Compass Tire Prototypes: Really Big Tires!

travel_gifford

Our very first Enduro Allroad prototype tires started out as knobbies with supple casings – then we had the knobs shaved off by Peter Weigle. We wanted to test the concept of a very wide, supple tire before committing to expensive tire molds. We were happy to report that the tires performed even better than expected! So we decided to proceed.

Last week, the project reached another milestone: We received prototypes made from the actual production molds. So while these are made as a very small batch and required even more hand-work than the final tires, they are basically the tires that you will be able to buy and ride in a few months.

compass54-559

The first samples we received were the 26″ x 54 mm tire. (For some reason the tire mold was changed to 58 mm after we approved the text!) This batch uses the “standard” (supple) casing. When we put one of the tires on the scale, it weighed 454 grams – quite light for a tire this wide.

26_caliper

Mounted on a 23 mm-wide rim, the tire measured a little over 49 mm. In the two days since, the tire has “grown” by 2 mm. The “Extralight” tires tend to stretch even more, so when used with wider rims, they’ll probably be close to the anticipated 54 mm.

compass48-584

Then we received a second box… This time, it contained the 650B x 48 mm tires – made with the extra-supple “Extralight” casing. Out came the scale again, and we measured 413 grams – remarkable for such a big, puffy tire.

650B-caliper

Mounted on a 23 mm-wide rim, this tire measured just over 48 mm right away, and like the 26″ tire, it has grown 2 mm in the days since we mounted it. That means that this tire is slightly wider than planned. Its width is just a millimeter or two narrower than the 26″ tire.

650B_gifford

Of course, measurements don’t tell us much about the tires: What we really want to know is how they ride. Fortunately, our friend Alex Wetmore has two bikes with similar front-end geometries (both have 40 mm trail). One is his “normal” bike, set up for 650B tires (above). The other is his “Travel Gifford”, which runs 26″ tires (photo at the top of the post). These two bikes are perfect candidates to compare the new tires.

Aired up to about 28 psi, I took to the streets and trails in Seattle’s Ravenna neighborhood. On the broken pavement of the residential streets, I wondered why we don’t ride these tires all the time. Even the 42 mm Babyshoe Pass tires of my Grand Bois Urban Bike, which I had ridden to Alex’ house, were surpassed for comfort and secure handling by these even bigger tires.

Riding the two bikes back-to-back, the differences due to the different wheel sizes were very noticeable. The 26″ bike felt very nimble and agile. It was easy to pick a line, but the handlebars required a light touch to maintain that line. The 650B bike, with its larger wheels and greater rotational inertia, felt much more stable. It required more input to change its line, and catching a slide on gravel took a hair longer than it had on the 26″ bike. The 650B bike also had an (empty) front rack, which further stabilizes the steering. While the steering of the unloaded 26″ bike was a tad light, adding a rack and handlebar bag would make it more stable. Both bikes handled fine, they were just at the opposite ends of what I consider “fine handling”.

The real revelation came on gravel. Both bikes felt like good road bikes. The uphill traction was amazing. Sprinting out of the saddle was easy. Only the cornering speeds were lower than on pavement – when the gravel starts sliding under your wheels, no tire can maintain traction. These tires really are a revelation – they have changed how I think a bike can perform on gravel.

Production of the new tires is scheduled, and we hope to have them in stock by July or August. Click here for more information about Compass’ existing tire program.

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.

72 Responses to Compass Tire Prototypes: Really Big Tires!

  1. cbratina says:

    Can I buy a pair of 26″ tires for testing on the east coast?

  2. Gert says:

    It sounds very promising, maybe my next bike should be a 650B, to take advantage of the wider tires. Right now I am hoping for the 700-35 tires for P-B-P my self, and with delivery time I am a little worried whether they will be ready in time

  3. Willem says:

    Wonderfull. I am glad the 26 inch variety is not as wide as I feared. If it had been much wider it would have created problems on many real life loaded touring bikes. 51-52 mm should be fine, and for a loaded gravel road tourer I will stick to the heavier version.

