Why Are Recumbent Bicycles Poor Climber?

[look 171]

Originally Posted by Tobra

Depending on the course, I think a recumbent would run away from a conventional bike, just from an aero standpoint. I have ridden them a few times, and in a straight line you can really fly without that much effort. Tried one with a fairing that was ridiculous. It was a bit heavy and awkward, but once you were rolling you would really go. A windy downhill would have slowed me way down, it did not handle well.

A 30 mile race in a velodrome. The recumbent with the fairing will win for sure. A 30 miler with a 3000feet mountain pass then down the other side, the road bike is a goner. Especially if you have a 4 guys working together. the gap will become too big for the human power vehicle to catch up. Even if there are four of them. You are right, it depends on the course.

[island911]

Originally Posted by gtc

I think Red-beard's point is that rider weight is irrelevant...

While the rider's weight is irrelevant, I'm not sure that's Red's point.

Originally Posted by gtc

Using the handlebars for leverage is a separate issue. ...

The leverage is either thru the bars or thru the seat. ..other than a very small inertial force of the frame/body during opposing pulses. Anyway, even if spinning, there has to be a counter torque to oppose the torque of the offset pedals.

[red-beard]

Going up a hill takes energy. The energy required is the same, assuming the bike and rider are the same weight. energy=mass*height*gravity. Velocity is also energy and you can trade height for velocity and vice versa. This will not change with a recumbant.

On a standard bicycle, the maximum force you can apply to a pedal is equal to your weight, unless you can come up with a way to create leverage, like by pedal pulling on the opposite crank or other means.

On a recumbant, you are limited only by leg strength and frame strength. If they are geared the same, and setup properly, a recumbant should be able to out climb a standard bike. Most of us have more strength in our legs than our weight.

People get out of the saddle to increase maximum force. If you're sitting on the saddle, the maximum force you can produce is less. As you hit the hill, your velocity starts to drop. To compensate, you get out of the saddle to increase the force on the crank and keep your speed up. This will work for a little while, but your velocity most likely will drop and you need to gear down. Getting out of the saddle means less gearing down, but more force and hence energy in shorter time period.

The recumbant does not have this disadvantage.

I think the problem is gearing. Since the recumbants are fast, the gearing is probably very tall. These people may not change the gearing for hill climbing and have trouble. I also see potential problems in weight distribution. The weight is even less distributed on a recumbant. I expect there is a weight penalty on a recumbant, all other things being equal.

I ride a course in Bastrop State park with some pretty mean hills. I regularly out climb people that weigh a lot less than I do because I gear for hill climbing and I know how to shift. These people are in too tall a gear when they hit the hill and the lowest gear they have is 39t front and 21-23 in back. My gearing goes down to 30t front, and 27t back. When I run out of velocity, I have myself already in 30t x 24t. I generally still have 2 more gears to go. I end up running quite slow at the top, but I can keep it going. I also have a 175mm crank arm.

The person with a 170 mm compact crank and a 52t/39t front with an 11-21 rear cassette is poorly setup for hills. They hit the hill in the tallest gear and don't downshift in time. I see these people all the time and I, a 260+ rider, pass them up hill. It is all about properly setup bike and riding skills.

[Racerbvd]

racerbvd. i pedaled something similar to that in Mazatlan. i was drunk, and thought i could do better than the man we hired..i almost puked.

LOL, yea, it is not the easiest thing to pedal by yourself, and uphill is a real workout!! I got rid of it because I couldn't get a proper extension on my knees and since I had one fixed, didn't want to screw it up..

Originally Posted by jyl

I asked not because I'm all that interested in a recumbent bicycle, but more because I'm interested in the velomobile concept (enclosed trike). In most (all) of these, you sit in a recumbent position. I'd sure like to see pics of petrolhead's machine, and more pics of racerbvd's trike.

I'll pull it out & get some more pix..
Just wondering, how many of you posting on this thread have actually ridden one (I know a few have).
One thing that hasn't been covered is the stability at maintained speed, they can get speed wobbles, and while 300lbs may give a great down-stroke, but our old friend Mr. Gravity that is fighting to pull that fat ass back down the hill.. As I said, it uses different muscles than a typical road bike/MTB/ Beach Cruiser or even BMX bike and since I own & ride all(and have activing riden since a kid, even after I got a car), I'm speaking from the seat of the pants...

[PabloX]

Originally Posted by red-beard

Going up a hill takes energy. The energy required is the same, assuming the bike and rider are the same weight. energy=mass*height*gravity. Velocity is also energy and you can trade height for velocity and vice versa. This will not change with a recumbant.

