[Closed] How fast actually are 'fast' gravelly tyres on tarmac?

Schwalbe G-Ones are plenty fast enough and would be grippy enough for towpaths.

G-One Bites on mine, happy on the road and always seems to surprise roadies how well they are going.

I think 35-38 may be overkill for your stated usage.

I would be looking more at 32-35. Something like a g-one as above or maybe a donelly strada

I've got Gravel King SK and they feel fine on the road, but as others have said you might be better off with a more slick tyre given the limited amount of off-road you'll be doing. I guess the semi-slick tread on GK SK's won't last long on the road. Vittoria Hypers would be fine and they are cheap on PX?

Clement XPlor USH in 35c here on my Croix De Fer and they seem pretty quick compared to my road tyres on the other bike

I've got a set of Specialized Roubaix Pros in 32mm and they seem reasonably quick and despite being basically slick are fine on gravel and the odd bit of singletrack as long as it's reasonably dry. The place I mostly notice is if it's a bit muddy and uphill then grip is a bit tenuous. I'd have no problems with them on a towpath.

I've just gone from 35c Vittoria Voyager Hypers to 35c Gravel king Sk on my steel Charge Plug, which I presume is the model prior to yours.

The Vittorias were tubed, gravel kings are tubeless, which was the main reason I changed. I've only had one short ride so far, running lower pressures and I suspect the Vittorias were a little faster on tarmac. Honestly I don't think there's much in it, and I expect the gravel kings are better in hard packed dirt. The vittorias came up larger than the gravel kings too.

Have you considered the normal Gravel king slick?

I was out riding with a mate the other day - he was riding 30mm Schwalbe S-Ones tubeless and I was on my SS with tubeless 45mm Riddlers - on a long gentle downhill where we weren't pedalling, I was rolling just as quick. It's only when riding at speeds above 30kph do I found the extra effort noticeable.

OEM/Cheap tyres with wire beads and thick sidewalls will feel awful in comparison

How about putting some 27.5 wheels on!

That should add a little pep to acceleration?

Might even get a wider set in and the diameter / geometry probably be the same as 700 26c.

At the moment I’m running OEM Charge wheels with 28c GP4ks and it’s fine.

I only commute on road but maybe 10% of the time I’d like to go via the towpaths.

Just continue using the GP4000 tyres, they will be fine for your 10% tow path use. That way 90% of your ride will be on optimal tyres rather than 10% (if you switch to a gravel tyre)

As I believe I have mentioned, I had a good day and put some effort in on my 29er with 2.3 Ralph's and got a series of PBs on well worn segments. So there's not that much in it 🙂

https://road.cc/content/review/243187-ritchey-alpine-jb-wcs-stronghold-tyre

Fast, grippy, skinwall.

Recommended.

I'm running a Vitoria hyper on the back, and a fast gravel tyre (terrene Elwood) up front. Most of the speed of slicks, but surprisingly ok off road too. I've run slick rear and light tread front for ages now, and the extra drag from a rear treaded tyre is much more noticeable than the extra speed from slicks both ends.

I have some Vittoria Terreno Zero’s which are supposed to be a fast gravel tyre. Not that impressed to be honest. Great grip but they are too big to be fast in the way that a 28c or even 33c Jack Brown is.

If you don’t want a £70 mistake, you could do what I did and get a pair of £5 Sport Contacts from Planet X. Then the worst case scenario is a £10 mistake, but so far (admittedly early days) I rather like them.

View this post on Instagram

I've done a lot of miles of Vittoria Adventure Trail TNT on tarmac and pathways and they're fast and grippy enough.

get a pair of £5 Sport Contacts from Planet X. Then the worst case scenario is a £10 mistake

They've gone up to £8 now... 😉

Bloody Brexit!

I honestly think there is a big difference in speed and feel. I use 38mm G1 tyres, 32 Bontrager R3s and 25mm Michelin Power Comp.
The wider tyres handle well, but they don’t have that same feeling of acceleration, or just general speed when riding fast.
I ride in a fast group ride (generally all racers or ex racers) not a chain gang but still a hard 60 mile ride. I can notice how difficult it is to stay with the group when I’m on the wider tyres. (All on the same bike)
If the real fast boys are in the ride I put the 25mm tyres on.
For playing about on though I absolutely love the 38mm tyres and 99% of the time I use those tyres for fun rides on my own. Over the last year my commute has changed and I don’t get to ride the wide tyres off road as much, missing that as it’s much more interesting than thinking about flat out speed. Probably overall the speed isn’t massively different, but it is noticeable more effort for the same speed on the wide tyre.

My Sport Contacts should arrive tomorrow, ordered after seeing Bez's Instagram post last week 🙂

I'm replacing some well worn 35mm Conti Cyclocross tyres with them so expecting a clean sweep of KOMs on every Strava segment.

I’ve done a lot of miles of Vittoria Adventure Trail TNT on tarmac and pathways and they’re fast and grippy enough.

