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  1. #1
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    Bead hook-less rims, are they the future?

    Hey guys, I was just reading about Specialized's new Roval wheels which comes with hookless carbon rims. Any of you guys tried it? I'm just trying to get that idea to sit in it's quite hard to imagine you can secure the tire without any bead hooks.

  2. #2
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    I'd want to see a lot more consistency in bead shape, strength, and diameter for tubeless But hookless rims are nothing new.
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  3. #3
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    Difficult to make a durable carbon bead hook. I doubt you'll see hook-less aluminum rims any time soon.

  4. #4
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    Bead hook-less rims, are they the future?

    Aren't vehicle wheels hookless/tubeless?

    Edit: The engineer inside me thinks that the concept works well in a very ASTM-guided, static environment like the automotive industry. In the bike industry, not so much. Lots of tweaking, rapid technology development and implementation, combined with a variable stress input (terrain). Show me a dude riding these at Red Bull Rampage and I'll be a believer in the concept. For light XC, it might work.
    Last edited by MTBeing; 01-31-2013 at 05:16 PM.
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  5. #5
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    They are not new. They are old technology that has been discredited and discontinued. Next Specialized will bring back cottered cranks and quill stems.

  6. #6
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    Quote Originally Posted by jasonwfreak View Post
    Hey guys, I was just reading about Specialized's new Roval wheels which comes with hookless carbon rims. Any of you guys tried it? I'm just trying to get that idea to sit in it's quite hard to imagine you can secure the tire without any bead hooks.
    Only if the tires are specifically designed to work with them. Current mtb (and road) tires are not.

    Quote Originally Posted by MTBeing View Post
    Aren't vehicle wheels hookless/tubeless?

    Edit: The engineer inside me thinks that the concept works well in a very ASTM-guided, static environment like the automotive industry. In the bike industry, not so much. Lots of tweaking, rapid technology development and implementation, combined with a variable stress input (terrain). Show me a dude riding these at Red Bull Rampage and I'll be a believer in the concept. For light XC, it might work.
    Exactly. The tire and rim are designed to work together. The bicycle ISO spec is fairly good as far as it applies to tubed use, and the UST spec is ISO approved for tubeless.
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  7. #7
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    Rim makers will approach tire makers to come up with a new standard if it can be a win-win for both, that's how the industry works. "Hookless Ready" tires? I'm guessing Specialized will come up with their own version(?less + 2bliss, get it?) first if it works well for them. and whichever oem factory that makes their tire will too.

  8. #8
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    No need for hookless ready tires. I have been using the new Roval rims with Rocket Rons for a few rides now and have yet to have an issue with them. Even when I sliced a side wall and the tire was loosing air it stayed on. I know several people that have been using the rims with zero issues as well.

    Very east to set up tubeless too. I experienced absolutely zero leaks from around the bead.

  9. #9
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    Quote Originally Posted by shiggy View Post
    Only if the tires are specifically designed to work with them. Current mtb (and road) tires are not.
    I can't speak for road tires, but the mtbr reviewers were able to touch a c-clamp together on a tire mounted tubeless on hookless rims. I would have no reservations riding a set of hookless rims.

  10. #10
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    Quote Originally Posted by Berkley View Post
    Difficult to make a durable carbon bead hook. I doubt you'll see hook-less aluminum rims any time soon.
    Take a good look at the Stan's Flow
    EX... Not much hook at all in fact before I put tires on mine I googled the hell out if them to make sure they weren't some sort of goofy factory defect

  11. #11
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    Bead hooked rims and clincher tire beads to mate, were started in the early '70's for tubed tires needing high pressures, 65 to 100+ psi.

    If running tubeless converted clincher bead tires with sealant, bead hooks have absolutely no benefit to keep the tire on the rim.

    With tubeless conversions of clincher tires the tire bead simply must not stretch or be off center to reach over the edge of the rim to blow off from air pressure. Rims designed to be tubeless ready or TR are now very common, having wide inside bead shoulders on both sides of the middle deep channel to be sure the tire bead is centered inside well below the edge of the rim.

