Enve and Zipp hookless rims and Rene Herse tires

Rene Herse tires are safe to use on hookless rims from Enve and Zipp – even when mounted tubeless (for tubeless-compatible tires). Over the last year, we’ve worked with the engineers from both companies to ensure the full compatibility of our tires with their rims.

Tubeless tires are an emerging technology. They’ve been around for decades on cars and motorcycles, and they’ve taken over mountain biking in a storm, too. These are all relatively stiff tires that run at relatively low pressures.

Adapting the technology to road, all-road and gravel bikes has posed special challenges. The supple high-performance tires we love have less casing stiffness, and they run at somewhat higher pressures. (Few cars, motorcycles and mountain bikes exceed 2.5 bar/35 psi.) Both factors combine to create much greater forces at the tire/rim interface than on other vehicles.

At Rene Herse Cycles, we’re always interested in new technologies for off-pavement riding, and we’re working with other rim and tire companies to establish the first ISO standards for tubeless tires. These standards still are some ways out, but our collaboration is already showing results.

Over the last year, we’ve worked with Enve’s engineers to make sure that our tires are safe on their hookless rims – even when mounted tubeless. Most carbon rims are hookless, because creating the hook requires a very complex mold. It’s not so much the associated cost that had Enve move to hookless rims: The simpler hookless mold allows them to make their rims to closer tolerances. Instead of a variation of 2 mm in the diameter of a rim with hooks, Enve’s hookless rims are within 0.2 mm. This means that the tire fit is much more consistent. And good fit is what you want for tubeless tires.

Since the hook helps retain the tire bead (above), we were wary when hookless gravel and all-road rims were first introduced. Hookless rims work great with low-pressure, stiff mountain bike tires. They are fine with many gravel tires that are derived from mtb tires. But how would they perform with our supple high-performance tires? Would the benefits of the better tire fit outweigh the missing ‘safety net’ of the hooks?

We tested a number of tires and rims, and Enve also tested multiple samples of our tires with all four different casings: Standard, Extralight, Endurance, Endurance Plus – more than 16 tires total. Enve tested the bead length, bead stiffness, casing stiffness, blow-off pressure and a number of other parameters.

Now the official report is in: Our high-performance tires have passed Enve’s tests with flying colors – confirming what we’ve found ourselves. Rene Herse tires (all casings) are safe to use with Enve rims. For tubeless installations, you need tubeless-compatible tires (marked ‘TC’). And don’t exceed the maximum of 60 psi (4.1 bar) that we recommend for tubeless tires – plenty for most gravel and all-road applications. The actual blow-off pressures are much higher, but we really don’t want to take any risks.

Enve also confirmed that the diameter of our Rene Herse tires is very consistent, so there is little danger of getting a tire that fits poorly because it’s a bit on the large side. Together with the close tolerances of Enve’s hookless rims, this creates a predictable, secure fit of the tire on the rim.

We’ve also worked with Zipp to ensure optimum tire/rim compatibility. Zipp’s engineers confirmed what we found in our own testing: Eliminating the hook decreases the blow-off pressure, but if the rim’s diameter is within very narrow tolerances, the better tire fit makes up for that. As a result, Zipp rims are safe to use with Rene Herse tires, too. And indeed, Ted King (above) has been running his Rene Herse tires tubeless on Zipp rims for over a year now, with zero problems.

What about running Rene Herse tires on other hookless rims? It really depends on the quality of the rim. If the diameter is just right, there shouldn’t be any problem. That is one advantage of carbon: The rims come out of a mold, so they can be very consistent – if they are manufactured with quality tooling and with care. (Removing the rims from the mold before they are fully cured, to speed up production, can distort them.)

What about aluminum rims? They are formed from extrusions (imagine squeezing frosting out of a pastry bag when icing a cake). They can be any cross-section, and putting hooks to the sidewalls is easy. Aluminum rims are rolled into a circle and welded together, which means that the tolerances for the diameter are always going to be a bit greater. So it’s good to have the hook as an additional precaution against blowing the tire off the rim.

In other words: top-quality hookless carbon rims are fine, but aluminum rims need hooks. The correct diameter is important for both, of course – it’s just that the hooks of an aluminum rim give you an extra layer of safety to make up for the larger manufacturing tolerances.

When you mount your tires, pay attention to how the tire goes onto the rim: If the fit is a little tight as the tire seats, then the diameter is correct. Ideally, the fit should be good enough that a floor pump is all you need to seat the tire. There is nothing wrong with using a compressor, but if you need repeated large blasts of air to seat the tire, then the rim is probably undersized. We recommend building up the rim bed with extra layers of tape, but there is only so much you can do before the rim’s sidewalls aren’t tall enough to hold the tire securely. (The current ETRTO standard requires inner sidewalls with a ‘G height’ of 5.2 – 6.5 mm.)

