Calf fatigue--recalibrate?

[Sobaka]

I commute about 3 miles each way on my new KS14S and love it. I'm two weeks in and have unlocked the speed. But I do have one question. My calfs get fatigued after a couple miles. It just always seem like I have to be at a slightly beyond comfortable forward incline to maintain speed, especially up the hill. This is even though my toes dangle a bit off the front of the pedals and I'm leading with my hips. Do you think this means I should recalibrate it, maybe even setting the level with a very slight back-tilt? Or should I just wait and let the muscles strengthen, and my balance improve such that I use them less?

[mrelwood]

You can try different calibrations, we all have our own preference. Just keep it reasonable, say +-4 degrees (use a level app on a smartphone lying on the pedal).

But I think your feet are positioned too far back. You say your toes hang ”a bit” over the pedals. How about the heel? Usually a good starting point is to level the back of your shoe to the back of the pedal. Then your toes will probably hang a lot more.

[steve454]

Check out this short video by @Simon Tay.  Are your feet positioned like his?  

 

[Sobaka]

I think you're both right on foot placement. Moved the feet forward this morning and it means the weight transfers through my heels rather than the balls of the feet. Made all the difference. Excited to see how it works for the uphill leg tonight.

 

Thanks to you both!

[LanghamP]

Hopefully some of the engineers can chime in.

I feel most, if not all, foot and leg problems can be solved by making wheels far more responsive and delicate to user inputs. Say make wheels three times more responsive ie require just 1/3 the force on the pedals to move the wheel.

Since foot problems are caused by constantly pushing the nose of the wheel down via leaning heavily forward, it follows  making wheels super sensitive would require virtually no leaning forward; ergo, the feet problems mostly go away!

 

[Hunka Hunka Burning Love]

I wonder if there could be a “cruise control” mode that could be toe switch activated after the wheel reaches a certain speed.  Braking could turn it off.  That might allow riders to not have to lean so far forwards on straight stretches of road.  Or do people think the forward lean is mandatory to be in balance with the wheel?  I think it theoretically could be possible.  That might save the stress on the calves being in a forward lean stance all the time.

[Keith]

17 hours ago, Sobaka said:

I think you're both right on foot placement. Moved the feet forward this morning and it means the weight transfers through my heels rather than the balls of the feet. Made all the difference. Excited to see how it works for the uphill leg tonight.

 

Thanks to you both!

Do ensure you check your braking as well. The surefire way of knowing that your feet are now too far forward is when you find it much harder to brake than accelerate - you don’t want to discover that when a car pulls out of a drive just in front of you!

You may find also that there isn’t one “correct” position. If cruising at speed for a long time on an open road or trail where a need to suddenly brake is unlikely a more forward position may give you less fatigue. In a busy area where you are likely to need to do a lot of braking you might need to have your feet a bit further back. 

[Arbolest]

7 hours ago, LanghamP said:

Hopefully some of the engineers can chime in.

I feel most, if not all, foot and leg problems can be solved by making wheels far more responsive and delicate to user inputs. Say make wheels three times more responsive ie require just 1/3 the force on the pedals to move the wheel.

Since foot problems are caused by constantly pushing the nose of the wheel down via leaning heavily forward, it follows  making wheels super sensitive would require virtually no leaning forward; ergo, the feet problems mostly go away!

 

I'm not so sure I agree with this... Making a wheel 3 times as sensitive means that ANYTHING that causes the wheel to tilt even slightly could possibly cause a sharp jerk or even a buck that could dislodge the rider... Imagine riding over a 1/2 inch pebble and the control board reacting as if you just ran over a 2x4 and sending a huge spike of power to the motor. Now imagine that happening at the speeds some of these wheels are capable of...

Don't get me wrong, I would love to have a super-sensitive version of my MSuper that seemed to react to my every thought even before I think it, but at the same time, I really enjoy its almost mellow attitude, and it's such a powerful machine that I almost think it's a necessary safety precaution to have to really lean into it and tell it you want to go in order to have it give you its full power. What comes to mind for me is a new rider that just learned to ride a wheel stepping onto a super-sensitive version of their chosen wheel, leaning forward, and having he thing shoot out from under them. I mean,  if the wheel reacts too fast or too powerfully to your input, you won't even be able to get your center of mass positioned properly relative to the wheel (lean forward fast enough) for its acceleration to not put you on your rear end. And that's only on a perfectly flat, smooth surface. I wouldn't even want to try that on an offroad trail somewhere! 

[Chriull]

6 hours ago, LanghamP said:

Hopefully some of the engineers can chime in.

I feel most, if not all, foot and leg problems can be solved by making wheels far more responsive and delicate to user inputs. Say make wheels three times more responsive ie require just 1/3 the force on the pedals to move the wheel.

