Gearing vs Weight

[htwoopup]

Interesting question. Back in the Bronze Age I was a competitive runner. I vaguely remember there was some study that said something like lose a pound lose 2 seconds of time per mile. Don’t think I have ever seen a study that did it on cycling and/or then converted it to gearing.

[robt57]

After a few seasons of trials, I've some to this conclusion for me since crossing over 60 years old.

1) If lower that about 25 GI, it became counter productive on climbs you not 'have' to stand on. Too low for me, I loose momentum between strokes. And that hurts worse for me.

2) For 'road' bike riding, as in 'go fast' riding, over 28mm tires seemed counter productive.

Notes: I am 210 lb at the edge of Clyde. And without question loosing weight makes a way bigger difference.

2018 I went from 236 to just under 200. 2018-9 I spent more time in the big ring than about any seasons in quite a while. Like when I was a bunch younger.

Arbitrarily, 34/34 is about as low as I go for go fast riding. I do have an All road with 28 small ring I did Crater Lake with a 30t cassette. That is like one gear lower and I used it only a few times briefly and up-shifted quickly. Maybe muscle memory from so much 34/34?

[Mark McM]

As a practical example:

Say there are two identical twins who each weigh 162 lb. and can both produce the same power output for a sustained effort. One is riding a 38 lb. Schwinn Varsity (200 lb. total) with a 34/33 low gear, and the other is riding a modern 18 lb. bike (180 lb. total with a 34/30 low gear. The rider on the modern bike has 10% lower total weight, and a 10% higher gear. At the same power, the rider on the modern bike will be going 10% faster, and since his gearing is 10% higher, he will be pedaling at the same cadence as the rider on the Varsity. So at any given point along the climb, both riders will be riding at the same effort level (power and cadence).

But here's the difference: Because the rider on the lighter modern bike is going faster, he/she will finish the climb sooner, and therefore expend 10% less total energy. Maybe for a short climb this won't matter, but for a long climb (or a long ride with many climbs), the energy savings can add up

[unterhausen]

I have often thought that if I manage to lose 10 pounds, hills get a lot easier. That seems to be the point where I notice a difference. But if I lose 10 pounds, it means I'm riding a lot. So not a good experiment.

[Dave]

According to an online calculator it takes about 20 watts to carry an additional 10 pounds up a 13% grade. At 135 pounds or less, I have little excess weight to lose. My bikes have a 30/44 lowest gear ratio that will produce a little over 4 mph at 80 rpm. I couldn't hold a straight line going any slower. Add a strong headwind like I've ran into several times this year and even the 30/44 can be tough to pedal.

My ebike is a better solution. Programmed properly, you'll still work plenty hard during steep ascents with a head wind, but you'll be traveling a lot faster. I've used my 46/38 gear ratio and it was adequate with the power output limited to 150 watts. I'm going to try a 10-36 cassette soon, since my current 38 seemed more than adequate. It only requires 6% more torque to spin it. I used a 30/36 gear ratio on my acoustic bike for seated climbing and 30/24 or 30/28 while standing, only a few years ago. I can't do that for 10-12 minutes anymore.

[benb]

If you’re losing excess fat and you’re doing it from training and not being sick or something I think there is more going on and the gains are much larger than calculators would say.

If your body composition is improving I think there are additional effects from your body just running better. More power at certain points in your power curve, or a given wattage up that hill is suddenly aerobic whereas it wasn’t when you’re heavy.

20lbs lost through healthy living and hard training should be earth shattering.

I had many years I had 5-10lbs to lose at the beginning of the season and the bike stays exactly the same. I’d have said even by the time I lost the first 5lbs I was going to be dropping the heavier version of myself.

Heck I’ve just about done this so far this season and that process was somewhere around a 1.5mph difference in typical pace.

So IMO no changing your bike isn’t going to do very much if it’s already a nice bike. But if it’s you that’s improving 20lbs is a huge huge difference. Maybe it’s less if you’re 50lbs overweight and you go to 30lbs overweight, but if you’re 20lbs overweight and losing that starts to put you into the “fast guy” BMI range it’s going to be a big change in climbing.

[weisan]

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?

yes, it does in so far as helping one ride up to the top of the hill a bit easier, note that I say easier, may or may not be faster.

Since this question is posed in the context of climbing, I will keep the discussion in this context.

Lowering one's weight will only help with climbing up to a certain point. The person who won the mountaintop finish at the tour is not the lightest in the peloton.

Using an easier gear will only help up to a certain point. The person who won the moutaintop finish at the tour does not have the easiest gear.

But anyone who have ambitions in winning the general classifications at the grand tours has to learn to manage their weight and get it under control. But reducing weight can only get them so far, they still need to work on other aspects too if they really want to win - time trialing abilities, team tactics etc.

