As I've mentioned before I've had problems with sidewall tears with the Forte kevlar (cross/k or something)tires. Granted, I did run over something but those sidewalls are really thin. Currently using the Michelin Transworld City with tire liners but 6 months into them the liners rubbed and I got a slow leak. Keeping in the liners now but I read some people never can fix the rubbing (and others have no problem) so I'll probably upgrade to something like Schwalbes next time.