me confused – so I took a kinesis cx disc wheelset with qr’s off a kinesis pro6 which has 135mm rear spacing – removed the qr adaptors and am now running it on a frame described as 142mm thru axle no problem – so why is the axle described as 142mm? and why I am confused about which wheels I have will fit (with qr adaptors) 135mm spaced frames – is it just that when you take a wheel that is 142mm thru axle add the qr bits it becomes 135mm?

Effectively yes, the QR pokes through the dropouts whereas the 142×12 sits flush with them.The internal width is normally added by recessing the hanger a little on each side. That is if the QR slotted into the 142 but now slightly more confused as I type it…

From Spec

cheers Mike that diagram helps – terminology is the problem axle length versus spacing – these are not one and the same as the thru axle sits in a pair of recesses though the effective frame spacing and chain line issues or non-issues stay the same and the thru axle wheels i want to put on a qr 135mm frame will work once I can find someone that has the converter in stock