electricpen Posted February 9, 2018 Share Posted February 9, 2018 (edited) I just wanted to chime in here in wishing for a swift and full recovery @Rehab1. I actually got a speed wobble on my Mten3 today. I've been riding it a lot more on account of my KS16s rim issues. While I did get the rim somewhat straightened and I have ridden it at least 20 miles at full speed over varied terrain so I know it is usable - it feels like I'm riding a Gotway - it could decide to quit at any time. j/k. sorta. Anyway since I've been riding the Mten3 quite a bit I have also started riding it in the street at high speeds for short distances. Today I got a pretty severe speed wobble while going maybe 18-19 mph. I didn't hit any noticeable bumps and the area I was on was fairly flat and level. I just started to wobble like crazy. Fortunately, I managed to get it under control but I suppose it could easily have thrown me too. It just reminded me of this thread so I thought I'd put this here since it seems to be the de facto 'speed wobble' thread. Unfortunately I don't know what caused it so this isn't very constructive except to say it happened to me too without hitting anything. So I do believe it is possible. Edited February 9, 2018 by electricpen 2 Quote Link to comment Share on other sites More sharing options...
Rehab1 Posted February 9, 2018 Author Share Posted February 9, 2018 15 minutes ago, electricpen said: I just wanted to chime in here in wishing for a swift and full recovery @Rehab1. I actually got a speed wobble on my Mten3 today. I've been riding it a lot more on account of my KS16s rim issues. While I did get the rim somewhat straightened and I have ridden it at least 20 miles at full speed over varied terrain so I know it is usable - it feels like I'm riding a Gotway - it could decide to quit at any time. j/k. sorta. Anyway since I've been riding the Mten3 quite a bit I have also started riding it in the street at high speeds for short distances. Today I got a pretty severe speed wobble while going maybe 18-19 mph. I didn't hit any noticeable bumps and the area I was on was fairly flat and level. I just started to wobble like crazy. Fortunately, I managed to get it under control but I suppose it could easily have thrown me too. It just reminded me of this thread so I thought I'd put this here since it seems to be the de facto 'speed wobble' thread. Unfortunately I don't know what caused it so this isn't very constructive except to say it happened to me too without hitting anything. So I do believe it is possible. Thanks for your kind comments and sharing your story. Scary stuff! Glad you pulled out of it. I won't know about the condition of that section of the trail until the walk the area in a few weeks. I had posted the following video on a ride I took the day before the accident where I was traveling at a similar rate of speed with no wobble issues. I wish the camera was running the day of the accident. So puzzling. 3 Quote Link to comment Share on other sites More sharing options...
Hunka Hunka Burning Love Posted February 9, 2018 Share Posted February 9, 2018 (edited) When I had my wobble on the Telsa going at about 28 kph, I tried to fight my instinct and just relaxed my legs more figuring I could ride it out. It seemed a bit counter-intuitive at the time, but I compare it to trying to correct a car that is fish-tailing on a slippery road. Often your input makes the problem worse so in relaxing more my oscillation reduced thereby avoiding an intimate encounter with the ground. With your spike pedal mod, I wonder if it is better not to have the spikes locking the feet in place as I've gone over bumps where my foot position landed way off, but I was able to shuffle the foot back into place. With spikes I don't think that would be possible unless you're adept at riding with one leg (which I still have to learn how to do). Edited February 9, 2018 by Hunka Hunka Burning Love 2 1 Quote Link to comment Share on other sites More sharing options...
The Fat Unicyclist Posted February 10, 2018 Share Posted February 10, 2018 2 hours ago, Hunka Hunka Burning Love said: With your spike pedal mod, I wonder if it is better not to have the spikes locking the feet in place as I've gone over bumps where my foot position landed way off, but I was able to shuffle the foot back into place. With spikes I don't think that would be possible unless you're adept at riding with one leg (which I still have to learn how to do). l was wondering that too... l noticed in that last video that @Rehab1's feet were significantly offset (see 1:00m in). When I ride, I know l shift my feet very regularly. So would removing the ability to adjust in that way cause an issue? And I'm into saying it caused the accident, but might it have been a factor in reducing your ability to recover? Did you also have a custom tyre fitted? 1 Quote Link to comment Share on other sites More sharing options...
