Terrific - but will it be effective off-road ?


enjoythesilenc

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Liked your response 😀

This is the only video of my Redshift in slippery conditions-
We seem to have two camps here. A good healthy debate. I love odeds videos because I see him taking the same lines i would take. I can also predict where he is going to have an issue very accurately. He doesn't get stuck per say but I can predict where electric overspin is likely, even on the dry terrain video.

I just watched the wet video and see that at the 3 minute mark there is a perfect example of electric overspin. watch and also listen to the motor go "zing"

Its not a deal breaker for me as the problem might rear its head in 1% of riding scenarios. The 99% of the rest are often superior to my "fire bike with clutch" experiences offroad.
 

fsfs

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HRV
If the Alta had a clutch it would probably be the best bike I have ever ridden.
I've said it before here, in order to control wheelspin regardless of ICE or electric, the power must be mitigated by a clutch. There is no traction control (nor would I want it). The rider should and must have final control of the power delivery to the ground for maximum traction as well as increasing RPM's by pulling a clutch and delivering the power exactly when you need it.
Stark supposedly extended run time, implemented my dream of an app for custom maps and sharing with your buds, and even gave it KYB's, super stoked! But really bummed that they do not see the need for a clutch.

Do not assume the Alta (or Varg) with a clutch will behave anything like an ICE bike with a clutch. When you have rotating mass there is potential energy that you can then transfer to the wheel using the clutch. There is very little rotating mass in the Alta (or Varg). So now we need a flywheel. You will burn energy accelerating this flywheel -- reduced range. You will burn energy slipping the clutch -- reduced range. There is additional weight -- reduced range. Now we have a gyroscope -- bike is not as nimble.

Also, it will be difficult to hear or feel how fast the flywheel is spinning -- some kind of feedback to the rider needs to be implemented.

However, in many respects a clutch lever is different from a twist throttle. Going from 0 to full torque on the clutch lever requires little movement while going from 0 twist (closed) to wide open takes significantly more movement (and time). Also, precise throttle control in difficult terrain is not easy.

We have some ideas to solve this. At this moment I am not allowed to say exactly what they are. We know this issue exists and are working on it. However, top priority now is production.
 

rayivers

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Compared to a current traditional 2S enduro bike, what kind of of expectations should one have on how precisely the power can be modulated on an E bike ?

In map 4 w/stock tires I was able to slowly accelerate (not just roll) my MXR on sheet ice, with little or no wheelspin. On ICE bikes I always rated my throttle control as 'poor', but after getting used to the Alta things are better now, mostly due to the bike.
 

Number Six

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Do not assume the Alta (or Varg) with a clutch will behave anything like an ICE bike with a clutch.
Indeed, there's several videos of extended trail rides by a fellow in Hawaii on one of the Electric Motion bikes with a hydraulic clutch - from what I can tell it's more of an 'all or nothing' type of engagement than what we're used to on a gas bike.

We have some ideas to solve this. At this moment I am not allowed to say exactly what they are. We know this issue exists and are working on it. However, top priority now is production.
It's encouraging that Stark realizes there's a need, would hope that the previously mentioned wheel sensor & programmable TC would be high on a list of solutions & likely be the most easily implemented prior to full production.
Most would be willing to wait ( ok, maybe not ) on a machine with a wider range of operation.
The MX tribe could just turn it 'off', or .. it'd be quite an advantage on a dry-slick or muddy track, although any form of TC does present an issue regarding Starks pro racing ambitions. Easy & verifiable to disable though one would think.
Thanks fsfs for your willingness to join in the conversation with an insiders viewpoint.

I've begun to look at my noisy, petroleum dependent, 50HP gyroscope in a different light. The Kool-aid is mixed & I've poured it into twelve thousand dollar glass ...
.
 

enjoythesilenc

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Here is a related overspin issue as it might relate to those bikes in the portugal enduro video going over the wood pallets or fishtailing around the slimy highspeed turns, or to folks that might want to flat track these bikes and steer with the rear wheel.

This video was shared on the AOF and it happens to show overspin taking a bite out of a new-to-electric rider in slick conditions. Most would probably agree this is a better than average rider? Cue the video to 7:15 for the example:


I'm not trying to talk anyone out of buying the Stark, just showing what, at worst, you might have to adjust to or at best, what Stark might be able to address with the software.
 

fsfs

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Indeed, there's several videos of extended trail rides by a fellow in Hawaii on one of the Electric Motion bikes with a hydraulic clutch - from what I can tell it's more of an 'all or nothing' type of engagement than what we're used to on a gas bike.


It's encouraging that Stark realizes there's a need, would hope that the previously mentioned wheel sensor & programmable TC would be high on a list of solutions & likely be the most easily implemented prior to full production.
Most would be willing to wait ( ok, maybe not ) on a machine with a wider range of operation.
The MX tribe could just turn it 'off', or .. it'd be quite an advantage on a dry-slick or muddy track, although any form of TC does present an issue regarding Starks pro racing ambitions. Easy & verifiable to disable though one would think.
Thanks fsfs for your willingness to join in the conversation with an insiders viewpoint.

I've begun to look at my noisy, petroleum dependent, 50HP gyroscope in a different light. The Kool-aid is mixed & I've poured it into twelve thousand dollar glass ...
.

