Tires are great for cross or gravel as long as it's not too muddy. Fast rolling on pavement and great grip on dirt/gravel roads. Really comfy running tubeless and can run lower pressures. Not too difficult to mount on tubeless rims and don't leak like WTB.
I just put these tires on my CX bike to get some rides in before the Oregon Stampede (130 miles, 70% GRAVEL). I am a 5'3 woman so I was reluctant to put this big of a tire on my bike for fear I would think it was too slow when not riding gravel. The tires feel fine on the road but they really do shine in gravel. After riding for a few hours in Forest Park (Portland, OR, gravel roads are fire roads) I was most impressed with how I was able to get out of the saddle and accelerate in gravel, especially up steep uphill grades, without that sinking in or spin out feeling at all. The tire also feels very secure through corners (even if one has to brake through the corner to avoid a dog that should be on a leash). On pavement, the tires feel faster than traditional cross tires. If I do any early season CX racing in dry conditions I would even consider leaving these tires on for racing.
When I got my cyclocross bike I primarily got it for gravel and after riding with the stock 32 tire on gravel I decided to try something different. The stock tires walked a lot on gravel and were slow when I was on the road. I read a review of the Gravel Grinders by Guitar Ted and decided to try them. I have rode about 500 miles on them and I love them. No more walking on gravel unless it is very loose. They are fast on the road as well despite their size due to the file tread pattern in the middle of the tread. I had a lot more control on mud as well with them. Mud does like to stick to the sides due to tread on the sides. I highly suggest them and I haven't found anyone who doesn't like them.
I ride lots of dirt roads and rail trails in New England. These are the best all round ones I've found so far (have ridden Vittoria XG, Maxxis Mud Wrestler, Clement MSO 40's). They are light for a 38mm, wide enough to avoid pinch flats, quiet and fast enough on pavement, and provide great traction on a wide variety of surface and allow you to stand on graveldirt hill climbs. They dampen the ride without being too bouncy.
As the hosts of the unofficial Gravel Worlds, you'd imagine we've got plenty of gravel around Lincoln, Nebraska and we do. I settled on a 38mm set of these to roll on my CX to give me a little more width, but still roll well. They do their job well. Riding on pavement, they're smooth. Riding all types of gravel they handle well too.
Hard to review these tires as they looked just the ticket for me, I was looking for a light, fast hard pack tire. Unfortunately I was about to mount them and on the sidewall in barely visible writing it says not for hookless rims. As I have hookless rims I had to return them. This was not stated on the website description or anywhere I could see. Why manufacturers hide this kind of information is beyond me, continental were the same with their road tires for a while too. Disappointing. Buyer beware.
So to start these tires are not described correctly on this website. There is no double puncture protection and the max psi is 53 not 80. The sidewalls are extraordinarily weak or I got a defective product.
Literally day one of riding on roads the sidewall got a puncture that can't even be seen by eye, and rendered the tires worthless since you can't really plug a sidewall. It's a shame that the tires are terrible and that I was misled by the description. Avoid at all costs.
I use these tires set up with Vittoria Gravel Inserts and Orange endurance sealant - set up was easy, they hold pressure and do not leak sealant with this set up. On 24mm internal rims, these tires measure 47mm width and have a high volume with low weight. I can run lower pressures which makes for a grippy and comfortable set-up. They seem to roll as fast on the road as my previous WTB Byway 40mm (which were more like 38mm). In short, it seems like all upside: lightweight (especially compared to other tires in the *actual* size of 47mm), fast rolling, grippy, comfortable!
I've got a few hundred miles on these tires now-a pretty even mix of good aged chip & seal, fresh loose chip & seal, crappy patched and potholed chip & seal, and plush marble-sized river-rock gravel. I don't notice any real rolling resistance on pavement, and they stick like Velcro even in the really deep gravel. I haven't climbed much, but the bit of climbing I've done was fine and more importantly I had full control on the descent. I am running them with tubes at 55ish psi, haven't had any flats (punctures aren't likely here, no thorns or sharp rocks) and they do a pretty good job at smoothing out all but the worst bone-shakers. I'd definitely recommend these as a good all-around tire.
This is my third set of these tires, I love them.
The first set were 33s, now I'm using the 38s. They are setup tubeless with Stan's Grail rims running at 40 psi rear, 38 psi front on a Trek Crocket (I'm about 170lbs).
I ride New England gravel roads, double track, cinder trails and single track and find the tires plenty grippy in all but the wettest conditions and tough enough for the bony single track sections. The tires have a supple ride feel and roll very well on those necessary paved sections that get to the next dirt segment.
