Climbing and Sprinting technical talk

[battleaxe0]

This graphic is not meant to be modern art. It's a bird's eye sketch of the relationship between the hips and pedals when the boom is in neutral vs angled left (red) and angled right (green). If you are ready for some seriously geeky analysis, keep reading below.

View attachment 665

I wanted to quantify the change in distance between the hips and pedals that comes from the upper body angling the boom. I turned our kitchen table into a drafting table, and set up a scale drawing based on 24 inches from the steerer (head tube) axis of rotation to the middle of the BB axle. For calculation purposes, I used 2 inches of lateral movement of the BB axle, which corresponds to 4.76 degrees left and 4.76 degrees right angling. I used a distance of 12 inches for the center-to-center distance of the human hips....

View attachment 666


Next I used a "stance width" of 268 mm for a typical road bike crankset, from this excellent article.
View attachment 668
Next, I calculated the total change in distance from the hip to the ipsilateral (same side) pedal with boom angling, when the pedal is straight up or down, which is 1.125 inches or 2.86 cm.

Next I calculated the average speed of the fore/aft movement of the pedals at a cadence of 80 rpm, calculating that to be 76.2 mm/sec.
Then using a little calculus, estimated the peak speed of the pedal to be 120mm/sec (0.12 m/s).
View attachment 669


So now, in the Force diagram below, I inserted an approximate speed for the BB-end of the crank. Now I am not sure how to calculate the effect of that motion on torque. I'll sleep on it tonight, but let me know if you have any insights.

Jim
View attachment 675

Let me further this line of thinking, but philosophically instead of mathematically (it's been too many years since multi-dimensional calculus).

We have 3 different actions - sitting up, pulling on the bars, and swinging the bottom bracket side to side.

When you sit up, you do 2 things - you close the hip angle and shorten the boom. Closing the hip angle is what Lightning swears is the secret sauce to the climbing prowess of their bikes. Whether that's true or not, it is one of the effects. As you sit up and your hips close, you slightly rotate your hips which rolls the hip joints slightly towards your feet. In essence this shortens the boom, which changes the knee angles slightly and lets you use slightly different parts of your leg muscles that have untapped or less tapped potential.

Pulling on the bars and swinging the BB side to side has the effect of putting slightly more power into the end of the power stroke, which speeds the pedal from about 12-3 o'clock. This is a similar concept to Q-rings. Get through the power stroke faster which also gets the opposite leg through the dead zone faster.

Moving the BB side to side also shortens the distance between power hip and its foot, but lengthens the distance between opposite hip and its foot. In essence, you've shortened the cranks.

These effects are all in silly millimeters and milliseconds, but they compound. You turn your Cruzbike into a Lightning with shorter boom, Q ring, and shorter cranks.

 

[Jim Parker]

Let me further this line of thinking, but philosophically instead of mathematically (it's been too many years since multi-dimensional calculus).

We have 3 different actions - sitting up, pulling on the bars, and swinging the bottom bracket side to side.

When you sit up, you do 2 things - you close the hip angle and shorten the boom. Closing the hip angle is what Lightning swears is the secret sauce to the climbing prowess of their bikes. Whether that's true or not, it is one of the effects. As you sit up and your hips close, you slightly rotate your hips which rolls the hip joints slightly towards your feet. In essence this shortens the boom, which changes the knee angles slightly and lets you use slightly different parts of your leg muscles that have untapped or less tapped potential.

Pulling on the bars and swinging the BB side to side has the effect of putting slightly more power into the end of the power stroke, which speeds the pedal from about 12-3 o'clock. This is a similar concept to Q-rings. Get through the power stroke faster which also gets the opposite leg through the dead zone faster.

Moving the BB side to side also shortens the distance between power hip and its foot, but lengthens the distance between opposite hip and its foot. In essence, you've shortened the cranks.

These effects are all in silly millimeters and milliseconds, but they compound. You turn your Cruzbike into a Lightning with shorter boom, Q ring, and shorter cranks.

Lacking hard data, I think conjecture and arm-chair research are perfectly OK for trying to form theories as to what features, or combination of features, improve climbing/sprinting performance. I like your summary. I would point out that lengthening the distance between the hip and pedal on the back/up stroke is also a good thing, as the rider is pulling back with the leg, a lengthening action would get more torque into the BB axle (shoe clipped-in of course).

Jim

 

[MrSteve]

Rocking the bike from side to side does free up some energy that you'd normally use for steering the bike, when climbing/sprinting.
Rocking the bike allows the lean of the bike to counter the steering forces and complements the input of your shoulders/upper body.
The stiffer the chassis of the rocking bike, the more efficient the counter steering will be.

