A True Dual-Purpose Knobby

steilacoom_paved

“Don’t do this on knobby tires!” would be most cyclists’ advice when looking at the photo above. Everybody knows that cornering hard on pavement and knobby tires don’t go together.

And yet, the photo shows me on Compass Steilacoom knobby tires. And I didn’t take any undue risks. It was a cold winter day, and the pavement was still moist from a recent snowfall, so I didn’t push the limits, and the tires always had plenty of grip in reserve. (I apologize for the blurry photo – there wasn’t enough light for high-speed photography on this dark winter day.)

We took this photo during an all-paved ride around Mercer Island – a fast-paced route with many corners and subtle (and not-so-subtle) ups and downs. It’s a challenging course to ride fast. And it’s even more challenging when riding with my friend Ryan, who trains here several times a week and knows every inch of the road.

I rode a bike with Compass 700C x 38 mm Steilacoom knobbies (above), because I wanted to find out how well they perform as dual-purpose tires.

steilacoom_action

After a full season of cyclocross, we already know the Steilacooms work great on mud and loose surfaces… What about rides that are mostly on pavement, but include enough muddy trails that you’d want some knobs on your tires?

I had always been bothered by how terrible my cross bike felt on the few paved sections of the race course. Those sections rarely measured more than a few meters, but if there was a corner, I had to take it carefully. Annoying when I really wanted to go all-out. I figured that there had to be a better way. And when designing the Steilacooms, we thought hard about how to make a knobby perform well on pavement, too.

steilacoom_on_pavement

How do you make knobbies that perform well on pavement? We designed the tread pattern together with the engineers at Panaracer. They were excited to bring all their knowledge to the project, with no concern about “what people expect a knobby tire to look like.” Together, we spent a lot of time thinking about knob shapes and spacing, and how the tire transitions from one knob to the next.

The key difference to previous knobbies is that we didn’t look at each knob individually. We treated them as a system that interacts, not just as the tire is rolling forward, but also as it leans into a turn. We made sure that there always is the same amount of rubber on the road, not sudden changes as you transition from one row of knobs to… sometimes almost almost no rubber at all.

We also discussed knob sizes with Panaracer’s engineers. They have to be small enough to dig into the mud, but large enough that they don’t fold over during hard cornering. It’s not rocket science, but it requires visualizing what the tire will do as it rolls and corners.

On the Steilacoom, you don’t fall off one knob and then climb onto the next, so the tires roll more smoothly than most knobbies. And the knobs are big enough that they don’t squirm, which also helps with your speed and cornering.

steilacoom_corner2

I had high expectations for the Steilacooms, but even I was surprised how well they perform on pavement. On that ride around Mercer Island, I had no trouble keeping up with Ryan, even though he was riding his new titanium bike with smooth Compass Babyshoe Pass Extralight tires. The Steilacoom knobbies did not just perform well on the straights, I also didn’t lose any ground in the corners. Of course, this doesn’t prove that the Steilacooms roll quite as well as the Babyshoes, but if there is a difference, it is much smaller than I anticipated.

During our next “BQ Team” ride, I switched bikes with Mark. At first, he was reluctant. “Why would I ride knobbies on the road?” he asked. But then he, too, was surprised. He said: “When you hear the knobs sing on the pavement, you think the bike will be slow. But on the downhills, the wind drowns out the tire noise, and then you realize that they perform pretty much like a good 38 mm road tire would.” And this from the guy who had sworn off knobbies for good when he designed his 650B randonneur bike.

Now, we understand that many readers will be skeptical when a maker claims that their new tire revolutionized how well a knobby tire rolls. So we took a few photos… with a little tree to show that we didn’t just tilt the photo to make it look more dramatic. The Steilacoom really raises the bar beyond what even we thought possible.

steilacoom_sx

The optimized arrangement of knobs is only part of the story. Just as important for the Steilacoom’s speed is the supple Compass casing. The result is a knobby tire that is faster than most slick road tires.

Are there drawbacks of the Steilacoom tread pattern? Of course, otherwise, we’d all ride knobbies from now on. First, once we test them on the track with a power meter, I fully expect that they will roll a little bit slower than our other tires. That is unavoidable, but the difference is too small to notice on the road. That is pretty remarkable.

