newbie:Speed modification? Best cruising posture?

[Tallguysf]

I rented an i2 in Ventura this weekend, and I'm almost ready to buy. The one thing I didn't like was how it behaved near its top (limited) speed.

(A) the 12 mph limit is really slow on an open stretch. I expect to feel foolish spending $5,000 on something where people will pass me on bicycles. Is there anyway to make this thing go faster?

(B) even once I accepted that I would be stuck going slow, I couldn't find a comfortable long-term cruising posture where I could just relax and not worry about the Segway trying to tilt me back every 30 seconds, so I'd end up with the bar shoved into my abdomen. I am pretty tall (6-6), but my shorter partner was having the same problem. How do you maintain a comfortable cruising speed that keeps both rider and Segway happy?

Any suggestions would be much appreciated.

[Segwaiian]

...to smell the roses.

Welcome, Tallguysf!

Sorry, but that's the speed limiter telling you to slow down. It's a safety feature. The sensors and controllers monitor operating conditions and activate the speed limiter to signal you to slow down. On bumpy/rough surfaces you'll get speed limiter at slower speeds.

The only feasible way to increase your top speed is with larger diameter wheels/tires. But, then, acceleration is decreased. There are several previous threads on this subject that you can find with Search This Forum on the General Discussion page.

If you need more speed in a non-polluting mode of transportation, you might not be totally happy with a Segway. JohnM, customer in this aisle.

You get used to being able to take in more scenery, hear the birds, interact with others on the sidewalk. Life is good on a Segway. :D

It's all about the glide. :)

Aloha,
Roger

[rrc1962]

At fill speed, the wheel RPM is 12.9 RPM. Using that number, you can figure the wheel diameter needed for a given speed. I'd like to see 18MPH which would be 26.6" wheel diameter. Increasing wheel diameter will effect applied torque. In other words, when you lean forward and the Segway moves ahead to keep you upright, with big wheels, you could be increasing the torque to a point that the Segway can't keep up as you lean. I don't think increasing to 26" will cause that unless you are accelerating or stopping at the outer designed performance limits. We're in the process of selling our house. That is one of a few Segway projects on hold until we get moved.

On long cruises we also end up leaning against the speed limiter. It's hard going that slow on a long, straight stretch of road. Around town and on the sidewalks you'll think you are flying.

[SegwayDan]

The Segway's speed limiter is an intrinsic part of its design. Best to get used to it, as it's difficult/expensive to modify it, and various attempts by some don't seem to have been successful, or at least not really worth the effort.

If you try to push it, it WILL push back--not to be obstinate, but to WARN you that you are taxing its performance envelope. Keep in mind that a major part of the machine's work is to keep you upright. If you were somehow able to go substantially faster than 12 mph, the system would most likely not have enough reserve power to keep you balanced in an extreme situation, such as hard braking or when negotiating major inclines.

12 mph also makes the machine more welcome on sidewalks. Faster speeds would inevitably invoke restrictions against its use there.

The best cruising posture is standing upright and TOTALLY relaxed. There is no need to "hold on" as such. Hold the handles with just enough grip to keep the handle with your body as your lean forward and back, side to side. The safety video warns you not to press your body against the handle. Find a speed somewhat below top speed. It saves on battery power and you'll be safer if you're not constantly taxing the machine's power limits.

[Neelix]

The best advice I have is to ride where it is comfortable (i.e. the point just before it starts aggressively pushing you back). The reasons are threefold:

1) You're not overtaxing the machine.
2) You're better able to maneuver.
and
3) It's more comfortable come on that one was easy!

If you keep pushing into it it's just going to fight you harder.

[KSagal]

One thing that I do sometimes to ease the effort on my ankles and calf muscles, is to slide one foot slightly forward of the other. This is a comfortable stance for me anyway, and to maintain a certain speed, it becomes a matter of how much weight is on my right leg or my left.

Of course you still tweek it with your angle of lean. For long long trips I find this more comfortable, but be carefull. It affects your reaction time when doing emergency maneuvers.

When I say one foot farther forward than the other, I am saying about an inch or two is more than enough.

[cmonkey]

I've done a really great superman impression at 12.5 mph a few times and it's not fun. And I've ridden segs that can go faster than 12.5mph. Faster speeds are easy to get used to, but that's the problem it's easy to get complacent, and irregularities in your path can be very difficult to contend with at higher speeds. Just hit a 1 inch curb cut at full speed, and at an angle and you'll see (actually to be safe, slowly work up to a higher speed). If you're expecting it, that's one thing, but unexpected at 13, 14 or even 15mph and you could be in for a world of hurt.

Any much faster than than their current capabilities and the potential for injury is that much greater. Also as stated, they would no longer be sidewalk legal.

