u/gravykarrasch

Per Silca, “When speed off road is the goal, Protocol RCG-1 is the go to option. The first ever gravel tire that was developed around modern sizes first. RCG-1 is the fastest option available for the biggest races.” RCG stands for Race Casing Gravel.

I’ve been testing prototypes of this tire for months, as indicated by the tire in my photos, but other than the label this particular tire is THE Protocol RCG-1 production version released today. Generally, I would refuse the initial prototype phases and wait for the final ones, but agreed to all of it as they were kinda what I wanted to see exist but didn’t yet.

Claimed weight for these is 535 grams, I think mine were a few over that but close. Light. They aired up easily and are exactly 55 mm wide on a 25 mm internal width rim. Silca suggests their own sealant but I used Orange Seal per usual with an identical amount used in other 700 x 55 tires I have tested for absolute consistency in my own testing.

These have what is called a Pulsar compound for absolute speed and GhostShield protection (vs SealSkin on the RCG3 and RCG4) with a Race casing. They also have a 120 tpi casing, going to show again, tires are more than their individual specs, as plenty of high thread count tires aren’t fast.

The results are quite clear here. Fast. Insane fast.

I tested them back to back each surface with previously tested 700 x 55 RS Pros from Schwalbe, my current control tire set. It’s always nice to have absolute certainty, as well as some subjective impressions on a new tire.

Silca suggests running 1-2 psi higher than other similar gravel tires, which I can back up as I realized it on my own based on ride feel.

All outdoor results are my own via VE testing through GitHub Virtual Elevation Analyzer. Thanks Hannes.

Per Hutchinson, the Caracal Race is "engineered for elite racing and high-speed gravel riding. Crafted with cutting-edge technology and precision, including Hutchinson’s innovative SwiftEasy casing and Mach Tread 3.0 compound, borrowed from the development of our new road racing tyre. The Caracal Race delivers unmatched agility and performance. Experience the thrill of speed with the Caracal Race – redefine your gravel riding experience today." The road tire referenced is the Blackbird, available in sizes up to 700 x 34.

The Caracal Race originiated in a 40 mm width (March 2025 test) and was followed by a 45 mm (September 2025 test) which both produced incredibly fast test results along with a luxurious ride feel. The 50 mm Caracal Race leaves off a puncture protection layer, which is available in the Grid Skin version.

My tan wall set of CR50s weighed an average of 630 grams, with a 1.00 mm thick sidewall. For context, that is similar to Schwalbe's Super Race tan wall casing. Flat bead to bead width is 139 mm, giving an actual width of 53 mm on a 25 mm internal width Reserve rim. All sizes of the Caracal Race blow up about 2 mm wider on a 25 mm rim. The 45 and 50 have fairly rounded profile, so lend themselves to use on wider rims if that's your thing.

I had no issues with these tires, and quite liked them. The ride feel is one of the smoothest out there and they roll incredibly fast… tying the 60 mm G One Speed Pro with a 0.0036 CRR value on smooth pavement. The 45 is a bit faster on Cat 1 Gravel, while the 50 is clearly faster rolling on Cat 2 gravel. Generally speaking, Hutchinson's speed claims hold up across the Caracal Race size range, with different test surfaces showing clear volume benefits as the ground gets rougher (and softer).

All outdoor test results are my own via Chung Method / Virtual Elevation testing.

Note: Everyone wants to know…what pressure am I using? Obviously, larger tires will require lower pressure than smaller ones to get the best speed and handling in general…especially off road. The Wolf Tooth Advanced calculator is very good in my usage for gravel and mtb tires. The Rough Gravel setting seems to get quite close to best pressure for not only rolling efficiency (yes, even on gravel that’s not super rough) but also comfort and handling. I will start with that based on the measured tire size, go ride some, recheck pressure once the tire warms up, then reasess the setting based on how the tire is riding. If it feels obviously harsh, go down 1 psi…. If it feels squirmy or I am smacking the rim on hard hits, I will go up 1 psi, maybe 2 in that situation.

Often I end up sticking quite close to what the calculator says initially but it isn't written in stone. Rolling efficiency is actually almost identical (reference some testing I posted spring 2025 for this graphically) across a bigger span of tire pressures off road than most realize, which means it is quite easy to get the pressure where the tire will be fastest…the rest is fine tuning to rider preference. Even though I’m testing, I am also enjoying being out there so take the extra steps to see how the tire performs best. Ultimately there is no magic “best” pressure… it is up to rider preference with no real speed penalty unless you really mess it up one way or another, and that is a big reason I am explaining this in such detail. It’s not to justify my results, it’s to encourage folks to keep an open mind about how they set their tires and get the best ride possible. All the Smooth Pavement testing I do is with the tires set to the PSI I would use for riding on average pavement, so in practice about 5-7 psi higher than I would use for off road riding.