Since foot problems are caused by constantly pushing the nose of the wheel down via leaning heavily forward, it follows  making wheels super sensitive would require virtually no leaning forward; ergo, the feet problems mostly go away!

 

 

59 minutes ago, Arbolest said:

I'm not so sure I agree with this... Making a wheel 3 times as sensitive means that ANYTHING that causes the wheel to tilt even slightly could possibly cause a sharp jerk or even a buck that could dislodge the rider... Imagine riding over a 1/2 inch pebble and the control board reacting as if you just ran over a 2x4 and sending a huge spike of power to the motor. Now imagine that happening at the speeds some of these wheels are capable of...

Don't get me wrong, I would love to have a super-sensitive version of my MSuper that seemed to react to my every thought even before I think it, but at the same time, I really enjoy its almost mellow attitude, and it's such a powerful machine that I almost think it's a necessary safety precaution to have to really lean into it and tell it you want to go in order to have it give you its full power. What comes to mind for me is a new rider that just learned to ride a wheel stepping onto a super-sensitive version of their chosen wheel, leaning forward, and having he thing shoot out from under them. I mean,  if the wheel reacts too fast or too powerfully to your input, you won't even be able to get your center of mass positioned properly relative to the wheel (lean forward fast enough) for its acceleration to not put you on your rear end. And that's only in a perfectly flat, smooth surface, I wouldn't even want to try that on an offroad trail somewhere! 

The control loop is not a solely proportional feedback (more lean leading to an proportional higher acceleration), it's some PID controller with proportional, integral and derivative terms. So an important "dampening" is achieved (no or just feasible overshoot to a step response) - if not, problems like the "oscillation bug" occur. 

With a "perfect rider" (fixed pole/cylinder) overshooting (but stable) controllers are no real problems - with a rider on top trying desperately to survive such an overshooting system can easily "be changed" to some unstable control loop freaking out...

But the main part of this control loop is the underlying "physical reality" - the EUC and the rider, with all the "angles, forces, levers and motor capabilities" itself which is to be stabilized - it is and should be a self balancing vehicle! (... and this with a "chaotic and unpredictable" rider on top...)

So going up an incline with some given geometry (footplate length, riders weight, ...) needs a given downforce on the forward tip of the footplate/pedals to "form" a stable system. If such an uphill ride could be achieved by a slight pressure applied by the little toe the unicycle would not be self balancing anymore (at least not easily with a human rider on it).

The sensitivity could be increased but this easily leads to unridable unicycles by the driver input/behaviour... So maybe we get one day a slider in the app to change the sensitivity a bit. Maybe the control loop design by now used by most unicycles is just a rough first attempt and once a gifted control loop expert catapults unicycle "behaviour" to the next level. But with all hopes and prayers something like three times the sensity is just unfeasible.

Also new control loop behaviour could maybe once be implemented for "expert riders" sacrificing a bit of the self balancing ability - by something like changing the pedal tilt a bit and by this introducing some speed control instead of solely acceleration control... (this is just an absolutley half-backed first idea coming to my mind as an abstract example...)

For now some revolutionary new "control mechanism" is not really on my wishlist for new unicycles - next goal should be reliability/bullet proof design/lower weights/higher efficiency/etc...

... and longer footplates/pedals (which would be great anyways for european/american bigfoots like me ) as they would also lead to (like already posted some times around here) a bit higher sensitivity.

[Rehab1]

5 hours ago, Hunka Hunka Burning Love said:

Great idea! Given the history of occasional faulty EUC electronics I do worry that the switch might malfunction with the wheel stuck on high speed.  Can I add TPMS (tire pressure monitor system)  to your EUC  convenience package?  How about pot hole detection? I would gladly pay extra!   

[mrelwood]

9 hours ago, LanghamP said:

I feel most, if not all, foot and leg problems can be solved by making wheels far more responsive and delicate to user inputs. Say make wheels three times more responsive ie require just 1/3 the force on the pedals to move the wheel.

Since foot problems are caused by constantly pushing the nose of the wheel down via leaning heavily forward, it follows  making wheels super sensitive would require virtually no leaning forward; ergo, the feet problems mostly go away!

The physics of self-balancing doesn’t quite work like that. But correct foot positioning, pedal calibration and good shoes goes a long way in removing foot pain while riding.

Spoiler

 

It seems whenever the word ”responsiveness” is included when talking about unicycles, physics are left a bit disregarded.

EUCs are very simple devices. All they can do is spin a wheel. What tells it to spin the wheel is only it’s front-to-back rotational position. The wheel doesn’t even know how much you lean, for example in a headwind. Or how much you press with your toes.

