Originally Posted by
littleArnold
I was almost going down to a 32 or 28 but a guy at a bike shop I was at told me tires don't come in ranges for rims, its only one size tire for one rim if you want be 100% safe on the road. He said other tire sizes may work for that rim, but they wont be as 100% safe as the 35mm tire I have. He thought if I went as low as a 28 it would not work and was worried about my safety. He said i would have to overinflate tire for it to fit on rim and that is not good for tire, pops easier or could snap out of place.
I talked to a Trek representative and he said maybe 32 for my rim, but no thinner than that.
I think my rim size is 21mm
My experience runs completely counter to "one rim size = one tire size." I guess your bike could have come with something closer to the narrowest allowable, with more room to go wider. Now that said, there is certainly an acceptable range of tire width to use that would correlate to a rim size. As far as hybrid vs flat bar road, I don't think there are firm definitions, but I would say be more concerned with what you personally want out of the bike performance wise. I see some bikes labeled as hybrids with very light suspension forks, and some with rigid forks, whereas anything I see labeled as flat bar road has a rigid fork. Gearing and rider position is something else to look at. When I think road, I think of something with a road gearing that accommodates higher speeds. Many bikes labeled hybrid are equipped with triple chain rings and lower gearing.
If you are looking at a change in tire to accommodate a better road feel, look at tread and not just tire width. Even for a larger tire width, a good road slick will help out with both rolling resistance and noise reduction. I see people putting tires up to 32 on endurance road bikes, so you aren't far off, and gravel bikes which also double as all-road bikes often use 35, 38 or wider tires with no issues and are able to hang on group rides with roadie friends. Many recreational road cyclists are moving to wider tires for a smoother ride, and see no real speed penalty.