[Closed] Road bike ...... tyre size

Lots of folk (me included)  don't ride 23mm/25mm on the road these days. I'm 28mm now.

Not sure how anyone else can answer that for you but 30mm is massive compared to 23mm in overall air volume but it ultimately depends on what you find comfortable or you require.
I am happy enough riding 25c over everything for example so my opinion is not going to be much use to you just as others would think 28mm is still way too small.

I run 23 or 25s on my fancy carbon road bike as it has tight clearances at the back and some 23s go up wide,I don't mind it in the summer.

Have a spare set of road wheels for my gravel/tourer/commuter with a set of 28s .They also have a cassette and chain to match so swapping over takes 5 minutes.Works for me.

Thanks folks.

Perhaps I should have asked what the go to tyre with is for road these days?

I appreciate that this is equally subjective as road condition will vary hugely as will frame compliance/comfort etc.

25-28 is 'normal. Old school still run 23mm. People do ride 30-32

Perhaps I should have asked what the go to tyre with is for road these days?

Continental GP 5000 are hard to beat. You can take your pick of tubed or tubeless. 25s if you err on the side of speed, 28s if you err on the side of comfort. (But I'm not sure it's a huge difference between the two sizes.)

25mm on the plastic road bike (Cervelo S2)
32mm on the Audax bike (Steel)

Both in GP5000 with tubes.

32mm on the Audax bike is comfortable enough and fast enough for all day and multi day rides, possibly a bit slower than the race bike but it's designed to be a mile muncher not for thrashing.

Essentially for road stuff:
23c - smooth road race / tt
25C - fast general use / not smooth road race
28C - Comfort general use / endurance / cobble road race
30c - Super plush / Gravelish

Although weight matters too, heavier loads being more inclined to larger tyres.

Given you've got the Camino to cater for larger tyred riding there doesn't seem much point in having a 2nd bike that caters for larger tyres.

Continental GP 5000 are hard to beat. You can take your pick of tubed or tubeless. 25s if you err on the side of speed, 28s if you err on the side of comfort. (But I’m not sure it’s a huge difference between the two sizes.)

I have tubed 28mm GP5000s on Ksyrium rims and at 80psi they measure 26.2mm across.

Given you’ve got the Camino to cater for larger tyred riding there doesn’t seem much point in having a 2nd bike that caters for larger tyres.

This is what I am keen to avoid.

What I'd like to get my head around is 28c considered large for road use or normal?

28c to 38c is a fair jump up in terms of not duplicating bikes.

That said I could see the Camino going if I went with a dedicated road bike.

Now I could just run some narrower tyres on the Camino .......

28mm Vittoria Corsa tubed on the fast road bike. 30mm (come up 32mm) Corsa control tubeless on the Audax/winter/ touring bike. Back in June/July I did three consecutive weeks with long road rides. First week was a 105 miler on the Audax bike with 44c Snoqualmie pass tyres and average speed was 17.2mph, week after was just 100 miles on fast bike (on 28s) but windy and average speed was 18mph, week after that was 130 miles on fast bike with 28s and average was 17.2mph. I don’t think tyre width makes a huge difference over longer distances other than rider comfort. I’ve settled on the 30/32mm tyres for now but would happily go to 35mm for distance as they’ll still go under mudguards.

I run two wheelsets on my road/gravel bike. 700c wheels with GP5000 TL for road riding and swap to 650b wheels with 4sc WTB Resolutes for gravel. It's just over a year old with 4300km of riding and I haven't had any issues with chain / cassette wear so far.

What I’d like to get my head around is 28c considered large for road use or normal?

It's within the range of the new normal. Lots of road bikes are now shipping with 28mm as standard.

My 'proper road bikes' are both on 25mm tubed tyres, and while I will occasionally take them down the odd towpath and regularly ride rougher roads I'd not fancy 25 or 28mm for my Gravel bike.

I've had 32mm tubeless on the gravel bike and they were a tad bit more comfy than a road tyre would be and obviously having tread and 2/3rds the pressure, gripped a bit better offroad.
Currently I'm running quite heavy duty, tubeless 38mm tyres on a 25mm wide rim and I've run thinner walled 40mm tubeless as well.

