I 've used the TA rings on a Stronglight 49 crank since 1980, I have a 49-45-28 half step+ setup, but I don't use the 49 t ring much anymore, and want a 46-36-26 combo. The replacement cost of TA rings is high. One dealer charges a dollar a tooth. $42 for a 42t ring; $44 for 44t etc. Sounds dentistry.