Hi M54 - Unfortunately Gates bought Mectrol and Gates technical publications aren't as good as Mectrols where. IMO the GT and AT sections don't have much difference in performance from what I can read. If you want a true backlash free belt the only one I can find is an ATL spec. This is specifically made for linear motion applications not power transfer applications. They are twice the cost of an AT belt and have zero clearance teeth. But in this application with a 180deg wrap all belts at correct tension will have very very low backlash probably zero... Its more important to look at the specific stiffness of the belt to make a decision in this application, the stiffer the better and make it a medium size pulley not too small. I can't find this info in the Gates manual for the GT-5MGT series unfortunately... Plus we are in Austraaaalia which is at the end of the earth so we have limited sources of lots of things. Even though they are in the catalogues, distributors don't stock and importers don't import stuff...We can get stuff mail order from China to here faster then I can get stuff from Gates for instance, if Gates Oz have it that is.... Peter
https://www.gatesaustralia.com.au/~/...us-nz-2018.pdf