alexdrozd

From everything I have read, DFs have a slight edge on steep hills. But what I haven't read is that because you are standing on the pedals? If you sit on the DF and don't stand, are they than comparable? Or does the DF still have a slight advantage?

aikigreg

There are lots of theories, but no science to back it up. One theory is standing on the pedals, but I believe that body position (possible mechanical advantage) and muscles involved, plus weight of the bicycle, plus the training of the individual all make a difference.

If you take a brand new cyclistr on a decent DF bike, he/she can tap into at least one of those possible advantages I mentioned above and be faster on a hill climb on the DF. Put that person on a bent and it's such brand new territory that they have no choice to be slower.

Take that same guy and move him to a good performing bent, give them a lot of training miles and time to develop bent muscles, and he will be an equal climber.

I ride both bikes, and I'm fast on both. I compete in triathalons and such and finish in the top 10% on the bike easily. And what I know is that I am just as fast on the bent uphill as I am the df. However, a paceline or a well-trained triathalete will beat me up a long hill every time. On very short hills where I have speed on the bottom though, I will beat them all. It takes more energy (muscle AND aerobic wise) to do so on the bent. But I make up for it with less energy expenditure on the flats and descents.

Why all this is, I have no idea, but I've observed it time and time again.

Oh, during a pay ride last in one of the hilliest areas around here, I literally towed a DF rider up a couple hills. He put his hand on the back of my p-38 and had me help him.

caotropheus

Please fellows help me here with a defenition, what are the exact words for DF?

Trsnrtr

Like Greg said, with time and training, I seem to be as fast on a bent as I was on a DF depending upon the hill. If it's a long enough grade, I've noticed that DFs don't pass me or even that I can drop them. If it's a very short power hill, they often can sprint over the top by standing, but it benefits them little other than their ego because any hill over a few hundred feet long, they'll be sitting down again and I'll catch up.

Trsnrtr

DF = diamond frame = upright bicycle

GreenGrasshoppr

I would love to have a photo of that scene.

BlazingPedals

Another factor for very steep hills is that a DF rider can balance at nearly a standstill, whereas a bent rider has trouble (depending on the bent) at speeds below about 2 mph. But usually when recumbents' hill-climbing liability is mentioned it is referring to the speed aspect, not the ability to actually get up the hill at all. Like Greg wrote, there's lots of possible reasons for the speed discrepancy, and in fact the bent often has the advantage, especially on short hills. I'll have to get a video of what I mean - DFs often drop a lot of speed at the beginning of a climb, but a bent can cruise past them and lose speed further up the hill. Final climbing speed may be slower on the bent, but the DF has to make up the already-lost ground; and if the hill is short, it can't.

Technically, the proper name for a DF is a Safety Bicycle, given that moniker because when they were introduced they were safer to ride than the 5-feet-in-the-air penny-farthing design.

Doug5150

The only reasonable explanation I've heard is that by standing on an upright, you are using a different portion of your leg extension as well as other muscles in your body that aren't already exhausted. Stuck on a recumbent in one position, you're not free to do that. ....Recumbents also tend to weigh more, but I don't feel that's the main factor.

Recumbents are mainly about riding comfort.
Some bents are faster than an upright (for the same exertion) while many are slower, but just about any recumbent will be more comfortable than an upright is.

If you're cutting your riding short because of upright-bike pain issues, a recumbent can quite possibly cure that totally. A typical person can probably sit on a recumbent and pedal it at least three times as far as they would go on an upright.
~

aikigreg

I nearly cried, it was so beautiful.

aikigreg

I would say that as of recent years, recumbents are no longer just about comfort. When you see us lowracers blowing by the pack, and all the speed and distance records being broken every month by recumbents, it's definately becoming as much about performance and aerodynamics. I didn't get into benting for comfort, I got into it for speed. I wanted to be able to maintain above 19mph for many many miles and I didn't want to have to insert myself into a dangerous paceline to do it. Bents gave me that freedom.