As I mentioned in last year's test of the 2.4 Terreno XC Race, these new models (available in brown or black sidewalls) are a major update from the prior generation Terreno XCR (tan wall I also tested last year). Vittoria says, “The new XC Race construction delivers the numbers: 20% more speed, 8% more grip, 44% better puncture resistance, and 9% improved riding comfort.”

The 2.25 shares it's construction with the rest of the XC Race lineup, with a 60 TPI casing (maybe more isn’t better…) and Graphene + Silica Race Formulation compound. These measured in at an average of 658 grams and inflated to 56.5 mm on a 25 mm internal rim. Sidewall thickness is similar to the black sidewall XC Race tire at 0.8 mm. I had no issues inflating these and they were easy to deal with day to day for all riding and testing. These 2.25 Terrenos are the tires ridden to victory by Hailey Hunter Smith (on a prototype Factor) at this years Rift event, notorious for the demands it places on a rider's equipment.

Results wise, these are a big step up from the prior gen Terreno and show consistenly very fast results across all test surfaces. For a tire with minimal tread, these again proved to overperform their looks with impressive traction as long as you aren't in slimy mud. I haven't seen any performance variation related to the sidewall color within this Vittoria range, for anyone curious. Technically, these are an MTB tire, but worth a look for anyone with a gravel bike that will clear them!

Other 2.2s and 2.25s are similar speed to these, with the Terreno XC Race also serving up nice ride feel on pavement as a bonus. As we all know, numbers and lists are cool, but your bike should ride how you want it to ride! As much as I liked these, I have to end with a request for Vittoria…how 'bout these in a 32 inch version? All results my own via Chung/VE outdoor testing. Wattage values are for a pair of tires, and calculated from test CRR values.

NOTE: Everyone wants to know…what pressure am I using? Obviously, larger tires will require lower pressure than smaller ones to get the best speed and handling in general…especially off road. The Wolf Tooth Advanced calculator is very good in my usage for gravel and mtb tires. The Rough Gravel setting seems to get quite close to best pressure for not only rolling efficiency (yes, even on gravel that’s not super rough) but also comfort and handling. I will start with that based on the measured tire size, go ride some, recheck pressure once the tire warms up, then reasess the setting based on how the tire is riding. If it feels obviously harsh, go down 1 psi…. If it feels squirmy or I am smacking the rim on hard hits, I will go up 1 psi, maybe 2 in that situation.

Often I end up sticking quite close to what the calculator says initially but it isn't written in stone. Rolling efficiency is actually almost identical (reference some testing I posted spring 2025 for this graphically) across a bigger span of tire pressures off road than most realize, which means it is quite easy to get the pressure where the tire will be fastest…the rest is fine tuning to rider preference. Even though I’m testing, I am also enjoying being out there so take the extra steps to see how the tire performs best. Ultimately there is no magic “best” pressure… it is up to rider preference with no real speed penalty unless you really mess it up one way or another, and that is a big reason I am explaining this in such detail. It’s not to justify my results, it’s to encourage folks to keep an open mind about how they set their tires and get the best ride possible. All the Smooth Pavement testing I do is with the tires set to the PSI I would use for riding on average pavement, so in practice about 5-7 psi higher than I would use for off road riding.

I've done some aero wheel testing in the past but wanted a look at some of the newest stuff coming out…in this case, something you aren't going to see on many bikes yet! Ascent's offering tested here, the Big Chungus, had some specs that caught my eye so I got them. 32 mm internal width with a hooked rim, 40 mm external width, 59 mm front rim depth with a 54 mm rear, 24 CX ray bladed spokes front and rear, all with a quite competitive weight of under 1450 grams for the set. Serious business.

Everything about these wheels is absurd, including how fast they are. I tested these back to back (identical bike, tires, rotors, and cassette) with Reserve's 25GR shallow gravel wheels with a rim depth of 18 mm. They have similar bladed spokes to the Ascent's. 29 x 2.1 Thunder Burt's measure 52 mm wide on the Reserves and 54.6 mm wide on the Ascents so I ran 1 psi less on the bigger set to equalize things. If the CRR values look a bit lower than some others, it is due to increased temperature outside.

