

Yeah, this got a bit off topic but it still is quite on topic. Why do need a real small gear...so you can wear down your knees even faster by bending that metal back and forth more times?

sstorkel

Your knees must be more forgiving than mine... I find that mashing a tall gear up a climb inevitably leads to knee pain at the end of the day whereas spinning a lower gear doesn't.

shipwreck

Agreed. My right knee is pretty beat from spinning a potters kickwheel for hour upon hour in my youth for a tourist attraction. Then having it stomped on by bouncers in a bar fight I wasn't even in
Add that to my body weight of 200 some pounds, bike, gear, water and food. My current low gear is 20 something inches, with a 24 front-32 rear.

For credit card touring, I will do a thirty 34front-28rear, but only if I have some miles in and am not going to be on the road for more than four days. I only carry water and one extra bike shorts and tools doing this though.

wahoonc

I believe most orthopedists would agree that spinning (high reps at light load) are better than mashing (low reps at high load). Kind of like tapping on a rock with a light hammer vs beating it with a heavy sledge.

I have very bad knees and spinning is always a better choice for me.

Aaron

wheelinthai

Thanks for all inputs. Please keep them coming. For light touring, I think I'll settle for a low of 25 gear inch, with 46/30 front and 10 speed 12-32 rear cassette. This way I can participate with fellow bikers' enthusiasm for friendly racing. For normal load touring 30lbs or more load, I prefer 18 or less gear inch. BTW I never full load tour. Cooking is a No No for me.

nun

Obviously there is a limit to gearing....too high and you won't be able to turn it over on a hill.....that's why I said "I don't need really low gears". I spin up long steep hills, but I also get out of the saddle. When I say "patience" is necessary I'm thinking of some who use low gears and frantically spin away at 100rpm because they feel they are going so slowly. In any gear you should ride at a sensible cadence.

nun

A few years ago I experience some knee pain riding 67" all day up hills in England. I was carrying about 20lbs and was about 15lbs heavier than I am now. Since then I've ridden a lot more and haven't experience the same knee pain, even riding 67" all day.

bikenh

Okay, now you bring up another interesting point. You're scoring big time today Nun.

What is a sensible cadence? I learnt a year ago the difference in cadences thanks to breaking my ankles and not letting that keep me off the bike on the open road. I started riding one legged and rode 500 miles one legged while waiting for the other leg to heal up. I found much above 60-65 rpm I was jerking the pedal versus pedaling smoothly. When you are pedaling 100, 110, 120 or even 90 rpm, are you truly pedaling smoothly or are you just letting the action of one leg take over and control your other leg. Are your legs designed for that?

Think about it for a minute. Most people can only spin at 60-70 rpm without jerky motion on the pedals, one legged. Try it one legged and you'll see what I'm talking about. The only reason you get more rpms is because you are 'free floating' the back leg instead of applying smooth power throughout the entire pedal stroke. Now you have the extra movement of the dead leg, even though it's not applying power you still have the movement, you still have the wear and tear of the motion...heck an extra 30-60 times a minutes at one or two points in each pedal stroke. In the long run, how healthy can that be for the knees.

RR3

40/28 mountain double and an 11 speed 11-32 would be sufficent for most light touring and would be my choice unless the hills are steep, really steep.

46/34 compact and 11 speed 11-28 is what I am putting on my new rando rig that I plan to do some touring but only carrying around 10 pounds-the extra twenty are already on MY frame. A 14% grade with a light touring load requires me to put out 300W to manage 4.5MPH and when tired, 200W to crawl up at 3mph. Even a 20 inch gear at 3 mph corresponds to about a 50 RPM cadence on a 14% climb with lightly loaded bike and rider in the 220# range. They don't make gears low enough on a double for mere mortals to spin up some of the Appalacian hills/walls. Even a National Class racer with 5W/Kg would grind away at 6.5 mph on a 14% climb on a lightly loaded touring bike. The moral....if you plan to do hills steeper than 10% or so.....get a 24T triple or if the budget allows, go for the Rohloff hub.

bikenh

The body adapts over time...if you let it. Earlier in the trip I'm on right now I had a bit of knee pain as well. I've had several times off the long distance/load touring during the trip while visiting with family...planned stop. Since I started back up on the current/last leg of the this trip I haven't had a bit of knee pain at all.