Whereas I found them sluggish and wooden (tough though). Changed to Gravel Kings SKs which have more grip, are lighter, and much more supple. When on the road I'm 2mph down on my road bike with 25c Power Endurance.

If you are riding true gravel and tarmac then a large volume slick or file tread will be best. For those of use that also ride singletrack and bridleway more of a compromise is required. I kept the SKs on all winter and just avoided anywhere with clay. Clay is no fun even with half suitable tyres.

grippy enough for towpaths.

infairness you can get away with slicks on towpaths! 😆

the good news is gravel tyres seem to get faster all the time, i'm waiting for them to be so good i can stop pedalling ....

recently rode the same gravel road 2 days running firstly with my usual 35mm sammy slicks (small side nobbles) and then 32mm swalbe marathons and what I did notice was that on any heavily cambered sections it was much easier to get out of any loose gravel I'd dropped into and "up the camber" back onto compacted gravel with the side nobbles - previously I'd have said nobbles only help in wet and for uphill traction now changed my mind

Cheers all 🙂 Some helpful info.
Regarding the size - I'm happy to try 35s but do't really want to go bigger.
Unfortunately some of the suggestions (like the bargain Contis) are a no go as I want to run tubeless. And I'm not listening to reason or very valid arguments about it 😀

I've tried the GP4000s on the towpath, and they a) puncture, b)were a bit scary, and c) felt pretty harsh. Hence upsizing a bit.

Gravelking (non SK) seem like a good compromise, plus skinwall (skinwall is a BIG preference) - as do the Ritchey's that CFH suggested, but they don't seem very available in the UK.

One thing I won't be doing is Singletrack. I have zero desire for that. That's what I have fun bikes for.
Looks like GKs may be most suitable then 🙂

FWIW I'm not a fast road rider, average speed is probably 15/16mph.

Ah, sorry, missed the tubeless bit. Doh.

(skinwall is a BIG preference) – as do the Ritchey’s that CFH suggested, but they don’t seem very available in the UK.

Approved!

My LBS got me a pair within a day or two of asking. If you're anywhere near Wiltshire...

I’ve tried the GP4000s on the towpath, and they a) puncture, b)were a bit scary, and c) felt pretty harsh. Hence upsizing a bit.

Fair enough. I ride 23c tyres everywhere and don't find them scary or harsh but admit I would get a lot of punctures if I used a tyre as fragile as a GP4000. At 10% of a ride I would just put up with it for the better 90% but we are all different.

I ride 23c tyres

I think that puts you in the minority nowadays. 25 - 28 is where its at.

I think that puts you in the minority nowadays. 25 – 28 is where its at.

No doubt. I personally find no difference on road or gravel between a 23 a 25 or a 28 so I go with the 23 as it is lighter and gives a more agile feeling. I also wouldn't base my tyre choice on 10% of my ride but as I said, we are all different.

I personally find no difference on road or gravel between a 23 a 25 or a 28

so I go with the 23 as it is lighter and gives a more agile feeling

do you see what you did there?

The 38mm Gravel King slicks are very fast and light, less than 350g (quoted at 320g, mine weighed 330-340g)

Tanwall as well, and relatively cheap at Merlin, Sigma Sport...

Or you could go for the 32mm version if spending minimal time offroad.

do you see what you did there?

Yes, other than the weight (and things associated with the weight) I find no difference. If you are trying to prove a point here you are wasting your time - I prefer 23c tyres, shoot me.

Yes, other than the weight (and things associated with the weight) I find no difference. If you are trying to prove a point here you are wasting your time – I prefer 23c tyres, shoot me.

The point is you claim a 23mm tyre will give better performance on the 90% tarmac. This is well known not to be the case.

Thanks again all, and thanks for the pointers. Just ordered a pair of 38c Tanwall GKs. Will see how I get on.

Yes, other than the weight (and things associated with the weight)

Oh yeah, and a 23mm GP4K weighs 215g, a 28mm weighs 235g. Are you really suggesting you can feel that 20g difference?

The point is you claim a 23mm tyre will give better performance on the 90% tarmac.

To be fair, the claim was that they are lighter (correct) and more "agile feeling" (given that they're lighter, probably also correct—at least logically if not palpably).

"Better performance" needs qualifying. What people tend to mean by that these days is "lower rolling resistance", but even that needs qualifying. What most people on cycling forums tend to mean by that these days is "lower rolling resistance according to the very limited test applied by Bicyclerollingresistance.com", ie rolling resistance with constant load in a straight line over a series of bumps that are all of the exact same size, profile and frequency.

Going way of tangent - but trailwagger - 23mm does give better performance on tarmac (rim dependent). But most road rims are "faster" with 23mm road tyres (or at least the correct combination of road tyre).
Newer ENVE rims are designed for 25mm tyres, but majority of the older rims are faster with a 23mm.