I had super good weather for these tests, as seen by how clean the Virtual Elevation plots are! The results are quite clear, with a savings of .017 CdA for the Ascent wheels vs baseline. This works out to a savings of 7 watts at 32 kph and 23 watts at 48 kph…again, serious business. These are without a doubt some of the fastest gravel wheels on the market, and only a couple ticks off the even wider new Enve G SES 6.7s but lighter.

The absolute CdA values are for my Trek Checkpoint in upright hoods position, which is actually quite similar to some of the fastest aero gravel bikes in the recent CyclingNews wind tunnel testing. I mention this as it is still true the rider is the biggest portion of aero drag, so get your fit dialed first and foremost! For anyone looking at a set of the Big Chungus hoops, holler at the Bicycle Station crew or direct at Ascent.

Given the remarkable speed of the Thunder Burt, many folks want to know which casing option is truly the fastest one. Schwalbe utilizes their Addix Speed compound on all the TB models, but there is a choice between the tan sidewall Super Race construction and the black sidewall Super Ground construction. The Super Race is described by Schwalbe as "The ultimate competition design for XC racers - when speed counts" along with the Super Ground as "Our improved SnakeSkin construction for a wide range of applications - from XC to All Mountain."

The Super Race TBs I tested weighed an average of 567 grams, a bit over advertised but still 20-30 g lighter than the Super Ground TBs in the same 29 x 2.1 size. The Super Race has a slightly thinner sidewall at 1.05 mm compared to the Super Ground at 1.10 mm and they certainly feel different in hand. The Super Race would certainly be considered the more supple tire and are a bit harder to inflate but not bad at all. They measured 52 mm wide and 49 mm tall on a Reserve 25GR rim. I did puncture one of these but Orange Seal did it's job quickly and I had no other problems during testing. Drum testing results have some variance between models here, as many already know.

My testing shows that the Super Race has a small advantage (0.0040 CRR) over the Super Ground (0.0042 CRR) on smooth pavement, but across all off road testing areas the two options are identical in their rolling speed. As we have seen with other tires, it is really tough to predict absolute off road efficiency without testing off road. Schwalbe has blended the best attributes of the two casing options discussed here to create the XC PRO casing offered on the newer Rick MTB tire, which I think is a smart move. Some of their pro riders have been on Thunder Burt Race PROs…so there are updated labels, but I don't know anything definitive beyond that.

All outdoor results are my own via Chung/VE testing protocol. PSI notes below…

Everyone wants to know…what pressure am I using? Obviously, larger tires will require lower pressure than smaller ones to get the best speed and handling in general…especially off road. The Wolf Tooth Advanced calculator is very good in my usage for gravel and mtb tires. The Rough Gravel setting seems to get quite close to best pressure for not only rolling efficiency (yes, even on gravel that’s not super rough) but also comfort and handling. I will start with that based on the measured tire size, go ride some, recheck pressure once the tire warms up, then reasess the setting based on how the tire is riding. If it feels obviously harsh, go down 1 psi…. If it feels squirmy or I am smacking the rim on hard hits, I will go up 1 psi, maybe 2 in that situation. Often I end up sticking quite close to what the calculator says initially but it isn't written in stone. Rolling efficiency is actually almost identical (reference some testing I posted spring 2025 for this graphically) across a bigger span of tire pressures off road than most realize, which means it is quite easy to get the pressure where the tire will be fastest…the rest is fine tuning to rider preference. Even though I’m testing, I am also enjoying being out there so take the extra steps to see how the tire performs best. Ultimately there is no magic “best” pressure… it is up to rider preference with no real speed penalty unless you really mess it up one way or another, and that is a big reason I am explaining this in such detail. It’s not to justify my results, it’s to encourage folks to keep an open mind about how they set their tires and get the best ride possible. All the Smooth Pavement testing I do is with the tires set to the PSI I would use for riding on average pavement, so in practice about 5-7 psi higher than I would use for off road riding.

In late 2025, Vittoria introduced the XC Trail variants of its popular XC Race tires, bringing along a totally new construction for the XC Trail tires that is also shared with the knobbier Trail lineup. Per Vittoria the Trail casing "is a durable 60-TPI nylon casing built for exploration. It resists abrasion and punctures while maintaining your connection to the trail with a mid-tier suppleness." The 4Compound Formulation "strategically places 4 optimized compounds where they are needed for an unparalleled blend of speed, grip, and durability."

