You know, this kind of confirms something in my mind. I've ridden a Trek Stache (29x3.0) four or five times now and it always "felt" crazy fast here on FL single track which is usually sandy, loose over hard and sometimes clay. Bontrager's Chupacabra tires aren't anything special from a construction standpoint: 120tpi nylon casing and a generic 50 or 60a rubber compound. However given the likely size of the contact path, they probably don't compress the surface much compared to a 29x2.0 XC tire.

This makes me really want to try out the Continental Speed Kings now in 27.5x2.2 on my "gravel" bike :)

And yet ANOTHER reason for me to build up a 650B wheelset...not to mention that fact that they'll also fit in my old 26" full suspension MTB ;-)

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I'll confirm the Challenge Gravel Grinder 38s (120 TPI) roll very nice.
I got a pair of the Pro 36s (On Tom's advice), but they are a SOB to mount.
Now he tells me the standard 120 TPI are just as fast. I'd stick with those just for the ease of mounting. They also have a really good tread pattern.

mjdwyer23 wrote:

How about the WTB Riddler 37c? I'm on G-One 35's at the moment but need more teeth in socal sandy corners without losing speed.

I have extensive experience on the Riddler 37c and about a week on the Gravel Grinder 38c TLR.
(At least in more CX conditions). For reference I ran 28c Schwalbe Pro One's in the BWR and typically run 30c G-One speeds as a mixed surface tire.

Each is currently mounted on otherwise identical Specialized Cruxes.
I also have 33c Vittoria Terreno Dry on a 3rd wheelset. I've put a few days on them.

Short answer: I do believe the Riddler will have the cornering grip you're looking for, but I fear you may lose a little speed. Depending on Tom's Gravel Grinder TLR vs. Latex tubed GG, one of those is probably your best bet for the best of both worlds.

1. Riddler Measures at 37.8 and GG at 38.9 on 23mm internal width rims. (30 psi)
2. Riddler is significantly heavier and stiffer. I never thought it was a slow rolling tire (given it's intended use), but after getting the GG TLR , I was blown away at how much lighter and more supple the GG is. Terreno's are in-between in terms of suppleness.
3. Riddler is more confidence inspiring with corning traction because it is more predictable. It has 70% grip 100% of the time. ie on the CX course they lose grip a touch sooner, but have limited and controlled slippage when they do. GG tends to be an on/off tire. They hold 75% well for 90% of the time. This may be because of the larger side knobs and more pronounced gap between center tread and side knobs. However, touch the brakes and suddenly you're sliding on that diamond tread. Terreno Dry in 33c are way undergunned for grip, I'd arbitrarily rate them at 50%. For reference, I'd rate a Maxxis DHF mountain bike tire at 100% grip and a typical 28c Road tire at 30% grip. G-one Speed at 40%. I'd rate a Donnelly MXP CX tire at 80% grip 100% of the time. Arbitrarily, of course.
4. On the CX course, GG has surprisingly good steep climbing traction. My opinion is that because the side knobs are further up the casing, they are helping to augment straight line traction. On the Riddler, the side knobs are further down the sidewall so you are relying more on the microknobs in a straight line.
5. Riddler is wearing out fairly quickly. Both the center knobs and side knobs are shedding rubber. However, given the diamond pattern of the Gravel Grinders, I do not expect them to be a high-mileage tire either.

Choose:
Riddler: If you want ok rolling and confidence inspiring cornering grip on looser surfaces. My opinion is that this is best on routes with greater than 50% on dirt with a good bit of that dirt being technical (e.g. challenging corners). These are over-kill for primarily dirt roads.
Gravel Grinder TLR: if you want better rolling resistance at the expense of a little cornering grip. Arbitrary figure: Best on courses about 50% dirt with some technicality.
Terreno Dry: I don't know why. They don't roll particularly well nor grip particularly well. Maybe if you find the larger sideknobs on other options too "floaty" on pavement. Or something. I don't know. Maybe the larger sizes are better, but they weren't available at the time.


My opinion, anyway.

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Great side-by-side review. Thanks.

I love the GG as an all-around tire for my CX bike. As cross season approaches, I'm thinking of whether/when to switch back to a non-filetread. How do you think the GG would work as an early-season CX tire?

I just threw a set of Snoqualmie Pass on my gravel bike... cushy and smooth.

I have the same tires. At 32 psi, they sort of hovercraft over chatter and roll surprisingly fast on pavement. I don't understand the RR test above for Compass tires above, these are fast tires. Also, mine have proven remarkably durable (knock wood).

In my roller testing, the Snoqualmies rolled quite well...the Bon Jon Pass tire I had, not so much.

The BJP that Jarno at BRR tested also didn't appear to roll very well, so it's not like that's a "one-off" result...

