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[Crissa]

I've seen videos of people wiping out on Zeros while accelerating but now that I'm looking for one, I can't find any.

I saw one where a guy turns left onto a highway and then spills as his rear wheel touches a manhole and it's wet/raining?

-Crissa

[TheRan]

Managed to find this one, only one I've ever seen. Rarefied Road has an on board video of him sliding but managing to recover it and some other "reviewer" has a third person video of him nearly coming off but I can't remember the channel name.

https://youtu.be/DPJyCjlYGXU?t=236

And here's my contribution with a near crash



Off topic, anyone know how to embed videos? I see other posts with them embedded but quoting those posts to find out what they put just turns it into a URL. There's a button to insert image tags on the posting page but nothing for video.

Edit: Turns out my video has automatically embedded, would have thought that would show up when I previewed my post. Does the other video not embed because of the starting time added to the end of the URL?

[BrianTRice@gmail.com]

There's a very good one on Facebook that I'd like to embed on the unofficial manual:
https://www.facebook.com/groups/zmcowners/permalink/2524495690952957/

[TheRan]

There's a very good one on Facebook that I'd like to embed on the unofficial manual:
https://www.facebook.com/groups/zmcowners/permalink/2524495690952957/

I notice in that one he doesn't seem to apply any additional throttle, or at least very little (I purposely rolled back on it, was expecting some wheel spin but not that much), so was that just a case of the torque increasing once the speed was over about 15mph? I've read that the torque is limited at low speeds and picks up above about 15mph, I was expecting it to be a smooth increase but that looked quite sudden

[BrianTRice@gmail.com]

There's a very good one on Facebook that I'd like to embed on the unofficial manual:
https://www.facebook.com/groups/zmcowners/permalink/2524495690952957/

I notice in that one he doesn't seem to apply any additional throttle, or at least very little (I purposely rolled back on it, was expecting some wheel spin but not that much), so was that just a case of the torque increasing once the speed was over about 15mph? I've read that the torque is limited at low speeds and picks up above about 15mph, I was expecting it to be a smooth increase but that looked quite sudden

You do not need to increase torque or accelerate in order to experience a tail slide or fishtail on a Zero.

If traction is reduced on the road surface with a constant throttle enough to break the rear wheel free, it will accelerate rapidly as has been noticed by commenters on a frame-by-frame analysis. The rear wheel spins up extremely quickly (I think 80mph peak reads out on the display) in less than â…“ of a second, fast enough not to expect most riders to be prepared.

This has happened to me quite a few times when I rode my 2013 DS in Seattle. By encountering a wet patch of leaves, the rear wheel would lose traction and spin up rapidly.

After the first incident, I trained myself to expect it and relax the throttle hand even in Eco Mode to limit the wheel spinup, while also immediately moving my weight down through my feet to stabilize the motorcycle. I've never gone down because of one of these events, but they're still dangerous because you're very vulnerable to traffic and other hazards while you recover.

For these reasons, I would strongly encourage Zero to develop a "poor man's traction control" that would limit the wheel spin-up rate on Gen2 bikes (S/DS and FX) to just ahead of the bikes' maximum acceleration under traction per specifications, and then let users toggle it off with ABS when they want burnouts etc.

[TheRan]

There's a very good one on Facebook that I'd like to embed on the unofficial manual:
https://www.facebook.com/groups/zmcowners/permalink/2524495690952957/

I notice in that one he doesn't seem to apply any additional throttle, or at least very little (I purposely rolled back on it, was expecting some wheel spin but not that much), so was that just a case of the torque increasing once the speed was over about 15mph? I've read that the torque is limited at low speeds and picks up above about 15mph, I was expecting it to be a smooth increase but that looked quite sudden

You do not need to increase torque or accelerate in order to experience a tail slide or fishtail on a Zero.

If traction is reduced on the road surface with a constant throttle enough to break the rear wheel free, it will accelerate rapidly as has been noticed by commenters on a frame-by-frame analysis. The rear wheel spins up extremely quickly (I think 80mph peak reads out on the display) in less than â…“ of a second, fast enough not to expect most riders to be prepared.

I get that if an outside factor causes the tyre to lose traction it'll spin up, but in that video it looks like the guy has good traction on a fairly decent road but then it suddenly breaks loose once it gets above around 15mph. It's not like the guy's going hard on the throttle either with that smooth and slowish acceleration.

Good idea for the traction control, has anyone tried suggesting that to Zero and got a reply? It'd also be nice to be able to adjust the threshold for the slow speed torque limiting, if it does work the way I've read. Eco mode levels of torque below 30mph and then full torque (with a gradual increase) above that would be good.

[BrianTRice@gmail.com]

The problem is neither the level of torque nor the initial speed. The problem is what happens when traction breaks, and then the motor spins up the relatively massless drive train as fast as the current drives it, which is faster than a rider should be expected to deal with.

The suggestion is to limit the number of acceleration in RPMs per second of the rear wheel until/unless disabled.

I have suggested it to Zero engineers and generally been talked down to or gotten vague excuses for why this work hasn't been done. Zero's support team ought to be able to make a rough estimate of how much damage riders incur from a loss of traction to justify the engineering time, but I'm guessing that they haven't.

[NEW2elec]

It's one of the forum members but I forget who.
On FB he said he forgot he had not broke in his brand new tires and said he needed to change his pants later.   

[TheRan]

The problem is what happens when traction breaks

Sure, but what's causing that loss of traction? The guy had enough traction to accelerate up to 15mph and then suddenly he doesn't. He didn't roll on the throttle, the road surface looked decent with nothing obvious to decrease traction Sure the tyres were new but again they had the traction to get up to 15mph.

In the few videos I've seen of people losing traction it's always been around the same speed, usually after making a slow turn. I've never seen someone spin it up from a stop, which makes sense with the torque being limited down low, but I also haven't seen it break loose at like 30mph. These close shaves have also been from riders with plenty of riding experience on many different bikes of varying levels of power and torque and who know to be easy on the throttle.

I don't know how locked down the software side of these bikes is but has anyone been able to get in there and see what the torque curve actually looks like? Also is reprogramming them with custom firmware a thing? I think I read somewhere that Zero use a third-party off the shelf controller, but I guess they could do some sort of modification to lock it down

[BrianTRice@gmail.com]

It doesn’t matter what causes the loss of traction. Oil lifted to the surface by recent rain is sufficient to cause a loss of traction on Zeros traveling at 30mph with no acceleration and no turning.

I’ve spun up the rear wheel from a stop on wet grass and on light mud. Every time, I don’t find the loss of traction the actual concern. The concern is how rapidly the wheel spins up so I can safely recover.

It’s just not safe to have a very fast spinning wheel reencounter traction and jerk the bike as a result.

[NEW2elec]

Any bike can loose traction.



For me the key is to release the throttle just as quickly as gas riders would pull in the clutch.  AKA no cruise control of any kind.  Also keep a fair amount of regen on.  Hurts your range a bit but even jacked up when you release the throttle that rear tire slows and stops pretty fast.
 
But mostly don't fly around curves or make quick direction changes.  On 90 degree turns don't hit the throttle until your upright.

As the guy said on FB "new tires are slick".
TheRan yours looks like the road patch hump got ya.

[TheRan]

TheRan yours looks like the road patch hump got ya.

Nah I purposely yanked on the throttle, just wanted to see what sport mode would do. Also the tyres were cold, it was like 5°C, and that road isn't the best for traction. The next day it even managed a little slide in eco mode although it was more controlled.