The 29 x 2.1 Peyote XC Trail tires I tested have a 1.7 mm sidewall thickness, so about twice the XC Race construction thickness and quite similar to the EXO+ casing from Maxxis in thickness. My set was an average of 780 grams and blew up to 52 mm wide and 49 mm tall on a 25 mm internal width Reserve carbon rim. In general, I have found it a good idea to give tires some break in miles before any racing, but even for testing…and this tends to take a bit longer when tires have a thick casing like these!

After lots of riding and testing with the Peyote XC Trails, I can see these as a totally viable choice when you are in rougher, more flat prone areas…even moreso if you are racing in a group where you can't see every sharp rock in the road! These are certainly not the fastest tire I have tested, but I think it's good to keep the beefy construction in mind here as sometimes you can't have it all! For a direct comparison, these are a similar speed everywhere to the Race King 29 x 2.0 Pure Grip and have a much thicker construction.

The Peyote XC Trails have quite a good ride feel everywhere and notably good handling on pavement when run at off road pressures. Given the thickness of these, many will find happiness with lower pressure everywhere than what your favorite calculator might suggest.

All testing my own via outdoor Chung Method/ VE.

Everyone wants to know…what pressure am I using? Obviously, larger tires will require lower pressure than smaller ones to get the best speed and handling in general…especially off road. The Wolf Tooth Advanced calculator is very good in my usage for gravel and mtb tires. The Rough Gravel setting seems to get quite close to best pressure for not only rolling efficiency (yes, even on gravel that’s not super rough) but also comfort and handling. I will start with that based on the measured tire size, go ride some, recheck pressure once the tire warms up, then reasess the setting based on how the tire is riding. If it feels obviously harsh, go down 1 psi…. If it feels squirmy or I am smacking the rim on hard hits, I will go up 1 psi, maybe 2 in that situation. Often I end up sticking quite close to what the calculator says initially but it isn't written in stone. Rolling efficiency is actually almost identical (reference some testing I posted spring 2025 for this graphically) across a bigger span of tire pressures off road than most realize, which means it is quite easy to get the pressure where the tire will be fastest…the rest is fine tuning to rider preference. Even though I’m testing, I am also enjoying being out there so take the extra steps to see how the tire performs best. Ultimately there is no magic “best” pressure… it is up to rider preference with no real speed penalty unless you really mess it up one way or another, and that is a big reason I am explaining this in such detail. It’s not to justify my results, it’s to encourage folks to keep an open mind about how they set their tires and get the best ride possible. All the Smooth Pavement testing I do is with the tires set to the PSI I would use for riding on average pavement, so in practice about 5-7 psi higher than I would use for off road riding.

Per Rene Herse, "All-road tires don’t get any better than this! We name our tires after the passes in the Cascade Mountains that inspire them: Snoqualmie Pass was the route of the Olympian Hiawatha express train to Seattle. Today, a trail heads up the pass, with spectacular views as you traverse the old railroad trestles. You’ll enjoy the speed and grip of the supple casing on the paved sections of the climb, and the large air volume will have you float over the rough gravel rather than grind through it."

RH optimizes their tires for real world performance, so many will be excited to see results here in the real world for what is their most supple construction option - the Extralight. I measured the sidewalls on these at 0.40 mm thick, which is easily the thinnest of any tire I have tested. They took and held air well…actually even better than the Standard casing Oracle Ridge I tested last spring. My set weighed an average of 338 grams and had a flat bead to bead width of 111 mm, airing up to right at 44 mm wide and 41 mm tall on a 25 mm internal width rim. Tubeless setup with Orange Seal Regular, as usual.

I have tested a few other tires in the 40-45 mm size range, which gives us some interesting comparisons on smooth pavement as well as easy gravel which many will consider the RH slicks for. These were pretty quick on pavement and Cat 1 Gravel, but a bit off the pace of the absolute fastest options on both surfaces. I think this size range of all road slicks is a good one, as it allows for comfort as well as performance. I had no issues with these RH slicks, and for anyone not into the minimalist sidewall construction of the Extralight, RH has beefier options with the same compound and tread.

After recently having the chance to analyze some well done timed lap style testing, I will stick to my guns that well done Chung Method/Virtual Elevation is easier, faster, and has better repeatability and accuracy. All outdoor results here are from my own VE testing.