The knobs also add weight to the tire. And the bigger you make the knobs, the heavier the tire gets. Thanks to our lightweight casings, the Steilacoom still isn’t a heavy tire, but it weighs about 30 g more than our Barlow Pass with smooth tread. This won’t slow you down much even when climbing mountain passes, but if you don’t need knobs, why carry the extra weight?

Like all knobbies, the Steilacooms tend to wander a bit while going straight. You are rolling from one knob to another, rather than on a continuous tread. Again, it’s not a huge deal, but if your ride doesn’t require knobbies, I would pick one of the other Compass tires with their road-optimized tread. And finally, there is more noise from the tires as they roll. But compared to other knobbies I have ridden, all these disadvantages are very subdued.

naches_highland

The Steilacoom’s excellent pavement performance opens up completely new rides. Imagine you are heading into the mountains and expect muddy sections along your course, but most of the ride will be paved. No problem with the Steilacooms. They will make short work of the mud, without holding you back on the paved portions of your ride. That makes the Steilacoom the ultimate multi-purpose tire.

Click here to find out more about the Steilacoom 700C x 38 mm tires.

Photo credits: Ryan Hamilton (Photo 1, 4), Heidi Franz (Photo 2), Duncan Smith (Photo 5), Hahn Rossman (Photo 6).

About Jan Heine, Editor, Bicycle Quarterly

Spirited rides that zig-zag across mountain ranges. Bicycle Quarterly magazine and its sister company, Compass Cycles, that turns our research into high-performance components for real-world riders.
This entry was posted in Testing and Tech, Tires. Bookmark the permalink.

28 Responses to A True Dual-Purpose Knobby

  1. Gary Cziko says:

    Will there be a 650B version of the Steilacoom?

  2. Jeff Potter says:

    This tire sounds really neat!

    One area where knobbies tend to suffer is durability. Maybe performance also changes as knobs wear. That’s something to consider with dual-use. But it might still really be worth a shorter lifespan to get good results in both paved and dirt dimensions. …Perhaps you’ve somehow designed the knobs to keep gripping equally well as they wear all the way down. 🙂

    I basically never ride my favorite CX tubies on pavement just so they last longer.

    We do have quite a few race courses with maybe half hardpack or pavement. So it would be neat to have a tire that’s fast then but also grippy. Our best locals often use filetreads to get hardpack/paved speed. I’m not skilled enough (yet) to use them since I slide out in the grassy or slightly softer corners that are also mixed in. (Sliding isn’t always bad but I need more skill.) At the same time we rarely get your true PNW mud. So my favorite is the classic all-round Grifo — but I’m guessing it’s slower on the hardpack and pavement. Hopefully someday I’ll try your tires and compare!

    My friends and I have REALLY enjoyed our experiences so far with Compass tires. We are using a variety of different Compass tires and so far my impression is that they are far superior to anything else we’ve ridden — from what I hear from my friends, they all agree. Great work! (Though my wife throws up her hands once our gang starts talking tires.)

  3. Wayne says:

    Is there any chance of you making a 45mm version of this tire? That would be perfect for some mixed terrain bike packing.

  4. John Dewey says:

    Do you think you’ll ever make your standard casings with black sidewalls? Would buy lots of them!

    • It would be nice to offer the standard casings in black as well. Unfortunately, this would mean adding a lot of tires to our program – and then keeping them in stock. It’s not really feasible, so we’d have to drop one other variation. Tan sidewalls are more popular than black ones, and the Extralight is more popular than the standard casing. So the standard casing in black would be not as popular as the other models. If you need black tires, we offer almost all models with the Extralight casing in black. You won’t be disappointed!

  5. david says:

    Very excited about these. Looking forward to these in 650B for sure

  6. Edwin says:

    I am surprised that they “kept up” with the other compass tires on your ride, but you all are full of surprises with tires.
    Which makes me wonder: are knobbies really much slower on the road, or is it just that most knobbies are slow tires that happen to have knobs on them?

    • My FMB “Super Muds” are super-fast tires with small knobs that squirm and flex. They are great in mud, but not so good on pavement. So it’s not just the casing – the knob shape and spacing made a big difference.