People run from the slightest pain. They might as well do nothing at all as any muscle movement done often enough will cause pain. Hence why you find body builders in the early days having a lot of sore muscles. You'll get the same thing with any endeavor until you get in shape.

nun

You'd have to know the effects of chronic low impact vs acute high impact motion on the knee......I imagine both can cause damage.
I find that I change up once I hit 80 rpm. I ride between 70 and 80 rpm when seated on the flat and will go down to 50 rpm on steep hills, below that I'm pushing.

cplager

OK. This is what I don't get about a bunch of posters here.

Just because your knees don't mind mashing doesn't mean this is the case for everyone.

If not having low gearing works for you, then that's great. Suggesting to anybody else that they don't need low gearing without knowing either their terrain or the state of their knees is just, well, "less than optimally intelligent."

bikenh

Exactly. This is just like the concept of practically everyone on this message board saying the only way to go on a bike tour is to use rack and panniers. I've got over 4500 miles in so far on the bike trip I'm on and I'm not use rack and panniers, I'm using a backpack.

The problem you have is with the advent of the internet you have people being able to talk to each other all across the planet(one of the stupidest concepts ever invented) and now people that don't know each other are trying to give each other advice. What does this solve? Like you said Charles, it's less than optimally intelligent.

The people on this message board have the tendency to take one side and one side only...you should only spin madly in a REAL low gear when you go out on a bike tour. I hardly spin much more than 60-70 rpm whenever I ride, no matter where I ride. Most people on this message board are big proponent that the only way to climb a hill is to remain in the saddle. I never stay in the saddle to climb. I always get out of the saddle to climb and let my body weight help do the climbing for me. Yes, I spin at a much slower rate than most. Whenever I ride at a much higher rpm I feel like I'm not even going anywhere, it feels like I'm just spinning for no reason at all. It doesn't even feel good. It feels awkward.

People think that if they try something for 5 seconds and it doesn't feel right, look right, sound right, etc that it's no good. Take a look back over the past couple of weeks at the posts about using backpacks versus panniers and you'll see what I'm saying. Gals like Machka...I tried a backpack once and rode for 20 miles(or whatever) and I didn't like it so I never used it again. The fact is simple...if you hop on a bicycle after not having ridden a bicycle for 10 years and go out and started riding do you think a 20 mile ride is going to be enough to tell you whether or not you like biking. The only way you find out is to go out and give yourself a fair opportunity to try it out. 20 miles isn't trying it out...that's just pure lunacy. The body takes time to adapt to anything that isn't what your use to. It's the same way with anything...running, weight lifting, biking, swimming, you name it. Your body takes time to adapt to the new rigors that you are trying to make it do. Until you give it a fair shake you can't say whether you truly like something or not. The same goes with riding big gears versus lower gears.

I wouldn't doubt the extra wear and tear on the knees of pushing big gears, especially if it is something you are doing everyday for many years running and doing a lot of it each and everyday.

People are so scared to let themselves get into shape that they never do get into shape. They just continue to sit in front of the TV and whine or they do everything in their power to avoid pushing themselves to greatness. This world is so full of people that aren't all they could really be...simply because they never bother to try. I could never have imagine being able to ride 200 miles in one day fully loaded...until I did it back at the end of June this year. I loved it. It ended up being one of two days that I've had the experience of getting to the end of the day and not wanting to stop. It felt so good I just wanted to keep going. Maybe it had something to do with riding into the sunset. I sure do wish I could figure that one out. Both times have been on days of riding 200 miles and finishing after sunset. I've not had the same experience though on other days when I've ridden 200 miles or more.

Get out there and challenge yourself...you might surprise yourself as to what is possible when you stop setting limitation on yourself.

nun

The OP asked for opinions about gearing for a light tour across the USA, making gear inch suggestions seems to be the whole point of this thread. We also have a fair amount of information about the OP to go on.

