Re:Motorbike crashes: highside and lowside crashes explained
by emmelaich on Thursday June 08, 2023 @12:58AM
(#36237404)
Accelerating enough to be always spinning the back wheel is also the way to avoid high-siders. Perhaps only very powerful bikes can do this predictably at any speed. It's the same technique as a speed way bike, but on bitumen and far higher speeds.
Mick Doohan was a master at this. https://www.youtube.com/watch?v=Bs0Kg-niVk8
Re:Motorbike crashes: highside and lowside crashes explained
by natmaka on Thursday June 08, 2023 @01:14AM
(#36237522)
On the 'supermoto' side of things:
https://www.youtube.com/watch?v=6SXtaUQxsWk&t=27s
Re:Motorbike crashes: highside and lowside crashes explained
by seanhunter on Thursday June 08, 2023 @01:20AM
(#36237559)
Yeah that controlled drift thing at speed is completely terrifying and amazingly skillful. Not for me, though. I was always taught to set up before the corner with the bike still vertical "in slow, out fast". I guess that's why on the one hand I could never be a racer but on the other hand I never crashed.
Re:Motorbike crashes: highside and lowside crashes explained
by MarkMarine on Thursday June 08, 2023 @03:10AM
(#36238335)
Mick had a much different body position than is standard now.
If you spin the rear while you’re hanging off like a current MotoGP rider, you’re going to get flung into the atmosphere.
I’m sorry but this is conjecture about how to save or prevent a highside, you shouldn’t actually try to put this advice into practice.
Re:Motorbike crashes: highside and lowside crashes explained
by MarkMarine on Thursday June 08, 2023 @03:21AM
(#36238403)
When you’re putting input into the bike at lean, it won’t wobble. The wobble is a progression that starts with a lightly loaded front tire, and every bike I’ve ridden with a good quick front suspension geometry will wobble in the right circumstance. A steering damper will kill the progression of a wobble, but if you’re accelerating the front can still give a wicked shake on a bike with a damper. Enough to loosen the front brake pads, smash thumbs, etc.
When racing, if you have a hill crest that you’re accelerating over and you set the front down after the hill, it’s common to get a good shake. You learn to ride through it.
This is the death wobble for people who don’t know. https://youtu.be/eoc1EM6yUSc
In this video the rider handles it perfectly and doesn’t crash but you can easily see how this has caused many crashes. As I understand it, it is a harmonic wobble that intensifies and is due to a flaw in the design of the rear suspension on some Harley Davidson models that they have chosen not to fix to keep the designs authentic. Make of that what you will.
Another terrifying variant on the “death wobble” is the “tank slapper”. This is typically caused by a flaw in the front steering (specifically having the steering geometry too vertical). Having the front forks close to vertical makes the bike handle very fast so is favoured by sports bikes however if the bike steers too quickly and hits a bump the steering will veer uncontrollably from side to side eventually causing the riders wrists to hit the sides of the petrol tank as the bike careers down the road weaving uncontrollably. The most terrifying part of all is slowing down makes a tank slapper worse so pretty much the only way it’s possible to recover from a tank slapper is to accelerate hard, get the front wheel off the ground and put it down straight. As a rider even thinking about the prospect of accelerating hard when in that situation makes me feel sick. Tank slappers are prevented by fitting a steering damper. I had a (crazy) friend[1] who bought a bike that was infamous for tank slappers[2] and then remove the steering damper to “see what would happen”. He had a tank slapper on the West Side Highway in Manhattan.
[1] Hi Kirat!
[2] Old Suzuki TL1000s