    • huges84 says:

      There are two ways a tire can be slow; 1) slow in a straight line, 2) being unstable, which causes you to feel that you have to slow down to not crash, such as in a turn. I think most people think about reason 1) when they think of knobby tires but forget about reason 2). This article is claiming the Steilacoom is good in both these aspects.

      • 1) (slow in a straight line) is only a nuisance, but knobby tires that suddenly break away in turns as the knobs fold over (2) can be dangerous. I had a friend in college who leaned over a bit far on his mountain bike while riding on campus, and broke his leg.

  7. mike says:

    Real cyclocross (mudwrestling) is still a domain for classic tubulars. Just because you can limit the pressure even further. Therefore I haven’t expected the Steilacoom to be a real competition mud specialist and always saw him in the multi-purpose area.
    I expect the need to adjust the pressure of the Steilacooms here and there when the surface changes?! What are your experiences here?

    I prefer “multi-purpose tires” on many bikes I ride due to the mixed nature of our tours. Tires, that don’t make you slow on pavement, but perform well on dirty and wet roads. Most of them have a decent pattern in the middle and some knobbies at the sides. If the knobbies at the sides don’t have an irritating feeling in corners on pavement, then there is a chance to hold a good dual purpose tire in your hands.
    There are a couple of tires doing that dual-purpose thing, but the price for this mostly is a low performance on real mud. I didn’t tried the Steilacoom so far, My rule of thumb so far: “You need to decide: Performance on mud or on all other purpose”. Let’s see, if this can change 😉

    The problem for me is not – like it might be obvious – on the rear. The problem is in muddy corners at the front. Mountainbikers know about this and often use tires with decent knobbies at the back and more rough (and maybe wider) ones at the front.
    This is especially a problem when tires get wider. I love the way the big Rat Trap Pass makes rough gravel feel like smooth pavement, but in the woods after a rainy day, when some corners are still slippery, smaller tires (even without knobbies) can give you more control, because the smaller tires can sink in and develop some grip where the big ones just drift over. 38mm with knobbies might be a good choice here …

    • I think you are absolutely right – digging into the surface is what creates cornering traction. On gravel, even a 54 mm tire digs into the loose gravel, but on mud, the limit may be narrower. Certainly, the experience of the last cyclocross season shows that 38 mm tires have no trouble, but riders on mountain bikes with much wider tires seems to have had less traction than those on narrower tires.

      • RobStC says:

        I would certainly agree with this. Here in Scotland we get a fair amount of mud on tracks and paths, and my Rat Trap Pass tyres definately have much less bite into the sides of ruts or in mud generally than my Babyshoe Passes, and they, in turn, have less bite than the Stampede Passes that I also use…..
        All of them are lovely tires, for suitable conditions, but definately not good in mud! No criticism intended, because they are, after all, road or gravel tires. Would be very tempted by Steilacooms in 650 x 42, if ever produced…..

  8. Guy Simpson says:

    Do you have any experience or recommendation using these tires with fenders? Usually knobbies and fenders don’t make good bed fellows, but if these tires are useful for rides with considerable (potentially wet) road riding along with stretches of muddy trail, it would be tempting to think about fenders.

    • That is a good question! I have no experience with knobbies and fenders, having used knobs only in cyclocross and on un-fendered gravel bikes. To be comfortable using knobbies with fenders, I’d want moto-cross-style clearances, because the knobs a) will pick up more debris and b) will push anything the tire picks up into the fender with much more force…

      Do other readers have experience of using knobbies with fenders?

      • DaveS says:

        I have fenders on my commuter that I put knobby tires (26×2.5) in the winter for traction in the snow and ice. The fenders that I use are Ward and they are 73mm wide and the bike provides generous clearance (1+ inch). So far I have not had an issue with snow building up in the fender that prevents the tire from rotating. I do have an issue that the knobs on the tires occasionally rub on the fender stays. This does not happen when the Compass RTP is on the bike. Part of the blame is due to the flex of the Ward fender stays.