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Which was surprising to me as I went from the BJP to the Snoqualmies. I thought the BJP was the perfect crossover between road and gravel and did a whole slew of 100 mile road rides and brisk paced group rides on them and was very happy with them.

I need to take the Snoqualmies on one of the local coffee shop rides to see how they shake out!

It was surprising to me as well based on the construction and my experience with the Snoqualmies...and may say more about "batch to batch" variation on the Compass tires than anything else. Maybe the earlier batches were faster...and then something was changed?

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I have been riding the 40C version all season. I've tried to give these tires a chance.
They just feel heavy, slow and I have not had any confidence in cornering.
In deep fresh gravel I outperformed my buddies who were on narrower tires, but any wider tire would probably do that.
They are not really bad, but they're definitely not great.
I wouldn't use the Terreno Dry 33C version for CX racing either. Donnelly MXP FTW.

Oh man, I mounted a set of the Strada Bianca Pros yesterday and my hands are ruined today.

alexZA wrote:

Oh man, I mounted a set of the Strada Bianca Pros yesterday and my hands are ruined today.

Didn't you follow my tips for mounting those? I can usually do them by hand.

https://forum.slowtwitch.com/...ost=6629362#p6629362

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Yes, was about to reply to you on that thread. Thanks v much for the tips. Did it entirely by hand, but without the beer (because race weight), and it was brutal. They should be much easier now that they've been "stretched", but I'm still dreading a flat. I'm looking forward to the tubeless versions.

Awesome feedback, I'll look into the GG's. Thanks!

They are currently my plan for early season in Colorado which is consistently very dry and very bumpy... Heck that's most most of the Colorado Season.

I did some good cornering practice yesterday prior to junior's practice and was quite impressed with their ability to hold on grass at fairly high pressures (27 / 28.5psi on 38c tires). On par with an MXP / BOS and better than a PDX. With the improved rolling resistance and similar grip, I think they beat MXP and BOS in the dry.

On looser corners, like at our office practice course, they can be a bit floaty. A few times I wished they made a Baby Limus TLR 38c for the front, but frankly I was probably just being lazy.

On courses with decisive off-cambers or a bit of moisture I'll run MXP Tubulars (f/r)
On Mud Courses I'll run PDX (f) / BOS (r) Tubular combination.
Otherwise, my dry condition / rough course plan is currently the GG's (f/r).

(If only Donnelly made a Tubeless LAS with sideknobs... Maybe I can persuade Donn to make the DEN!)

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IME, that's an important step...not to be missed ;-)

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Hopefully that isn't the Challenge tire that Sven was using at DK. Didn't work out well for him. :)

I think you're spot on, Tom. Regarding slick vs a small knob tire (comparing a Gravel King Slick to a Gravel King Small Knob) i would go with the small knob about 99% of the time. I've seen slick tires take out/injure more gravel riders than aerobars, and i just don't feel like slick tires are faster on dirt/gravel. The knobs on the gravel kings seem to act like little shock absorbers. At BWR, i think you're right that maybe a slick would be a better choice based on the amount of pavement, but i haven't done it so i can't say for sure.

Do you think there is a point on gravel where the aero penalty of a wide tire negates the RR benefit?

At Gravel Worlds I chose to go with 32s since the gravel is really tiny on most of the course, and i knew there would be a lot of climbing (the 32 GKSK is light). I think i probably should have gone wider. A 35 or 38 probably would have been a better choice. The 43c gravel king (max 700c size on my Exploro) probably would have been overkill, IMO. It's heavier and must be less aero, but man... it FEELS fast and just floats over everything.

Of course. Even if rolling resistance keeps improving at wider and wider widths, the potential gains are bounded; you can never go below zero rolling resistance. But the weight and aerodynamic profile of a tire are unbounded, there's no limit to how high they can be as you keep making the tire wider and wider.

Uh, the aerodynamic profile is bound by what the bike frame can accommodate. Not sure what your point is here...

The question I was answering didn't constrain to a particular frame. And even in practical terms, it's easy to go quite wide; there are off-the-shelf bike frames designed to fit ~5" tires!

Probably but it would be very difficult to quantify as "gravel" is such a variable surface and each course is unique in its composition.

Thanks. Very consistent with my own experience. I'll give them a go for the first race of the season, assuming it stays relatively dry.

So, the Mavic Allroad 30/35C would be a bad choice for gravel?

My 2 cents is that everyone is going to have different preferences and different surfaces. For "Colorado Gravel", which tends to be a hard-packed brown road,slicks are fine. If you're surfing through deeper gravel, your experience may vary.

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I talk a lot - Give it a listen: http://www.fasttalklabs.com/category/fast-talk
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The above poster has eschewed traditional employment and is currently undertaking the ill-conceived task of launching his own hardgoods company. Statements are not made on behalf of nor reflective of anything in any manner... unless they're good, then they count.
http://www.AGNCYINNOVATION.com