The way I am seeing it, with a fixed gear, your leg is either propelling the pedal or giving it resistance. Even 'floating' through the stroke is not the same as coasting through it.

There are several factors, but a valid question would be weather the resistance in a freewheel is more than the resistance of someone's leg 'floating' through the dead spot.

In which case, I have wagered that it is not.

on a bike with freewheel you are forced to expend energy to pass through the dead spot. on a fixed gear your momentum will carry you through. effectively the effort required to hold a higher cadence is less.

However, the momentum that carries you through the stroke on a fixed gear is resisted by your leg, which in turn resists the wheel.

With a freewheel, that momentum keeps the wheel turning at the resistance of the freewheel, without any resistance by your leg.

Even if the drivetrain pushes you through the stroke, it is always at some cost.

you are missing my point. the force of the rotating wheel easily overcomes your leg. thats why skidding is 'so hard'.

we can argue this forever but i'd rather just agree that climbing is fun, except for when its not. :tandem:

（╯°□°）╯︵ ┻━┻

But the force of the rotating wheel on your leg has nothing to do with the actual distance the wheel covers.

/istotallywillingtoarguethisforever

Try Rotor RS4X system cranks for climbing. More time and slower cadence in the power phase 1 to 5 o'clock.

On this page: Too much "physics", not enough "htfu"

It requires the exact same amount of work to climb a hill with either a "fixay" or a freewheel. If your pedaling technique is actually so sloppy that you are allowing the fixed gear to rotate your legs through the rotation, then you are slowing yourself down. Where do you think the momentum thats moving your legs through the dead spot comes from? It comes 100% from you....not the fixay. Pedal correctly and (1) you will climb more efficiently, and (2) the type of drive train (FG or SS) will have absolutely no effect.

Yes yes yes, we are all familiar with the basic physics of work and mass and distance and elevation. The endpoints are the same so the work is the same. But you're well aware that's not the point.

This is the point: with the help of your momentum carrying your leg through parts of the pedal stroke (which may be reliant on easily-fatigued muscle groups), stronger and/or fresher muscles can carry more of the load..

This is especially evident when climbing out of the saddle, because you can focus your efforts on the most powerful parts of the stroke - the push down and the pull up - with relatively little consideration for the problematic bottoms and tops.

Sure this isn't a problem with perfect technique and unlimited stamina, but most people don't have those things. This is especially true when out of the saddle, after long climb, when you're fatigued and trying to power through to the top. Round pedal strokes go out the window. Some muscles fatigue more slowly than others, and the fixed drivetrain allows those muscle groups to carry the load better than non-fixed.

Furthermore, given that you can rely on momentum to carry you through certain parts of the pedal stroke, you can rest entire muscle groups by focusing on the other parts of the stroke. The energy expended is very obviously the same, but you can better decide which muscle groups expend that energy.

http://i.imgur.com/sCDWn.gif

Example:
Say you can feel your hip flexors are fatiguing, so you want to take the 9:00 to 1:00 part of the pedal stroke easy for a few revolutions. Your quads/glutes (the big, strong muscles) feel fine.

On a freewheel you have two options:
A) Stop pedaling all together, and coast. Your hip flexors do zero work, but until you turn them back on, none of your other (potentially fine-feeling) muscle groups do either. you slow down considerably.
B) Push lightly through that part of the stroke with your hip extensors (or compensate by pulling harder on the equally fatigable hamstrings), then back on the power with your quads. Your hip flexors use less energy than normal, but don't get to rest entirely.

On a fixed gear you can do option B, or option C) Turn off the hip flexors entirely and "coast" through that part of the circle, and still have the pedals get around to 1 o'clock for the power stroke.

The same is true for any other combination of fatigued or fresh muscle groups. To coast on a freewheel robs you of the opportunity to maintain speed by compensating with other muscle groups. To "coast" on a fixed gear lets you work which groups you want.

Nice bike!

For me, I always try to keep my cadence up, as soon as I start to slow down and mash, I can't keep it up for very long.

For short climbs I'll just mash, but for long climbs (4-5+mi) I'll keep my cadence up and spin, spin, spin.

Easier said than done

QFT. There is a climb at the beginning of my commute. Usually, on the roadie, I would huff it in a low gear and take about 1:20. I did on my fixed and had no choice but to hit it hard and fast to keep the momentum up. I did it in 0:54.

EDIT: just for clarity, I am pointing out the "mental" part of this scenario, not the perceived effort/betterness of a fixed gear.

I just try to keep mt cadence up and focus on my cadence rather than how much my legs hurt. I'm far from a pro at climbing but this is what I do and it works for me.

Hills are fun. Always hurts when I get to the top though. :(

the good hurt

be "fun" to try this fixed
http://www.mapmyride.com/s/routes/vi...angeles/676969

this is what i was trying to say without so much intelligent detail. agreed 100%.
the momentum of the rearwheel has a mechanical advantage over your force applied/body weight/whatever on the cranks. you 'float' through your dead spot.

Again, it takes the exact same amount of work to ride up a hill regardless of DT. If you can pedal a freewheeled bike without ratcheting the freewheel then it makes no difference when pedaling if you are riding a FG or SS (assuming equal DT friction). You don't need a fixed gear to do anything you are describing. The exact opposite muscle group of the oppsosite limb (according to your figure) still rotates the pedals in the situation you have described. If the hip flexors relax, the extensors of your opposite leg (which "feel fine" accorind to your scenario) will continue to rotate the pedals...thats why one phase is called recovery phase and the other is called the power phase....you have two legs. Because you have two legs, you can easily pedal complete circles with no muscles contractions during the recovery phases, even with a freewheel (millions of people do this everyday). To argue that a fixed gear is necessary for this is absurd. If you know how to pedal in complete circles without ratcheting the freewheel (everyone can do this), then having a fixed gear serves no advantage when climbing.

The perceived advantages of climbing with a FG are largely illusory. In fact it is a disadvantage if you allow the pedals to move your legs through any part of the pedal stroke, because not only are you loosing the same momentum that you would by coasting, but you loose additional momentum by having the drive train drain continue to drag your legs in circles. Loosing momentum means that you are going to have to expend more energy in the next pedal cycles to regain the momentum. If you loose more momentum each cycle, that means you also need to recover more momentum each cycle during the power stroke or you will eventually come to a stop. Its far more efficient to maintain as close to a constant velocity as possible.

This is true everywhere except at the 6/12 o'clock position, where you're generally between muscle groups.

I'm not convinced that's true, otherwise it would be very difficult to ride without foot retension, which millions of people do everyday. Without foot retension, the muscles groups of the recovery phase (shown in blue yellow and green) cannot move the pedals. They can only lift the foot off the pedal, or make the foot move with the pedal, but can't really contribute to pedaling, nonetheless it is possible to pedal smoothly without retention.
The figure posted above is greatly oversimplifed. Many of those muscle groups clearly work beyond the ranges shown. For instance, knee extensors can move the pedals through the 12 o'clock position, even without foot retention and ankle plantarflexors can move the pedals at least a few degrees past the 6 o'clock position.
There is probably a paper out there testing the role of various muscles used in the pedalling cycle, but I've never seen it.

you are forgetting that there are two crank arms. cruise around on your bike with one leg and come back.

thats funny but no.

http://i.imgur.com/sCDWn.gif

this is one leg/one crank arm. to accurately indicate the forces being directed into the drivetrain you must overlay the same image 180deg.

come again?


:giver:

Yeah, I know.