Gearing vs Weight

[fourflys]

So I had some thoughts running through my head on my ride today..

I often read about folks trying to figure out how to get lower gearing on their bikes (as have I) and some folks I know obsess about being able to easily spin up hills.. other folks obsess about bike weight (been there as well)..

my question is whether dropping weight can have the same effect when riding up a hill as having a few teeth lower big cog? Meaning if I drop 20# of my total system weight, will that equate to going from a 32 to a 36 tooth cassette for example? (number of teeth just for example)

did a search, but nothing quite like this question popped up..

just some food for thought..

[deluz]

These two things help the most for climbing

1. Drop body weight. Most people can loose more weight than their bike can and it’s a lot cheaper than shaving grams on bike components.

2. Increase power. Easier said than done and it takes time and effort.

For a while I tried a 46/30 crankset on one of my bikes.
I concluded that on steep hills that while I could pedal at a higher cadence it wasn’t really easier than using a higher gear and pedaling slower and overall the gearing just felt wrong for road biking so I went back to 50/34.

[Ken Robb]

I think relative gains of weight vs. gears for a given rider may vary depending on the steepness of the climb.

[fourflys]

Originally Posted by Ken Robb

I think relative gains of weight vs. gears for a given rider may vary depending on the steepness of the climb.

my question is on a climb of the same pitch..

Would xx pounds of weight lost feel the same as gaining xx number of teeth on the largest cog?

I could certainly stand to lose xx pounds of weight..

[Ken Robb]

Originally Posted by fourflys

my question is on a climb of the same pitch..

Would xx pounds of weight lost feel the same as gaining xx number of teeth on the largest cog?

I could certainly stand to lose xx pounds of weight..

I think it depends on the pitch. If you can muscle up by standing on the pedals it might be about the weight but if you absolutely need lower gears to make it up at all it's probably not going to help if you lose a few pounds.

I have never been a good climber and getting lower gears only helped so far and I got to a place where I was spinning as fast as I could pedal but my speed was so slow that I had trouble maintaining my balance.

[tomato coupe]

Originally Posted by fourflys

my question is whether dropping weight can have the same effect when riding up a hill as having a few teeth lower big cog?

The short answer is no. Lower gearing lets you climb at a slower speed without dropping to an uncomfortably low cadence, but it doesn't change how much work/energy is required to ride up the hill. Lower weight reduces the amount of work/energy required to ride up the hill.

[zmalwo]

The benefit of having lower gearing will always outweigh lower bike weight by a significant margin. It's no brainer almost.

[bigbill]

In 2022, I lost close to 60 pounds and in doing so, lost much of my fitness. In rebuilding my fitness since, I am a better climber without changing gearing. It's hard to quantify other than average speeds over the same courses. For comparison, I look at my MTB routes since there are fewer variables such as wind and temps. For gearing, my gravel bike has a 34/46 with an 11-32. I like the double because I can run a tighter cassette and a 34-32 is low enough for what I ride. My MTB is has a 32 chainring with an 11-46 cassette, which is low enough, even for the stuff around Flagstaff at 7700 feet and up on Burgess Junction at 9000 feet. My main roadbike has a 35/48 and a 10-33. I don't think I have used the 33 yet.

But weight, I won't worry about bike weight until I'm at my 90s racing weight, and that will probably be never. In 1994, I raced Cat 2 so I could do P/1/2 races with a teammate. I lived like a monk, weighed my food, and essentially eliminated processed foods and white sugar. I dropped from 185 to 172 at 6'2". I went from a strong time trialist and breakaway rider to a climber. I could crest the climbs with the front group, but I didn't have the overall wattage from before. After the season, I petitioned down to cat 3 since I was turning 30 and master's races were 3/4. I eventually got my speed back.

I don't get the 1X setups with a big cassette unless it is for a specific course. I like motoring along and finding the ideal gear. A cassette with big jumps doesn't do much for me unless it is on my MTB.