sch

An unmentioned factor is weight, it is only recently that a sparse
few bents that are within 5# of the weight of an equivalent DF
have been available. Lower weights allow more acceleration for
a given power input and hence faster up the hill. It is an unusual
steel bent that weighs under 28-30#, and Al that weighs under 25#.
DF bikes costing over $1000 these days are almost all under 22#,
and by the time you get to lightweight bent price range DF will be
in the #15-17 range. Low air resistance in a bent helps a bit, but the
advantage evaporates below 15-17mph and is marginal below 20mph.
Few hills are climbed at these speeds unless the rider is launched
from a previous downhill. I find that on my Rotator Pursuit, if I can
stay above 12-14mph going up a hill I will as or faster than the DF
riders I am with, but as soon as I go below 12, I am toast. DF can
get an immediate 10% boost in power (some more) simply by standing
up. Bents can't modulate high power outputs so easily. DF riders
also have significant input from the upper body on hills, for some
idea how much, go out and do some hill climbing on your DF with
just your finger tips on the bars, then repeat with the standard
grip. Very few bents allow any upper body contribution to rider
power.

It should be noted than Trsnrtr, Blaze and Aikigreg all appear to have
bigger motors than most of us do. Trsnrtr's videos of his centuries
are illuminating in this regard.

LandLuger

enjoyment would be a more encompassing than "comfort." I suppose I'm in the minority, but I don't ride 'bents as a "give up" bike in fact I'm in the DF saddle more often than not. The recumbent offers a more enjoyable open-cockpit, head-up experience that doesn't compare to a DF. Granted, the recumbent isn't the best weapon for many environments, but I grow weary of having to fight this ridiculous stigma more often attributed by those that have never owned a recumbent.

aikigreg

Actually, I mentioned it but you've certainly expanded on it! I still can't figure out why a bent can "pop" over some small rollers with almost no loss of speed where a Df will slow down measureably. I agree that advantage is lessened with a decrease in speed, although pacelines seem to be able to climb with less effort. A good paceline will always beat me up a hill. I don't have a bigger engine, but I do have bigger pistons, i.e. thunder thighs.

SoonerBent

OK, I'm going to vent a little here. I rode DFs for around thirty years, no physical problems at all. Then I discovered High Racers, to be specific a Bachhetta Corsa. The most fun I've ever had on two wheels. It took a few months to build different muscles but after a thousand miles or so I could climb any hill just as fast as I did on an upright. And I haven't peaked on the Corsa, I'm still getting faster. Most of the climbing problems with 'bents fall into two categories. 1) A lot of 'bents do fall into the 30+ pounds category. This doesn't bode well for defying gravity. However there are now quite a few 25- pound 'bents available. 2) Riders that aren't so fit as many DF riders. For instance, on a local ride a couple of months ago about six of us (me on the Corsa and the others on DFs) ran off and left a rider on a Bachhetta Ti Aero on a hill. When he caught up to us he blamed the bike. "Bents don't climb very well you know". WHAT! I topped the same hill with the front guy. The Aero rider in question hasn't seen the down side of 250 in some time. It wasn't the bike!
Another theory is that DF riders can stand and we can't. Gravity limits a standing DF rider to his/her body weight + any force exerted by pulling up on the bars while pushing down on the pedals. Usually estimated to be at most 120% for body weight + pulling force total. I can easily single leg press 120% of my body weight. I do it regularly in the gym at work. It's part of my training program. BTW, I'm 155 to 160 lbs.


Now, I may be a fanatic about training and riding to prove that 'bents can climb with DFs. But my point is that for a performance 'bent the motor is the main hinderance to climbing. Side note: Something like Le Alp D' Huez would be an entirely different thing.

aikigreg

Sooner - I agree with most of what you said, but leg press ability doesn't carry over much into cycling - recumbent or not. I can squat 2x bodyweight and leg press 5 imes my bodyweight, but I neither squat nor press in a rotating fashion. I think you hit the nail on the head with 1 and 2 though!

SoonerBent

But, a DF rider can't spin standing. So climbing is closer to comparing a mashing DF rider and a mashing bent rider. In both cases most of the power is produced by simple leg strength (or in the DFs case gravity) pushing on the pedals in more or less a straight line. The only thing controlling that line is the curve caused by the crank arms. BTW, the machine I use in the gym at work very closely mimics my position on the bike, so I am building the same muscles I use to push the pedals. An example of how this does make a difference is a hill I hit last night. We were on a bike trail I had not been on before. It goes under a bridge, makes a hard left and before you is a steep, hundred foot long hill. I was in way too high a gear and never would have made it up the hill six months ago (before spending every lunch break in the gym).

