Review: Panaracer GravelKing 700x38C (40-622)

It’s time to update my first impressions on the Panaracer GravelKing Slick tires. I’ve ridden them on my fixed-gear Surly Cross-Check for a full season, from April to November 2018. Over that period, I rode about 3000 km (1900 mi), much of it for commuting and riding around town but also on camping trips hauling a trailer or the Lake Monona 100. In November I switched to my studded winter tires, and now that spring has returned to Madison, the Gravel Kings are back on the bike.
This post will focus on ride quality, number of flats, width, and wear.

Ride quality

I have little to say about ride quality—and that’s a good thing! Jan Heine of Bicycle Quarterly makes the argument that a good bike (and consequently good components) disappears under its rider. There are no annoying noises, the tires don’t feel harsh, they corner well, and they don’t seem to slow me down. They also don’t feel overly sensitive to pressure, which is nice for a bike that gets ridden every day. Usually I pump up the tires to 2.7–3 bar (40–45 psi) and then only top them up when they look really low, which could be as low as 1.7 bar (25 psi). I hesitate to make more quantitative statements about how “supple” or “fast” the Gravel Kings feel. I don’t believe that the subjective feel of those qualities is at all reliable, and I haven’t done any quantitative testing. But as I said: They certainly don’t feel slower than any of the other high-quality tires I have in my fleet, including Compass/Rene Herse tires with regular casing and Panaracer Pari Motos.

Width

Hard to keep the calipers straight and camera in focus at the same time...

In the comment section of my first impressions post, several people asked whether the tires grew in width over time. As a reminder, these were the measurements right after mounting them:

• On a DT Swiss TK540 (inner width: 18.2 mm), the tire measured just under 36 mm at about 40 psi. 
• On a Mavic T519 (inner width: 19 mm), the tire measures just over 36 mm at about 50 psi. 
• And finally, on the wider Sun Rhyno Lite (inner width: 22 mm), the tire again came out to just over 36 mm at 50 psi. 

As I mentioned in an update to the previous post, within a week the tires had grown by 1–2 mm. So how wide are they now? At 50 psi (as displayed by my pump’s gauge), the tires measure somewhere between 38 and 39 mm on both the Rhyno Lite and TK540 rims. For a tire labeled 700x38C* (40-622), I’d say that’s true-enogh to size. (If you want to learn more about tire sizing and tire size labels, I recommend the article “Tire Sizing: A Mysterious Art” in the latest issue of Bicycle Quarterly).

* Technically it should be 700Cx38, but this is a common labeling mistake nowadays.

Wear and Flat Resistance

Former front tire, now in the rear. Center tread still visible

Before remounting the tires this spring, I closely inspected the tread. One of the downsides of running full fenders is that it prevents a quick visual inspection of the rear tread—which of course is the tire that wears quicker. And indeed, on the rear tire the center tread had clearly worn away. On the front, the little tread dots were still visible, and so I decided to switch front and rear tire. I haven’t noticed an increased number of flats, and in general I have encountered few flats  (even though I did have one just two days after reinstalling the tires in the spring...). Frequent flats are one of my main indicators for replacing the tires. The casing is in excellent shape still, despite me lock up in public and the above-mentioned carelessness about tire pressure. I’m hoping to get another 1600 km (1000 mi) out of this set of tires, but we shall see.

New

One somewhat related observation: In my first impressions, I mentioned that installing the tire on the Rhyno Lite rim was nearly impossible. This has gotten much better and I can now mount and dismount the tires without tire levers. I have not tried setting the tires up tubeless and I have no plans of doing so.

After 3000 km (this is the rear tire): Center tread is mostly worn away

Overall verdict

I don’t regret buying these tires at all. My main concern had been wear. And so if the GravelKings do indeed hold up another 1600 km (1000 mi), for a total of about 4500 km (2800 mi), that’s good enough for me. I would probably still replace them with Compass/Rene Herse tires, mostly so that I could compare the cost per mile over the lifetime of the tire. At market price, the Rene Herse tires are over one third more expensive, and I think it's possible that I could one third more miles out of them. If it is close, I’d always opt for the more durable tire for environmental reasons.

PS Please note that within the GravelKing series, there seem to be substantive differences in tire construction based on size. Especially the 650B x 48 (48-584) has gotten some bad reviews and is much heavier compared to the Rene Herse tire in the same size.

Review: Innova 700x35C Studded Tires

Back in November, I published a "first look" article on my newly mounted Innova snow tires. After having ridden them for only a few kilometer they seemed like reasonably nice tires: cheap, not too heavy, not too much rolling resistance. Since then I have ridden the tires for approximately 1500 km and my verdict is very different now. The Innovas turned out to be a bad investment for me.

Before...

...and after

The main reason for this are the steel studs. In the initial review I pointed out that steel studs have a reputation for not lasting long, and now I can say for sure: yes, they really don't. I admittedly rode more than usual this winter and a lot of it was not on snow or ice but just bare pavement. But the degree of wear just isn't acceptable. On the pictures you can see that a lot of studs have completely sunken into the tire. In addition, I have lost two studs in the front tire, despite following the manufacturer's advice to break in the tires by careful asphalt riding for the first 50 km¹.

The studs on the rear tire have completely sunken into the tread

The problem is exacerbated by the overall low number of studs. 110 studs make for light weight and low rolling resistance, but on a 622mm tire they limit the performance on ice. I got a taste of that when -- somewhat foolishly -- I endeavored to ride over a bike path covered in snow that had been turned into ice by freezing rain. I quickly realized that this probably was not a very good idea but once you're on the ice there is not much you can do. So I kept going at a very slow pace, but after maybe ten meters it was over. Wham! The front wheel slipped and down I went. I landed on my behind and aside from a painful bruise no physical damage was done. The mental damage, a loss of trust in my tire, however, was quite severe. In my post-accident analysis I've come to the conclusion that 110 studs is not enough for riding on uneven ice on a 622mm tire. A 35-622 tire has a circumference of 2168mm, meaning that the studs are about 40mm apart on each side. On uneven ice that's definitely enough to take you down.

Do I have anything good to say about the tires? Well, they have a nice tread which works well in snow. And as long as the studs were still reasonably new they worked well enough for Montreal conditions. Because of the wear issues I can definitely not recommend this tire; however, if Innova would produce the same tire with carbide studs, like the very similar Suomi Tyres W106, it would make a pretty good commuting tire for urban conditions with infrequent ice. For next season, I will probably switch to something like the Schwalbe Marathon Winter with 294 studs. 

Product details:

Innova TR5263 Snow tire
110 steel studs
700x35C (37-622), also available in 700x45C
Price 40-75 USD

¹ This is fairly common, however, even with more expensive tires from Schwalbe or Continental.

Flat tire, or rather: flat tires

My first flat with the Conti GatorSkins. Last Tuesday I was riding to the Cornell Orchards and hit what probably was a little pebble. This was followed by a clearly audible hissing sound and to both me and a pedestrian standing nearby it was immediately clear what had happened. Pinch flat. Fortunately I always carry a spare tire and so this was not a big deal. I even made it to the orchards and back to a meeting in time.

Unfortunately, three days later I realized that my tire was somewhat flat again. I didn't have time to check it and just put in more air. So this morning I checked again, and yep: it was pretty flat. My immediate suspicion was that the first flat maybe hadn't been a pinch flat after all and that I had missed something in the tube. But the water test showed that this was not the case. Instead, the valve was slowly leaking air. This really sucks, as it was a brand new tube. I'm now down to no spare tube and will ride out to the LBS on Monday and see if they'll replace the tube and/or get new ones.

Odo bike 1: 2601 km