When in doubt, you can always run your tires with tubes. The tube reinforces the joint between tire and rim, and the risk of blow-offs is much-reduced.

Tubeless technology is maturing, and rim makers are realizing that the rim tolerances need to be closer than they were in the old days. Enve and Zipp have shown that the best hookless rims can be safe with high-performance tires.

Click here for step-by-step instructions how to set up supple high-performance tires tubeless.

36 Responses to Enve and Zipp hookless rims and Rene Herse tires

  1. Anders February 24, 2020 at 8:28 am #

    Good news that you’re looking into this, it’s very difficult and confusing as a consumer to have a good overview of different standards and compatability. I have bought a pair of DT Swiss GRC 1400 Carbon hookless: Any thoughts on how Rene Herse tires would work tubeless with these rims?

    • Jan Heine February 24, 2020 at 8:38 am #

      We had a set of DT carbon rims on a Bicycle Quarterly test bike recently, and the tire fit seemed very good on both front and rear rims. I’d like to test (and measure) a few more wheels before saying anything definitive, but it seems fine. You’ll notice the fit when you mount the tires – if it feels right (easy to get an airtight seal as the tire seats), you’ll have no problems.

      • Anders February 24, 2020 at 12:04 pm #

        I’ve recently installed a pair of 38mm Steilacoom’s, and those fit really well on the DT wheels. Seated really easy and fast, so it felt really reassuring. Thanks!

  2. Daniel S. February 24, 2020 at 10:10 am #

    Thanks for this clarifying post. Is this also true of older gen RH “TC” tires that have Compass badging? I have some “Compass” Steilacooms that I’m hoping to mount on my Enve hookless rims (g23 or 3.4AR) – do they pass the test as well?

    • Jan Heine February 24, 2020 at 10:13 am #

      As long as the tires are marked ‘TC’ (tubeless compatible), they pass the test and are safe to mount on Enve rims (and others that have the correct diameter).

      • Daniel S. February 24, 2020 at 10:17 am #

        Many thanks, Jan!

      • Tuomas Määttä February 24, 2020 at 9:22 pm #

        Thanks for this clarifying post! I’d like to hear your thoughts on Easton’s hookless carbon gravel rims regarding this matter. I have been running my carbon EC70 AX wheelset tubeless with the Steilacoom Extralights without any issues. It’s a wonderful combination btw. I have stayed under 40 psi on the pressures as that is my preference.

        • Jan Heine February 24, 2020 at 9:47 pm #

          I don’t have any experience with Easton rims. Fortunately, you’ll notice how the tire fits when you mount it. If it works well, then it’s good. If the mounting is really tricky, with lots of air escaping until you really blast it with a compressor, then the tire fit probably isn’t good enough for safety without hooks.

          • Tuomas Määttä February 25, 2020 at 1:03 am #

            Thanks!

      • Marius Clore February 26, 2020 at 4:40 am #

        Has anything changed with your TC tires since last year. If not, I believe your report is inaccurate. As you know, from our correspondence, I had at least 2 failures with Extralight Compass TC tires (Barlow Pass TC and Bon Jon Pass TC) with two different sets of ENVE G23 rims. In both instances, the tires were installed tubeless and seated perfectly fine, but they blew off the rear rim totally inadvertently while riding, one as far out as around 500 miles from initial installation. In no instance was the pressure above the recommended upper limit of 60 psi. In fact for the Barlow pass tires it was set at around 45 to 50 psi. Since I very much doubt that ENVE have changed their molds, the only possible way your current extralight TC tires could be safe with ENVE hookless rims is if you have changed something with the beads.

        There is no question that the ride quality of the Compass/Rene Herse extralight tires is fantastic. But unless something has really changed, I wouldn’t ride these tubeless on ENVE G23 or other ENVE hookless rims.

        I might also add that I ride around 8000-9000 miles per year, and or the last 3 years I have only ridden tubeless. I have never had an issue the Schwalbe G one speeds in either 35 or 38 mm versions, WTB byways in 40 and 44 versions, and WTB Resolutes in 42. All of these were mounted to either ENVE G23 or M525 rims.

        And I

        • Jan Heine February 27, 2020 at 10:22 am #

          As mentioned earlier, Enve’s rims and our tires keep evolving, even if it’s not always apparent to the customer. You are one of a handful – very few – customers who’ve experienced blowouts (almost all have commented in this post), and your experience was the reason we reached out to Enve to do the testing that we’re reporting here.

          Our supple high-performance tires don’t have the same casing stiffness as the mtb-derived gravel tires you mention. That is why they offer more speed and comfort (and traction), but the tolerances of the rim/tire interface need to be tighter.