Since I am accustomed to counter steering motorcycles, this how I prefer to steer my bike.

 

[Bruce B]

My head is spinning! Since I began riding, first the S 1.0 and now the V20, I had always thought upper body engagement was to prevent pedal steer. Well, this thread changed that idea.

This morning I rode the V20 and tried out Jim's technique. Riding was done on flat roads. My bike has 50-34 Q- rings and a 12-32 cassette. I used the 50 tooth ring throughout the ride. The pedals are Crank Brothers Eggbeaters.

I'll be the first to say this evaluation was very subjective in nature.

By doing what Jim described, I felt I was proactively rather than reactively engaging the upper body in the pedal stroke. There was a sense of smoother and more forceful application of power. Of course the faster I pedaled the less time I had to angle the bottom bracket. Pedaling between 70-80 rpm in fairly high gear was most effective for me. Above 85 rpm I was unable to incorporate the upper body action with the pedal stroke.

A fair amount of resistance to the pedal stroke seems to be in order to make this technique work. I will be interested to hear what those who like to spin have to say.

Thanks Jim

 

[DavidCH]

I will be interested to hear what those who like to spin have to say.

I too have been re-evaluating my riding technique following the Jim presentation. I find that I can engage my shoulders more if I lift my head off the head rest. Its a lot easier to do either going up a hill or against the wind. You have more resistance and put into a gear that you have to mash with instead of spin. I also read somewhere that you should try to have a cadence rate of 60 RPM when going up hills. Certainly I am going up the 7% and 8% gradients a lot faster.

 

[BentAero]

I also read somewhere that you should try to have a cadence rate of 60 RPM when going up hills.

60?
If I tried a cadence that low I'd need knee replacement in less that a month.

 

[DavidCH]

So what is the best cadence rate of going up a 7% gradient? I have Q rings , my knees at 60 RPM are good and I certainly get a good burn in the muscles in my legs... I guess I do it to get my heartbeat up , if I don't get the heart beat up then I am not burning fat quickly and I do cycling to feel good and to develop strength and speed. I guess when I am done burning fat then I switch to a higher cadence rate for going up longer climbs. It's an interesting subject for sure and one that I am particularly interested in. I find with the V if I am riding flats that the heart beat doesn't go up very quickly and if I get at a stop sign it drops too quickly. A good climbing hill is perfect for what I want, in fact I found a perfect ride for the V yesterday using www.cycleroute.org



The darker colour is a 10% and the yellow is a 7%.

Quite a lot of the pro cyclists around Europe train in Tenerife because of the height of the Volcano. I like cycleroute.org as you can quickly move the route around interactively around and seeing the different terrain mapping out underneath.

 

[Jim Parker]

So what is the best cadence rate of going up a 7% gradient? I have Q rings , my knees at 60 RPM are good and I certainly get a good burn in the muscles in my legs... I guess I do it to get my heartbeat up , if I don't get the heart beat up then I am not burning fat quickly and I do cycling to feel good and to develop strength and speed. I guess when I am done burning fat then I switch to a higher cadence rate for going up longer climbs. It's an interesting subject for sure and one that I am particularly interested in. I find with the V if I am riding flats that the heart beat doesn't go up very quickly and if I get at a stop sign it drops too quickly. A good climbing hill is perfect for what I want, in fact I found a perfect ride for the V yesterday using www.cycleroute.org
...

This is a snapshot of Ben Tomblin's record-setting ride on the V20 up the highest mountain in eastern North America (the AOMM). His cadence on climbing is about 80 (the yellow line). Take note of the green line. His climbing speed during the last ten miles of the 103 mile race was about 6-8 mph.
On the downhill in the graph his top speed was 53.8 mph.

 

[Jim Parker]

My head is spinning! Since I began riding, first the S 1.0 and now the V20, I had always thought upper body engagement was to prevent pedal steer. Well, this thread changed that idea.

This morning I rode the V20 and tried out Jim's technique. Riding was done on flat roads. My bike has 50-34 Q- rings and a 12-32 cassette. I used the 50 tooth ring throughout the ride. The pedals are Crank Brothers Eggbeaters.

I'll be the first to say this evaluation was very subjective in nature.

By doing what Jim described, I felt I was proactively rather than reactively engaging the upper body in the pedal stroke. There was a sense of smoother and more forceful application of power. Of course the faster I pedaled the less time I had to angle the bottom bracket. Pedaling between 70-80 rpm in fairly high gear was most effective for me. Above 85 rpm I was unable to incorporate the upper body action with the pedal stroke.

