Tyre widths - 28c or 32c?

[langy]

I recently got myself a Domane with Bontrager Aeolus Pro 3 Disc Tubeless Ready wheels and tyres are Bontrager R3 Hard-Case Lite, 700x32c.

My riding style is on road, 80 - 100km at weekends and a couple of 40 - 60 Km’s mid week. I’ve got the Dragon ride and L’etape coming up later in the year. Annual distance for last couple of years 7k km.

I’ve found that the Bontrager tyres don’t seem to roll very well, so looking at swapping them out for a pair of Continental GP5000’s or Schwable Ones (both tubeless). I’ve used both before on previous tubeless setups and happy with either.

The question is, what width? 28c or 32c? Am I missing out on a small bit of compliance with the 28’s? or are the 32’s going to be that little bit more aero. Or am I realistically not going to notice the difference?

Comments and advice appreciated

[Barchettaman]

Eh? Those Bontrager tyres roll really well. You may be confusing the plusher feel of a wider tyre with increased RR.

Anyway, for commuting, I ended up using 32 back 28 front. Seemed to work OK.

[Kawasicki]

The volume of a 32 is much bigger than a 28.

Many people use too high pressures with higher volume tyres, which increases rolling resistance on rough roads.

I‘d also be surprised if the 32 was more aerodynamic than a 28.

[Randy Winkman]

Doesn't aerodynamics depend on the specific wheel/tyre combo and how one matches the other?

[Master Bean]

28 will be more aero, 32 more comfy. I'm interested in the general answer as I've just bought exactly the same bike as you.

[langy]

Barchettaman - I guess it could be that i'm still getting used to the Domane and comparing it with my previous bike. Admittedly the Domane is approx 1.6kg heavier.

Kawasicki - I currently run the Bontrager tyres at around 70 psi and a similar pressure on my previous bike using 25c GP5000's.

As for aero benefits, the wheels / bike are capable of running 38c's (not that I ever will). One of the guys at the Trek store did say they put 32's on the bike when new to demonstrate that it can run wider / larger volume tyres. I doubt there is a noticeable aero (to me) difference between 28's and 32's.

Master Bean - nice aren't they (apart from mine is currently on the turbo for the winter)

Thanks for advice / comments so far

[Kawasicki]

So you ran 25mm tyres at 70psi

I would think you need to run the 32mm tyres at about 45psi.

[langy]

Kawasicki said:

So you ran 25mm tyres at 70psi

I would think you need to run the 32mm tyres at about 45psi.

That was tubeless. I've seen that graph (or something very similar) before. With tubes i normally run 95-100psi

[Kawasicki]

langy said:

Kawasicki said:

So you ran 25mm tyres at 70psi

I would think you need to run the 32mm tyres at about 45psi.

That was tubeless. I've seen that graph (or something very similar) before. With tubes i normally run 95-100psi

why would tubes or tubeless make a difference?

[TheInternet]

langy said:

[70psi] was tubeless. I've seen that graph (or something very similar) before. With tubes i normally run 95-100psi

Is that offset normal? Seems like a lot.

[langy]

Kawasicki said:

why would tubes or tubeless make a difference?

https://road.cc/content/feature/268427-how-do-you-... (which also includes the graph you posted above).

I don't right the 'rules' just follow them (ish). The pressures I've mentioned above work for me and my kit, it'll probably differ for others.

[Harpoon]

Handy graph if you're a racing snake, useless if you are packing slightly more energy reserves and thus off the end of the X axis!

I've been running Hutchinson Fusion5 11Storm Performance in 28mm at 75psi (tubeless).

[Kawasicki]

Harpoon said:

Handy graph if you're a racing snake, useless if you are packing slightly more energy reserves and thus off the end of the X axis!

I've been running Hutchinson Fusion5 11Storm Performance in 28mm at 75psi (tubeless).

What weight are you?

The graph is wheel load vs pressure, not rider weight vs pressure.

[langy]

Kawasicki said:

What weight are you?

The graph is wheel load vs pressure, not rider weight vs pressure.

Must admit, the thought of track standing in the garage on 2 bathroom scales isn't high on my priority list, although it would probably be worthy of £250 on You've been Framed

I guesstimate.

[Kawasicki]

I weigh 65kg. The bike and water and tools weighs about 10kg. Total 75kg.

That will mean there is about 50kg rear wheel and 25kg front wheel.
I ride on tubed 23mm...with about 65 psi in the front tyre and 100 psi in the rear.

The graph will work up to about 105kg total mass. That would mean a rider about 95kg maximum.

[langy]

UPDATE

Well after getting a puncture in one of the original Bontrager tryes that didn't self seal (and I couldn't fix), I got myself a pair of Continental 5000's tubless, 28c's. Only had one ride, but the bike certainly feels a bit more 'zingy' and feels like it has a lot more get up and go.

Need to have a play with tyre pressures to try and get a bit more comfort. Inflated to them to approx 75psi

No issues with the fitting or sealing of the tyres and I could inflate using a standard track pump.

So far so good and I'm pleased with the switch of tyres and slight reduction in width.

[okgo]

Bontrager Hardcase tyres are horrible. I ran a set right down to the canvass on my commuter and you still couldn't break them.

[psykx]

32 on the back, 28 on the front gives the best mix of feel, comfort and speed for me.

I always go for schwalbe tyres except for snow tyres where I have a (now discontinued) set of continentals I love.

[langy]

okgo said:

Bontrager Hardcase tyres are horrible. I ran a set right down to the canvass on my commuter and you still couldn't break them.

I wish mine hadn't punctured beyond repair. Glad i've replaced them though.