St i25 st rims create an affordable solution to the previously cost prohibitive hurdle of tubeless mountain biking ust compliant bead hooks border a tape and sealant driven inner rim profile providing standards based repeated tubeless consistency enjoy the benefits of tubeless riding without breaking the bank tcs the tubeless compatible tcs rim profile is especially designed for tcs or ust tyres and is also compatible with tube type tyres when used with tubes i beam the i beam adds strengt