A fair amount of resistance to the pedal stroke seems to be in order to make this technique work. I will be interested to hear what those who like to spin have to say.

Thanks Jim

My pleasure, Bruce. 99% of the time that I'm riding around my very flat part of the Carolinas, I'm riding in "normal" mode, with the BB straight ahead.

But as a drill, I will practice:
1) one-legged pedaling ( a safe way to approach and cross blind intersections... you can stop on a dime because one leg is already clipped out)
2) sitting straight up during an acceleration (my DF riding buddies love it when I do this because they get a better draft). This gives me an upper body work and can substitute for hill-work in the flatlands, and
3) the dynamic boom technique where you focus on moving the BB slightly to the left during the left leg down-stroke and slightly to the right during the right leg down-stroke. Getting comfortable with all these techniques takes practice.

Jim

 

[DavidCH]

This is a snapshot of Ben Tomblin's record-setting ride on the V20 up the highest mountain in eastern North America (the AOMM). His cadence on climbing is about 80 (the yellow line). Take note of the green line. His climbing speed during the last ten miles of the 103 mile race was about 6-8 mph.
On the downhill in the graph his top speed was 53.8 mph.
View attachment 682

I am impressed with the red graph. BPM, even going down hill its still above 150! That was some race. Many thanks for the information.

 

[jond]

That may be the issue with us noobs feeling wobbly going downhill - having the timing backwards increases the steering oscillation until it feels out of control?

yes when the timing goes astray so does the bike however with more seat time comes less whoah there nelly moments. till they one day almost disappear.

 

[ratz]

2) sitting straight up during an acceleration

Also good when accelerating out of a turn when uprights still are coasting to avoid pedal strike.

 

[jond]

My head is spinning! Since I began riding, first the S 1.0 and now the V20, I had always thought upper body engagement was to prevent pedal steer. Well, this thread changed that idea.

This morning I rode the V20 and tried out Jim's technique. Riding was done on flat roads. My bike has 50-34 Q- rings and a 12-32 cassette. I used the 50 tooth ring throughout the ride. The pedals are Crank Brothers Eggbeaters.

I'll be the first to say this evaluation was very subjective in nature.

By doing what Jim described, I felt I was proactively rather than reactively engaging the upper body in the pedal stroke. There was a sense of smoother and more forceful application of power. Of course the faster I pedaled the less time I had to angle the bottom bracket. Pedaling between 70-80 rpm in fairly high gear was most effective for me. Above 85 rpm I was unable to incorporate the upper body action with the pedal stroke.

A fair amount of resistance to the pedal stroke seems to be in order to make this technique work. I will be interested to hear what those who like to spin have to say.

Thanks Jim

spinning allows similar power figures to be generated but at a higher cadence. the benefit being manifest on a long climb with preservation of glycogen store. this is why i prefer to spin up a decent hill (5-7% steady gradient over 1klm length) once my carry speed has run out. of course it helps to have a close ratio cluster but that is not possible with very hilly terrain and my personal gearing on the v. horses for courses.

this spinning is what lance did when he came back after his bout with cancer lighter and leaner. his new style has been emulated ever since and proven itself with most talented climbers. his legacy exists today in the peloton. it is also common to see compacts in the mountains in addition to the aforementioned spinning technique.

for most of us taking our effort beyond 65% of our FTP results in burning our limited matches.

and i personally have chicken legs so mashing is not beneficial so much. have nil choice but to spin.

the techniques jim mentions are employed by myself and are still being refined. now with 4000klm on the bike i would say that i still have a lot to learn to get the most out of the platform, and most importantly myself.

revisions are required.lower gear choice required is easier to push and practice climbing is required. result faster more capable up hill.

i need to learn to love hills as much as i do the vendetta speed . now if someone could just tackle the torque.

 

[Robert Holler]

This is a great thread and definitely technique and practice are the order of the day. The effects for me became much more subtle over time and now I barely notice the inputs anymore unless on a sudden sprint.

 

[Alan Clucas]

I'm by no-means an expert on this. My only recumbent experience is on my Vendetta 2.0 for about 1000miles.

I spend most of my climbing time doing the sit-n-spin technique. But I discovered I have two separate ways of "honking" the V up hills.

