Hi,
today i watched qualif and free practices of last weekend and they were talking about the different parts can be changed on bike.
A part that can be very interesting for gpbikes is the possibility to move the fork forward or backwards, from my memory they can move it from max to min with 16mm(i can find the right measure).
i think about that because ricco chicco said me he changed this value, just a little, and the bikes became very better to ride.
Thank you.
(http://img11.hostingpics.net/pics/289189modifierfourche2.jpg) (http://www.hostingpics.net/viewer.php?id=289189modifierfourche2.jpg)
Quote from: janaucarre on May 05, 2015, 05:45:37 PM
Hi,
today i watched qualif and free practices of last weekend and they were talking about the different parts can be changed on bike.
A part that can be very interesting for gpbikes is the possibility to move the fork forward or backwards, from my memory they can move it from max to min with 16mm(i can find the right measure).
i think about that because ricco chicco said me he changed this value, just a little, and the bikes became very better to ride.
Thank you.
Sounds interesting....... I'm presuming this isn't the "Rake" angle your talking about here?
Nice to see you back here Janau! ;D
Hawk.
Move the fork forward/backward ? :o
I've never heard of this: only tweaks close to that that I know of are the rake and the fact you can slide the fork up/down in the triple clamps (not sure this last thing is used a lot though).
MaX.
You're right, i'm not talking about rake angle.
Max i'll sent you the video where a man from ducati explain this(in french), as soon as possible by pm.
Triple clamps with different distances from pivot to forks position could do this.
I mean , not slides but different triple clamps sets. It will modify distance between wheel centers also (if same rake angle is kept)
so... it's mean fork offset?
also I heared somtimes racing bikes can changing it in garage.(GPB not do it yet)
Quote from: Warlock on May 05, 2015, 11:01:29 PM
Triple clamps with different distances from pivot to forks position could do this.
I mean , not slides but different triple clamps sets. It will modify distance between wheel centers also (if same rake angle is kept)
Hmm, that's not equivalent to what jannaucarre seems to be saying: he says they can move the steering axis fwd/back, what you can do with the triple clamps is alter the fork offset. It's very different.
MaX.
(http://img11.hostingpics.net/pics/776055modifierfourche.jpg) (http://www.hostingpics.net/viewer.php?id=776055modifierfourche.jpg)
Quote from: HornetMaX on May 06, 2015, 07:26:18 AM
Quote from: Warlock on May 05, 2015, 11:01:29 PM
Triple clamps with different distances from pivot to forks position could do this.
I mean , not slides but different triple clamps sets. It will modify distance between wheel centers also (if same rake angle is kept)
Hmm, that's not equivalent to what jannaucarre seems to be saying: he says they can move the steering axis fwd/back, what you can do with the triple clamps is alter the fork offset. It's very different.
MaX.
Move the axis? wow :o
(http://img11.hostingpics.net/pics/289189modifierfourche2.jpg) (http://www.hostingpics.net/viewer.php?id=289189modifierfourche2.jpg)
Quote from: Warlock on May 06, 2015, 01:04:53 PM
Quote from: HornetMaX on May 06, 2015, 07:26:18 AM
Quote from: Warlock on May 05, 2015, 11:01:29 PM
Triple clamps with different distances from pivot to forks position could do this.
I mean , not slides but different triple clamps sets. It will modify distance between wheel centers also (if same rake angle is kept)
Hmm, that's not equivalent to what jannaucarre seems to be saying: he says they can move the steering axis fwd/back, what you can do with the triple clamps is alter the fork offset. It's very different.
MaX.
Move the axis? wow :o
Yeah, that's what I think too. I don't really see how this is doable without some serious complication in a critical part of the chassis.
MaX.
Indeed, that would be an engineering master piece
I think there actually is a piece of kit that gives you some adjustment! Dont know much about it though..
In my world I slide the forks through the yoke by about 10mm lol
Hmmm ... have been looking around and I've found some adjustable triple clamps. Examples:
http://nuovafaor.it/en/sez-parti-moto/1/piastre-regolabili.htm (http://nuovafaor.it/en/sez-parti-moto/1/piastre-regolabili.htm)
http://www.xtrig.com/en/Products/Triple-Clamp.html (http://www.xtrig.com/en/Products/Triple-Clamp.html)
The explanations/drawings are a bit scarce, but I think it's just an offset adjustment (which indeed we do not have in GPB).
Sort of a confirmation:
https://www.youtube.com/v/1RG0TUul9Jo
Maybe it makes sense to have this in GPB: some bikes will have both rake and offset adjustable, some just offset, some nothing at all.
