RDX spool or differential? Choosing the rear end for an MMC drift chassis

All three MMC chassis take either a differential (Rhino Racing C-LSD, Yokomo YD-2 or equivalent) or an RDX spool. The short version: the spool is the affordable option that still works well, the differential is the advanced one.

Where each option comes from

The MMC chassis were designed around a Rhino Racing C-LSD differential: it was the differential the design work started with, and MMC’s own cars all run one.

Later came the need for more affordable components, and the RDX spool adaptation was developed. You can see it in the manual history: the XP2 was modified to suit the RDX spool in V1.1, and the XP1 gained RDX spool compatibility in V1.5.

Which one to choose

	RDX spool	Differential (Yokomo YD-2, Rhino C-LSD or equivalent)
For	A more affordable car that still works well	A more advanced car
How it works	Locks both rear wheels together	Lets the rear wheels turn at different speeds

How each one fits

The rear pulley is what changes:

• XP2. The RDX spool builds into its own sub-assembly (step 17 of the XP2 build guide): the pulley screws to the spool, then the bearings and, with the RDX only, the end caps go on. The same step works with a Yokomo, Rhino or KKPIT differential.
• XP1. The “38T-Rhino” pulley press-fits onto a Rhino differential, and the same part also works with a Yokomo. For the RDX spool, use the “XP2-1429-RDX” part instead (step 36 of the XP1 build guide).
• D3. See the parts list in the D3 build guide.

Where to buy

These are the shops listed in the MMC manuals:

• RDX spool
• Rhino C-LSD differential
• Yokomo YD-2 differential