The engineers did a great job of producing a device that's really sidewalk compatible.
When I feel the need to go faster on two wheels, I'll spend a day at Streets of Willow. :D

Note, you can change the physical dynamics of the segway with larger tires, or other speed mods, but you can't change the software to compensate.
So the starting & stopping ability of the seg will change, compromising it's current level of safety.

I wonder how long it took this guy to start up and slow down?

http://www.waldenwoods.org/eswing/trials_save1.htm

(notice the helmet)

[Five-Flags]

is that the design speed of 12.5 mph was to ensure the EPAMD legislation would be easier to enact if it already met most states' speed limits for motorized wheelchairs (which just happens to be 12.5 mph). What a coincidence!!!:rolleyes::rolleyes:

Or just possibly a little prior planning???;);):)

[PeteInLongBeach]

The device was designed to supplement / replace walking, not driving, not biking. The Segway was designed to interact safely with pedestrian traffic.

If you need more speed than this type of mobility device provides, there are other devices out there. Go-peds, for instance. But, you can't legally ride them on sidewalks / indoors, and I found stability to be a problem. But then, I'm spoiled.

[mark1qhorsey]

The device was designed to supplement / replace walking, not driving, not biking. The Segway was designed to interact safely with pedestrian traffic.

If you need more speed than this type of mobility device provides, there are other devices out there.

Amen to 12.5! Consider, for a moment, that your forward motion is 18.33 feet per second at that speed. That means your brain is processing road/sidewalk conditions for up to 36 feet ahead of you to react in time to unexpected abnormal situations.

[rrc1962]

I'm going for the official Segway speed record. :) You guys are just no fun.

[JohnM]

Amen to 12.5! Consider, for a moment, that your forward motion is 18.33 feet per second at that speed. That means your brain is processing road/sidewalk conditions for up to 36 feet ahead of you to react in time to unexpected abnormal situations.

Somehow the operators of other transportation devices are able to process road conditions at much higher speeds. Is there something about the brains of Segway owners that makes this this impossible? ;)

[mark1qhorsey]

Somehow the operators of other transportation devices are able to process road conditions at much higher speeds. Is there something about the brains of Segway owners that makes this this impossible? ;)

Yes ha, ha, true, but gliders and their PTs have a different set of issues unique to sidewalks, corners, holes and other impediments to consider. There is Nothing wrong with 12.5. An old Amish saying is: "The hurrier I go, the behinder I get".

[cmonkey]

Somehow the operators of other transportation devices are able to process road conditions at much higher speeds. Is there something about the brains of Segway owners that makes this this impossible? ;)

Yes, we're too busy enjoying the scenery to bother with road conditions! :eek:

Actually, although the diameter of the wheels lets us go over much larger obstacles (than the wheels of a skateboard or razor scooter).... they are still smaller than a bike's. So, obstacles are felt more sharply on a seg than a bike. That, and the position of the wheels has a lot to do with it. On any inline wheeled device the impact doesn't affect your balance point. Your wheels are under your center of gravity. Not so with the seg, so an unexpected bump can have some unwanted results.

[jgbackes]

It's a pretty fun physics problem... On a bike the center of mass is way behind the wheel as it starts over a speed bump, on a segway, it's almost directly on top of it. A bike tilts and the rider rocks backward, on a Segway, the rider goes mostly upward. The two times I've hit speed bumps on a segway at 12.5 had the same result... YARD SALE!

[JohnM]

Fair enough answers. Would it be reasonable to say that the Segway alone would probably be safe at speeds well beyond 12.5 mph, but the addition of an unstable rider is the limiting factor?

[cmonkey]

The segway can be made to go in excess of 20mph.

It's the terrain, and lack of suspension that are the issues (all laws aside)

Now by unbalanced, you mean a 5150 rider, yes definitely. Otherwise the technology does all the balancing.

[Gihgehls]

Fair enough answers. Would it be reasonable to say that the Segway alone would probably be safe at speeds well beyond 12.5 mph, but the addition of an unstable rider is the limiting factor?

No, if anything the rider helps to dampen dangerous movements. A segway alone would bounce up on much smaller bumps, and unless it hit the bump perfectly, the segway is going to turn a little bit in the air. Now the wheels will not be parallel to the direction of travel, and since the wheels can't pivot to turn toward the direction of travel, it hits the ground and essentially high-sides.

[mark1qhorsey]

..A segway alone would bounce up on much smaller bumps, and unless it hit the bump perfectly, the segway is going to turn a little bit in the air. Now the wheels will not be parallel to the direction of travel, and since the wheels can't pivot to turn toward the direction of travel, it hits the ground and essentially high-sides.

Great points in these posts about the unique riding & physics of Segs. Thanks all, I learned something here.

[Spider108]

I read a crash coming.....

