Upgrading to 40mm gravel tires from 37: Your experience?

I haven’t ridden 37mm but going from 40-45 was a significant improvement in comfort with no reduction in speed so i imagine you’d notice similar. I think speed feeling constant had to do with upgrading from stock Bontrager tires to some nice Continental Gravel tires.

Width is one part of tyre performance. What tyre do you have now? Will you be staying with the same tyre or changing? The tread pattern and compound will have a big influence too, probably more than 3mm of width.

Tubeless is probably better overall, though it can be a pain to set up and you need to know how to fix a puncture that won’t seal by itself. TPU tubes offer better ride feel but they can be fragile.

I went from 38 to 40. And tubeless. No difference in comfort. Might be a big faster now though. Not sure why 🤣

My tire max psi is 87. Was told to not do more than 55 for comfort. But I usually ride at 70-75 and this the best for me.

I have this[Vittoria Torreno tires.](https://vittoria.com/products/terreno-t30-gravel-endurance?variant=50350106411296&utm_source=google&utm_medium=organic&utm_campaign=Vittoria%20US%20Google%20Feed&utm_content=Terreno%20T30%20Fine%20Loose%20Gravel%20Endurance&gad_source=1&gad_campaignid=21660299457&gbraid=0AAAAADOK2zeEPkBlln8eNzitTbK_ZfirO&gclid=Cj0KCQiAk6rNBhCxARIsAN5mQLt-4Iyt2qUVyfII2OvNvaiacqu5qmYZm2S_2dvPj2X_8C7JexJe6P8aAkqBEALw_wcB)

That small a difference just isn’t something to hesitate over- change the tires and move forward with something else to occupy your mind.

A lot of 40mm tires roll faster than a lot of 37mm tires because the tire design and materials prioritize reduced rolling resistance.

Point is, there is no universal experience for how going from 37mm to 40mm will feel.

I went from 33, to 40 and finally 45 (max clearance)

What’s bike max clearance? Go as wide as you can!!! My cinturato ms with around 25 PSI. Absolutely FLY. Very surprising for me, but my god is it so fun.

I love how forgiving these tyres are. With the correct tyre pressure, so much confidence hitting any trail

A 38 and 40 basically feel the same to me. If you compare across manufacturers then it’s basically just noise. The smaller one is objectively marginally lighter but not really enough to feel when riding. Sometimes I’m on a 38mm tire and I lose grip and think I should have been on a 40mm but I think that’s all just mind games.

37 to 40 is barely a difference and not something I’d be super particular about. If you already have 37s, just keep them. If you’re thinking about getting the exact same tire but in a 40mm width, yeah…there’s not gonna be a huge difference. Just take the plunge and go with 45s… if it’s the same tire, you’re not gonna lose much speed what so ever…maybe even none at all considering you’ll be running a lower psi and reducing rolling resistance.

Thanks everyone for the feedback! Going to 45mm

Absolutely unnoticeable.