On my latest ride I managed to put a cut in the sidewall of my front tyre (Specialized S-Works Purgatory 26x2.2"). The sealant (Stan's No Tubes) didn't manage to seal the cut, presumably because the sealant lines the tread and not the sidewall.
While I was out on the trail I re-inflated the tyre and lay the bike on its side to seal the cut. Everything seemed fine until I got on the bike to ride it again, as the tyre rolled it deformed slightly and opened up the cut again. I managed to get home but had to re-inflate the tyre a couple of times to get there.
As you can see, the cut seems fairly minor but the sidewall is quite thin, is there any chance of repair or is it time to invest in some new rubber?