speed wobble

So had my first real bad one this morning at about 40 mph....scared the censored outta me.managed to hang on and tried not to panic,just sat up big and let wind resistance do its thing.
So as a matter of interest what actually causes a speed wobble,been at 40 before and no problems but today was all over the shop.dont want to repeat that experience again.
So as a matter of interest what actually causes a speed wobble,been at 40 before and no problems but today was all over the shop.dont want to repeat that experience again.
Lapierre Aircode 300
Merida
Merida
0
Posts
Every object has a natural resonance.
If you're unlucky, with you on it, at certain speeds the natural resonance will match the vibrations you're getting from the road - hence it starting to oscillate much more strongly - hence the speed wobble.
Merida
With the rear wheel you can feel the balance by putting the bike in a stand and swinging the crank in a big gear - you get a vibration from the wheel. From the front wheel, I don't know - seeing how much the wheel want to pendulum into one position might give an indication: they always do a bit. You could play about to see it it will balance. It's only a theory though.
Should have stopped there.
Sad person
No wonder I'm always lagging behind - max I've topped out at is 32mph, and that's tucked in going down hill, but I got a little bit of speed wobble then as well.
I'm not sure quite what speed you begin to get vortex shedding on a spinning tyre - most of the stuff I play around in CFD land is fixed wings! I might see If I can find some time in the wind tunnel to simulate the rolling road & wind at 60mph though
Bike 1 (Broken) - Bike 2(Borked) - Bike 3(broken spokes) - Bike 4( Needs Work) - Bike 5 (in bits) - Bike 6* ...
I'll be expecting an acknowledgement on your paper when you discover the Wolfsbane Effect (Coander, eat your heart out)
I recall that Coander effects is very much about direct impinged effects isn't it? I was thinking of the side shedding vortex's, which last I heard was 'too complicated to model'; instead its been researched by someone else again at my own uni. Dang!
http://www.southampton.ac.uk/~aijf197/Wheels.pdf
Since the CFD stuff I play with is mainly rc model driven nowadays, I am out of touch!
Bike 1 (Broken) - Bike 2(Borked) - Bike 3(broken spokes) - Bike 4( Needs Work) - Bike 5 (in bits) - Bike 6* ...
Obviously very out of touch http://www.altairhyperworks.com/html/en ... MNGodo.pdf
And thinking properly, that was a really stupid thing to say... There are full on specialists across the world interested in wheel dynamics for world class cycling, what's a hobbyist aerodynamicist with no cash going to add to the world!
Think before opening you mouth!
Bike 1 (Broken) - Bike 2(Borked) - Bike 3(broken spokes) - Bike 4( Needs Work) - Bike 5 (in bits) - Bike 6* ...