  4. José Pereira says:

    Any plans for a 700c version?

    • A 700C version would fit many mountain bikes (29ers)… As for custom-making a gravel bike for wheels that big, you run into many compromises, because the wheels get huge. We prefer 650B and 26″, which allows us to use road cranks, not have toe overlap and also keep the handling nimble.

      • Rod Holland says:

        Enthusiasm for the 559-54 tires aside (I’ll put them on two or three bikes, pronto, including a Rawland Ravn on pre-order), I’d like to put in a plug for two additional 700C sizes: a 622-42 Extralight tire would fit lots of touring and cross bikes (including one of mine that’s currently happily running Barlow Pass ELs, so this is more greed than absolute need), and a 622-54, or possibly -58, for the Legion of 29ers.

        In any case, bravo!

    • Another vote for 622!

  5. Mike Jenkins says:

    I am looking forward to trying the new 26 x 2.3 tires, tire junkie that I am. Besides width, it would be helpful to know the radius of the mounted tire so as to insure the frame and fork have adequate clearance for tires and fenders. Thanks.

  6. marcpfister says:

    Will there be a wider Grand Bois fork crown produced to fit these tires?

  7. Christoph says:

    I assume Panaracer changed the ETRTO size of the 26″ tire in order to align it to the dimension in inches – 2.30″ is equivalent to 58.42mm rather than 54mm.

    By the way, it’s great these tires don’t run as wide as the sidewall claims, as this will allow me to use them on my trusty 26″ all-road bike that has clearance for 50mm tires whereas 58mm tires would be a tight fit. Finding quality tires for this bike has become increasingly difficult now that most big manufacturers have abandoned the 26″ size in favor of 27.5″ or 29″ (as far as road-to-trail tires are concerned). Thanks a lot for making the effort of bringing these nice niche tires to market.

    • Our plan was for a 54 mm tire, since that size fits between the chainstays of a custom bike, and still use a) round chainstays and b) road cranks with low tread/Q-factor. But 51-52 mm is close enough, and as you say, it means that more riders can enjoy these tires.

  8. MichaelR says:

    Time to go measure my frame clearance.

  9. N. Zornitta says:

    Good news !!!

  10. Doug Wagner says:

    we’re always looking for a good tire for our 26″ wheeled DaVinci tandem. Currently using the Compas 26×1.5 but it is at the top of its PSI rating for our weight. Any idea of the PSI rating/ limit on this new tire?
    Doug and Cheri
    north Port , FL

  11. Bill Russell says:

    Us velomobile riders are thrilled with the prospect of that fat 26″ rubber; any chance I/we could get one or two in time for PBP?

  12. Tyler says:

    SweeeeeT!
    Just a plug for 700c x 52 size…:)

  13. B. Carfree says:

    I have to repress an evil smile when I see all the people asking for these tires in 700C. It reminds me of last year when those of us who roll 26″ were begging for higher performance tires than what you had on offer. (Although the 26X1.5 are wonderful and the 26X1.75 are better yet, so we’re talking about moving from very good to over-the-top great as opposed to just complaining.) I still laugh at myself for being hesitant to try the 26X1.75 because of the weight. You casually dismissed my concern and I am very happy to have listened.

    I’m over the moon that you are taking the chance on us by paying for the molds and first runs. My dear captain is getting on in years (though she’s younger than her stoker) and will definitely appreciate the wider tire on the many wonderful coastal logging roads we ride.

  14. John Q. says:

    Jan, Very interesting. I look forward to the production fat 650B’s. I am wondering for touring what the best tire you have, or will have, might be.

    John Q.