Rehab1 Posted February 10, 2018 Author Share Posted February 10, 2018 2 hours ago, Hunka Hunka Burning Love said: When I had my wobble on the Telsa going at about 28 kph, I tried to fight my instinct and just relaxed my legs more figuring I could ride it out. It seemed a bit counter-intuitive at the time, but I compare it to trying to correct a car that is fish-tailing on a slippery road. Often your input makes the problem worse so in relaxing more my oscillation reduced thereby avoiding an intimate encounter with the ground. So glad your instincts were correct and everything went well! If only the wobble I experienced had increased at a reasonable rate I think subtle involuntarily adjustments to my posture and speed would have brought the ACM back under control. Instead the rapid oscillation came at me like a banshee. 2 hours ago, Hunka Hunka Burning Love said: With your spike pedal mod, I wonder if it is better not to have the spikes locking the feet in place as I've gone over bumps where my foot position landed way off, but I was able to shuffle the foot back into place. With spikes I don't think that would be possible unless you're adept at riding with one leg (which I still have to learn how to do). You might be right. I only have 2 spiked pedal rides for comparison. That puts my success rate at 50/50. Once I get the new shells and led covers from Jason I will have my staff help me install them along with the new pedals. It will look and perform just like new being it already has the updated motor and board. I also have a second new board. Does this sound like an advertisement? 3 Quote Link to comment Share on other sites More sharing options...
Rehab1 Posted February 10, 2018 Author Share Posted February 10, 2018 5 minutes ago, The Fat Unicyclist said: l was wondering that too... l noticed in that last video that @Rehab1's feet were significantly offset (see 1:00m in). When I ride, I know l shift my feet very regularly. So would removing the ability to adjust in that way cause an issue? And I'm into saying it caused the accident, but might it have been a factor in reducing your ability to recover? Did you also have a custom tyre fitted? Yes i have the knobby tire. The ability to adjust my feet at high speeds was difficult. I noticed my foot position as well but the spikes were so comfortable it did not bother me. The buyer will be able to experiment with each pedal version and make up their own mind. Quote Link to comment Share on other sites More sharing options...
Marty Backe Posted February 10, 2018 Share Posted February 10, 2018 1 hour ago, Rehab1 said: So glad your instincts were correct and everything went well! If only the wobble I experienced had increased at a reasonable rate I think subtle involuntarily adjustments to my posture and speed would have brought the ACM back under control. Instead the rapid oscillation came at me like a banshee. You might be right. I only have 2 spiked pedal rides for comparison. That puts my success rate at 50/50. Once I get the new shells and led covers from Jason I will have my staff help me install them along with the new pedals. It will look and perform just like new being it already has the updated motor and board. I also have a second new board. Does this sound like an advertisement? You will test ride first, right? 1 1 Quote Link to comment Share on other sites More sharing options...
DaveThomasPilot Posted February 10, 2018 Share Posted February 10, 2018 Quote I love the egg shaped and the circle form factor; nevertheless I believe wheels would function much better if the heavy batteries were located anywhere but the directly along the vertical wheel axle Makes sense. If the center of mass was off axis front to back, this would increase "angular stability" or increase the moment. It would take more force to induce a yaw (think twist) deflection. Thinking about it, if the center of mass is directly over the wheel axis (front to back), the only thing that will dampen a yaw deflection is the friction of the tire--which might be quite variable with knobby tires, debris on the road, etc. It makes sense to me that a little offset of the weight to the front or back could do a lot to stabilize yaw oscillations--as LanghamP says. But, it might may it harder to ride very slow (and get started?), when quick twisting is necessary to maintain balance. 1 Quote Link to comment Share on other sites More sharing options...
WARPed1701D Posted February 10, 2018 Share Posted February 10, 2018 16 minutes ago, DaveThomasPilot said: Makes sense. If the center of mass was off axis front to back, this would increase "angular stability" or increase the moment. It would take more force to induce a yaw (think twist) deflection. Thinking about it, if the center of mass is directly over the wheel axis (front to back), the only thing that will dampen a yaw deflection is the friction of the tire--which might be quite variable with knobby tires, debris on the road, etc. It makes sense to me that a little offset of the weight to the front or back could do a lot to stabilize yaw oscillations--as LanghamP says. But, it might may it harder to ride very slow (and get started?), when quick twisting is necessary to maintain balance. Conversely an increased mass away from the COG will make recovery from a wobble harder due to increased momentum of the outer edge of the wheel. It could even exaggerate a wobble much like a trailer with too much weight behind the COG will fishtail and eventually jackknife. 1 Quote Link to comment Share on other sites More sharing options...
fryman Posted February 10, 2018 Share Posted February 10, 2018 So if our weight gets to far off the COG that could cause wobble? Quote Link to comment Share on other sites More sharing options...