In the Spokane area, the gravel routes are usually unpaved county roads and summer roads between fields. They can be loose dusty sand or washboards with gravel used for chip seal (without the oil seal), packed out mud, or just plain mud, all within a few miles. Throw in consistent and persistent 10-14 percent grades and you'll have your work cut out for you. These tires and their file like tread perform great in all of the conditions. I've even used them on some CX before fitting a narrower CX tires. I weight about 200 pounds and ride this around 45 psi (38mm) back and a few pounds lower in the front. Had one puncture, through the tread, that didn't seal up great, but that was no fault of the tire. Big holes are big holes. They also roll great on the tarmac.
I live in Kansas and am from Emporia, the heart of Dirty Kanza and Flint Hills territory. I have used these tires thru 3 Dirty Kanzas, 2 Almanzos, 1 epic fail at Landrun(mud and weather, tires were fine) and countless other rides and races through Flint Hills Gravel. Two flats, both were pinch flats and totally my fault for running too low of pressure under my 190 lbs. About 53-55 PSI rear and 48 PSI front seems to keep me out of pinch flat trouble even in the Flint Hills Gravel. Rolling resistance is minimal on hard pack, yet traction remains great in the loose stuff. They do tend to wear a little fast, but at the price and weight well worth it. As a side note, on the two flats I did have, they go on and off the rims using no levers for a quick change under the stress of race conditions. In gravel cycling the tire of the moment always seems be in every conversation, but I have found no need to experiment or go tubeless with these tires around and will continue to run the Gravel Grinders.
Of all the Gravel Tires I've tried, these are hands-down the worst for punctures. I had punctures in the sidewall right out of the box. B.T.D. graciously replaced that. I bumped up one star because I had no problems setting them up for tubeless... but I had sealant spraying out of both tires the first time I rode on gravel, so tubes in them after that. Even running tubes with sealant, I averaged approximately 1 puncture per 5 miles of gravel. By 250 miles, (6 tubes, 15 CO2s) inspecting the center track of the tire shows numerous small cuts. I have /never/ had this issue on other gravel tires. The Sidewalls are thin and supple and vulnerable to cuts. The Center track has small nubs, low rolling resistance and is vulnerable to cuts and punctures. The side knobs provide decent traction cornering, as long as that sidewall doesn't get cut. I don't know what they were thinking, but by me gravel is made of rocks which frequently have sharp points or edges. I /never/ rode these tires "off road" and rode 90% on smooth pavement.
Got these for my CX bike and a gravel race. Running them with latex tubes. Race had some single track with hills and some mud. Surprised how well the gripped. Have now been running them on pavement and see that my average speed is not much slower than on my road bike. No flats. Very pleased.
I needed tires for a dirt road event in Vermont and after reading a lot of reviews, I settled on the Gravel Grinders. I wanted something wide, with reasonable rolling resistance on paved roads and hard-packed dirt, but aggressive edge lugs for cornering in looser conditions. This tire has all of that and excellent durability, too. I couldn't be happier with their performance.
FYI, at 174, I ran these at 50/55, frontrear and that was perfect on a hard-packed course. My 110 girlfriend ran them at 30/35.
This tire is my go-to tire from May-mid September. I opted for the Gravel Grinder after realizing that a 40mm MSO just didn't fit right in my bike. Sacrificed 2mm of width, but gained a hell of a lot of acceleration and versatility of use. Really like that I can use this tire for the early-season races and it's super-puncture protective.
Also, even though it's not technically a tubeless tire, it hooks up like a dream on both my Stan's NoTubes wheels and my DT Swiss rims on my Asylum Meuse.
Prior to this I have been racing on Challenges high end open tubular Grifo XS in 33mm and soon its high end open tubular Gravel Grinder in 700x36mm tire. For training and commuting I do not want to burn through [$] high end tires when I can burn through the same tread for less than half the money and have an even tougher casing than the open tubular design saving them for race day! For training I have been riding every type of nail file tread pattern I could buy, My favorite up until this tire was released was in this order, Clement Las 33mm (actually a 36mm)for fast gravel country roads and finer gravel, or for rougher gravel Clement USH 35mm, Vittoria Pro XN 32mm(actually 30mm), Schwalbe Sammy Slick 35mm (actually a 31mm), and for rougher gravel and dirt Kenda Happy Mediums in 35mm or 40mm (both slightly undersized as well. I hope that Challenge continue to make Vulcanized Versions of its already top OT tires like The Grifo Pro now, as I wish they would make a Grifo XS 32mm vulcanized soon for my wife as this is her favorite tire! Do your self a favor and get this tire, it is the best!