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Rumble in MaxHUD - discussion

Started by HornetMaX, July 20, 2015, 12:13:16 PM

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h106frp

Thanks, I think  ???

If Y is vertical, is X across the bike or in line (front to back) ?

Looking at the acceleration outputs from my DAC's on the scope it is not obvious. Just deciding if project 'Super tri-axial acceleration seat shaker' is practical  ;) ;D

HornetMaX

I logged 1 lap on the oval track, it's easier to figure it out: Z is bike longitudinal (fwd/back), X is lateral, Y is "vertical" (in quotes as it's vertical with respect to the bike, but if the bike is wheeling ...).

MaX.

h106frp


Napalm Nick

ooo oo oh.

just remembered I wanted to say this:

With MaxRumble you can feel (literally) the start of the oscillation that results in the front end tuck at slow corners.

Why is that interesting?
1. Allows you to take avoiding action (brilliant).

2. Maybe if the source of the oscillation signal can be identified it might provide a hint to the most annoying problem in the world?

Is that feasible?
"The post you are writing has been written at least ten times already in the last 15ish years. Its already been reported, suggested, discussed, ignored or archived (but mostly ignored). Why are you doing it again?"

h106frp

From my dabblings the biggest source of oscillations are on the bike lateral X axis. I was surprised at the magnitude of lateral vibrations compared to those on the vertical axis.

If you ask MaX very nicely he might be persuaded to add a bar meters to MaXHUD for X, Y and Z vibration magnitudes. I have them on my rig control widget and they are quite interesting to observe.


Napalm Nick

Thanks H good info. Not knowing how to interrogate these things, a visual indication would only show me what I can feel but could be useful too.

Maybe the gorgeous Hunk of an Italian Scot could interprete the data to find the source.  :D Then we could all worship him as the new leader.
"The post you are writing has been written at least ten times already in the last 15ish years. Its already been reported, suggested, discussed, ignored or archived (but mostly ignored). Why are you doing it again?"

HornetMaX

For point #2 in Nick's post above: I don't think the front weave/wobble is properly a bug. Real bikes do have this kind of behaviours so it would be hard to look for a "source" of that.
True, in GPB these seem to be a bit too present, but I have little hope to investigate them with the info at hand, even assuming that there's something to investigate (which is already not sure).

MaX.

Napalm Nick

Fair enough we will continue to worship the old leader then  :P

But.....the GP250 only suffers about 10% of the 'wobble' seen on the Fz6 (which is also about 50% less than the stock Gp125s).
Which implies what we already know - either a core physics-engine problem lessened/worsened/amplified/nulled by bike design or a bike design problem in the first place.  (Or something completely different like 'we are not Yan-enough').

Its all good discussion though while we await the genius to resolve it. I just get the feeling it's shouting out the problem but we cant hear it yet.
"The post you are writing has been written at least ten times already in the last 15ish years. Its already been reported, suggested, discussed, ignored or archived (but mostly ignored). Why are you doing it again?"

HornetMaX

Core physics problem is the less likely option, IMO.
Most likely it' a mix of bike physics parameters (e.g. mass distribution), bike geometry (the fz6 suffers less, but that's just normal no ?) and maybe virtual rider interaction.

MaX.

Napalm Nick

Indeed. In the mean-time, Rumble helps with avoiding the problem a little so thanks for that. :)
"The post you are writing has been written at least ten times already in the last 15ish years. Its already been reported, suggested, discussed, ignored or archived (but mostly ignored). Why are you doing it again?"

h106frp

I think bike geometry issues are very likely playing with the Donnington track i was amazed at how easy it was to back flip the Yamaha 600 on the back straight but the default 990 just does a nice gentle 2 wheel off the ground jump at the same point under the bridge. The Yamaha geometry must provoke this response and is just not believable.

HornetMaX

Quote from: h106frp on August 25, 2015, 02:46:41 PM
I think bike geometry issues are very likely playing with the Donnington track i was amazed at how easy it was to back flip the Yamaha 600 on the back straight but the default 990 just does a nice gentle 2 wheel off the ground jump at the same point under the bridge. The Yamaha geometry must provoke this response and is just not believable.
Could be also due to the suspensions and/or the tyres.

MaX.

h106frp

It just too extreme a difference, the 600 traveling straight in 6th gear will instantly just do a 360 back flip off the small bump. Its not even like its an overly developed wheelie, the bike just seems to rotate around its axis - very weird.

CapeDoctor

i've experienced exactly the same with the GSXR 600, so it's not just the Yamaha, but likely all the 600's, at least....
instant backflip.
not as it should be, i'm sure....