    • For a loaded touring bike, I’d pick the 26″ x 2.3 Extralights. You can “ride light” but your luggage still is going to make the bike hit the bumps hard, and the extra air will make even rough roads fun. And when descending hard, with low-riders front and rear (and thus a very low center-of-gravity), the wide tires will grip and grip and grip, allowing you to have some serious fun. Come to think of it… perhaps another bike project?

      • John Q. says:

        Jan, If I run the 2.3 extralights on a 650 wheel what width rim would you recommend. I have been enjoying a better ride with wider rims on my mountain bike as per Jeff Jones suggestion.

        Thanks, John Q.

      • With supple tires, rim width doesn’t matter much. The tire doesn’t stand on its sidewalls, like a sturdier tire does. So you need to run higher pressures, but the supple casing still results more comfort, speed and traction. (That is how professional cyclocross and mountain bike racers can use tubular tires, which have a very narrow “effective” rim width.)

        Where rim width is important is with the brake pads on canti brakes. It’s hard to set up cantis if your tire is bulging significantly beyond the rim.

  15. teamdarb says:

    So how’s it feel to know you and the crew will probably be responsible to the repurposing those mid 80’s MTB that have 120-126 rear spacing and horizontal top tubes? Long sentence.
    -Wilson

  16. jimmy livengood says:

    Hi Jan,

    Any issues with the tires folding under hard cornering on pavement? What pressure did you run them at? I’m a “clydesdale” class rider and that’s the one issue I’ve had with fatty road tires. To be clear I’ve never had one come off the rim, but it’s a disconcerting feeling mid-corner to feel the bike start to squirm and get unsettled and a bit off line. I’ll be curious to see how your tests continue, especially if you at some point try these tires on significantly wider rims.

    • No issues. They corner insanely well, because there is so much rubber on the road. I ran them at about 28-30 psi, and as you could see in the photos we published in the Spring 2015 Bicycle Quarterly, we leaned the bike over very hard. (Those were the first prototype tires, but they behave the same as the current ones and the production ones that are still to come.)

    • Doug Wagner says:

      We and our tandem weigh 375ib; the Compass 26x 1.5 wobble in corners at this weight; perhaps OK for a single bike though.

      • Supple sidewalls need more pressure than tires with sturdy sidewalls that contribute to holding up the bike. Despite the higher pressure, the supple sidewalls results in a more comfortable and faster ride. Of course, at some point, you bump against the maximum pressure rating of the tires, at which point you’d ideally switch to wider tires, if you bike has clearance for them.

  17. Dax Soule says:

    Is it true that you are also prototyping a tubeless version of the Babyshoe Pass?

  18. mwebb says:

    Given the extra width of the 650b tire do you think it will fit under the Grand Bois fork crown? I was hoping to be able to remove my fenders and try them out.

  19. Really happy to hear the new 650B tires are going to stretch to somewhere around 50mm!
    It will be nice to have an alternative to the Thunder Burts I’ve been riding when the Hetres & fenders come off for summer touring on rocky terrain.
    50mm seems to be the sweet spot for bombing rocky forest roads loaded with camping gear.
    Even if I stick with the Thunder Burts for certain rides it will be nice to have your new tire folded up in the bag as a spare ready for any sidewall cuts.

  20. kurtsperry says:

    The 26 seems like the most rational size to me, the total wheel diameter then is about right and there are lots of cheap, quality old steel MTB frames where clearances would be no problem.. Are any quality alloy fenders available that would really fit that version of the tire?

  21. Alex Wetmore says:

    I used the brown Gifford with these tires on my dirt commute last night (which is about 6 miles of dirt on a 12 mile commute). There are two (short) steep climbs on sandy terrain that were easy with the 650B x 48 tires that are very challenging with the 42s.

    I’m curious to explore the traction in mud (where knobs might help), but with Seattle’s summer so far that could be a long time in the future.

