Can I go to a more aggressive tire for in town riding?

I’m new to road biking and I just purchased a new Cannondale Synapse. The stock tires on the bike are Kenda 700 X 25. I will be doing some road riding, however, my area lacks good bike trails so some of my riding will be around town streets, which will bring my tires in contact with a lot of road grit, rocks and sharp things. My questions are, can I install a more aggressive tire on this bike, one with some tread ?, how big of a tire can I go to without having to purchase new rims ?

Hey Mark (@Flipper),

Sorry for not noticing your post earlier. Congratulations on the Synapse! Which one, exactly?

If you intend to go to bigger tires, your first consideration is tire clearance. How much bigger a tire can you put on that it will still clear the bike’s frame at the downtube and stays? A few years ago this didn’t matter much - most road riders were good with 20-28mm tires and their bikes fit up to 28mm fine. But now people like you want to enjoy the benefits of wider tires, maybe for some dirt or gravel riding, so manufacturers have been making space in many of their frames to accommodate. The space on aero bikes tend to be less generous, and with tighter tolerances to keep them aero fast, so it’s always good to check the manufacturer specs and then test a tire at a local bike shop before committing to a purchase.

Yes, you can go wider with your existing rims. Your 2018 Synapse is spec’d for up to 30mm tires on the 19mm ID rim. There might be some room in the frame to go even wider, but as it seems you know, rim width is also a limiter. Below is part of a chart by DT Swiss that illustrates potential tire/rim width combos (full one as PDF here). Your 19mm ID rims can technically handle a much wider tire than you can probably fit to the frame, and besides, going wider comes at some trade-offs in ride quality.

Thinking about your main reason for wanting to go bigger, because of road grit, rocks and sharp things," going bigger doesn’t exactly solve for those. I do think you’ll find wider (28-30mm) tires great for road, gravel, and dirt, but you should also focus on tire composition that offers puncture-resistance. Check out our “7 Best Wide Road Tires” article for some ideas.


Thanks for the info Anthony, you have given me plenty to think about. Sounds like my best move would be to take the bike to the shop and let those guys check it out.
The bike I bought is a 2017 model with the Sora package on it, rides real nice.