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Suspension travels

Started by h106frp, November 23, 2015, 12:09:31 AM

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h106frp

November 23, 2015, 12:09:31 AM Last Edit: November 23, 2015, 12:13:20 AM by h106frp
After riding spa for a bit i though i would use MaxHud and observe the suspension movements.

It seems that with the 990 under any acceleration (even light acceleration) the front suspension is at full extension and the rear does not move much at all. Playing with the settings for front and read suspension really does not seem to make much impact. I was under the impression that the rear suspension geometry is supposed to give some opposing reaction to keep the suspension more level (and keep some load on the front tyre) under acceleration. What am i missing?

I thought it worked like this
http://www.sportrider.com/more-fun-geometry

HornetMaX

The thing that would affect the anti-squat behavior is the swing arm pivot setting in the garage (figure 6, yellow line). But on the 990 (and on most of the other bikes) this setting is irrelevant ans there's no difference in the 0,1 and 2 setting (min/mas point are identical in the .geom).

In many situations me too I find the front to be way too light (and to lift too easily). Let's just hope what PiBoSo is doing on the rear suspension will help.

C21

try it on the rsw500, the pivot setting is working on it.
# Member of the CAWS Racing Team #


Napalm Nick

+1 Front needs more load during acceleration. This will help with tankslappers, inability to change direction, front washouts IMO.

For BoB (saves his fingers):     BoB would also like a steering damper please.  :)
"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

Quote from: HornetMaX on November 23, 2015, 12:27:29 AM
The thing that would affect the anti-squat behavior is the swing arm pivot setting in the garage (figure 6, yellow line). But on the 990 (and on most of the other bikes) this setting is irrelevant ans there's no difference in the 0,1 and 2 setting (min/mas point are identical in the .geom).

In many situations me too I find the front to be way too light (and to lift too easily). Let's just hope what PiBoSo is doing on the rear suspension will help.

Tried swing arm with 990 - does not seem to alter squat under acceleration  :(

Yohji

November 23, 2015, 06:04:25 PM #5 Last Edit: November 23, 2015, 06:06:55 PM by Yohji
here is my test  Bike to known Geometry
https://drive.google.com/file/d/0B8z1c8mntGtLdG1NR2pwMjJ3ckE/view?usp=sharing

bese is RC990. I edited Swingarm angle 5degrees to low, pivot position, and little CoM.

at first, you get ride Pivot Position "0" thats not working for anti squat,
next changing Pivot Position to "5" that has big anti squat moment geometry.

thats testing to get feel anti squat,

and this bike static balance is "front down" "rear up". this cause many front weight, but that cause less dynamic front fork caster angle, plz reset caster to big (23→25)

it cause better balance at Acceleration, but not good at braking (too many front weight!)

offcouse, i know that Test bike balance is not good to Racing Ride :P


I think, GPB has to more Improvement to Pitch (or dynamic wight distribution)
(so, now Piboso working new rear sus sim, I hope it cause better to ride )

h106frp

Brilliant, it works!

Much better on the flat turns  :)

yoshimura

November 24, 2015, 07:37:54 AM #7 Last Edit: November 24, 2015, 07:53:18 AM by yoshimura
The elbows against the tank, still rubbing the ground, are against real progress due to the tires. Coefficients of adhesion achieved today is approximately 2. This means that a tire that supports a weight of 100 kg will skid soil for horizontal thrust force of 200 kg !!! (1 adhesion means that the vertical force and the horizontal force would be identical). This allows pilots to look at 60 °, which corresponds to 2 G of centrifugal force! It's huge but also very complicated to manage and you'll understand why the flexibility of frames ... is another puzzle Japanese head (and Italian).

Technical MOTO GP: Travel to the limits of physics

Variable flexibility
The fact that the motorcycle and the driver take 2 G in turn, means that in this situation, the load on the suspensions is huge and they are then strongly compressed. Therefore, to drive the more it will take a major effort, which does not facilitate the natural absorption of bumps in turns. That is not good for handling. Worse, if a lump of 2 cm is in the wheel, the suspension being not at all in the working axis, but inclined of 60 °, it will have to compress 4 cm, so that the wheel actually up 2 cm gold ... we have said it already had more than a good part of his race ... a result, engineers are playing on the lateral flexibility of the frame and the swingarm to absorb some dents in this context for the less delicate. Again, like charging for transfers, it is a virtuoso work to handle the art of compromise so that flexibility provides handling that is not bouncy curve and rigidity is sufficient braking, as straight and fast corners. It is for this reason that many executives and swingarm are tested constantly to suit the circuit and the sensations of the driver.

source/http://www.lerepairedesmotards.com

h106frp

Quote from: Yohji on November 23, 2015, 06:04:25 PM
here is my test  Bike to known Geometry
https://drive.google.com/file/d/0B8z1c8mntGtLdG1NR2pwMjJ3ckE/view?usp=sharing

bese is RC990. I edited Swingarm angle 5degrees to low, pivot position, and little CoM.

at first, you get ride Pivot Position "0" thats not working for anti squat,
next changing Pivot Position to "5" that has big anti squat moment geometry.

thats testing to get feel anti squat,

and this bike static balance is "front down" "rear up". this cause many front weight, but that cause less dynamic front fork caster angle, plz reset caster to big (23→25)

it cause better balance at Acceleration, but not good at braking (too many front weight!)

offcouse, i know that Test bike balance is not good to Racing Ride :P


I think, GPB has to more Improvement to Pitch (or dynamic wight distribution)
(so, now Piboso working new rear sus sim, I hope it cause better to ride )

Hello Yohji,

I tried a bit more with this bike and the changes in the handling are very interesting. Using the pivot adjustment allows for more realistic suspension movements and i also noticed that the bike is noticeably different when using softer suspension settings and/or the longer swing arm - with the original bike i have found it difficult to notice much change in the bike when adjusting suspension.

The bike also seems a little less prone to the front randomly folding and the rear slides longer (more chance to save) before letting go, i did not notice any big problems with braking as the more predictable bike is more controlled if it does weave a bit. The nice thing is it does not make the bike 'easier to ride' like some fixes, just a bit more predictable.

Have you considered submitting it to the bike MOD so that it can be used online, i think it might generate some useful discussion and feedback.

Thanks

Vini

This is totally awesome, Yohji!!
Can you include your seamless gearbox in this modified RCV?
It would be very interesting to try.

Wheelie is a lot better of course but also braking and rear wheel feel (powersliding works much much better).

..Now I have high expectations for the PiBoSo's improved rear suspension geometry simulation.

BOBR6 84

Not tried it yet but it sounds like bike setup porn! Nice one  8)

HornetMaX

Yohji, it's probably better if you create a dedicated thread to discuss the changes you've done.

h106frp

Quote from: BOBR6 84 on November 24, 2015, 11:36:55 AM
Not tried it yet but it sounds like bike setup porn! Nice one  8)

Its encouraging that a geometry modification has a positive or predictable effect on the bikes handling without messing (fiddling) the physics.

Still does not like inclined turns though (we know why) -  Roll on B8

Yohji

November 24, 2015, 02:26:50 PM #13 Last Edit: November 24, 2015, 02:36:11 PM by Yohji
here is V2 bike
https://drive.google.com/file/d/0B8z1c8mntGtLN1N0cjdVN1pfT0U/view?usp=sharing

some moddified at front, and transmission(near-seamless Shift)

but, I will not more modding this bike now. because, beta8 will comming soon. and that has big change at rear section.


h106frp

Thanks Yohji,
Not sure about the seamless shift myself, seems very strange after being used to the default and has quite an impact on the way the bike feels. Going to experiment more with the V1 bike.