On a standard bicycle, the maximum force you can apply to a pedal is equal to your weight, unless you can come up with a way to create leverage, like by pedal pulling on the opposite crank or other means.

On a recumbant, you are limited only by leg strength and frame strength. If they are geared the same, and setup properly, a recumbant should be able to out climb a standard bike. Most of us have more strength in our legs than our weight.

People get out of the saddle to increase maximum force. If you're sitting on the saddle, the maximum force you can produce is less. As you hit the hill, your velocity starts to drop. To compensate, you get out of the saddle to increase the force on the crank and keep your speed up. This will work for a little while, but your velocity most likely will drop and you need to gear down. Getting out of the saddle means less gearing down, but more force and hence energy in shorter time period.

The recumbant does not have this disadvantage.

I think the problem is gearing. Since the recumbants are fast, the gearing is probably very tall. These people may not change the gearing for hill climbing and have trouble. I also see potential problems in weight distribution. The weight is even less distributed on a recumbant. I expect there is a weight penalty on a recumbant, all other things being equal.

I ride a course in Bastrop State park with some pretty mean hills. I regularly out climb people that weigh a lot less than I do because I gear for hill climbing and I know how to shift. These people are in too tall a gear when they hit the hill and the lowest gear they have is 39t front and 21-23 in back. My gearing goes down to 30t front, and 27t back. When I run out of velocity, I have myself already in 30t x 24t. I generally still have 2 more gears to go. I end up running quite slow at the top, but I can keep it going. I also have a 175mm crank arm.

The person with a 170 mm compact crank and a 52t/39t front with an 11-21 rear cassette is poorly setup for hills. They hit the hill in the tallest gear and don't downshift in time. I see these people all the time and I, a 260+ rider, pass them up hill. It is all about properly setup bike and riding skills.

This sounds all great in theory, but a typical rear cassette is a 12-29. Also, none of this directly talks about lactic acid buildup which is the real problem on any long climb. A rider on a standard bike is only limited by lactic acid tolerance/production.

I ride quite a bit though I'm by no means the fastest person I know on a bike. I also ride in an area with a lot of cyclists and I've ridden a fair number of centuries in a pretty hilly area. I've never seen anyone on a recumbent out climb a good rider on a standard road bike.

It's really all about being in shape.

[red-beard]

Explain why lactic acid buildup will be different on a recumbant vs. a standard road bike.

[red-beard]

Originally Posted by PabloX

This sounds all great in theory, but a typical rear cassette is a 12-29. Also, none of this directly talks about lactic acid buildup which is the real problem on any long climb. A rider on a standard bike is only limited by lactic acid tolerance/production.

I ride quite a bit though I'm by no means the fastest person I know on a bike. I also ride in an area with a lot of cyclists and I've ridden a fair number of centuries in a pretty hilly area. I've never seen anyone on a recumbent out climb a good rider on a standard road bike.

It's really all about being in shape.

Also, 12-25 is a fairly standard cassette. 12-29 is not, at least around here. Most of the "serious" riders use an 11-21. I was simply exploring the myths presented here and refuted them with physics.

Of course a good rider will out climb a poor one. But that was not the discussion!

[PabloX]

Originally Posted by red-beard

Explain why lactic acid buildup will be different on a recumbant vs. a standard road bike.

It would be different because a recumbent is never lighter than a standard bike of equivalent cost.

That was really a retort to your comment about leg strength and the ability to transfer that to the pedals. That ability is really immaterial unless you're lifting yourself off the bike. You should be spinning faster than that. Also, a standard bike does allow a person to use their whole body, not just the legs, by means of rocking the bike back and forth like you see on a sprint. That helps to not overload the leg muscles with lactic acid.

As I said, I ridden plenty of centuries and the guys on recumbents never keep up despite some of the advantages they have (less core fatigue for the rider, more aero).

[HardDrive]

Lets cut the crap and get to the point: recumbents are poor climbers because only 50 year old white guys pilot them.

[red-beard]

Originally Posted by PabloX

It would be different because a recumbent is never lighter than a standard bike of equivalent cost.

That was really a retort to your comment about leg strength and the ability to transfer that to the pedals. That ability is really immaterial unless you're lifting yourself off the bike. You should be spinning faster than that. Also, a standard bike does allow a person to use their whole body, not just the legs, by means of rocking the bike back and forth like you see on a sprint. That helps to not overload the leg muscles with lactic acid.

As I said, I ridden plenty of centuries and the guys on recumbents never keep up despite some of the advantages they have (less core fatigue for the rider, more aero).

Nothing you are putting forward refutes the physics of the situation. The rocking you suggest as "helping" is more an instability occuring during time when you're not spinning enough. It is a byproduct of maximizing output, not the most efficient way to ride or you'd be doing it all the time.