  3. Forrest February 24, 2020 at 10:22 am #

    A report that will give confidence to many. I’ll stay with inner tubes, though, thanks.

    • Jan Heine February 24, 2020 at 10:28 am #

      Inner tubes are a great choice for most rides. Tubeless is useful when the terrain is so rough and the speeds so high that pinch flats are a real concern.

      • Rick Thompson February 24, 2020 at 11:38 am #

        And goatheads. Tubeless with sealant has solved that very annoying problem in some parts of the country.
        Thanks for the endurance casing. My new endurance Barlow Pass are the ideal tire for most of my road and gravel riding. The ride may be slightly less plush than the extralight casing, but there is zero sealant leakage from the endurance sidewalls and pressure holds up much longer.

      • marmotte27 February 25, 2020 at 4:30 am #

        “Tubeless is useful when the terrain is so rough and the speeds so high that pinch flats are a real concern.”
        There I was reading the article and not feeling really concerned…

  4. Jairp February 24, 2020 at 12:14 pm #

    Do the Pacenti Brevet rims have hooks? I am using those rims with tubes, and have been planning on tubeless application in the future.

    • Jan Heine February 24, 2020 at 12:56 pm #

      Most aluminum rims have hooks. The Pacenti Brevets and the HED Belgium both have hooks. We sell them because they work very well with our tires.

  5. Lisa February 24, 2020 at 4:43 pm #

    Is there a minimum tire pressure recommendation? Running pretty low pressures (high 20s) due to low rider weight (100 lb).

    • Jan Heine February 24, 2020 at 6:03 pm #

      No minimum pressure recommendation exactly because it all depends on rider weight. High 20s (psi) is not too low – of course, depending on your tire width.

      Check this post for more information about minimum tire pressure.

    • Mike M February 26, 2020 at 4:28 pm #

      I regularly ride (outside of winter, anyways) on Rat Trap Passes inflated to 25-30 psi per my car tire gauge. I’m also considerably heavier than 100 lbs. It’s really amazing what you can do with such a large volume of air in a supple tire…

  6. Micha O. February 24, 2020 at 5:07 pm #

    Great article. Very informative. I am a larger and heavier rider. The problem is that I’m too heavy for carbon rims and there’s exactly one rim manufacturer that sells hooked aluminum rims with 36h. Feeling a little under-served by the cycling industry again. Fortunately, there is that one manufacturer so I will be buying your tires soon.

    • Jacob Musha February 25, 2020 at 7:06 am #

      Is anyone making an aluminum rim these days *without* hooks? The only ones I can recall are from the 1970s and early ’80s. There are still plenty of aluminum options in 36h in virtually any wheel size.

      • Micha O February 25, 2020 at 5:43 pm #

        I have looked and most seem to go up to 32h. White Industries now makes hookless aluminum .

        • Mike M February 26, 2020 at 4:25 pm #

          36-hole rims aren’t exactly hard to come by. I’ve been looking around for a couple of rims to replace the worn-out ones on my current wheels. Two that come to mind are Velocity Atlas and SunRingle Rhyno Lite, both available in 36h for ISO 559 wheels (my preferred size). You can find many 36h wheels on shopping sites, though they’re most likely complete wheels, not rims, and the quality is… questionable, unless you go with a name brand.

    • Stuart Fogg February 25, 2020 at 9:28 pm #

      You can still get these European 36H aluminum rims:
      DT-Swiss TK 540
      Mavic A 719
      Ryde Andra

      Also e-bike rims might be suitable for larger riders.

    • Erik H February 26, 2020 at 10:24 am #

      Velocity USA makes plenty of “Clydesdale” rims with 36, 40 or even 48 holes.

      https://www.velocityusa.com/product/rim_applications/clydesdale

  7. Still Concerned February 25, 2020 at 1:13 pm #

    I had a Barlow Pass blow off an Enve M50 rim several years back. It was inflated within your recommended specs. Fortunately I was not riding at the time. In addition to this blow off I had constant burping (air loss) issues with this tire/rim combo (no other tires I subsequently ran ever burped on this rim). As a result I completely stopped riding your tires. I currently have 2 sets of Enve M525 and a set of 4.5 ARs that I use for my gravel racing. Has Enve changed their hookless rim design between M50s and M525? I know that the M525 has the blunted leading edge to help with pinch flats but even though my experience is a sample size of 1, unless something is fundamentally different between the M50 and their current hookless tires I certainly will never run a Compass/Enve (or any other hookless) ever again. Thoughts?

    • Jan Heine February 26, 2020 at 8:50 am #

      It’s hard to comment on a single case – we’d have to check that particular rim, that particular tire, the installation, etc.

