Rock Bison
Weight: 5.5g
Mid-sized AR which is similar to Cross Dranzer but with slopes facing the other way, making them less accessible.
Identical performance in Left and Right Spin
Main contact point end up being the thick corners of the horns, as other edges have little effect, making for somewhat inconsistent performance.
These hit rather hard but suffer from heavy recoil. The slopes do provide some minor destabilization/Upper Attack but this is inconsistent due to how obstructed they are.
Overall, not worth using with the existence of harder hitting, less recoil prone ARs such as Mountain Hammer.
Weight: 16.1g
Heaviest legal Weight Disk.
Compact size and weight distribution makes it excellent defensively but not useful for Attack
Excellent for sustaining RPM – helps with defense, grinding, force smash, upper, and also defending against the last three.
Primary choice for Compacts, Traditional Upper Attack, Weight Defense, Circle Survivor Defense, and a competitive choice for Force Smash and Driger V2 combos.
With faster Attack Blade Bases (i.e. Defense Grip Base (Tip Inverted) and SG Grip Change Base Tip setups), Ten Heavy can be used without loss of speed, and its high weight becomes quite useful with Attack Rings such as Square Edge and Hayate Attack Ring, improving their rotational Smash characteristics however the reduction to the flywheel effect otherwise provided by Wide Defense or Ten Wide tends to result in more recoil KOs. It is nonetheless an acceptable option.
Overall a very versatile Weight Disk and a must-have part, outclassing both Heavy and Eight Heavy in all aspects, as well as being generally superior to Heavy Attack.
Right Engine Gear (Circle Defenser) and Right Engine Gear (Mystery Cutter) are the same part, but given different names based on coming with different CEW Parts.
Weight: 6.9g
Regular right Engine Gear with a selection of usable tips: able to use Circle Defenser, Circle Survivor, and Mystery Cutter - see those pages for information on how it functions.
Circle Survivor is the only useful one, the other two suffer recoil and serve no real purpose.
Allows the use of bases other than Normal Base (Rock Bison Version) and Normal Base (Wolborg 4 Version) with Circle Survivor, as well as elevating the bulk of the combination.
The latter is the most relevant, providing a good boost to Circle Survivor Defense combinations - Normal Base (Wolborg 4 Version) is very low recoil and other bases generally make an easier target for attackers. The main advantage of elevation is it moves the WD and AR further out of the way of attackers, making hits against the top part (generally the primary weakness of Circle Survivor Defense) much less effective, increasing both Defense and Survival ability.
The other use is allowing the use of First Clutch Base (Zeus Version) with Circle Survivor, fixing the latter in place and creating one of the Heaviest SG+BB setups possible (roughly on par with SG Metal Ball Base with 4 Balls and a Heavy Metal Core). This creates a bulky, tall, round setup which has a mix of characteristics of Circle Survivor Defense and Weight Based Defense.
Lastly, has some use in a gimmick combination using Hasbro's Flying Defense, Wide Defense, Circle Defenser and a lower-recoil Final Clutch Base, as a counter to taller, more compact Circle Survivor Defense combinations (in particular using this very EG alongside Ten Heavy and Roller Defense Ring and other similarly thick ARs).
Weight: 5.6g
Small, round base which sets engine gear to "always on" - it activates as soon as it is wound enough either by being manually wound or wound from hits during the battle.
Has small rectangular protrusions around the edge, compared to the smooth edges of Normal Base (Wolborg 4 Version) it is generally inferior if it can be hit, but only marginally.
Normal Bases are the two non-bulky Engine Gear Bases, which generally means they are the best choices for Attack Type Engine Gear customs, however they lack clutches.
Lack of a clutch means engine gear is engaged as soon as it is wound, meaning that it needs to be held in place when launching to avoid early discharge. This also means that with Circle Survivor and other large CEW Parts, the EG is charged up through hits as well as pre-battle and can activate throughout the battle.
Has better LAD than most EG Blade Bases, though still poor compared to top tier options like Defense Grip Base 2
Overall, a decent part but generally overshadowed by Wolborg 4's implementation, especially as Wolborg 4 comes with the useful Circle Survivor - one of the few legitimately useful Engine Gear parts, however as this part comes alongside one of two ideal EGs for the setup it makes for an effective backup in the unlikely case Wolborg 4's fails.
It is also worth noting that Final Clutch Base (Desert Sphinxer Version) comes with the same EG but is a marginally better Blade Base choice for Circle Survivor Defense.
Does perform slightly better than Wolborg 4's version with Right Customize Gear (Free Shaft Version) setups due to a slightly better weight distribution however, which provides an actual advantage to the part. Like that part, it is effective due to allowing Wide Survivor to take care of LAD thanks to its small diameter.
Weight: 4.0g plus 0.23g Clip
A large, low to the ground disk on a tall-ish flat tip with slightly bevelled/rounded edges (kind of a very wide semi-flat).
Tip shape is actually quite nice, allowing for well controlled movement and loose flower patterns, and catches the ridge well.
Is capable of absorbing hits to some degree, making it somewhat harder to KO, however the large recoil-laden protrusions (the trailing slopes would be better but there are no compatible Left-Spin EGs) mean that opposing Attackers are capable of knocking all of the spin out of the user (between rotational recoil and induced scraping from hitting it off-balance), resulting in even rubber-tipped attack types being capable of outspinning it.
Disk has generally poor LAD due to width, and spins out wildly if it scrapes.
Nonetheless it is technically okay at taking hits, and can occasionally pose an unexpected surprise in a tournament setting.
Has very niche use with Hasbro's version of Flying Defense and Final Clutch Bases as a counter to very specific Circle Survivor Defense combos (those using taller ARs such as Roller Defense Ring) where the height allows Flying Defense to scrape their top and interrupt their spin while Circle Defenser reduces Flying Defense's tendency to scrape. This allows for consistent OS as well as KO victories, however the setup is ineffective against pretty much every other combo, including other Circle Survivor combinations.
Overall an interesting part, but not truly competitive.
Overall
Rock Bison's EG and WD are staples of Circle Survivor Defense, and while they can use alternatives, Rock Bison is a strongly recommended purchase. It is worth noting though that the WD is easy to obtain elsewhere and Desert Sphinxer comes with the same SG and a marginally better BB for the type.