I don't think I'll ever go above 40mm personally 38-40 seems to be a bit of a "sweet spot" for me in terms of offroad comfort Vs on-road rolling and weight, but I prefer to ride the bike on forest trails, bridleways, jink off on random bits of singletrack when I spot them and generally keep the road riding to a maximum of 50%ish of any ride on that bike... 32mm seemed to get a bit harsh for me after more than 20 odd miles of mostly offroad riding (I've fitted them to a SSCX bike now, so an hour of thrashing around a muddy field probably suits them better IMO)...

But if the balance was more towards road riding and keeping the bike moderately "offroad capable", like you seem to indicate you want OP, I'd be looking at something arround 30-32mm tyre width with minimal/no tread, at least on the centreline, to optimise rolling.
Rim width and tubeless are factors too, I reckon you want to be on at least 19/20mm internal rims and if you can run tubeless, do so.
Trying to achieve a sensible balance of comfort, rolling resistance and weight saving without giving up the ability to hammer along the odd bridleway…

All of the above assumes 700c.

28c seems to be the new normal.

I've found they are faster (on a newer, stiffer but heavier bike) than my old 25c tyres, as well as being waaaaay more comfy.

But if comfort is the priority, why not go 30c.

But if the balance was more towards road riding and keeping the bike moderately “offroad capable”, like you seem to indicate you want OP, I’d be looking at something arround 30-32mm tyre width with minimal/no tread, at least on the centreline, to optimise rolling.

Exactly what I went for. 30mm Ritchey Alpine JB WCS. Skinwalls, obviously.

Fast enough on road, tough enough for fire roads and gnarmac.

Given the state of some of the roads around here, fatter tyres are very welcome!

This year's Giant Defy comes with 32mm tyres as standard, although the TCR is still on 25s. Almost everyone in the local club is now running 28s.

Been riding road bikes for 16 years. Started on 23mm, next bike took 25mm, then went up to 28mm on the next one as road surfaces disintegrated.

Was happy enough on 28mm, including a few local stretches on towpaths. That bike got written off and I replaced it with a Scott Addict that comes with 30mm tyres. No difference in speed, but more comfort and grip.

There's a rather s****y winter/Audax/light touring bike on order at the moment, and on their suggestion it will have 32mm tyres. Tried some on my Arkrose gravel bike on the road and although in my head they felt more draggy, Strava didn't notice the difference.

This year’s Giant Defy comes with 32mm tyres as standard

New Tarmac will take up to 32mm as well.

Aero bike 23mm front and 25mm rear. Fastest combination on that bike. Size makes a difference.
Winter bike I’ll run 32mm Bontrager R2’s in the bad months. I’ll also use 28mm Bontrager R4 classics from when the weather starts improving.
I find there is a speed difference between tyre sizes, 28mm on my winter bike is ideal, 32mm and it’s typically slower (even when using the same compound). Only anecdotal and based on a study of 1, but I do ride to power on all my road bikes and have a good idea of my routes and average speeds/power for each ride. 35mm tyres I found slow, Bon Jon Pass, but these get a good right up. They were comfortable and I would try them again.

https://www.thewoodscyclery.co.uk/shop/tyres/rene-herse-compass-bon-jon-pass-extralight-700x35c-tan-wall/

I just had to changes tires and the old 23mm specialized tires that came on the bike (2015, it has not had a lot of use and the tires perished....) are wider than the 26mm that I replaced it with, these are spesh tires as well. So might be worth checking the actual width of tires if you are looking for something specific.

I bought a bike that had 28s on once. Haven't looked back! In fact, 30s are appealing...

I do weight 94kg+ though....

Generally, I've been running a 23mm GP5000 up front (for the smoother, more aero, transition to the Hunt rims) and an old 28mm GP4000S II (that's really ~31.5mm) on the rear for comfort on my Cube Attain GTC Pro Disc this summer. I have a 25mm GP5000 to transfer from another rear wheel to take with me for my upcoming Mendips rides from our vacation base.

No complaints from me regards the tyres, definitely feels a bit quicker and I've not really noticed any discomfort from the smaller widths, which surprised me a little. For three years, I'd run nothing narrower than ~27mm real world width tyres.

I think I read this year's new model Domane takes up to a 38mm tyre and I think it's fractionally more upright than the Cube Attains, which is a rarity... My Cube is far from an aero design with 388mm reach and 610mm stack (unusually measured to top of conical spacer, not top of head tube).

Continental GP 5000 are hard to beat. You can take your pick of tubed or tubeless. 25s if you err on the side of speed, 28s if you err on the side of comfort. (But I’m not sure it’s a huge difference between the two sizes.)