[cmonkey]

Fricken speed bumps! @ ! :eek:


SPLAT!

[Segwaiian]

It's a pretty fun physics problem... On a bike the center of mass is way behind the wheel as it starts over a speed bump, on a segway, it's almost directly on top of it. A bike tilts and the rider rocks backward, on a Segway, the rider goes mostly upward. The two times I've hit speed bumps on a segway at 12.5 had the same result... YARD SALE!

Fair enough answers. Would it be reasonable to say that the Segway alone would probably be safe at speeds well beyond 12.5 mph, but the addition of an unstable rider is the limiting factor?

There are two other potential inhabitants of our stability universe: Unicyclists and in-line skaters. ;)

I used to be an in-line skaters, and a very unstable one, at that (Not in a 5150 sort of way, though.). :eek:

Hey, very entertaining thread, folks! :)

The good thing about the maneuverability of a Segway is that many potential problems sighted 36 feet away can be avoided. As long as we're not admiring the scenery. :D

Aloha,
Roger

[MagiMike]

I'm going for the official Segway speed record. :) You guys are just no fun.

OK but heres the compatition

http://www.waldenwoods.org/eswing/trials_save1.htm.

http://www.waldenwoods.org/eswing/lock%20bm2003/christo.jpg

[KSagal]

Fair enough answers. Would it be reasonable to say that the Segway alone would probably be safe at speeds well beyond 12.5 mph, but the addition of an unstable rider is the limiting factor?




I believe the unique nature of the segway and it's design are the determining factors here. Not so much the rider or the interface between man and machine.

Simple laws of physics make inline wheeled devices inherently more stable, on straight flat paths. It is far easier to keep a bike upright at 12 miles per hour, that at 1.2 mph.

Segways work just the opposite. The machine has to work much harder, since it is using electric motor torque to compensate for the balance points and momentum that tend to help the high speed bike, but hurt the seg in the same situation...

Add to this factor that the biker can turn the front wheel. This goes a long way toward balance that the seg does not have.

I rode bikes for many many years. Turning the wheel to turn the bike is something that is only done at low speeds. At higher speeds, turns are accomplished by leaning, and using the geometry of the tires to give your turn. Often, there is actually a slight opposite turn of the wheel in a high speed turn.

Segways do not have any of this. Therefore, to compare, it would be more like a bike with a fixed front tire. If that tire did not turn, then high speed turns would still be functional, but low speed turns would be much harder, as you would have to lean to turn at speeds far below optimum.

Now, I believe that a segway has much more difficulty in staying upright the faster it goes. I believe there is so much more reserve torque in the wheel motors at low speed that it is very stable, but the faster you go, the reserve torque diminishes at quantum speeds.

There are far better mathematicians out there then I, but I would guess that the momentum factors and other balance difficulties that the segway has to deal with at 12 mph compared to 1.2 mph is not a factor of 10x but more like 100x.

Compare that to an inline device, where the difficulty factor of a reverse comparison of 12 mph to 1.2 is more along the 10x line, because of the operators direct input with their weight shifts and the turn of the wheel.

Furthermore, because of all this, I believe that increasing the speed of a segway, by just a few mph, may double or even more complicate the difficulty in keeping it on it's wheels and under the segger. This may indeed be a situation where 10 or 20% more is just simply too much more. (unless it goes to beefer motors and the capacity to power them.)

[NotQuiteCode3]

It's starting to sound like a physicist convention in here!

Carry on! I'm enjoying this insight!

Lynn

[SegwayDan]

Actually, the Segway PT is a rather unique type of machine with respect to its "limitations."

These limitations are essentially NOT modifiable. And that's what sets it apart from other traditional machines. Slapping a bigger motor in it is simply not an option. Hacking its software most likely isn't an option either, nor is changing the diameter of its wheels, though isolated attempts have been made.

Though perhaps the majority of casual use of the Segway PT will be incident-free, it yet behooves each rider or owner to have a good grasp of how the machine works so that they can remain safe under most all circumstances while gliding, and not try, knowingly or unknowingly, to overburden the machine beyond these limits.

The warning signs are all there as provided within the machine's overall design: infokey displays, reduced performance mode, stick pushback, stick shake, saftey shutdown, etc. Those not accustomed to or unable to follow rules out of bravado or foolishness or chronic or acute lapses of consciousness will not win many such struggles with the machine.

Though the tendency of many "ordinary" people is to avoid technical matters, they should really make an exception with the Segway PT. What you don't know about it could very likely hurt you.

Though it's best to best to fully understand all the various technologies involved, one can at least know that it is indeed a good thing to "follow the rules" when it comes to Segway gliding, which includes paying close attention to the machine's warnings of non-optimum operating conditions.

It's starting to sound like a physicist convention in here!

Carry on! I'm enjoying this insight!

Lynn