There will be different opinions and people need to use their common sense to choose the gearing that's right for them. Many people will be just fine with 25" as a smallest gear others will need something smaller, some will be fine with even bigger gearing. Personally I find a low of 25" to be a bit less than I need.

staehpj1

We know quite a bit though. We know that he is asking about touring across the US. We know that he will have <20 pounds of gear. We know that he currently does most of his riding with about a 36.4" low gear.

That is enough that it is reasonable to suggest a gearing choice.

mm718

As a relative newbie I don't understand the need for high gears. With 44 x 11 (MTB gearing) you should be able to pedal to about 28 mph before you spin out. With more typical touring gearing you could pedal to 30 mph. Do we really need to be pedaling at >30 mph? Unless you have an ultralight set up it seems like you would always want to err on the side of lower gears?

nun

When I got my bike I immediately knew that 50x11 was pretty much useless to me while touring so I replace the 50t with a 46t ring. This made the gear range more sensible and put a comfortable cruising gear of 73" in the neutral chain line position. I use my 46x12 gear on downhills or if I have a strong tail wind, but I could easily do without it.

shipwreck

And this pretty much proves the point that while its ok to ask for opinions on the internet, the only way to know what is needed by an individual is to actually try things out for ones self. I would go crazy with a 73" top gear inch. I prefer at least a 100-ish top gear. Spinning out makes me feel out of control. Like the lowest gear, I don't use it all the time, but it makes my riding experience a lot more positive with it than without. I like to cruise at high speed without spinning to fast. Its also possible to climb in a very low gear at a slow pace without "spinning madly", despite what has been said about that.

RR3

The OP asked a really simple question. I am sure some who responded are not only very fit but have been riding seriously for many decades. The math is pretty simple. Experience maybe not so. In nearly 50 years of riding bikes, I have rarely lamented not having a bigger gear. How many of us can honestly say they have never reached for a little more help on a steep climb and realized they were already in their smallest gear.

Frankly, I laugh when some posters say they always spin at 75+ RPM on hills almost as much as someone dissing Macha as a Gal who doesn't like riding with a backpack. Pretty sure she has quite a few Grand Randonnee done and has circumnavigated the globe on a bike, so, her opinion is useful even if her needs differ from mine. Opinions are opinions. Riding with a backpack is stupid. There, I said it. I am old, grumpy, and in need of a workout. Glad it works for you. What works for one rider may not work for another. Gravity and 15% gradients force all of us to grind unless you are a national or world class rider with 5-6W/Kg power output. Most of us are about half that and therefore we grind on steep hills. Whether one chugs away at 30 RPM standing or grinds away at 40 RPH sitting is irrelevant. It is preference and also a function of frame design. Pick your poison....see you at the top.

I for one would love to have a rohloff geared touring bike.

nun

73" is not my top gear, it's the gear I choose to ride in most of the time and so I have arranged my gearing so that I'm in that gear with a straight chain line. My top gear is 46x12 (103").

nun

+1, particularly the bit about Macka.

shipwreck

Ah, understood.

LeeG

I have a 44/30 triple crankset with the outer ring taken up with an aluminum chainring guard and the option of a 12-28 or 12-32 cassette. I'm old and fat needing lower gears but even when I was young, light and fast up mtns. there was no need for a gear higher than 97" for touring. I did fine then with a 30" low.

The 44t w middle four cogs on the 8spd cassette provide a good chain line and useful gears for cruising speed. 44/12 is plenty high so no need for a bigger chainring. The 74bcd inner ring can get knocked down to 28 if needed.

Your reference of a 34/25 as a comfortable low gear isn't enough information for a reference without knowing if your hills are 500' climbs at 7% or 3000' at 7%. If it's more the former than the latter I'd suggest two more lower gears than your usual, something around 25"(34t) and 30"(28t). Over days, altitude and greater than normal load 30" will be the new 36" with 25"(34t) the bailout gear.

chasm54

Got one of them. As it is set up, lowest gear is around 19". Terrific bit of kit, truly impressive.

You're right about riding with a backpack, too.