LanghamP Posted February 10, 2018 Share Posted February 10, 2018 (edited) 4 hours ago, WARPed1701D said: Conversely an increased mass away from the COG will make recovery from a wobble harder due to increased momentum of the outer edge of the wheel. It could even exaggerate a wobble much like a trailer with too much weight behind the COG will fishtail and eventually jackknife. I think the wobble will be much slower weave which is recoverable instead of a fast wobble that requires great skill. My observation on my wheel doing a fast wobble is that the tire isn't even touching the ground half the time, so the damping you would get from the friction of the tire on the pavement is less. You can catch a weave pretty easily but a wobble just throws you. Mind you, I'm not even going half the speed of Rehab but either the wobble came and went before I could react or I got thrown. Thrown at 10 kmh. <snicker> So dramatic. I lifted my feet like someone threw a dodgeball at my feet, and walked these wobbles off. @Hunka Hunka Burning Lovementions relaxing to save a wobble. Wobbles where I've bailed on my own inevitably result in the wheel continuing, but often the wobble doesn't stop. Pushing my wheel on its own, usually the wheel stays stable but it often goes into a fatal wobble. Wheels are somewhat mysterious in their behavior. Edited February 10, 2018 by LanghamP 3 Quote Link to comment Share on other sites More sharing options...
EUCMania Posted February 10, 2018 Share Posted February 10, 2018 One reason for wobbling is resonance. This is can be mitigated by changing the mass of the EUC. Another reason, unknown to non-experts, is that the way we control EUC is a delayed feedback control, meaning that you sense the deviation that needs your reaction to control, by counter acting on the move one way, and your reaction is applied after some delay. Delayed feedback control system can be unstable. Just imagine that your reaction comes just as the oscillation turns to the other way. This delayed control will make the wobbling worse. To get out of the wobbling, one has to relax or tighten the leg or ankle muscle to change the feedback delay. 2 1 Quote Link to comment Share on other sites More sharing options...
trya Posted February 10, 2018 Share Posted February 10, 2018 53 minutes ago, EUCMania said: To get out of the wobbling, one has to relax or tighten the leg or ankle muscle to change the feedback delay. ... or to apply most of the weight to one leg (simulating one-leg riding) - this "delayed feedback" is almost impossible when riding on one leg 1 Quote Link to comment Share on other sites More sharing options...
Popular Post YoshiSkySun Posted February 11, 2018 Popular Post Share Posted February 11, 2018 (edited) I just got the news from @Marty Backe and @Jrkline "Wheel Whisperer" this morning...it breaks my heart to hear this, but we are all glad that you are still breathing. You’ve been a positive present in the EUC community and your spirit will be missed. Thank you for everything. Here’s to a speedy recovery. Godspeed. Edited February 11, 2018 by YoshiSkySun 7 Quote Link to comment Share on other sites More sharing options...
Popular Post Rehab1 Posted February 11, 2018 Author Popular Post Share Posted February 11, 2018 43 minutes ago, YoshiSkySun said: Here’s to a speedy recovery. Godspeed. Thank you kindly Yoshi. You had your close moments as well. As you are keenly aware having friends on this forum offering their support and friendship has tremendous healing power. Take care, Dan 4 Quote Link to comment Share on other sites More sharing options...
Rehab1 Posted February 11, 2018 Author Share Posted February 11, 2018 Somewhere under this canopy of trees is the scene of the accident. 2 Quote Link to comment Share on other sites More sharing options...
fryman Posted February 11, 2018 Share Posted February 11, 2018 Was there any ice around? 1 Quote Link to comment Share on other sites More sharing options...
