Jump to content

Speed Wobble Problem


ian5708

Recommended Posts

Hi guys, 

I've got about 3 hours on my EUC. 

It's an Inmotion V10 and at the moment I have it restricted to 25 kph. 

I find sometimes when I get up towards 25kph or when I went up to 30kph on one occasion, I experienced uncontrollable speed wobble that got even worse as I took of speed. 

Its the equivalent to skiing fast on very short ski's or a tank slapper on a motorbike. 

I know I must be doing something wrong for it to happen so I wanted to reach out to the community for help. 

I'm 95kg 185cm and have my tire set at 2.8 bar, the manufacturers recommended pressure. 

I know some of you will just say slow down and don't let it happen, fair enough, but I just want to understand the physics of why this is happening to me. 

Perhaps I'm too stiff, maybe I'm not standing upright enough, maybe I should hold the unit tighter or looser between my calves?

All advice and possible explanations  appreciated. 

Cheers, Ian 

  • Like 3
Link to comment
Share on other sites

4 hours ago, ian5708 said:

I know some of you will just say slow down and don't let it happen, fair enough, but I just want to understand the physics of why this is happening to me. 

RIght, plus going above 25km/h after 3 hours of experience is not a good idea either. It's much better for your health to experience the limits (which almost inevitably happens) at lower speed, plus, importantly, the margin to get over the limit becomes smaller with increasing speed.

Edited by Mono
  • Like 2
  • Upvote 1
Link to comment
Share on other sites

  • 6 months later...

This was a helpful thread. As of today I have put 62-miles on my KS18XL over the past three days and I was intermittently getting wobbles, sometimes pretty bad, usually around 15 to 18 mph. I would brake until they went away, but it made me wonder if something was wrong with my EUC. Good to know they are a normal thing that will go away with more experience. I already feel like they are happening less than before.

  • Like 2
Link to comment
Share on other sites

  • 1 month later...
1 hour ago, mrelwood said:

Straightening up works well for smaller or self-induced wobbles, but for severe wobbles at higher speed I feel a strong carving motion to be more effective. Or just leaning the other leg firmly against the wheel while the other doesn’t touch the shell.

A funny thing I’ve noticed: If I crouch low to lessen the wind resistance at 40-50km/h and lean on my knees with my hands, the wheel will slowly start to wobble. If I move both hands onto just one knee, the wobble goes away.

This also supports the wobble being a resonance, since making the conditions unsymmetrical dampens the wobble.

I agree on carving being the most effective. It means you're shifting your balance so that you're basically stabilizing the wheel with one leg.

I did notice when I crouch because of a strong headwind (at slightly lower speeds but possibly more wind), that I'm a lot more prone to wobbling. Haven't tried the trick with the hands, but another thing that seems to work for me is actually pushing both legs to the outside. On a 16X you can do easily this because the pedals have an angle. It seems counter-intuitive though,  as instead of relaxing your leg muscles you are tensing them. I do the same when I'm not crouched, but under-dressed (light trousers in freezing temperatures), and I get shivers in my legs, which leads to wobbling.

Edited by Tazarinho
  • Like 2
Link to comment
Share on other sites

12 hours ago, Ddolik said:

straightening the knees work for me too, but its ks16x, so different tire size than inmotion or 18xl

It works on my in motion v8 as well. 

  • Like 1
Link to comment
Share on other sites

Another vote for straitening up some for a bit.  I've also found relaxing, releasing unnecessary tension from my legs works too. Do both. ^__^

Building up needed muscles makes it much easier to relax. A lot of dynamic riding, carving / slalom, whatever can be quite a workout.  I've done a lot of this recently and it's made a noticeable improvement.

I also find shifting my weight on the petals, one foot mostly heel and the other mostly toe, works really well for killing wobbles. I use this now mostly for hard breaking and when straitening up isn't an option (uneven ground).

 

  • Like 3
Link to comment
Share on other sites

Slow riding is a worthwhile skill in itself and the wobbling  is a different kettle of fish to the speed wobbles. U need a different technique to combat the speed wobbles which come on unexpectantly when ur newish to riding. Carving if u can remember will kill off the speed wobbles and save u a few grey hairs.

  • Like 1
Link to comment
Share on other sites

On 6/9/2019 at 10:58 AM, meepmeepmayer said:

Ground variations, small muscle or steering movements, wind, etc. constantly induce sideways motions that can start a wobble. Usually, the rider dampens the oscillations away quickly and automatically, that's just a normal part of riding. But if the leg muscles are tense (new rider, tired, bad stance on the pedals, unusual thing happening like a wind gust, etc.), that attempt to dampen will be out of sync (your body reacting too late, essentially) and actually amplify the wobbling instead of dampening it (or at least you'll not be able to reduce the wobbling and it will increase by itself). That's the working theory how you get speed wobbles.

Stand as relaxed as possible (that comes with experience, 3 hours is nothing - and grabbing the wheel may be counterproductive!) and if you get wobbles, do something that starts a strong and new leg muscle tension like braking (or even accelerating, but braking tends to be safer for obvious reasons) or going into a curve. Your tense leg muscles' delayed reactions is what causes the wobble, so changing the muscle tension is how you can get out of this rut. [TLDR: just brake.]

