Hashut’s Blessing:
I’ma leave mine on cavalry - too much effort to change when the hardest ruling is for cavalry. If we get a definitive (rather than a “should be, kinda, what we planned to maybe do”), I’ll change them 
Nicodemus:
An idea that came to me was to combine all of the potential base sizes into a single movement tray… crazy?? Like a fox maybe, but not totally out to lunch. My main reason for doing this is to just have a movement tray that could be used in games, but is mostly to showcase the models.
The movement tray will be fully static and none of the models will be specifically based, the whole movement tray will be the base.
The models will have brass rods in their feet and the tray will just have pre-drilled holes for inserting the models at various spacings according to the prescribed base size. I realize with either Ravening Hordes or the Legion of Azgorh army lists the 25x50 base size combination is exceptionally large and perhaps not useable, even with just the first rank, but the 40x40 or 50x50 are certainly doable in larger point games and saves me from actually choosing a base size until I work out my army list and decide how big the unit should be. I’m not telling what the movement tray is really going to look like just yet though :hat off
By having the Bull Centaur models individually pilled but not glued down I can just remove casualties during a game, I’ll just need a dummy peg board to keep the removed models upright so they don’t get damaged, but that’s hardly enough work to justify not doing it. This way I can also just drill holes into individual bases of the size I want and still use the Bull Centaurs as standalone models (Lord/Hero perhaps?), in other formations or just as unit fillers when needed.
~N
Edit For reference, the movement tray for the above application is ~8"x8", with a little bit of room around the border, smaller than the GW movement tray border by about half, but that doesn’t impact anything.
cornixt:
Seems like a lot more work than just switching between cavalry and 50mm bases by adding appropriate sized spacers between the cavalry-based models.
Wifstrand:
The simplest solution, I believe, is to keep them on cavalry bases. You can then use blu-tac/pins/magnets to allow the cavalry bases to attach to either a 40 mm or a 50 mm base. Sure, it adds a couple mm to the model’s height, but you don’t have to tear them off of their bases or venture out into constructing some huge (but very clever and beautiful) movement tray.
Nicodemus:
Seems like a lot more work than just switching between cavalry and 50mm bases by adding appropriate sized spacers between the cavalry-based models.Nah! The point isn't really to save work/time. I've been planning an involved unit/diorama that would require all of the models being on bases that all go together as part of the total look of the unit. I've been reluctant to start it for about a year now because I've been feeling wishy washy about base size. This'll look better than making multiple separate bases or multiple version of the unit's movement tray and bases ... you'll see ;)
cornixt
Wifstrand:
I for one don't doubt that, I'd be inclined to do this myself.Seems like a lot more work than just switching between cavalry and 50mm bases by adding appropriate sized spacers between the cavalry-based models.Nah! The point isn't really to save work/time. I've been planning an involved unit/diorama that would require all of the models being on bases that all go together as part of the total look of the unit. I've been reluctant to start it for about a year now because I've been feeling wishy washy about base size. This'll look better than making multiple separate bases or multiple version of the unit's movement tray and bases ... you'll see ;)
cornixt
Nicodemus
ChungEssence:
I’m leaving mine on the 25/50. Nothing to say that I shouldn’t in the Tamurkan book and it’s the base they came with. For example if you have an old S dragon that came on a 50/50 base it’s still legal to play with it as that’s the base it came on even though the new Dragon’s have bigger bases.
I think 40/40 probably looks best.
Baggronor:
For example if you have an old S dragon that came on a 50/50 base it's still legal to play with it as that's the base it came on even though the new Dragon's have bigger bases.On the whole, I try to rebase stuff to fit the current bases. My War Hydra for example is the 3rd ed one - people get funny about it being so much smaller than the current model, I dread to think how they`d react if it showed up on a 40x40mm base too.
rabotak:
i also rebase my oop models to fit the base sizes of their current incarnations... i think that should be without question (even if a certain avatar looks kind of lost on its base now), but here lies the crux about this issue: we neither have current models nor do we have an official, not even a consistent statement from wf regarding bc's base sizes...For example if you have an old S dragon that came on a 50/50 base it's still legal to play with it as that's the base it came on even though the new Dragon's have bigger bases.On the whole, I try to rebase stuff to fit the current bases. My War Hydra for example is the 3rd ed one - people get funny about it being so much smaller than the current model, I dread to think how they`d react if it showed up on a 40x40mm base too.
Baggronor
Relando:
EMAIL TO FORGEWORLD SENT
I recently pick up my Throne of Chaos book, so I could play my Chaos dwarfs with it
I have all my old bull centaurs with Cavalry bases and was wondering if they need to be re-based to 40s or 50s for the rules in the Throne
Thanks
Relando
RECIEVED
Hi there. As the Bull Centaurs in the Tamurkhan book are Monstrous Cavalry, we would recommend putting them on 50mm square bases. Thanks
Tris Buckroyd
Thommy H:
Which is based on nothing (no pun intended…) since they’re actually Monstrous Beasts and, as Nico has made clear, unit type is no precedent for base size. Even WF themselves can’t give a coherent answer!
Time of Madness:
RECIEVEDWeird response from Tris as they are Monstrous beasts. I think you will see the new bull centaur models on 50mm bases, but that is just speculation.
Hi there. As the Bull Centaurs in the Tamurkhan book are Monstrous Cavalry, we would recommend putting them on 50mm square bases. Thanks
Tris Buckroyd
Relando
Time of Madness
rabotak:
monstrous cav!? be it as it may, i’m waiting for the FAQ… all of this is getting ridicilous. x.x
Thommy H:
At this point, you might as well stick them on 40K bases.
Hashut’s Blessing:
Oliphaunt base anyone? 
I think the gist is, don’t be ridiculous - keep it quadrilateral, bigger than infantry and not chariot or largr and you should be fine
Nicodemus:
Exactly. I was told 50x50 over the phone as well. That size works well for Juggernauts of Khorne, but until I see how big and bulky the new-and-improved Bull Centaurs are, I'm sticking with my asertion that anything will work, and 40x40 is just as good as 50x50... although given that all my guys (with the exception of a few for my temple movement tray) are still on 25x50 bases, I'm hardly jumping in with both feet.
Which is based on nothing (no pun intended...) since they're actually Monstrous Beasts and, as Nico has made clear, unit type is no precedent for base size.
Thommy H
~N
RTMaitreya:
but until I see how big and bulky the new-and-improved Bull Centaurs are, I'm sticking with my asertion that anything will work, and 40x40 is just as good as 50x50... although given that all my guys (with the exception of a few for my temple movement tray) are still on 25x50 bases, I'm hardly jumping in with both feet.My bull centaurs are the normal ones most of us have too. I will definitely be mounting them on 40x40, since they don't rank at 25x50, and they're nice enough models to warrant some extra attention. I will be putting them rearing up on cork just to bulk them out a little more as well, to help justify that heavy duty toughness.
~N
Nicodemus
Borin Sourfist:
I also had an email from Tris saying that Bull Centaurs should go on 50x50 bases (no mention of unit type though).
So 50x50 it is for me, though I do think they’d look better on 40x40.
Hashut’s Blessing:
Been meaning to say this since the Demigryphs came out - it most likely will be on a 50mm by 75mm base like they are. That’s right, a new base size - a monster and a half or six large infantry or three sideways cavalry or whatever you want to think of it as. Makes sense to use that size though - I doubt they’d be bigger than the demigryphs and I doubt they’d be as small as a monstrous infantry base.
Thommy H:
I thought the same. It would make sense.