[Mark McM]

Originally Posted by zmalwo

The benefit of having lower gearing will always outweigh lower bike weight by a significant margin. It's no brainer almost.

It's true that weight savings from the bike alone is fairly small. But most of carry more extra weight on your bodies than we need, so much so there is room for a significant improvement in climbing by reducing body weight.

Like tomato coupe said, the benefit of lower gears is being able to go slower when climbing, whereas the benefit of weight loss is not having to do as much total work for the same amount of climbing.

[fourflys]

Originally Posted by Mark McM

Like tomato coupe said, the benefit of lower gears is being able to go slower when climbing, whereas the benefit of weight loss is not having to do as much total work for the same amount of climbing.

this would make some sense to me as touring bikes of bygone years were always the ones to have "low" gears (you know, a 28 tooth big cog.. )

Logically, it makes sense it would take less energy to haul 200# up the mountain than 220#..

I mean I still love me a 1:1 ratio (or better on some days), but I was just wondering.. and, yes, taking grams off the bike means nothing when I've got extra LBs to take off the body first..

[ridethecliche]

I doubt that dropping a pound or two off a bike or even a few off yourself would be anywhere as effective as adding a tooth or two to the cassette.

Now if dropping a bunch of pounds measurable increases power to weight, then yeah sure, you'll be able to spin the same gear at a higher cadence even if you're producing the same wattage.

[spoonrobot]

Originally Posted by fourflys

my question is whether dropping weight can have the same effect when riding up a hill as having a few teeth lower big cog? Meaning if I drop 20# of my total system weight, will that equate to going from a 32 to a 36 tooth cassette for example? (number of teeth just for example)

Something like that. A long time ago, In the span of about three years I went from 155 to 195 back to 155 and then settled at 175 when I am today.

There are hills I physically could not ride up on my 70 inch fixed gear at ~175lbs that I had no problem tackling at ~155lbs. I would have needed at minimum 50-55 gear inches, maybe lower. When I was 195 I couldn't ride that fixed gear anywhere except where it was mostly flat. Anything over ~5% was impossible.

To my mind, that shows that if you keep gearing constant, but gain a bunch of weight, the capability to use that gearing decreases significantly.

On the road side; I did a ton of mountain racing and climbing with 50/34 12-23 and never thought about gearing at all, I just rode it without hesitation, when I was 155lbs.

As I gained weight I started to need lower gearing, When I was 195 I needed a 34t cassette for many climbs. At 175lbs I can still do some climbing with 12-23 but anything over ~15% no way. Looking back when I was 155lbs I could take a 23 up to 22% probably a little more.

[martl]

Originally Posted by fourflys

my question is on a climb of the same pitch..

Would xx pounds of weight lost feel the same as gaining xx number of teeth on the largest cog?

I could certainly stand to lose xx pounds of weight..

For what is the question. The option of losing system weight improves the climbing vertical velocity, based on the standard formula for potential energy mass times g times height equals energy, and kinetic energy 1/2 mass times speed squared . With the same amounts of Watt input and reduced weight you will reach the summit faster.

The option of a lower gearing influences the cadence - either you climb at the same speed but can maintain higher cadence, but the factors for the forumula, you will not improve climbing speed. Or it makes it possible for you to do the climb at all, if the climb is too steep for your combination of mass, lowest available gearing and minor factors such as road surface condition.

[Ralph]

I think to understand the answer to your question....you need to understand the levers and pulley principles we studied in high school. And more in college. The answer is not directly percentage proportional.

[prototoast]

Using data from bike calculator, a 200 lb. Rider with a 20 lb bike doing 250 watts up a 7% grade would go approximately 7 mph.

With a 34 x36 gearing, you would need to spin at approximately 60 RPM.

If you drop 20 lb, at the same power you'll be going 7.66 mph.

That equates to approximately a 34x34 at 60 RPM.

The the actual specifics depend a lot on the grade, your weight, your power, and your gearing, but to answer your original questions succinctly, yes, for a given power, if you lose weight, you will go faster which will allow you to spin a higher gear at the same cadence.