I expect the reason is closer to what Hard Drive suggests. I do not believe any sanctioned races allow recumbants, so no top riders are using them.

[look 171]

Originally Posted by red-beard

Nothing you are putting forward refutes the physics of the situation. The rocking you suggest as "helping" is more an instability occuring during time when you're not spinning enough. It is a byproduct of maximizing output, not the most efficient way to ride or you'd be doing it all the time.

I expect the reason is closer to what Hard Drive suggests. I do not believe any sanctioned races allow recumbants, so no top riders are using them.

Off the saddle means max torque on the pedals. This is a time where you try to kill the others on a cllimb during a race to show how much power and lung you have left to the finish. During racing, off the saddle usually means dropping a gear and out of the saddle to attack. Many times riders get out of the saddle to relax the muscles a bit to change position to reduce lactic acid build up. Correct gearing is the key. I ride a 39/53 with 21 largest cog in the back. It is almost never use unless I am dead tire going home. I have a little more then a one mile climb up to my house. A 23 will be install if I know I am going to go over 5000' of mountain. If not, I suffer through it.

Do they even race those recumbants in a mass start race? they would be super hard to control around a turn.

[fanaudical]

The UCI has very stringent definitions of what constitutes a "bicycle". These rules were created after a 'bent rider totally humiliated a bunch of other riders in a race long ago. That's the only reason there are no recumbents in the wedgie races.

My SWB bent runs a 34-12 rear cassette (9-speed) with triple chainrings up front (30-42-52). The first thing you do when you move to a recumbent is give up any consideration of what "normal" bikes do.

I've been riding recumbents for 10+ years and know several others younger than me who ride them as their primary form of transportation. I'll have to remember the "50 year old white guy" crack when I get there in another 10 years...

[look 171]

Originally Posted by fanaudical

The UCI has very stringent definitions of what constitutes a "bicycle". These rules were created after a 'bent rider totally humiliated a bunch of other riders in a race long ago. That's the only reason there are no recumbents in the wedgie races.

My SWB bent runs a 34-12 rear cassette (9-speed) with triple chainrings up front (30-42-52). The first thing you do when you move to a recumbent is give up any consideration of what "normal" bikes do.

I've been riding recumbents for 10+ years and know several others younger than me who ride them as their primary form of transportation. I'll have to remember the "50 year old white guy" crack when I get there in another 10 years...

Years ago I showed up to a local race (USCF) way back and had a disc wheel covered with a stretch fabric over a regular wheel set. they call it a fairing and wouldn't let me start. I had to take it off. With that thing on my wheels, I would fly on the flats. I suck on hills even when I was in fighting weight and shape.

[PabloX]

Originally Posted by HardDrive

Lets cut the crap and get to the point: recumbents are poor climbers because only 50 year old white guys pilot them.

When's the last time you saw anyone other than a white guy climbing a hill on any bike?

Also, I misspoke about cassettes above. Mine's a 53-39 in front and a 11-28 in back and a SRAM Force group.

[Flieger]

^I've seen white girls climbing a hill on a normal bike.

[herr_oberst]

Originally Posted by fanaudical

The UCI has very stringent definitions of what constitutes a "bicycle". These rules were created after a 'bent rider totally humiliated a bunch of other riders in a race long ago. That's the only reason there are no recumbents in the wedgie races.

The story might be true, I have no idea, BUT . . .

If a 'bent manufacturer threw enough money at the UCI, I would imagine that the rules could be 'bent', pun intended. I remember when only round tube steel framesets were legal. These days? Not so much.

[jyl]

Totally OT but I thought it was interesting. Wonder if anyone actually does this? I have never seen a DF bicycle with any sort of fairing.

[nostatic]

Originally Posted by PabloX

When's the last time you saw anyone other than a white guy climbing a hill on any bike?

You're kidding, right?

On any given day I see every race and gender on 2-wheels either for transportation, training, or posing.

[red-beard]

Originally Posted by nostatic

You're kidding, right?

On any given day I see every race and gender on 2-wheels either for transportation, training, or posing.

+1. Some of the best amateur riders in Houston are a team called D.R.A.F.T. (Dedicated Riders Achieving Faster Times). These guys (and gals) are well disciplined, fast and all African American.

Dedicated Riders Achieving Faster Times D.R.A.F.T. CYCLING CLUB OF HOUSTON,TX

[island911]

Originally Posted by jyl

Totally OT but I thought it was interesting. Wonder if anyone actually does this? I have never seen a DF bicycle with any sort of fairing.

Fixed it for ya..


btw, cooling the motor is important. And, aerodynamically speaking, that doesn't buy much.