Originally Posted by
Arthur Peabody
I looked on ETRTO's web site and couldn't find this info. Schwalbe publishes a chart that it claims comes from ETRTO but they must have made a mistake.
It's published in the ETRTO's Standards Manual, which can be found in PDF form, but may not be publicly available on the ETRTO web site. Schwalbe, Sheldon Brown, and others have excerpted the chart from the manual and published it on their sites. It looks like Schwalbe's updated their web site and possibly their chart. They may be referring to a newer version of the ETRTO Standards Manual than the 2007 chart that's floating around in general circulation.
And even with that aside, the OP's 38 mm tires just barely exceed Weinmann's 35 mm recommendation. They'll be fine.