Herzlos

So I picked up a 2nd hand few week old bike a few weeks ago (Carrera Zelos), which comes on 700x28c tyres though the wheels can go up to 700x32c.
Am I (at 91kg) likely to notice much difference going 4mm wider?

pdlamb

Depends on your weight and the roads you ride, and the pressure you'd need in each size (not to mention which tire, which is a hole 'nuther thread).

I find 28 a bit rougher on rough roads, but slightly quicker on the front. YMMV.

c_m_shooter

That is an aluminum frame, so wider tire would probably be a little better ride. Tires are individual though, and I don't know your road conditions.

Herzlos

I'm in Central Scotland, our roads are pretty awful. I haven't been on a proper ride yet to see if it's too bad on the 28c's.

cyccommute 

I’d say no. Too much fuss is made about marginal width changes on tires. To give some perspective, take two 2 pence coins and stack them. (Two nickels for us “Mericans) That’s the width and height change. And the amount of change in ride characteristics is going to be about as valuable.

wthensler 

Huge difference.

I have both (tubeless) - 28s on the Bianchi Infinito and 32s on the Trek Domane.

The difference in volume is what gives the much smoother ride on the Domane.

When the Bianchi needs new tires, I will switch up to the 32s.

Herzlos

It may only be a 4mm increase, but that's nearly 15% at these widths.

I think that's where I'm at - I may just keep the 28's until I wear them out (I'm hoping to spend a lot of time on the turbo trainer over winter) and then replace them with 32's. Unless I stumble across a cheap enough set of 32's. If I recall correctly the inner tubes I have will work with both.

cyccommute 

The only place it matters is at the contact patch. I’ve done the calculations before and it works out to a few milliliters more volume. It’s tiny in the grand scheme of things.

skidder

The 28c tires I've ridden were rated for 110psi pressure, most 32c for 70-80psi. Purely my speculative opinion but it seems the 32c give a more 'cushioning' effect since its not pumped up to as high pressure and can flex a little over bumps and road crap. And . . .its easier to pump up a tire to 70psi than to 100psi when you're on the side of the road fixing a flat tire. Those last few pumps at 100psi can be a b!tch!

Herzlos

Very good point, I've never gone above about 50psi before and even with a track pump that's a bit of work. 100psi on a compact hand pump must be awful!

jfoobar

That's only really true if you don't account for the change in psi between thinner and wider tires. Considering a 180lb rider and two otherwise identical tires (using Schwalbe's recommended PSI for the Marathon Plus as an example), the contact patch difference between 95 psi (the recommended psi for 28c) and 80 psi (the recommended psi for 32c) is almost 20%. That is without even considering the additional increase in contact patch from the tire width increase as well.

Bill Kapaun

If your roads are rough, you'll probably appreciated that little extra "squish" to help "absorb" peak impacts. Especially sharp edged potholes.
Your wheels will appreciate it too, with smaller peak loads on the spokes.

Badger6

A little extra will always matter...we've got crap roads here in Belgium, too (not all, but many), as well as a fair amount of cobblestone and pavé. I've ridden 28, 30, 32 across all of this. Bigger is always more comfortable, and not necessarily "slower." Check out this link from SILCA for determining pressures, I use it, and have never had an issue, I pretty much don't care what is printed on the sidewall because it doesn't take into account all the factors at play such as total system weight, surface condition, actual measured tire width, etc.

Moisture

Just because a frame is aluminum does not mean it will always have zero compliance.

A small different in tire width wont make much difference according to the actual tire design as well as the tpi (threads per inch)

C.corri

FWIW. My older bike only fits up to 25c and the newer bike has 32c. After riding both for many years I grab the 32c bike much more than I do the 25c.

jsigone

I've ran panaracer gravelking in both 28 and 32s for several yrs now. I don't find there is much rolling resistance feel between the two but the comfort level in the rough stuff does feel different. They are soft and grippy tires in the turns w/ decent/good flat protection.

If you can fit it, 32 should be way to go. I run the slick(file thread version) and they are about $35 on amazon prime.
https://www.panaracer.com/lineup/gravel.html

Moisture

Different width tires will have the same contact patch with the surface when going in a straight line, if they are all ran at the same PSI.

jsigone

Well that is the beauty of larger tires. You can run them at lower tire pressures to get the feel or traction desired.

my 28s I’d run them about 80psi tubed

my 32s I’d run them about 60f/65r tubed

no point having all that case volume just to pump it up to max that is printed on the tire....

Moisture

Definetely. i want to try a tubeless setup in the near future.

Gotta also consider that the width of your rim will change overall tire width. I've played around with a caliper measuring tool here and there and noticed that nearly all tires run at roughly .1 inch narrower than what is advertised on the tire.

Herzlos

As an update; I went to buy a pair of 32c tyres for the bike, and in the end bought a new bike with 700x40c tyres on. So I've dropped from 90psi to 50psi and the comfort difference is incredible!

jaxgtr

well that is one way to do it.... Congrats.

Moisture

Going tubeless can also really improve comfort

tallbikeman

I have an old steel road bike with 700c x 32mm Gatorskin tires and am very happy with it. It does go off road but frankly my 700c x 40mm equipped bike is much better for off road. I also ride the older 27" x 1 1/4" wheel size with Schwalbe Marathon tires and it is quite comfortable and good handling. I ride the 27" wheels offroad a lot but again 40mm is better offroad. Had to get my two cents in.

Moisture

As far as i understand, 27" rims are the exact same size as 700c. I installed a 700c rim onto the front of my vintage road bike just for fun and it fit perfectly.

As for the rear rim, there is so little clearance between the chainstays, that even if the rim bends slightly, the tire begins to rub. I measured the tire as 1.1 inches wide using a park tool caliper thingy...

I simply tried to compensate by adjusting the angle of the rear rim between the chinstays. I've already trued the rear rim twice. I can't tension two of the spokes properly or the wheel will simply bend more. After doing whatever I can to make the rim almost perfectly true, it loses tension and becomes slightly bent again the very next day. I need to replace the rear tire but I'm sort of weary to even bother until I can get this rubbing issue figured out.

Other than getting a new rim, any suggestions?

jaxgtr

700c is not the same as 27, but they are very close. 27 in is 630mm and 700C is 622 which will explain the tightness you are getting. How wide are the rims and what size size tire are you running?