      What I can say is that our tires are constantly evolving. The Barlow Pass is on its third mold since we introduced the tire in 2014. Materials, dimensions and other parameters are constantly fine-tuned, even with the same mold. So a 2020 Barlow Pass will be a different tire from a 2014 one. I suspect the same is the case with Enve’s rims.

      The last 5 years have been interesting: For decades, tire technology had evolved mostly in terms of tread rubber – making it grippy and long-lasting, while also reducing the rolling resistance. Casing materials, beads, etc. remained almost unchanged, as the rim/tire interface was a known quantity. Then came tubeless, and suddenly, it was the tire/rim interface that radically changed. Fortunately, here at Rene Herse Cycles, we had a head start on this development: Several of our local riders have been experimenting with tubeless since 2012 – before there even were tubeless rims and tires. I remember the constant burping and hassles, but it gave us insights into how tubeless tires work.

      Last year, when hookless gravel rims first became widespread, there was a rash of blow-offs – with all brands of tires. I won’t mention names, but we got reports of all the big brands having problems. Yet I was surprised that no other tire maker issued a warning or at least guidance. Perhaps they didn’t get the feedback from the field that there was a problem? Or were they concerned that sales might suffer if they raised a concern?

      We’ll always put rider safety first. We won’t always be the first to market, but when we offer something, you can be sure it’s been thoroughly tested.

      • Still Concerned February 26, 2020 at 9:44 am #

        I did offer to bring my Barlow Passes and M50s over to you when I was having the burping problems and again after the blow off (I’m local to you). I no longer have these wheels as I used Enve’s trade in to get a second set of M525 (no objective data but subjectively I like the tire profile and handling of the wider internal width of the M525 over the M50).

        I really enjoyed riding and racing your tires, and it was a shame to give them up but based on the problems I had no choice. I do agree that this is not a Compass specific problem (Enve has a list of non compatible tires).

        In a separate dialog I also pushed Enve to explain their use of hookless. Specifically is hookless the best design overall, or the best design for a carbon wheel. The answer that I got was best for carbon and proven by the general rim/tire industry (i.e. not bikes). I did not find this particularly satisfying, especially given that my Enve 5.6s on one of my road race bikes uses a hook rim design.

        I appreciate your commitment to continued testing. I hope to be able to use your tires again.

        • Jan Heine February 27, 2020 at 10:13 am #

          Enve’s trade-in program is designed to get older rims off the road as they improve their designs. It may be wasteful (I wonder what happens to all the old rims), but it means that the safety improvements trickle down much faster. Glad you are on the improved rims now.

          Tires wear out faster than rims (and are much cheaper), so they get used up before there’s a need for a trade-in program. With your new rims and newer-production tires, I am sure you experience would be better.

  8. Charles Swart February 25, 2020 at 4:20 pm #

    Great news as I have brand new Enve G23 rims and 3 different pairs of Rene Herse tyres !
    Coming form a mtbiking background…it is tubeless all the way

  9. Francisco February 26, 2020 at 5:16 am #

    It’s great that you have worked with the two leading wheel manufacturers in the north american market to ensure that your tyres are safe to use with their products. It should not have been necessary, however, if manufacturers respected international standards instead of forcing their preferences upon consumers. I well remember the (black) listing of some tyre manufacturers that ENVE published a short while ago. They effectively blackballed a number of very well-regarded tyre manufacturers to cover up for their own rim manufacturing shortcuts. Although this had little practical import in the European market where I am, I was not amused by what I see as a clear abuse of position in their primary US market. In that case, ENVE declined to smooth the corners of its rim hooks. Now it is clear that ENVE hates to mold hooks of any description. Is it really credible that a serious manufacturer cannot get their tolerances with hooked rims down to less than 2mm?

    • Jan Heine February 26, 2020 at 8:51 am #

      To clarify, the 2 mm tolerance with hooked sidewalls is in diameter, so it’s a tolerance of 1 mm on each rim bed.

      • Derek February 27, 2020 at 2:44 am #

        2 mm of diameter is only 1 mm of radius, but over 6 mm of circumference. Seems pretty sloppy. No wonder tubeless didn’t work well before.

        • Jan Heine February 27, 2020 at 10:10 am #

          You are right, the circumference is what matters. The rim maker only can control the radius, and small errors get magnified. The Enve engineers called it “The Problem of Pi.”

          For tire makers, it’s a bit easier to keep the tolerances in check, since we directly control the circumference (bead length).

    • Jan Heine February 28, 2020 at 1:39 am #

      Fortunately, our tires weren’t affected by the issue with Enve’s overly sharp rim edges. We mold a ‘chafer strip’ into the bead that reinforces the area where the tire touches the rim. I’ve often wondered why some tire makers make their tires without any reinforcement there. I recall giving up on Conti tires during the ’90s, because even aluminum rims would cut through the sidewalls during our winter rides.