I can sort of answer that question... they are slightly flexible so they have a good bit of give to them.. I highly doubt you can actually break them, but they can bend... I tried an experiment with a bent one that I had and I straightened out with a lighter... worked great... The bent one I had was from a t-maxx that had a big block orion in it.. I think a 28.... just a slight twist was all the damage it had... possible due to the long length of the shafts... This mod shortens them considerably... I put the one shaft I finished in a vise and tried to twist it... didn't budge... Besides, PJ has his with this mod and a 28 and he said still running great.. His word is good enough for me..