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Discussion Starter · #1 ·
Two road bikes, both fitted to me. One 10% grade hill that's about a mile in length.

One bike is a touring bike, 29 pounds with a 30 tooth granny gear and 11-32 cassette.

Another is an aluminum framed compact road bike with a compact crankset 34/50, and a 12-26 cassette. This bike weighs 21 pounds.

Now, if I take either bike up on this 10% hill, utilizing the 34/26 combination on the aluminum bike and maybe 30/28 or 30/32 on the steel touring bike, which bike would be easier to pedal up the hill?

Is 7 or 8 pounds justified in a lower gear inch compared to a lighter bike with a bit higher gear inch? Let's say the climb becomes steeper and longer, would the weight penalty of the touring bike still give me low enough gearing to cruise through the hill, seated, with a stable and progressive effort to climb, or would I just burn out on a 20 pound road bike even with a compact crank?

So yeah, even with a lighter bike, is slightly larger gearing more efficient at climbing compared to a heavier bike with lower gearing?
 

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Depends

There's no simple answer to that. It depends on too many factors: your weight, fitness, and pedaling style; the exact grades, etc.

For me, 34x26 is low enough for that hill, so I'd go with the lighter bike.
 

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Discussion Starter · #9 ·
Ok, how about this. You have a 12% grade that lasts for 10 miles. The 34-26 gearing on the 20 pound road bike isn't enough for you to sustain 90 rpm, so let's say you pedal up at around 65 rpm without trying to bob or be inneficient.

On the low gears of the touring bike, you can spin near 95 rpm for the duration of the climb while seated.

Would spinning the low gears of the road bike make you faster up the hill compared to a 20 pound road bike on its lowest gearing with a relative rpm of about 65?

Is having a heavy touring bike worth the lower gears at the cost of 7 or 8 additional pounds, no matter how much climbing you do in a week? Would it be better to gain strength from too high of a gear rather than climb efficiently on the low gears of a heavy touring bike?

Would hills be better training than HIIT?

I'm so confused. lollol
 

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You're still feeling the weighing forces against you no matter what gear you're in. And even though power efficiency is dependent on gearing, a rider can at least adjust their riding form to work different gears.


Take the lighter bike.
 

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ProphetBanana said:
Ok, how about this. You have a 12% grade that lasts for 10 miles. The 34-26 gearing on the 20 pound road bike isn't enough for you to sustain 90 rpm, so let's say you pedal up at around 65 rpm without trying to bob or be inneficient.

On the low gears of the touring bike, you can spin near 95 rpm for the duration of the climb while seated.

Would spinning the low gears of the road bike make you faster up the hill compared to a 20 pound road bike on its lowest gearing with a relative rpm of about 65?

Is having a heavy touring bike worth the lower gears at the cost of 7 or 8 additional pounds, no matter how much climbing you do in a week? Would it be better to gain strength from too high of a gear rather than climb efficiently on the low gears of a heavy touring bike?

Would hills be better training than HIIT?

I'm so confused. lollol
This scenario is easier to answer, because climbing a 12* grade for 10 miles at a cadence of 65 is IMO going to place undue stress on the knees. There are no other factors present that override that concern.
 

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Ok, how about this. You have a 12% grade that lasts for 10 miles. The 34-26 gearing on the 20 pound road bike isn't enough for you to sustain 90 rpm, so let's say you pedal up at around 65 rpm without trying to bob or be inneficient.

On the low gears of the touring bike, you can spin near 95 rpm for the duration of the climb while seated.
There are some assumptions here that you should examine. You assume it's best and most efficient to remain seated and spin 90 or more for the whole long climb. For many riders, that's not true. There are a great variety of styles. More important, on a climb that long, staying in the same position the whole way will be very inefficient for most riders (I know it would be for me) because you're overusing some muscles and getting stiff and fatigued. On long climbs, I alternate standing and sitting (frequently), and I vary cadence, too. Watch the pros; you'll see them do that, too.

BTW, there are very few climbs that are both that long and that steep. Many long climbs have sections that steep, but the average grade is easier.

