How much do tyres affect ride comfort?

[orbits]

Does tyre choice (road not track) make a noticeable impact on rider comfort?… as in harshness or being fidgety over rough surfaces.

One of the garage has RaceTecK3s on it. The ride is too stiff / fidgety. I’ve just had the forks revalved and it’s an improvement, but it could still be better. I’m wondering if my next step is as simple as swapping the K3s for M9RR’s / Road 6’s etc, or whether the suspension is the dominant part of the suspension-tyre combo and I’ve more suspension work to do. Ta

[RyanGTXR]

Yes they can make a big difference to ride comfort, BUT Racetecs are sport tyre so should not be too bad.
Best example I can give from experience is the Michelin Road 4. Very stiff carcass / sidewall made for a very uncomfortable ride on my old GSXR streetfighter. Took them off and put on M7rr, way better ride.

[orbits]

Thank Ryan, good to get a view. There’s an inference in what you say that sport tyres are probably at the softer end of the spectrum anyway, and Metzellers may be some of the softest too. I heard a similar view (Dave Moss videos I think) that Dunlops tend to be a stiff carcass and full of bumpy feedback, and Metzellers soft and a bit calmer. Given I’m on sports Metzellers already, this may be a nod to having nowhere left to go re tyres, and the answer is more valving work.

Framing the issue in terms of car tyres, I’m looking for that night / day difference you get from ditching Run Flats for a normal tyre… when all that harshness just disappears. But I suspect I’m not going to see that level of improvement between bike tyres. Ta.

[Winger]

For the reasons Ryan already been into run Mich Power RS as all part of the process, as Covid put paid us tripping around Europe for the last couple of years and only run a 5 or 6 on the back anyway,and that’s for the other bikes as well as the XR.

But again for reasons already mentioned ran Dunlops for years beforehand.