No the tm2 is not weak. Can't remember the last time I broke a wishbone.

The rb5 wishbones are 3mm shorter than the team c, this is because the inner block is 3mm wider, not sure about the rb6 tho.
I've never had a problem with my tm2 or Evo, I run the ally blocks and castle too

Arms
 

I too run the Brass front block and alloy upper castle on my EVO (same front end as a TM2) an d yesterday at Maritime Raceway managed to hit a crashed car full speed on the main straight and the only damage to my car was a piece chipped off a front arm. It was still race able and useable! Was expecting more damage. Unfortunately for the other car (a YZ2) it was a different story.
There must be something binding or bent on your car for it to be eating arms.
Good luck in finding an answer.

I’ve run the TM2 for over 3 year’s and in my opinion the front wishbone are strong. This is not to say I’ve never broken a front wishbone. The early Ansmann wishbones weren’t great but the Team C plastic are defiantly on par with every other manufacturer.
If you haven’t already done so I would recommend grinding down the front wheel axel and use low profile serrated nut. I’ve broken a couple of wishbone where the protruding axel has clipped a track marker and snapped the wishbone at the pivot pin. I’ve find the servo saver take quite a lot of the initial impact on the front end when you crash. The TM2 front end is pretty tuff, but I did break a carbon fibre shock tower last week the first breakage in over a year’s running.

tm2 v1
 

I must admit touch wood, iv only broke about 3 in the last 12 months, :thumbsup: tm2 v1 is a grate car and I will not be up grading to the tm2 v2 :thumbsup::p