Originally Posted by mingoglia

I've spent the last couple weeks lurking, but figured I'd register since I had the same dilemma as you. I bought my 9yo an RTR to see if he'd follow in my footsteps (I was one of the apparently very common 80's racers that is now coming back to the hobby). Anyway, now that he's racing, I decided to upgrade to all the FT stuff (and the new Worlds Chassis). With reading all the issues with slop with the aluminum stuff, I found the RPM rear hubs for the B44. Looks like the B44.1 comes with the aluminum stuff, which is why I went a version back to the B44. Here's a pic of the difference. They're a direct replacement and run the same outer bearing as the FT hub (and same inner as both the RTR and FT). Keep in mind you need a different crush sleeve though than the b4 runs. Again, this is RPM stuff... but an associated B4 part number would also be a great upgrade. Here's a pic of the difference:

(on edit: Apparently since since I'm new here I can't link pics so you'll have to pop this in your browser. Perhaps someone can take the link and post it for me.)

htt p://i882.photobucket.com/albums/ac28/mingoglia/misc/2012-09-12193521.jpg