Essentially, everyone has speed wobbles. The question is just: at what speed do they appear? The faster the tire spins, the faster a sideways wobble will grow, so every rider will have a speed at which the wobbling is so violent that he can't balance it. The more relaxed the rider is and the more experience he has, the higher that speed is, and if it's beyond the wheel's top speed, problem solved:D

You can try this for yourself by riding slowly and starting to squat down (tenses your legs). You'll see a wobble appear. That's also why some people get wobbles when braking downhills, the unusual stance tenses the leg muscles too much.

this pretty much sums it up perfectly.. i havent experienced speed wobbles because i started off on a much slower wheel and rode it all the time every single day until i upgraded so by then i was experienced enough to not see them.. one thing that most will find very difficult to do but can quickly build up your leg muscles is to squat over the wheel and hold it until you get too tired, relax, carve around a little bit get loosened up and then try it again.. never do anything that doesnt feel comfortable like if youre very new you may start to get some extremely bad wobbles while bending down but if that happens just stand back up and slow down a little, you will find that over a short period of time you will be able to go lower and lower until one day youll be able to comfortably sit on the shell and touch the ground (not recommended lol)... when i first started practicing this i would wobble like a madman on my way down and then once i was in a full squatting position and able to grasp the wheel with my thighs or knees it would subside but actually controlling the direction of the wheel still was very bad, about as nimble as a bulldozer, but after practicing it for a long time it was one of my goals to be a good seated rider after learning to ride backwards so now i have much stronger leg muscles and can go up and down as many times i like and sit on top of the shell of any wheel with complete control and confidence, plus its fun as hell

Edited by Rywokast
  • Like 2
Link to comment
Share on other sites

  • 4 weeks later...
On 2/14/2020 at 7:16 PM, Daley1 said:

Slow riding is a worthwhile skill in itself and the wobbling  is a different kettle of fish to the speed wobbles. U need a different technique to combat the speed wobbles which come on unexpectantly when ur newish to riding. Carving if u can remember will kill off the speed wobbles and save u a few grey hairs.

Confirmed. I stepped onto my new MSX today and while I can ride super slow with no problems (it's actually really easy compared to the 14d, IMO) I experienced a kind of wobble I hadn't felt since my first real rides with the 14d, seemingly out of nowhere. This must be the speed wobbles again. I'm sure I'll just get used to the wheel sooner or later and they'll stop. Very unnerving with a heavy wheel. Carving does stave them off! Reminds me a little of snowboarding where you always want to be on the edge of the board to stay in control.

  • Like 2
Link to comment
Share on other sites

I find having an asymmetrical stance to be the biggest determinant to having wobbles. A perfectly even squat (as to sit on your wheel) induces no wobbling whatsoever.

I'd guess the asymmetrical stance tilts the wheel to one side when going up a bump, then tilts it the opposite way when going down a bump, and so the two tilts start an oscillation, especially at higher speeds when the tilting is faster and more severe.

Fix your asymmetrical stance and you fix your wobbles.

By the way, any experienced rider has perfect balance, that is, he will be able to place his weight evenly between his feet (as confirmed by the innersole machine as Walgreens). That skill isn't natural; riding a wheel trains that skill. That's why wobbles go away once that skill is developed.

  • Like 1
Link to comment
Share on other sites

On 6/9/2019 at 5:40 PM, HarpMudd said:

You'll be fine..the speed wobbles just go away after doing lots of riding. 

One thing to note on tire pressure, the manufacturer's recommended pressure isn't always best for the rider. A little less pressure is best for newer riders and as your skill improves, you will want to add more. Here's a good guide to help you figure it out: Guide to Tires & Appropriate Pressures on an Electric Unicycle

You'll be surprised that after time as your muscles and mind adjust, all of the little things you obsess over such as foot and body position, type of shoes, inexact tire pressure won't impact your ride as much. I think I still got the wobbles until about 2 months of riding.

Yesterday I was riding after increasing my tire pressure to 30 psi from 28. The first part of my ride felt very unstabe and wobbly at my normal speeds. That small change made a big difference in how my wheel behaved and felt. After about 4 miles I had to stop and bleed off some pressure. After that, no more wobbles.

I went on to ride over 20 miles at speeds reaching 28 mph. I think as I get better I will be able to increase the pressure but right now, low pressure is good for me.

Edited by AngryJackPCB
Link to comment
Share on other sites

On 2/12/2020 at 11:20 AM, macrhino said:

Here is an answer to stopping the speed wobble. 

I think sometimes that the people who have a lot of experience have so internalized their abilities so it makes it hard to assess what is happening. 

I started on an EUC in July of 2019. I rode the wheel (Inmotion V8) for a little while (300+ Miles)  getting these wobbles and having no idea what caused them. As it is said above, they tend to start diminishing after a time. Now they are almost non-existent on the v8. I am heavy (250LBS) and like to ride so I also purchased a Kingsong KS-18L. When I started with it, the wobbles came back. But by now my riding abilities had progressed to a point that I thought I would study the problem. 

This is what I found and hope it is not specific to me. 

  • Foot placement is important. I found that foot placement is perhaps the SECOND most important factor in speed wobbles. If the pedal of the wheel has a center point, the point should be immediately in front (anterior) of a centered logo (NB, Nike, ETC) on the shoe of the foot on the pedal. As well, your ankle should NOT be crammed hard against the wheel.(Lateral position)  Give yourself enough space to be comfortable. 
  • Inducing the wobble: Bend your knees slightly and stick your butt backwards a little, lean forward. As you speed up and hit uneven spots, you should start the wobble. 
  • STOPPING THE WOBBLE: (Ok here it is, at least for me)
    Make your back upright as possible, and STRAIGHTEN out your knees. Do not lock your knees but you can come close to a locked position. As you straighten out your knees and get your back straight, the wobble should simply go away and immediately. 
     

This works for me and it works every time. I would appreciate knowing if it helps other new riders. 

Your posture is very important. I was reaching down to turn on my headlight and as I bent  I started wobbling very bad. As soon as I stood up, it went away. No more bending until I start trying to use my seat. 

  • Like 1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...