If a wheel acts very responsively to this rotational position, it will correct the unbalance before you can reach a proper leaning position. It would feel very unresponsive. You would have to hold your toes up while you lean forward, making for a very tiresome ride. This was the issue with the V10F original firmware.

What helps is a less responsive wheel. On many wheels a softer riding mode will do just that. On the MSX even the softest mode is way too responsive, so it doesn’t help. The later V10F firmwares have solved the issue, and it even has a slider to dial in the exact softness. THAT is what would help in making all wheels wheel at home and exactly as responsive as the rider wants.

Larger tire diameter brings an issue of it’s own. Think about a rocking chair: If the arc of the feet is tiny, it will tilt very easily. If the arc is large, it requires more physical movement from the person to make it tilt. That’s why larger wheels require more ”lean” for the same acceleration, the centre of gravity has to be moved more for the same effective unbalance. A suitably less responsive riding mode will help in the right direction, but it can’t remove the difference in physics.

 

 

[LanghamP]

All my wheels seem about equally responsive when I push their nose down (I push on a part outside the tire).

For example, I line up my Segway S1 and my MSuper side by side and push down their noses. It's about the same amount of force to get them moving.

Now using the pedals to get them moving is very different. While the S1 moves easily, the MSuper feels like it is stuck in wet concrete. 

Would not having the MSuper's software modified to make the pedals incredibly hard make me require less force to push the wheel up a hill?

One interesting side note; I used to find it easier to climb hills on softer as it feels the wheel lets me lean it more before adding power. Now I simply clamp the wheel.

[Chriull]

2 hours ago, LanghamP said:

Now using the pedals to get them moving is very different. While the S1 moves easily, the MSuper feels like it is stuck in wet concrete. 

Would not having the MSuper's software modified to make the pedals incredibly hard make me require less force to push the wheel up a hill?

The difference between the S1 and MSuper should be mainly the geometry (lever between the front of the pedal and wheel axle). There was one post quite some time ago here of the calculations with which drivers weight depending on this geometry which incline is possible.

From this also a maximum acceleration for a given incline can be calculated (if this burden can be handled by the motor and the electronics).

Additionally bigger wheel diameters need more torque for the same acceleration. And the wheels all have current limitations to prevent the electronics from frying - so this current limitation could limit the acceleration of bigger wheels at lower speeds even more than for smaller ones.

3 hours ago, LanghamP said:

One interesting side note; I used to find it easier to climb hills on softer as it feels the wheel lets me lean it more before adding power. 

This seems to be a nice measure used and reported from many members. As you wrote Imo the softer mode has some "delay in balancing" - so for the first push on the pedals less force is needed and then the wheel "starts" balancing (accelerates and keeps the pedal straight again). 

But once one drives at a constant speed up a steady incline the situation should be the same again as in hard mode.

In the real world with uneven inclines the inbetween needed accelerations to overcome uneven parts could/should again need less force. But imo the "delay" could make it harder (balancewise) to drive up such uneven inclines and also lead earlier to "toes digging into the ground"

[mrelwood]

On 8/9/2018 at 6:28 AM, LanghamP said:

For example, I line up my Segway S1 and my MSuper side by side and push down their noses. It's about the same amount of force to get them moving.

Now using the pedals to get them moving is very different. While the S1 moves easily, the MSuper feels like it is stuck in wet concrete.

The ”nose” of the MSX is further away from the centre of the wheel, so by having more leverage you actually applied more force. The pedals are approximately the same length, which does not give the required additional leverage for the MSX.

On 8/9/2018 at 6:28 AM, LanghamP said:

Would not having the MSuper's software modified to make the pedals incredibly hard make me require less force to push the wheel up a hill?

You noticed this yourself on the softer modes being easier...

 

[LanghamP]

10 hours ago, mrelwood said:

The ”nose” of the MSX is further away from the centre of the wheel, so by having more leverage you actually applied more force. The pedals are approximately the same length, which does not give the required additional leverage for the MSX.

You noticed this yourself on the softer modes being easier...

 

I was mistaken! In truth I believe the easier to go uphill on softer settings has more to do with the entire wheel keeping close contact with legs; in other words softer settings let's the wheel tilt more and that tilt allows ones legs to clamp the wheel in an easier manner.

My experience with wheels is that the bigger the wheel the more force (lack of leverage?) is required. Bigger wheels are a pain to get uphill.

I wish bigger wheels were as easy and light to get uphill as small wheels. Is there no software related hack to make it so?

[mrelwood]

36 minutes ago, LanghamP said:

Is there no software related hack to make it so?

I don’t think I would ride with a hack that alters the riding charasteristics. The code is crucial to work 100% as planned under all riding situations. I haven’t heard anyone even hacking it.