Higher cadences are generally better, all else being equal, but there's nothing magic in a number. I have lots of routes around here that have sections of half a mile or more at 10%, and some short bits that exceed 15%. My lowest gear is 39x26. I can do all those hills (and I can reserve the 26 for bailout on the steepest sections). That means doing some sections standing at much less than the magic 90 rpm. I do this without damaging my 60-year-old knees, because I'm careful. If I had very long hills (2 or 3 miles are the longest around here) I'd have some lower gears, to allow more variety in cadence.

But again, it's not automatically more efficient to use the higher cadence seated.
 

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I'd imagine you could get up most hills in either.

The lighter bike will likely get you up most hills faster.

With a little practice most can likely keep a bike upright on very steep hills going as low as 3 or 4 MPH as long as they can keep the cranks turning.
 

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Loraura said:
With a little practice most can likely keep a bike upright on very steep hills going as low as 3 or 4 MPH as long as they can keep the cranks turning.
Some people can ride up hills faster than 3 or 4 MPH ??!!! :eek:

Seriously, my Americano touring bike and Cannondale CAAD 9 triple feel just about the same up a steep hill. That is to say, the heavy touring bike with 24/34 granny doesn't feel any easier to ride up really steep hills than my much lighter CAAD 9 with a 30/27.

My knees won't let me get up the steep without a triple and some low gears on any bike.

Another way to approach this is to play with a power/speed calculator such as http://bikecalculator.com/veloMetric.html Assume constant power and see what effect weight has on speed.
 

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lighter bike. I live in a development where to get to my house, I have to climb several 10% hills for about 1-2 miles...

I also have a MTB.....on the road, the road bike is easier... also, keep in mind, the rotational inertia, your touring bike (like my MTB) probably has heavier wheels, so, you have more rotational inertia to overcome....
 

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keeping to simple science for a moment. The gear ratio is equal the chainring divided by the rear sprocket times the diameter of the rear wheel. Assuming the rear wheel diameter is the same compare gear ratios by comparing the quotient F/R and that'll tell you which will require higher torque for any situation.

When climbing the total weight is what counts, that's the bike, you and any other stuff. If you're a slow climber wind and other factors no longer count. So 7#s out of a total of about 200#s is a 3.5% difference, not a heck of lot.

That's the science, now for the subtleties. The best gear for any climb varies according to the rider. Some prefer to sustain higher rpm others prefer torque, more powerful riders climb faster, and some like myself vary their preference powering up short steep hills, and using lower gears to maintain rpm and lower torque for long grades so as not to burn out.

Lastly, bike weight has effects different than simply adding more to the payload. A lighter bike feels lighter beyond the true weight difference, and is easier to maneuver and rock during hard climbs, this helps both physically and psychologically. Placement of the weight also counts, and lowering the center of gravity and reducing the polar moment help.

So the answer to the OPs question is that there's no simple answer. Once you're comparing similar gear ratios, the subtleties come into play and different riders will have different preferences.
 

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ProphetBanana said:
Two road bikes, both fitted to me. One 10% grade hill that's about a mile in length.

One bike is a touring bike, 29 pounds with a 30 tooth granny gear and 11-32 cassette.

Another is an aluminum framed compact road bike with a compact crankset 34/50, and a 12-26 cassette. This bike weighs 21 pounds.

Now, if I take either bike up on this 10% hill, utilizing the 34/26 combination on the aluminum bike and maybe 30/28 or 30/32 on the steel touring bike, which bike would be easier to pedal up the hill?

Is 7 or 8 pounds justified in a lower gear inch compared to a lighter bike with a bit higher gear inch? Let's say the climb becomes steeper and longer, would the weight penalty of the touring bike still give me low enough gearing to cruise through the hill, seated, with a stable and progressive effort to climb, or would I just burn out on a 20 pound road bike even with a compact crank?

So yeah, even with a lighter bike, is slightly larger gearing more efficient at climbing compared to a heavier bike with lower gearing?
given the lower available gears, your pedal effort would be less on the heavier bike, but you'll also be going slower

it's all mechanical advantage, and nothing's free, so if you get a benefit of pedal effort being lower, you have the "benefit" of lower speed as well
 
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