I run GP5000 28mm which come up as 26mm on my old 404s (narrow rim width) and just fit in the stays on my Scott CR1.

Old school still run 23mm.

Until just a few days ago I was running 20mm on an old road bike. They were labelled as 25mm on one side and 20mm on the other. They pinch flatted at the slightest excuse. When the rear one got a 2" long slit from a puncture I finally replaced them. I wanted 28 but they wouldn't fit so went with 25. Made a huge difference. Now it's a comfortable ride, doesn't track the slightest crack in the road.

28mm GP5000 tubeless on the road bike.
32mm GP5000 tubeless on the gravel bike I use for a 20 mile road commute.

Both faster than the old 25mm GP4000sII tyres I used to run (in my highly subjective opinion).

Unless you’re a reasonably serious racer there really is no point in going narrower than 28. It’s now been proven a myth that super slim tyres are faster, they might be marginally quicker in the hands of a 65kg elite rider, but for anyone else you’re not going to notice any benefit in 25’s or 23’s. I’ve just gone from tubed 28c gp4000’s at 90psi to tubeless go5000’s 28c at 75psi and the ride quality is noticeably better and I’m no slower on the two rides I’ve been on so far. Dare I say it you could even go to 30c’s without noticing any drop in performance. I’m running 32c tubed on my commuter and it’s still as quick as my better bike when I want it to be. I’d probably notice the difference on a longer ride, but over 10 to 20 miles it feels fast and efficient enough and not held back by tyres.

So I’d say 28 or 30’s maybe even 32’s, and tubeless if you can.

I run 28's on my KTM Revelator Lisse aero Road bike, Vittoria Rubino Pro clinchers, had GP5000TL on it, wouldn't use them if I was paid to, they're far too fragile and I'm not exactly heavy at 76kg. 28's are brilliant, fast, smooth and comfortable.

On the shit weather bike, a KTM Canic CXC (when I'm not playing at CX) I run 32mm Spesh Roubaix Pro 2bliss and they're brilliant if a tad slower.

28mm tyres are my favs, my plastic fantastic old road bike wont fit them. 25mm is OK. 30mm road tyres are nice but tend to be heavier I use 30mm Roubaixs on my gravel bike when its in winter road bike mode, they certainly feel slower than 28's.

Wobbliscott it’s not been proven that slimmer tyres are slower. It’s one of those innacurate statements that annoy me.
The right rims on the right bike with the right tyres on the right course then 28mm can be as quick or quicker than a 23mm tyre. Conversely a 23mm tyre on the right bike, on the right rim on the right course is faster than a 28mm.
Have a little look at this link and you’ll see the majority of tyres are 23mm with a fair few 25s and a 26. Why do you think this is? 25s come up faster than a 23mm on this example, but even Zipp and Enve agree that a 23mm tyre on the correct rim is technically the fastest tyre, but then there are a million variables that are not accounted for. I’ve posted the Zipp details on here before and I’m not digging it out again.

https://www.aero-coach.co.uk/time-trial-rolling-resistance-data

The main story about wider tyres being faster was by a website owned by the person selling wide tyres. I’m not saying there is much in it, but just wish general statements about wider tyres being fastest didn’t happen.

Rolling resistance (including tread pattern and deformation at a given pressure), road surface compliance, aero performance, weight, pressure.

All play a part in tyre “speed” and they are generally interactive.

I find fatter tyres at lower that I expected pressures (15% sag according to the chart I found) give me the fastest speeds for a given power input (I have a power meter).

Even then wind and how much moisture there is on the road affect it.

Wobbliscott it’s not been proven that slimmer tyres are slower. It’s one of those innacurate statements that annoy me.

My understanding is you're trading off three energy loss mechanisms:

1. Energy lost due to moving the frame & rider up and down due to surface roughness
2. Energy lost due to flexing the tyre
3. Wind resistance of the tyre

1 is minimised by having low pressure tyres, 2 is minimised by having high pressure tyres. 3 is minimised by having narrow tyres.

Depending on the road surface, tyre characteristics eg sidewall stiffness, you'll get a different optimal solution in each scenario.

On the average UK rough tarmac road, you're probably better off with a wider softer tyre. On a track you probably want a 200ps 23mm tyres etc etc.

My new emonda came with 28c but will take a 30c no problem and probably a 32 if you have stiff wheels.

