What Are The Dimensions On The Roadmaster Base Plate Adapter RM-025?

Updated 08/05/2025 | Published 07/31/2025

Question:

Recently bought rm622 tow bar and 521876-1 base plate kit to tow 2005 mini cooper s behind motorhome. Need rm025 crossbar to complete set up. I am asking to confirm mounting holes are 28 and 31 on center of crossbar. John

asked by: John H

Expert Reply:

Hey John,

The Roadmaster Base Plate Adapter # RM-025 is going to have a 28-1/2" measurement on center between the mounting holes where it attaches to the vehicle base plate. And the on center measurement on 31".

What are you towing the Mini with?

expert reply by: Nick S

John H.

8/4/2025

Towing mini cooper s with 521876-1 attached to front. Also mounted rm025 crossbar. However the rm025 crossbar is not compatible with Roadmaster Falcon 3HD (rm622). I am missing the ability to connect the mini to the towbar. Is there a casting that will bolt crossbar holes (2 each side, 4 total) to allow this ? I want to leave crossbar attached permanently and was hoping to avoid the quick attachment option.

Nick S.

8/5/2025

@JohnH The crossbar adapter from Roadmaster # 910021-00 is what is needed to make those base plates and tow bar work together. The Flacon 3HD is a fairly new towbar but still works with that older crossbar style adapter.