That being said, we are talking about micro differences. The majority of people whom I have seen say that there is no difference or even that wide tyres are faster, tend to be people selling wide tyres.

Personally I wouldn't race on anything above a 25mm tyre, I've never seen or heard of anyway racing in the UK on anything above a 28mm tyre (winter series I've used a 28mm tyre once or twice). But this is way off tangent.

I also don't want to derail this thread, but do you have any data to back you claims of 23mm being the better performer? Everything I have read for the last 5 or 6 years has said otherwise, so I am genuinely interested in where you have got your information.

According to Strava I fairly consistently average 4-5Kph less on cross tyres (Michelin Muds 33mm) vs. Conti GP4000s II (25mm). Might be a bit of winter lethargy though, as I tend to just leave the cross wheelset on for road rides too over winter.

re: the above - I have about half the punctures on 25mm than I do on 23mm so for me they are faster overall 😀 - crappy roads and to much belly fat round my way.

Hi Trailwagger,
Have a look at Hambini's blog about aero wheels ( https://www.hambini.com/blog/post/bicycle-wheel-aerodynamics-which-one-is-fastest/). There's also a fair bit of info from ENVE and ZIPP on the subject. I will dig out some of the info later tonight.
Its never as simple as saying 23mm is faster, or 32mm is faster. Far too many other variables and we are also talking about a small number of watts.
So some newer wheels (ENVE SES for example) are designed for 25mm tyres. These have an internal rim width of 21mm. For these wheels the fastest tyre is the 25mm.
My Reynolds wheels (17mm internal rim) are designed for 23mm front and 25mm back. The back is hidden away so a slightly bulbous profile isn't an issue. Reynolds actually say of there newer wheels there is no difference between 23mm or 25mm - but I think that is them sitting on the fence. Just visually I can see the 25mm is slightly more bulbous that the 23mm race tyres I normally have fitted.
From Zipp ( https://www.zipp.com/support/faq/faq.php)
Firecrest wheels with wider tire beds
The best aero and lowest rolling resistance is obtained with front 23mm and rear 25mm width tires running at the recommended tire pressures.
More details on that FAQ with Zipp even recommending 21mm as the fastest for older non Firecrest rims when performing time trials.
There is an ENVE version of the same info which I will dig out- also on one of the other forums I frequent both a ZIPP and an ENVE engineer also involved in the discussions specifying that on certain rims 23mm is the tyre to use. (But to reiterate - that is older ENVE rims)

In my opinion there is so little in it between 23 and 28mm that its not really worth discussing. I do find that 32mm is slower, but that just my observation.

Trailwagger - another link worth a read...
https://www.bikeradar.com/road/news/article/cannondale-systemsix-52536/

"The super-wide rim (well in excess of 30mm externally) and 21mm wide internally is shod with a 23c tyre, which sounds strange in these times of larger and larger rubber.

David Devine tells us that the wider internal means that a 23c tyre actually measures up at 26mm wide when fitted, and that the bike can take up to a 30c tyre, but aero wise it’s at its best in this combination."

I tried the bargain sports contacts from planet x - maybe I went too big as the 42mm felt like anchors anf seemed to self steer on the front...didn't help slashing a side wall on the first ride either. I really want the whole 'do it all' tyre thing to work, but no luck so far...maybe compass are the answer but can't spare 50notes/tyre to.find out!

Thanks for the links woodster

about 5km/h slower for the same effort

One of the confusions is the difference between "faster" and "rolling resistance" and "feels faster"

I think feels faster is largely put to bed. We use to think that harsh skipping feeling was fast, we now know its not

Although I agree that tyre rolling resistance measurements aren't perfect it seem pretty clear that bigger tyres have less rolling resistance. This is exactly what you would expect once you understand where rolling resistance comes from

https://www.bicyclerollingresistance.com/specials/grand-prix-5000-comparison

There is a Gp4000 comparison as well I think

But of course rolling resistance isn't the whole story. In a fast group tiny amounts of acceleration differences matter so weight is a factor. But most importantly bigger tyres are less aerodynamic. Whci is why cobbles aside 25mm is the norm for the pros. When you’re as slow as me aero matters less hence the balloon tyres

38c GKs fitted, 50PSI. And the answer to my question is...
Every bit as fast as the tyres that came off. With a 'bit' of a tailwind, the morning commute was within 10% of my fastest time, and the fastest I've done in the last month, with a 2nd fastest time on one section. Journey home was a lot more leisurely for various reasons, but just as quick as most of my journeys over the past month. Excellent. £56 well spent. I'll hack up the towpath when it dries out a tad and I've built some tubeless wheels.
FWIW they weighed in at 328 and 329g. Not too shabby at all.

I suspect any loss in speed was balanced out by the 47% increase in awesome that the tanwalls bought to the party.
https://imgur.com/8GVuCYY
Thanks all 🙂

Only downer is I now need to do the 4d jigsaw of trying to stop the 'previously ample clearance' guards rubbing.