In times when the tour organizers get extra sadistic and arrange for the mountain stage finish to end at an exceptionally steep ramp - finishers crossing the line fully spent and needing someone to push them from behind to keep them from literally falling off their bikes, we have seen GC riders consciously asked their mechanics to install a lower gear. It has happened a few times. Even the best climber in the world finds it helpful to have a suitable gear to meet the challenge of a difficult terrain.

And then, we have seen riders like Lance and others who popularized the idea of climbing at high cadence. Pantani's unique riding style of climbing in the drops.

Some people would say "I am a mesher", some would say, "I am a spinner". That's all fine and dandy, whatever help gets you up to the top.

Pushing a bigger gear taxes certain parts of your body or muscles. If your body is constituted to handle that kind of stress well, by all means, push a bigger gear all day long. Not everyone is.

Spinning at high cadence is not something you can do at will while climbing if you don't practice it enough. It doesn't always come naturally.

Whoever likes to cimb will tell you this, there's a lot more involved in climbing well than just managing one's weight or getting a lighter bike or using an easier gear....lung capacity, ability to "suffer", breathing techniques, mental games, shifting your weight around, alternating between sitting and standing climbing position, varying candence etc.

[Gummee]

There used to be a free site out there that would let you compare weight, grade, etc. I looked up WhyTF I could tow my riding buddy to the bottom of the Boulevard RR course east of Sandy Eggo at 20+ mph with him barely hanging on till we hit the bottom of the hill.

Then he'd walk away from me up the hill.

I put in my weight 165 and my buddy's weight 135 it spat out that he needed to push 2xxw up the hill to go Xmph. At my weight, I'd have to push 6xxw to go the same speed.

There's only so long I can maintain 6xx watts up a hill.

It's been a few years since I was on the site and have forgotten the url so that may not be as accurate as I remember.

Point is that when climbing it's weight more than it is gearing and once you run out of gearing, you'll end up pushing the same power but going slower

M

[tomato coupe]

Originally Posted by Gummee

I put in my weight 165 and my buddy's weight 135 it spat out that he needed to push 2xxw up the hill to go Xmph. At my weight, I'd have to push 6xxw to go the same speed.

I don't think it's possible to concoct a scenario where someone that weighs 20-25% more needs to output 3x the power in order to attain the same speed on a climb.

[Gummee]

Originally Posted by tomato coupe

I don't think it's possible to concoct a scenario where someone that weighs 20-25% more needs to output 3x the power in order to attain the same speed on a climb.

If I could remember the site, I'd go look up the data again.

...but I don't

M

[tomato coupe]

Originally Posted by Gummee

If I could remember the site, I'd go look up the data again.

...but I don't.

There are other web sites that can make the same calculation. I think you'll find that they all give results that are very different from what you remember.

[Mark McM]

Originally Posted by weisan

The person who won the mountaintop finish at the tour is not the lightest in the peloton.

That's right. Mountaintop finishes (and particularly for steep mountains) aren't won by the lightest rider, they are won by the rider with the highest power-to-weight ratio*. But if a rider loses weight but doesn't decrease their will increase their power-to-weight ratio. So for riders of similar power, the lighter ones will go faster.

Of course, its possible to take things too far. Every one has their own optimum weights, and trying to go below that weight may result in power loss, and their power-to-weight ratio may actually go down if they drop their weight too far.

*While power-to-weight ratio dominates on climbs, it should be noted that human beings don't scale perfectly proportoinally, and smaller (lighter) humans tend to have higher power-to-weight ratios. Sorry big guys, that's just the facts.

Originally Posted by weisan

And then, we have seen riders like Lance and others who popularized the idea of climbing at high cadence.

That's probably a bad example. Power is a combination of force and speed. Blood doping doesn't increase muscle strength, but it does increase the the rate (speed) at which the muscles can work. It has been noted that cadences increased during the peak of the doping era, and dropped back a bit in the post-peak era.

Originally Posted by weisan

Whoever likes to cimb will tell you this, there's a lot more involved in climbing well than just managing one's weight or getting a lighter bike or using an easier gear....lung capacity, ability to "suffer", breathing techniques, mental games, shifting your weight around, alternating between sitting and standing climbing position, varying candence etc.

If it only it were that easy. While optimizing your technique can help to some degree, climbing still comes down to power-to-weight ratio, and power is largely limited by the riders VO2 max (VO2 max is largely genetic, although it takes some training for a rider to reach their VO2 max).

[Dave]

Try omnicalculater.com. The difference between a 135 and 165 at 13% is around 60 watts.

I added 10 pounds for my ebike and only got an extra 20 watts at 13%. The weight helps on descents.

[tomato coupe]

Originally Posted by Dave

Try omnicalculater.com. The difference between a 135 and 165 at 13% is around 60 watts.

It's meaningless to state the difference is 60 W, because that is only true for one particular rate of ascent.

[fourflys]

appreciate all of the good discussion.. wasn't sure if this topic would be of interest or not..