  22. Dustin says:

    Jan, I’ve got a set of the Barlow Pass tires on a new custom any-road bike, I’ve put about 150 miles on them so far, with a mix of pavement, sandy roads, hardpack clay road, chunky gravel, even some singeltrack, and am in LOVE! But I have one request – please, please, PLEASE make a tubeless ready version! Don’t change anything about the tire other than using a carbon fiber bead that wont stretch. It doesn’t need to be an air tight tight that doesn’t require sealant, that would mean a less supple casing. I’m fine with sealant, as are most tubeless users, we want puncture protection so we’re gonna run sealant anyways. Just change the bead!

    I’ve got mine set up tubeless now, and they’re working great, but when speeds get high I have this nagging voice in the back of my mind reminding me the tires aren’t really supposed to be used tubeless, and I’m always a little worried they’re going to suddenly blow off the rim on me. Hopefully it happens in the garage when checking tire pressure before a ride, and not out on some steep gravel descent.

    It’s a great opportunity IMO, there is no 35-40mm tubeless slicks available. There’s some 40mm tubeless knobby tires, and a few 32mm tubeless ‘cross tires, but I don’t need knobs, lighter and faster rolling slicks make way more sense.

  23. The Spud says:

    Are there any fenders which will be able to be used with these tyres?

    • Fenders are tricky, because with a road chainline of 43.5 mm, you can’t use a fender wider than about 62 mm, otherwise, the chain hits the fender in the smallest gears… So we plan to use a 650B fender and just mount it a bit higher off the tire.

      • Oliver Smith says:

        I chose Honjo 62mm 650b fenders for my Elephant NFE with the intention of using the new 48mm tires. Hopefully they fit, but if they don’t, the disc brake setup should allow using the 26″ x 2.3 Extralights (with a separate 26″ wheelset).

  24. Roger Aasen says:

    Any plans to accept pre-orders for these new tires? Thanks!

  25. Tony Hunt says:

    I am wondering if there’s a way to tell if a well-proportioned 700c bike like my 62cm All City Space Horse would be able to fit the new 650B x 48, which currently runs 38mm Paselas + fenders comfortably. Sorry if you’ve covered this elsewhere. Thanks

    • jimmy livengood says:

      Doing some quick rough math tells me that your current set up is 698mm diameter, and that the 650x48s would be 680mm diameter. Even if my numbers are not exactly right, they could be used for comparison sake.

      You’ll have about 9mm more vertical room above the tire.

      Using the same rough math, I figure that the widest part of your 38mm Paselas is at 330mm from the axle centerline. For the 650x48s it would be at 316. Again, the numbers might be off a bit, but you can probably figure that if you measure down 14mm from the widest part of your paselas that tells you where the widest part of the 650bs will land. With that in mind you can then estimate if you’ve got enough frame/fork clearance or not.

      IMO this is some rough estimating, but in the past with other tires I have at least been able to get close enough to know whether it’s worth even trying or not.

  26. alliwant says:

    “The 26″ bike felt very nimble and agile. It was easy to pick a line, but the handlebars required a light touch to maintain that line. The 650B bike, with its larger wheels and greater rotational inertia, felt much more stable. It required more input to change its line…” I have a question on the stability contrasts; do you think it possible that the differences in frame geometry had an effect on the stability/agility as well? The travel bike with 26″ wheels likely had less BB drop than the 650B bike; that is what I might consider an important difference. I’ve come across commentary that bicycle wheels just are not massive enough to have much gyroscopic effect on stability. Is there any other way the wheels could affect stability?

    • The two bikes have similar geometries and BB heights. However, BB height has almost no influence on handling. What matters is your center-of-gravity, and that is about 3′ (90 cm) off the ground. Lowering the bottom bracket, even by a huge amount like 2 cm, will have a negligible effect.

      Regarding the handling differences due to wheel size and weight, we tested this and reported on it in Bicycle Quarterly 31. Three testers independently found the differences to be quite large and noticeable.

