Originally Posted by Amesja

You would have to do the math. Standard sizes would be 113mm and then 115mm as the next size up. That would not be enough as you would be loosing 2.5mm without the spacer and only gaining back half of 2mm -or 1mm. You could jump to 118mm which should be just right, but your left crank would be out 5mm further than before.

Another idea would be to drop down to 110mm instead, and then flip your single ring to the outer side of the spider rather than leaving it in the middle position. This would leave you pretty close to your original position and look nicer than having the empty slot on the spider where the outside ring used to be, and the ugly spacers you are using to reuse the longer 2-ring bolts. There is no guarantee that that the old granny ring mounting tabs wouldn't rub against the chainstay tubes though. You would have to measure and be sure you have the clearance, but it should be OK as you used to have the granny on there plus the chainring bolt and you are only moving it over 3mm.