We don't need a (rear) wheel sensor. There is a rotor position/velocity sensor on the motor. Since there is a fixed ratio between the motor and wheel we know wheel position and velocity -- except for chain slop. In short, no need for an additional sensor as this functionality is already present.
 

wfopete

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Land of NOD
I've known a couple of gnarly off road Alta riders here in the Arkansas/Mo area. Neither had issues with the Alta in gnarly riding. I ride a KTM "3 stroke" I've "Out Climbed" many riders with ReKluse equipped bikes so my clutch skills are decent. I took an Alta out in a nasty, hilly area that was chewed from HS races and morning thunderstorms. With about 15 minutes on the Redshift I took it out in the crap. I had the bike in map 4 just to make it harder and to push the envelope riding the bike. After a loop I came away with the opinion that I would like a clutch but it wasn't a show stopper and you CAN blow a gnarly climb on an Alta but you have to be a goober and totally screw up the climb process. A lot of technical climbing is about momentum and the Alta was great at getting up to speed in short order. You don't worry about all the ICE bike issues like being in the correct gear, bogging/over revving, throttle control or clutch slipping; you get to simply focus on your line selection. Yeah, I have my $100 bill in for a Stark.
 

Philip

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It's hard to tell what is and isn't hill in this video but I do ride a lot of mud and roots and rocks in general and find the Alta to have the best tractor capabilities of any bike I have ridden. My bike has full race tech gold valve suspension and a tubeliss tire system also. @Philip also has a video some where of himself passing a bunch of gas bikes stuck on a muddy hill in a previous 24hr. I ran a bunch of hairscamble this past fall that had a lot of gnarly muddy uphills with a ton of roots and I had no issue with the Alta. The key mostly is to use map 1 for tractoring, at least that's been my experience. Sometimes I hold the rear brake a bit to get a little more pop for larger objects and also bump up the map.
This video is epic!!!

@Matt, @OneLapper -- If yoiu are going to do this again, sign me up! Riding the Alta in the mud for 24 hours was some of the best time I have ever had on any bike!

Here is my hill climb video from the 2019 NE 24-hour Challenge:
 

Philip

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Here is a related overspin issue as it might relate to those bikes in the portugal enduro video going over the wood pallets or fishtailing around the slimy highspeed turns, or to folks that might want to flat track these bikes and steer with the rear wheel.

This video was shared on the AOF and it happens to show overspin taking a bite out of a new-to-electric rider in slick conditions. Most would probably agree this is a better than average rider? Cue the video to 7:15 for the example:


I'm not trying to talk anyone out of buying the Stark, just showing what, at worst, you might have to adjust to or at best, what Stark might be able to address with the software.
Judging by the punchy throttle response, the bike above does not have the same "traction control" as the Alta has. Play-riding some DIY electric bikes scares me regardless of how much/little power they have because of the unpredictable power delivery. Drifting and power sliding the Alta is a lot easier than that.

This is a very funny. I did not mean to laugh at the rider, but it still reminded me of the popular "Idiots in supercars" YouTube videos. Again, I am sorry, I am sure the rider has the above average skills. It is just that the bike has surprised him with an above average throttle response.
 

rayivers

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A lot of technical climbing is about momentum and the Alta was great at getting up to speed in short order. You don't worry about all the ICE bike issues like being in the correct gear, bogging/over revving, throttle control or clutch slipping; you get to simply focus on your line selection.

+1 ! Point and shoot. :)
 

Number Six

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Midwest
We don't need a (rear) wheel sensor. There is a rotor position/velocity sensor on the motor. Since there is a fixed ratio between the motor and wheel we know wheel position and velocity -- except for chain slop. In short, no need for an additional sensor as this functionality is already present.

Brilliant !
Guess the remaining pieces of the puzzle are just down to software / programming.
Carry on & thanks.
 

photon

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mass. us.
Slow technical terrain is what the Alta does best in my opinion. Mastering the throttle (not easy for those who have an ICE bike background, and used to tame the power with the clutch) is the key.
I agree 💯👍🏼, have raced the alta in muddy new england races, i would say throttle control is key!
 

photon

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Thanks for telling me I don't know how to ride ;-)

Now post a video of that same location (or even a different one) where roots, standing water, mud, and steep hills are involved.
Gnarly terrain is all we have in Massachusetts, rode the alta in water, Mudd crazy muddy Rocky hills, roots, mulch, u name it i rode it and the alta shines above them all! You just need more practice!
 

enjoythesilenc

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Here's my amateur analysis of this run. The first 19 minutes is great stuff with the ALta eating up the big hills of mine tailings. Anywhere it is dusty is probably good electric bike conditions, point and shoot! The next 20 minutes is in the woods singletrack where many scenarios developed that halted momentum, requiring restarting from a standstill. Bottle necks, logjams, switchbacks, off camber on exposed roots. Its still dry and the dirt is great but the struggle is on for everyone, including the 2 strokes. The last 10 minutes is in the boulder field, not sure if that is the actual "Carl's Diner" or not but it's pretty brutal. The ALta makes it out to smooth roads then runs out of battery after 50 minutes ride time minus a couple of minutes at a standstill waiting for bottlenecks to clear.

Specific spots of electric overspin where if it were me, I would have appreciated some sort of clutch, either virtual or actual. (Not that I would have even come close to making that far)
19:30
23:40
25:00
31:00
33:30
37:20
47:00
49:00

What settings on the Varg would need to be tweaked to optimize it for these conditions?
 
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