M.M. crashed at the French G.P. during practice, & wiped a winglet off one side of his Honda, but remounted the bike,
& resumed lapping fast.. (& worrying the Honda techs).. he then had this to say about the difference with assymetric aero..
"I was pushing*, but you feel it a little bit on the brake point, but for pushing it on 2, or 3 laps, it was ok."
Evidently then, aero does affect braking performance, somewhat..
*By pushing, he means riding hard, not literally 'pushing' the bike to restart it..
Re: 2018 FIM Moto GP World Championship
Posted: 26 May 2018, 11:02
by Tommy Cookers
everybody should read Tony Foale's articles on his experiments with steering geometry
accessed via the aerodynamics article that nacho has just linked
T.F. uses a vertical fork and claims the associated wobbling was due to the extended frame being insufficiently stiff
Phil Irving wrote that wobbling is inherent with a vertical fork/steering axis
such geometry would postpone rear lift and so improve braking as the wheel wouldn't move back with dive on braking
though dive can be eliminated with other types of suspension eg Elf-Honda
neither regarded traditional (bicycle-type) steering geometry as important - but Ken Sprayson did
ie the steering axis at the mid-height of the rolling radius - preventing steering effects from bike weight
Sorry but you´re confusing different things. They barely use any rear brake because the rear wheel is almost on the air, if not completely as shown above, so any rear brake input will only lock the wheel, stall the bike, and cause a crash. That´s the reason they had to reduce unwanted engine braking effects, any engine retention can cause a lock and the engine stalling. Not good.
Ducati´s longer wheelbase OTOH reduce this problem (so Ducati riders might use the rear brake more than their rivals), but magnifies a different one, steering while entering the corner, as longer wheelbase is more stable, but less agile, so they need to use the rear brake to cause some oversteering, or reduce understeering.
But DF while braking, if located at the front end, is useless. No bike need anti-lock systems on dry conditions (on tarmac!), as the limiting factor is not the front wheel grip, but the rear wheel becoming too light, jumping, and moving sideways causing serious stability problems to the rider
So DF at the front end, for braking, is useless. They´d need DF at the rear end to keep the rear wheel planted so they can hit the front brake harder and improve braking, but nowadays, unlike F1, front wheel grip while braking is not the problem, it´s the rear wheel becoming too light...
As for such ideas of engine braking "stalling" the engine.. yeah, that's in fact.. 180 degrees out..
- the concern was with big 4T engine rotating inertia either "stalling" the rear tyre - causing an unwanted slide,
or worse - a highside crash, by still 'motoring' the bike.. on a snap-shut throttle - slide-save attempt..
( esp' when the 'idle' was turned up to ~ 3-4000 rpm - to reduce the unwanted engine braking, from "stalling" the bike).
Expensive electronics-suite 'work-arounds' were necessary to settle these characteristics, but as a further example
of Casey Stoner's deft touch, he insisted on having these 'override' functions dialed down - to minimal settings..
I am certain that the removal of the winglets was the main reason for this braking instability and crash.
It was very frightening, he lost consciousness directly after hitting the tarmac, hope he is ok now.
Re: 2018 FIM Moto GP World Championship
Posted: 02 Jun 2018, 11:08
by Bill_Kar
Helloooo Marc.. He'll obliterate the field once again..
I think we should really doubt whether Vinales is as good as everybody says. I don't particularly like him and having to fight through Q1 whereas Rossi is 3rd adds up to the tally.
Re: 2018 FIM Moto GP World Championship
Posted: 02 Jun 2018, 14:54
by etusch
Old fart on pole. I don't know what happend to MM at his flying lap which was 0,4 faster at firt two sectors.
Old fart on pole. I don't know what happend to MM at his flying lap which was 0,4 faster at firt two sectors.
Poetry in motion: @ValeYellow46 electrifies Mugello for pole The ‘Doctor’ rides a stunner through the yellow haze
of the Tuscan hills for his 65th pole
Lorenzo had ride today like how he was riding when he ride a yamaha. Very consistent lap times.
Rossi and both suzuki were also good.
Out of pity that Mm93 couldn't save this time and it was unrecoverable. Far from that race could be more exciting with him.
Re: 2018 FIM Moto GP World Championship
Posted: 03 Jun 2018, 23:04
by Nonserviam85
Very entertaining race and the hope for a competitive championship returned again!
Re: 2018 FIM Moto GP World Championship
Posted: 04 Jun 2018, 00:40
by J.A.W.
Good effort, & well done, J.L - a flawless ride to Mugello G.P. victory, on the Ducati - at long last!
From holeshot to checquered flag, Jorge 'put the crush' on the rest.. inc' Dovi - 'like a boss'..
& after another early skittle-fest, inc' both factory Hondas (yet not 'crasher' Cal.. who finished as best Honda, in 6th).
Kudos to ol' Vale.. pole & podium.. plus 2nd spot points-wise, in the Championship chase, following M.M.'s non-score.
The ‘Doctor’ rides a stunner through the yellow haze