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Due to a bike replacement, I recently started using 700x40C tires, after several years of using 700x35C or 700x28C.

tires new vs old

Whenever I corner, I have the impression the bike is behaving differently than what I was used to. Especially in fast/narrow corners (90 to 120 degrees turn), I feel like a squeaking sound coming from the engaged side of the tire (think like when one rubs a rubber shoe on the floor), while with the previous bike, mounting narrower tires, I never felt the same.

How does the tire breadth influence cornering of a bike?

Additional info:

  • tires inflated at the high end of their suggested pressure range (75 psi) enter image description here
  • threaded tire
  • rigid fork
  • paved roads, dry and not dusty
  • approach speed 15 to 20 km/h
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  • Not sure it's relevant to your problem but 75psi seems very high for 40mm tyres.
    – David Richerby
    Commented Jun 24, 2019 at 10:40
  • @DavidRicherby, that's what the manufacturer printed on their side
    – L.Dutch
    Commented Jun 24, 2019 at 10:41
  • There are many possible answers, and 35 to 40 mm is too small difference to explain everything by width. Can you upload photos or your old and new tiers?
    – ojs
    Commented Jun 24, 2019 at 10:47
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    That's the maximum safe pressure, not a suggestion of what pressure to use.
    – David Richerby
    Commented Jun 24, 2019 at 10:47
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    I just noticed the part "while with the previous bike". Did you switch bikes too? Frame geometry has also effect on cornering.
    – ojs
    Commented Jun 24, 2019 at 12:56

2 Answers 2

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My guess is the squeak:

  1. Does not happen on all road surfaces
  2. Occurs while turning due to friction between the tire and the road generated during a turn.
  3. Is not related to tire width or frame geometry

Going out on a limb...
The squeak will go away as the "shine" is worn off your tires.
You might be able to change or entirely get rid of the sound by changing tire pressure.

In the original post nothing is mentioned concerning reduced traction or ride issues.
Tire pressure should be adjusted to gain the best traction and ride - not to get rid of this sound.

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    Just a random thought but is it entirely possible one of his breaks blocks is rubbing while cornering and hence the squeak is coming from the brakes? I ride pretty hard and only get tire screech if I lock the wheel pretty hard enough to cause skid noise
    – Dan K
    Commented Jun 24, 2019 at 18:07
  • @DanK Given what we've been told brake squeak is a possibility.
    – David D
    Commented Jun 24, 2019 at 18:55
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I think the squeak is a combination of two factors:

  • Rubber compound. Different compounds have different characteristics, and judging from the color, these are different from your previous tires
  • Tread pattern. The new tires have tread that consists of separate blocks. When cornering, they flex a bit under load and return to shape when that part of tire loses contact with ground. When this happens, they slide a bit and may squeak. Tires do always squirm under lateral load, but the blocks adds to the effect. Wider tires squirm more than narrow ones, but the difference is so small here that I doubt it's the case.
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