Everyone wants to know…what pressure am I using? Obviously, larger tires will require lower pressure than smaller ones to get the best speed and handling in general…especially off road. The Wolf Tooth Advanced calculator is very good in my usage for gravel and mtb tires. The Rough Gravel setting seems to get quite close to best pressure for not only rolling efficiency (yes, even on gravel that’s not super rough) but also comfort and handling. I will start with that based on the measured tire size, go ride some, recheck pressure once the tire warms up, then reasess the setting based on how the tire is riding. If it feels obviously harsh, go down 1 psi…. If it feels squirmy or I am smacking the rim on hard hits, I will go up 1 psi, maybe 2 in that situation. Often I end up sticking quite close to what the calculator says initially but it isn't written in stone. Rolling efficiency is actually almost identical (reference some testing I posted spring 2025 for this graphically) across a bigger span of tire pressures off road than most realize, which means it is quite easy to get the pressure where the tire will be fastest…the rest is fine tuning to rider preference. Even though I’m testing, I am also enjoying being out there so take the extra steps to see how the tire performs best. Ultimately there is no magic “best” pressure… it is up to rider preference with no real speed penalty unless you really mess it up one way or another, and that is a big reason I am explaining this in such detail. It’s not to justify my results, it’s to encourage folks to keep an open mind about how they set their tires and get the best ride possible. All the Smooth Pavement testing I do is with the tires set to the PSI I would use for riding on average pavement, so in practice about 5-7 psi higher than I would use for off road riding.

Continental's Race King (Dubnital as of 2025) originated in prototoype form during 2007 as the 26 x 2.2" Race King World Cup, ridden to a UCI Wolrd Cup Overall Title by Irina Kalentieva, and released in 2008 to the public in Supersonic and World Cup editions with the Black Chili compound. It took until 2009 for the thicker Protection version to gain the high performing Black Chili compound.

2009 also brought a 29 inch Race King with Black Chili compound and eventually combined this with the Protection sidewall for a fast and durable 29 x 2.2 in 2012 while the 29 x 2.0 variant had to settle for the slower Pure Grip construction, leaving many riders wishing for a high performance Race King in a 29 x 2.0 size. Conti released the tire tested here at the 2026 Sea Otter Classic a couple weeks ago. For all intents and purposes, the 29 x 2.0 Continental Dubnital Race Rapid is THE tire so many have waited to see.

My set of 2.0 Dubs averaged 573 grams and aired up to 50 mm wide on 25 mm internal width Reserve carbon rims. They had a flat bead to bead width of 133 mm reflected in their height off the rim at 49 mm. I used Orange Seal Regular here for the tubeless setup again. Sidewalls are 0.98 mm thick, so very similar to the 2.2 and 2.4 Dubnitals I tested last year. These were very easy to inflate and I have really enjoyed them so far.

Speed wise, these are very fast… competitive with the Schwalbe RX PRO 700 x 50, one of my favorite tires I have tested. The 2.0 Dubnital is also remarkably fast on the smooth pavement test course. The tread has broad coverage to the outer edges, giving some promise of bonus sidewall protection. Yeah, there are faster tires in this size range but not very many! Impressive work from Conti here and big thanks to Quality Bicycle Products making sure I got some of these to test!

All outdoor results my own via Chung Method/VE testing. This is significantly more accurate than rolldown, timed tests, etc. Wattages at speed are calculated from CRR values so easily scale to whatever speed you want.

Note- Everyone wants to know…what pressure am I using? Obviously, larger tires will require lower pressure than smaller ones to get the best speed and handling in general…especially off road. The Wolf Tooth Advanced calculator is very good in my usage for gravel and mtb tires. The Rough Gravel setting seems to get quite close to best pressure for not only rolling efficiency (yes, even on gravel that’s not super rough) but also comfort and handling. I will start with that based on the measured tire size, go ride some, recheck pressure once the tire warms up, then reasess the setting based on how the tire is riding. If it feels obviously harsh, go down 1 psi…. If it feels squirmy or I am smacking the rim on hard hits, I will go up 1 psi, maybe 2 in that situation. Often I end up sticking quite close to what the calculator says initially but it isn't written in stone. Rolling efficiency is actually almost identical (reference some testing I posted spring 2025 for this graphically) across a bigger span of tire pressures off road than most realize, which means it is quite easy to get the pressure where the tire will be fastest…the rest is fine tuning to rider preference. Even though I’m testing, I am also enjoying being out there so take the extra steps to see how the tire performs best. Ultimately there is no magic “best” pressure… it is up to rider preference with no real speed penalty unless you really mess it up one way or another, and that is a big reason I am explaining this in such detail. It’s not to justify my results, it’s to encourage folks to keep an open mind about how they set their tires and get the best ride possible. All the Smooth Pavement testing I do is with the tires set to the PSI I would use for riding on average pavement, so in practice about 5-7 psi higher than I would use for off road riding.

2007 race king World Cup photo credit to Luke Webber (cycling news)