Worth remembering that when comparing a 23c with a 28c that the difference over an hour will be less than a minute and will depend on how fast you are riding (aero), how many hills you ride up (weight) and what the surface of the road is like (rougher the road the better the wider tyre will be).

When you have worked all that out for your loop that you are riding you can then choose the best width tyre to save that 30 seconds each hour. Or you could just not bother and get some 28 or 30 or whatever fits in your frame as it will be more comfortable (which happens to be another factor as less fatigue on body will also help)

28mm Contis on my audax/LD bike, on 19mm rims they measure 29.5mm across. That's as big as the bike will take with guards and they feel pretty good. The bike's still a bit of a handful on broken up tarmac and bad lanes but on average surfaces it's ideal. I'd go to 32 or 35 on the right tyre but it starts to get tempting to go off-road, needs wider guards and discs, etc. Changes what the bike is. On another bike model, for fast but not race use inc some long rides I'd go 30 or 32mm.

My general winter bike has been on 25mm forever, they work OK. My summer best bike is on 23mm and I like the pure speed high PSI feel (it's a feel more than reality) but I rarely ride it more than 3 or 4 hours.

I still think the fastest road bike I've ridden on averagely-poor UK road surfaces was on 650x42 Pacenti Pari-Moto tyres though. Had about 38psi in them. It felt a bit softer if you were climbing hard out of the saddle etc but I was consistently quicker over a couple of longer routes (~6-7hrs) I ride fairly often on that bike - those routes are all on typically crap tarmac and chipseal surfaces. They flatted all the time though, that slowed me down more than the tyres gained.

Correct me if I am wrong but are those S-Works 28mm tyres in tubeless not faster than all Specialized tyres currently with exception of the 26mm cotton tyres that won a tour stage this week.

Wider can mean slower but not necessarily.

Personally my back likes fatter tyres!

My summer best bike is on 23mm and I like the pure speed high PSI feel (it’s a feel more than reality)

Yep, as what you're feeling is all the energy wasted vibrating you and the bike!

It’s now been proven a myth that super slim tyres are faster, they might be marginally quicker in the hands of a 65kg elite rider, but for anyone else you’re not going to notice any benefit in 25’s or 23’s.

Slimmer tyres can be faster but don't make as much of a significant difference as people previously thought.

You don't need to be a lightweight elite rider to be quicker on tyres >28c, however, you do need to care about a few seconds per km to notice and there are lots of other things that make a bigger difference such as riding position, clothes fit, tyre pressure etc.

When I compared my TT bike data I was faster for same power output on 23c tyres than 25c, it is anecdotal rather than statistically significant due to error variables but may have helped me be slightly higher from the bottom in race results a few times.

I put 30s on mine this time round, it came with 23 but I usually use 28. The skinny ones felt super fast but were definitely slower despite that- they give the feeling of every bit of effort you put in doing something, which feels awesome, but that doesn't really tell you about rolling resistance at all, it's a different thing so in this case at least was misleading.

The difference between my 30s (Schwalbe One) and 28s (some sort of Contis, I forget) seems to be as much about the different tyres as the size, don't regret the choice though. I'd have probably gone 32, but these were cheaper 😉

I'm not a proper roadie, mind.

When I compared my TT bike data I was faster for same power output on 23c tyres than 25c

Did you reduce the pressure correctly in the wider tyre? It matters. Only by seconds of course, but even so.

Yep, as what you’re feeling is all the energy wasted vibrating you and the bike!

Exactly. It feels fast, but isn't actually faster than the bigger+softer tyre bike unless it's on a very smooth road. Sometimes I ride a bike for how it feels and absolute speed / efficiency isn't always a concern - it's just good to feel like you're on the edge. Same as why some of us like a rigid MTB or a gravel bike off-road.

Essentially for road stuff:
23c – smooth road race / tt

I run 21c GP4000s on my TT trike - OK there are three of then on HED3 17mm rims, but they are fast as. I run 25c GP5000s on the road bike and race on 23/25c combo. I'm 72 covid kgs. If I was 20 kg higher I might go to 28c, but it's not a big deal.

Sometimes I ride a bike for how it feels and absolute speed / efficiency isn’t always a concern

Yep, and I bizarrely prefer the feel of narrower tyres, even on gravel. I know they are not as fast as they sink into the gravel more, don't deform as well around the small stones and so on but I just prefer them.