Is there a standard road bike q-factor and if so what is it? Been trying to find out the q-factor of my shimano sora double chain set (on a Ridley x-bow) but can’t seem to find it

Crank and pedal dependent.

No standard, no. Varies by brand and crank model. Approx 60mm from centre line of bike to inside face of a Sora double or similar spec Shimano crank, so 120mm plus the thickness of the crank arms is your QF – about 150mm. Generally 145-155mm for Shimano and SRAM road doubles.

Stance width includes the pedals, Q-factor is just to the crank mating faces.

Think it’s 146mm for D-A. For reference.

Easiest way to measure is calipers over the crank face and seat tube, both sides (sometimes they aren’t equal), add those and then subtract the diameter of the tube (given that it’s round of course)

Thanks, I figured it was crankset dependant which is why I wondered why shimano didnt state it. I want to get same q-factor on cross and mtb as I have dodgy hips/knees so getting q-factor, saddle height and fore-aft position etc the same as possible seems sensible. I’m guessing thats why xtr race is narrower (so it can be more like a road set up)

Remove non drive side crank, rotate through 180 degrees, replace and measure. I’d be surprised if there is much in it across cranksets (although most of mine are either 1x… or road doubles). I think saddle position is more important, personally.