1. Waggling the boom against the feet. I think this is what mostly is being described here. So I'm mostly bending the bike in the middle. It does sway sideways a little, but the bike is MOSTLY bending in the middle. This I learnt how to do first, and is the technique I use more often. This is NOT what happens on a DF bike, there the steering hardly moves.
2. Swaying the bike from side to side. The boom is hardly moving, it's just keeping me going where I want to go. But the bike is leaning from side to side with each pedal stroke quite a lot more, and this is much more like a DF rider honks, the steering being mostly still. I didn't deliberatly set out to do this, but one hill I noticed I was doing it, and have replicated it since. Maybe this is akin to what happens on a more traditional recumbent, I wouldn't know.

They feel different, and there is a definite concious action required to switch between them, or use either on my behalf.

I have no idea which is more efficient, neither feels like a bad way to do it when I'm doing it, and they both feel powerful. I just hadn't noticed anyone describing technique 2, so I thought I'd try to describe it.

 

[battleaxe0]

So I tried the full situp trick on some of our inclines this morning. Big tip for those that try it - don't forget to breathe. Luckily, our hills are so short I only missed 3 breaths. Once I caught on to what I was doing, I had to force myself to breathe on the last incline and finished by laughing at myself because it was difficult to do.

On my full out speed limit breaking attempt for the week, I got to 29 without wobbling - getting closer.

 

[jond]

hi guys just in case you dont know there is an alternative to a wolf tooth addition say to an xtr cassette 10 speed for a good spread of gear ratios for climbing those big hills.

it is made by www.praxiscycles.com and is a purpose built cassette 11-40 with a more even step than a wolf tooth addition etc. it is made as the one complete unit. i paid $160 for the complete cassette. check it out.

have not tried it yet so cannot comment but it gets a good review from the 1 x 10 crowd.

will let you know how it goes but have some time trials to do first

 

[Abbott Smith]

Yesterday I went out on a hill climbing training loop. 8.25 miles with 800' of climbing broken into three segments. The first hill is a long rounded slope that starts steeper and
gradually loses steepness until the crest. The second hill is a long steady climb with a constant pitch. The third segment has a number of varying pitches and each steep chunk can be attacked at a high tempo if I choose.
This loop is the shortest of a group of increasingly difficult hill loops that I've identified as useful training ground.

It will take me a while to refine my skills and understanding but I did realize one thing yesterday about the V20's climbing that is germaine to this discussion. We've talked about this geometry giving us options. As I attacked the steeper segments I realized that 'option' isn't accurate. There are times when I have to use my upper body if I want to get up the slope. The choice is use my arms or walk.

I don't ever recall my arms being this tired after riding a DF. Numb wrists yes. But arm exhaustion no. It actually reminds me of how I felt after the mile open water swim when I did my triathalon as a young man.

The Dynamic Boom requires a wide range of muscles to ride well and particularly uses the arms and core trunk muscles in ways that neither a DF or RWD bent require. It isn't simply a case of being able to use them. It is a case of needing to use them.

 

[Abbott Smith]

hi guys just in case you dont know there is an alternative to a wolf tooth addition say to an xtr cassette 10 speed for a good spread of gear ratios for climbing those big hills.

it is made by www.praxiscycles.com and is a purpose built cassette 11-40 with a more even step than a wolf tooth addition etc. it is made as the one complete unit. i paid $160 for the complete cassette. check it out.

have not tried it yet so cannot comment but it gets a good review from the 1 x 10 crowd.

will let you know how it goes but have some time trials to do first

Most of the manufacturers added extended range cassettes to their product lines this year. Earlier in the year tracking down these new cassettes was a bit problematic. As we move forward they should become more readily available and anyone looking for extended gearing of this type will have many more options. I was impatient and decided that the WT and Shimano combo worked for my needs. And one of my riding partners surprised me and picked up the 16t cog for me so I now have a very smooth gearing transition. I love it.

 

[jond]

Most of the manufacturers added extended range cassettes to their product lines this year. Earlier in the year tracking down these new cassettes was a bit problematic. As we move forward they should become more readily available and anyone looking for extended gearing of this type will have many more options. I was impatient and decided that the WT and Shimano combo worked for my needs. And one of my riding partners surprised me and picked up the 16t cog for me so I now have a very smooth gearing transition. I love it.

whilst the 11 speed options are indeed well covered right now with some dinner plate options the 10 speed poor men do not have the same major manufacturer options. eg my sram 11-32 xx cassette is not readily modifiable whilst my shimano 11-36 xtr is with a wolf tooth etc but nothing else from shimano in 10 speed. right now the praxis is a paper weight but soon i will test it and report . got to get out and ride now.........here i go.