      When others say that wheels don’t have an effect on stability, they mean that the gyroscopic forces of the wheels don’t keep the bicycle upright. That is true. However, how a bike reacts to steering inputs is greatly affected by the gyroscopic forces.

  27. Paul Richard says:

    Sorry if this has already been discussed. I can see the typical Compass fine file tread pattern on the 650B tire. The 559 tire looks totally lacking tread. Is this how the final product will look?

  28. Mathew says:

    Its pretty good to hear that. Thanks

  29. Jon Gehman says:

    I’m trying to decide whether to wait to get some of these before I start cutting and tacking tubing, there are some really neat bikes that can be built around these tires. Thanks for making this happen.

    I keep wondering about the name “Gifford” on the bikes Alex Wetmore built, I understand what makes a Gifford a “travel” Gifford, but is there some other significance to the term besides it being a cool name? Just wondering.

  30. Willem says:

    I am eagerly waiting for these, but they will not be in time for my summer camping tour (this time riding back from Prague to Holland). I could indeed do with something wider. Last summer I rode back from a mountaineering family holiday in northern Italy through Austria and Germany to Holland. It was wonderful and the many small roads and trails in Germany were particularly impressive. However, on forest trails and gravel roads the 26×1.75 size was sometimes pretty marginal, and I was longing for something wider. Equally, on tarmac I was glad I had decided not to fit my wider off road tyres with their course tread. So yes, I am looking forward to these Compass tyres, even if a bit apprehensive that they basically do not have any tread at all. How will they handle on forest trails with plenty of wet leaves? We shall see.

    • These tires definitely are intended for loaded touring as well. Wide tires inherently have more traction. I was amazed by how well the prototypes coped with loose gravel. A larger surface area helps… and wet leaves actually are a pretty hard surface, and the “file” tread of our tires might create more interlocking points than knobbies.

  31. SmoothestRollingBike says:

    Jan, I see many people request for extra wide 700C tire on your blog. Why is that? Many cyclists have more than one bike – one for road and one for off-road. Today the most popular off-road bicycle is 29” mtb.

    On the forums mtbr com there is about 4000 posts on the 26” subforum, 94000 on 27.5” subforum …but they have to divide 29ers into Bikes subforum and Components subforum, because so many posts – above 800000! Why is 29” so popular? Lowest rolling resistance? Increased ability to roll over obstacles? Yes, yes, but also 700C rims – most popular road rims.

    Many cyclists have to own only one bicycle for various reasons. Why they choose 29er? Versatility – they can use the best 700C road tires, the best 700C cyclocross tires and also the best 700C wide mtb tires. They dream about to have one bike and two tire sets – one knobby for mountains and one super comfort and fast for pavement and gravel. They are spoiled by 2.35” comfort mtb tires and they do not want to buy new wheelset to have 700Cx23 fast, slick tires. Ironically they even do not know that in real live conditions wide tires like Compass products can be faster than the best narrow road tires and they could have only one wheelset for both. Some of them like I already know.

    Jan, please help them and me to savor the most supple tire in the world in 700C format. Please make 622×60 or 622×58 or 622×54. One of them. For me the wider the better.

    • We’ll consider it. Realistically, few mountain bikers are aware of the advantages of supple tires, unfortunately. So even though there are a lot of them, they are not very likely to buy our tires. For now, we put our resources into the tires that we ourselves want to ride… and super-fat 700C tires will not offer the nimble handling we enjoy.

      That said, I am open to the argument that we all ride the bikes we own, not the ones we hope to own some day.

  32. Max Sievers says:

    Please consider producing a wide 20″ tyre (like 406-50 to 406-60). I’ looking for a tyre for the Smallhaul I will order.

    • John Q. says:

      Since I also have a recumbent trike with 406 wheels and a 406/559 wheel recumbent bike I would love to see Compass tires in a 406 size. The recumbent market is bigger than you may think and the riders are avid about comfort and speed. That is how I first heard about your 559 tires.

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