Originally Posted by
WhyFi
Cracking carbon fiber shouldn't be a concern, but a nice steel gravel bike would be sweet. If none of your existing bikes can take a 30-ish mm tire, that could be a game changer on pavement, too; I don't think that I'll buy another frame that can't take at least a 28 (and, given the trend, that probably won't be too much of a problem).
I know my S3 pretty tops out at 25c, as long as they measure close to spec. I have 25c GP5K TLs on it right now (ENVE SES 5.6 wheels) which measure 25.93mm and there's ample clearance in the back. It came with stock 23c Grand Sport Race which actually measured 25.73 so these new 5K TLs measure much closer to their specs than the GSRs and are essentially the same size.
My TCR came with 25c that measure a bit wide at 26.4mm. I think I've ridden it with my Aeolus Pro 3 wheels on with 28c GP5K TLs on it, which measured 28.81mm, but I don't recall if I measured how much clearance there was between the tire and the narrowest part of the chainstays.
But yes, whatever bike I get next should accommodate at least 30c, if not ideally 32c or larger if it's going to be gravel-focused.