Really Right Stuff (RRS) clamp for Bogen/Manfrotto 484RC2 on a Velbon ULTRA-MAXi tripod

I just found my travel tripod in the closet and I remembered the hard time I had last year searching the Internet for information on replacing the Velbon ULTRA-MAXi's default head with a more sturdy ballhead.
Now that I have a blog I guess it's the right time to post here my solution...

I decided to replace the head with a Bogen/Manfrotto 484RC2 ballhead and mount a RRS clamp on it.

The original 3-way pan-head of Velbon ULTRA-MAXi comes off easily by twisting it; it reveals a 1/4" screw. The 484RC2 head has a 3/8"-16 hole in its bottom, and to mount it on the tripod base you'll need a Reducer Bushing 7.5mm (3/8"-16 to 1/4"-20).

Now onto the RRS clamp... At the time I bought my clamp, the Really Right Stuff page listed B2 LR II or B2-Pro clamps suitable for Bogen/Manfrotto 484RC2, which was wrong (those clamps have a threaded hole to be installed on a ballhead with exposed 3/8"-16 threaded post, and they will not work on the 484RC2 ballhead, whose post has a hole after removing the original clamp and screw). I see that now the page was corrected to list B2 AS II and B2 Pro II. Anyway, I got the B2 AS II RRS clamp.

To screw the clamp on 484RC2 you'll need a M6 screw (RRS kindly provided me both with M6 and 1/4" screws). The screw that came with the 484RC2 head and the original Bogen clamp is also an M6 screw and fits the B2 AS II, too.

The clamp will not fit perfectly by default on the 484RC2's post because the post has two anti-twist tabs which are wider than the recessed "cross" on the back of the clamp (see the picture below).



The clamp will stay better if you rotate it 90 degrees.
For a perfect fit the tabs on 484RC2 have to be cut off completely or adjusted by thinning them with a small file. It's not hard to do it; it took me 10-15 minutes to thin the tabs and now the clamp fits perfectly; the original ballhead clamp continues to work fine, too.