MaX.
I can only talk about factory 500 bikes here but the possible adjustments concerning the front end were:
- Changing the rake angle
- Changing the offset (by changing the triple clamps)
- Moving the fork tubes up and down in the clamps of course.
The axis of the steering column could not be changed, but the steering angle was changed by a system within the steering column that I can't explain in english (Il y avait des cales dans la colonne correspondant aux différents angles, on peut monter les roulements dedans... En théorie on pourrait peut-être bouger un peu l'axe de colonne comme ça mais le but du réglage était l'angle de la colonne. Il y a de toute façon très peu d'intérêt à avancer la colonne). Hornet can maybe translate :P
Thanks Edouard !
So it seems we're indeed missing something in GPB, the possibility of changing the front offset in the garage.
Knowing it affects directly the trail, it could be very interesting. Today we change the trail changing the rake, but this has other side effects.
Also, it will facilitate the life of the modders (as they will be able to play with this setting in-game instead of changing it in the .geom).
I'm less sure about the need of being able to slide he fork tubes up/down in the clamp, but if we go for that it is maybe worth to consider another setting that is often available: the rear height (changing the length of the rear suspension links).
MaX.
P.S.
For the translation: changing the steering (axis) angle was possible thanks to inserts in the steering column (where bearings were installed). In principle this could change the position of the steering axis too, but it wasn't used for that, the goal was to change the angle. Anyway, there's little interest in changing the position of the steering column (added by MaX: because this would essentially alter only the wheelbase, thing that can be done in an easier manner at the rear swingarm).
Good stuff! It says in the description that gpbikes accurately simulates setup options... So all this needs to be added ;D ;D
Quote from: HornetMaX on May 11, 2015, 09:41:57 AMAnyway, there's little interest in changing the position of the steering column (added by MaX: because this would essentially alter only the wheelbase, thing that can be done in an easier manner at the rear swingarm).
It would change the wheelbase but it would also change the Front/Rear weight repartition differently than by altering the rear (removing weight from the front instead of adding some).
However it is still pretty pointless because on a GP bikes there are several (and simpler) ways to change Front/rear repartition and usually, after 1985 of so, the engines were pushed forward as much as physically possible (even on recent Ducati MotoGP bikes we've seen cutouts in the radiator to place the cylinders through it to move it forward as much as possible).
Quote from: EdouardB on May 11, 2015, 10:09:36 AM
Quote from: HornetMaX on May 11, 2015, 09:41:57 AMAnyway, there's little interest in changing the position of the steering column (added by MaX: because this would essentially alter only the wheelbase, thing that can be done in an easier manner at the rear swingarm).
It would change the wheelbase but it would also change the Front/Rear weight repartition differently than by altering the rear (removing weight from the front instead of adding some).
Well, if you shorten the swingarm length, you remove weight from the front, so (in principle) you can do both (add/remove weight to the front) with the swingarm.
But I agree on the pointless-ity of it :)
Ducati stuff: didn't they suffer from issues of front tire rubbing against the radiator under heavy breaking a while ago ? I think I remember a crash due to that. They probably pushed it that tiny bit too forward :)
MaX.
Quote from: HornetMaX on May 11, 2015, 10:43:24 AM
Well, if you shorten the swingarm length, you remove weight from the front, so (in principle) you can do both (add/remove weight to the front) with the swingarm.
Sure but if you do it with the swingarm you can't lengthen the wheelbase AND remove weight from the front at the same time. That's what I meant.
Quote from: EdouardB on May 11, 2015, 10:46:24 AM
Quote from: HornetMaX on May 11, 2015, 10:43:24 AM
Well, if you shorten the swingarm length, you remove weight from the front, so (in principle) you can do both (add/remove weight to the front) with the swingarm.
Sure but if you do it with the swingarm you can't lengthen the wheelbase AND remove weight from the front at the same time. That's what I meant.
Ah OK, clear now , thx !!
MaX.
And yes Ducati did have problems with the front tyre and the radiator. Solved with the GP15.
About Ducati, Tech3's technical guru Guy Coulon was at an event at the Paul Ricard recently (that I was riding at) and I heard him (in a private discussion) say that in his opinion the problem with Ducati is that until the GP14 they were designing an engine first and then try to build a chassis around it instead of doing like Yamaha and Honda who build the whole bike together with compromises on the engines to make a better chassis and better overall bike.
For the GP15 Ducati and Gigi dall igna conceived the bike as a whole and finally it's a good bike...