Scatcat Posted February 13, 2018 Share Posted February 13, 2018 I've had a few not so serious wobbles, and they stop immediately if you relax and sink down bending your knees and tighten them a bit forward of COG. Whatever you do, don't try to actively compensate, that will just make the resonance worse. I have thought a bit about why wobbles start easier if you stand far back on the pedals, as opposed to standing well forward. And it kind of makes sense, since the actual position where the tire hits the ground is forward of the upright center position. If you stand back on the pedals, not only are you mimicking having the steering wheels on the back of a car, but you also have less steering authority, as your input is further away and off-centre from where the pivot point is. Add to this that the pedals are way lower than the axle and so moves backwards a notch when you go forward, and the problem is aggravated. It kind of comes with the whole concept. Well, whatever. I am glad the surgery seems to have gone well @Rehab1. Surgery is never a trivial thing, even when you're a healthy guy. I got a bit flabbergasted by the extent of the damage, considering your relatively modest speed (well, not THAT modest, but neither was it an F1 crash). It kinda goes to show that a lot of luck are involved in the results of an accident. People driving MC-racers routinely walk away from crashes at 60-70 mph without more than superficial bruises, while you have to have reconstructive surgery after a crash going 20 mph-ish. But I suppose the geometry is part of the answer. The few crashes I've had have felt a bit like going over the handle-bar of a bike, rather than having it slide out from under you. 2 Quote Link to comment Share on other sites More sharing options...
Electroman Posted February 13, 2018 Share Posted February 13, 2018 (edited) Regarding that 3DF jacket mentioned earlier, I understand in for ex the US there is more to choose from, cheaper and so on but it is a long time ago I was motocrossing and things change for sure.. https://www.24mx.se/crossutrustning/crosskydd/skyddsvast#?pl&t=1 I really like the idea of not using layers and breast plate outer shell etc.. etc.., really looks comfortable with a single piece to put on for upper body protection whether soft or hard pads attached to that piece/jacket. Seems like a good fit for EUC and even soft padding around shoulder, elbow areas could potentially help a lot in a fall like the one that happen to Rehab1. @Scatcat, interesting points about EUC vs bike accidents, you might just be onto something and I would much like to know that as well having been in quite a few and more often than not walked away from them. I suppose being much younger back then and in good shape also helped but still. Edited February 13, 2018 by Electroman 1 Quote Link to comment Share on other sites More sharing options...
Rehab1 Posted February 13, 2018 Author Share Posted February 13, 2018 5 hours ago, Scatcat said: But I suppose the geometry is part of the answer. The few crashes I've had have felt a bit like going over the handle-bar of a bike, rather than having it slide out from under you. Geometry and erratic force vectors definately played a roll in my accident. My elbow hit hard but then acted as a conduit transferring the excessive forces up to my humeral head essentially squishing it. I do wonder if the way my feet were locked into the pedals with the spikes acted as a second driving force as the wheel torqued around as it danced on the ground. 2 Quote Link to comment Share on other sites More sharing options...
Popular Post Rehab1 Posted February 13, 2018 Author Popular Post Share Posted February 13, 2018 (edited) On 2/11/2018 at 5:15 PM, fryman said: Was there any ice around? No ice, but you just gave me an excellent idea for an excuse. “Honey I promise I will never, ever ride on ice sgain.” Edited February 13, 2018 by Rehab1 5 Quote Link to comment Share on other sites More sharing options...
Marty Backe Posted February 13, 2018 Share Posted February 13, 2018 11 minutes ago, Rehab1 said: No ice, but you just gave me an excellent idea for an excuse. “Honey I promise I will never, ever ride on ice sgain.” or, "Honey I promise I will never, ever ride with my feet stuck to spiked pedals" I still sense a small glimmer of hope that you'll ride again. We'll see six months from now 3 Quote Link to comment Share on other sites More sharing options...
WARPed1701D Posted February 13, 2018 Share Posted February 13, 2018 58 minutes ago, Marty Backe said: or, "Honey I promise I will never, ever ride with my feet stuck to spiked pedals" I still sense a small glimmer of hope that you'll ride again. We'll see six months from now Yeah. Six months is enough time to heal... Get a divorce... And sell your business. 1 1 Quote Link to comment Share on other sites More sharing options...
Rehab1 Posted February 13, 2018 Author Share Posted February 13, 2018 1 hour ago, Marty Backe said: or, "Honey I promise I will never, ever ride with my feet stuck to spiked pedals" I still sense a small glimmer of hope that you'll ride again. We'll see six months from now 1 hour ago, Marty Backe said: I still sense a small glimmer of hope that you'll ride again. We'll see six months from now Are you possibly a psychiatrist at Boeing? 2 Quote Link to comment Share on other sites More sharing options...
Popular Post Rehab1 Posted February 13, 2018 Author Popular Post Share Posted February 13, 2018 6 minutes ago, WARPed1701D said: Yeah. Six months is enough time to heal... Get a divorce... And sell your business. Of that’s brutal. I can’t divorce. No one else will have me. 4 Quote Link to comment Share on other sites More sharing options...
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