        I also wanted to comment about mud. There is different kinds of mud with different characteristics. In particular is mud that has the consistency of mashed potatoes and sticks in large quantities. On a multi day mountain bike trip (San Juan hut to hut), the group that I was with encountered such mud. Feeling the urge to get to the next hut, we pushed on. The bikes soon became very heavy with mud (50+ lbs) and totally unridable due to the drive train totally encased with mud. The only option was to push our bikes on the dirt road back to the paved road and hitch a ride to the nearest town. While pushing our bikes, a Ford F-350 with chains (typically used for snow and not seen in August, but had been put on because the truck became stuck) came by because the mud was that bad on that dirt road.

        My thoughts about this story is that, if the bike had fenders, the wheel would have locked up well before the bike got to such a bad condition that required us to abandon the trip.

      • I agree that mud can be very different. Sandy mud is fine even on “road” tires. I encountered this on the climbs during the Otaki 100 km mountain bike race in Japan, and I worried about my Rat Trap Pass tires, until I realized that I had plenty of traction. Silty mud requires knobbies – otherwise you just spin your tires. And in clay, all tires just get covered with mud and spin, no matter whether you have knobs or not. Fortunately, most mud is of the silty variety, so knobs work well. (Sand, silt and clay are actual geologic terms that refer to the grain size of the soil particles.)

    • Jacob Musha says:

      I’ve been using knobbies with fenders for many years, since knobby tires are a requirement for riding in the winter in Wisconsin. I’ve never had any more issues with picking up debris than with smooth tires. Fender clearance has been all over the map. Some of my commuter bikes were/are really cobbled together… But generous clearance is certainly a good idea. Most of my experience is on the road rather than off-road.

  9. I’ve been running Steilacooms for eight months on a mixture of surfaces from clay mud to tarmac. I’m a big fan of the grip they offer in all conditions and the low rolling resistance but my experience suggests that unless you’re running them tubeless then they’re far too prone to penetration punctures. I’ve lost count of the number of punctures I’ve suffered and on my last two rides I’ve fixed seven punctures caused by thorns, glass and shards of metal.

    • I am sorry to hear about the flats you got on the Steilacooms. Mine are set up tubeless and have been flat-free so far. We did intend the Steilacoom as a cyclocross racing tire, so it has relatively little rubber between the knobs.

      In my experience, the biggest factor influencing flat frequency is where you ride. On the shoulders of busy highways, you get all kinds of debris, and flats are depressingly frequent on almost any tire. On quiet backroads, where you ride in the main traffic lane, the surface is “swept” clean by passing cars, and flats are very rare. In the city, avoiding the “dead spaces”, where cars don’t travel and where debris accumulates, can avoid most flats.

      • Frank says:

        Jan, you wrote “In my experience, the biggest factor influencing flat frequency is where you ride.” With all due respect, I believe, this statement borders on Victim Blaming. If you can ride where no debris is, then of course you will not get any flats. What could be there to puncture your tire? On clean roads you can run puncture-prone tires just fine. And I don’t think, any rider on Compass tires deliberately rides through debris and glass.
        But IF you have to (or if you want to) also ride in areas where there’s risk of debris, then you will inevitably sometimes run over debris, for example because you didn’t see it at dawn. Then the biggest factor influencing flat frequency will be the tire, not a silly rider. Or maybe it is the rider because he didn’t switch to tires better suited to the expected road conditions. Then you can blame the rider, but actually it’s the tire.

      • Of course, I had no intention of “blaming the victim”. I was just trying to explain why most riders experience very few flats with Compass tires, but some have bad luck and find that the tires get flats at a frequency that makes them seek out sturdier tires. Like any high-performance equipment, there are trade-offs, and riders choose their equipment to make it suitable for their riding styles and environments. As the original poster suggested, running the tires tubeless with sealant may be all that is required for their conditions.

  10. greg romero says:

    Can’t stop thinking that a 700c 42-45mm version of this would really “corner” the market. There are not that many high quality tires in that range that I can think of. It could really give the Rock and Roads are run for their money..

  11. fnardone says:

    Maybe a stupid question, but if I have to loose (i.e. not mounted on a rim) tyres in my hands how do I tell which one is more supple ? Is it just down to how bendable are the sidewalls ?

    • As a first approximation, this will work. A supple tire has a much more flexible sidewall than a stiff one. Of course, there is more to it, and you really have to ride the tire to experience the difference. It’s a bit like the question: “How can I tell how much good the handling of a car is without driving it.”

Comments are closed.