Trsnrtr

My motor is fine, but I think it's probably Blazing Pedal's videos that deserve kudos.

aikigreg

I really need to edit video of our HPV race and throw it up there. Here's a pic of me leading the pack of VK2s though - they all drafted me as long as they could. I was sure they were going to let me exhaust all my energy and then slam me the last lap. I think my sprint surprised them since I started it with three laps to go and lapped them

That's a catrike 700 in the back.

Mars

what are those narrow tires on your front wheel? It's a 20" wheel, right? I can't seem to find such narrow slicks for my front wheel...

Trsnrtr

Excellent pic.

What's that above the trike guy's head? Looks like a mirror system or is it just something on the track?

aikigreg

I have no idea. I only rode the bike for that race - it wasn't mine. But they should have been whatever comes stock on a Fujin SL I.

banerjek

Not exactly. On a DF, it's much easier to rotate through different muscle sets. You stand for awhile, sit for awhile, move fore and aft on the seat. If you calculate the watts, it might not be efficient, but from a pain and speed perspective, it definitely works for the simple reason that you can spread the work out over more muscles.

The weight of a bent is a big deal on prolonged climbs, though I think it is a nonissue on flats and on shorter hills. I have a Seiran SL which is one of the lighter ones out there (spec is #21, honest weight is probably closer to #23). If you ride do 10,000 feet of climbing as might be done in a really hilly century, compared to riding an #18 DF, you have to do the equivalent of an extra 50,000 foot pounds of work.

That's not to say you can't climb on a bent. I can drop plenty of roadies even when I'm in my trike. However, I'm a pretty strong climber and when I'm on a DF, I can really move. The Seiran shows its true advantage on flat rides (or just some hills) when headwinds are involved.

cfblue

On the question of why do recumbents do better on rollers, I have a thought or two.

A number of people I see out riding seem to guess at what gear combo they need at the top, then get close to that combo, allowing their speed to drop until tey can match speed to gear inch, they loose thier momentum on purpose..

In an opposite event I was in a paceline with a group I hadn't ridden with before. The course was full of rollers and it was very familiar to all, the paceline was the only thing new to me. We had been crusing 23-25 on the flats when we reached the first ascent a short, not even particularly steep rise. They shifted up, stood up, lost more than 5 mph and I nearly ran over top of them because I shifted to a lower gear to spin up. this was on DF BTW. They gave up all their speed and momentum so they could stand. That so unnerved me I dropped out of the ride. Next week, better prepared for their technique, I was all ready to move around them.

As both a tandem rider and a recumbent pilot, I figured out a long time back how to work with momentum to get up rollers. I pedal down, sometimes agressively, and fight to keep it all the way up.

I was on my RS24 riding the Palm Spring century. The RS had a fairing at that ride. I found it fun to torment the other guys who were really battling a head winds on their uprights. They were coasting down and grinding up, I was pedaling down getting all the momentum i could, often close to 20, and coasting passing them on the way up. There were coming off the mountain, the descent were probably twice as long as the ascents.

aikigreg

Blue - I think it's all about the group. I rode for the first time last week with an ultra-serious, no bull**** club. We did a short 32 mile ride, but it was all hills, some of them SERIOUS.

We were cruising along at an easy 22-23 paceline speed as a warmup and then they got serious and dialed it up to 25. I hadn't ridden at anything close to that speed since last October, so I was ill-prepared and got spit out the back of the line. On the first big hill they took off like a shot and left me gasping.

I had to slow down since I didn't know the route at all and needed to let one of the slower riders catch up and I hung with him most of the rest of the route. I finished with a 17.5 average. Had I known the route I could have boosted it up to 20 I think, but the guys who didn't get dropped ended with a 21.75. No way I could have managed that in my current shape.

All these guys were 130-150 pounds and on very light bikes. I was beat and I knew it. We'll see what happens again when I ride with them this week, but the results will likely be much the same until I get better at the hills.

It was awesome. I've never had a paceline beat me on the flats before, but I've never ridden at speed on the P-38. Can't wait to see what happens when I'm back on the lowracer.

Dchiefransom

Don't forget that even when sitting, a DF rider still pushes down with their weight on the pedal. Watch anyone on a steep hill, and you'll see them lean over a bit on the down storke, even the pros.