    UST bead hooks mate with UST tire beads. The hook near the edge of the rim is useful for very high tire pressures, over 65 psi. And the UST hooks on the rim inside shoulders next to the center channel prevent the bead from squirming inward enough to fall off the shoulder and burping air or blowing off the rim during cornering when tubeless, and the shoulder bead hooks keeps the bead under the rim's edge hooks when tubeless without sealant and using higher air pressures.

    If inflating under 65 psi and using TR bead centering rims, then bead hooks are useless. We will probably see rims without bead hooks become the standard for mountain bikes in a few years, and tire bead design will follow.

    Having no bead hooks allows a wider inside rim width. And the rim edge can be thicker and more durable without adding more weight compared to a rim with bead hooks.

  12. #12
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    Quote Originally Posted by msrothwe View Post
    I can't speak for road tires, but the mtbr reviewers were able to touch a c-clamp together on a tire mounted tubeless on hookless rims. I would have no reservations riding a set of hookless rims.
    I would not. There is more to it than that.
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  13. #13
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    In response to Derby, I still think hookless rims are a bad idea. On the point that hooks are needed for 65+ psi : That is 65 psi on a road tire. The hoop stress, or the force that the tire sidewall tries to pull upwards on the bead, is proportional to both pressure and tire diameter. So the sidewall upwards pulling force for a 2" 32 psi mtb tire is the same as that of a 1" tire at 65 psi.

    Obviously, the hookless design has no protection at all from preventing the tire bead from lifting upwards slightly. This is critically important because if it lift upwards even slightly, you lose the sealing effect of the bead against the rim bed, and air can get underneath the bead, contributing to an additional upwards as well as inwards force. (Running a tube would prevent this, btw.)

    So the hookless design is even worse than Stan's in that it totally relies on circumferential bead tension to keep the tire tightly against the rim. How do you know it is enough under high cornering forces where there is additional tugging on the tire?

    UST rim and UST tire is a very good combination because the bead hook is at exactly the right height to keep the tire bead pressed down against the rim. Further, in the case of a tire bead or sidewall failure, or when using a tube-full tire, you can still use an inner tube, and the bead hooks will still keep the tire on.

  14. #14
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    Quote Originally Posted by beanbag View Post
    In response to Derby, I still think hookless rims are a bad idea. On the point that hooks are needed for 65+ psi : That is 65 psi on a road tire. The hoop stress, or the force that the tire sidewall tries to pull upwards on the bead, is proportional to both pressure and tire diameter. So the sidewall upwards pulling force for a 2" 32 psi mtb tire is the same as that of a 1" tire at 65 psi.

    Obviously, the hookless design has no protection at all from preventing the tire bead from lifting upwards slightly. This is critically important because if it lift upwards even slightly, you lose the sealing effect of the bead against the rim bed, and air can get underneath the bead, contributing to an additional
    upwards as well as inwards force. (Running a tube would prevent this, btw.)

    So the hookless design is even worse than Stan's in that it totally relies on circumferential bead tension to keep the tire tightly against the rim. How do you know it is enough under high cornering forces where there is additional tugging on the tire?

    UST rim and UST tire is a very good combination because the bead hook is at exactly the right height to keep the tire bead pressed down against the rim. Further, in the case of a tire bead or sidewall failure, or when using a tube-full tire, you can still use an inner tube, and the bead hooks will still keep the tire on.
    BikeRumor summed it up really well.

    "With a snug/strong (tubeless or tubeless-ready bead), the inside diameter of the tire (at the bead) canít climb up over the rim- it simply isnít big enough. In order to install or remove tires, part or all of the bead must sit down in the center channel, providing enough slack to get another section of the bead over the wall. No bead hook will keep an insufficiently-snug tubeless tire in place. This is a big reason that companies advise against using tire levers with tubeless/tubelish tires: they can stretch the bead and increase the chance of a blowoff."

    I have experienced this with tires before. I had a set of X-kings and nothing would keep those things seated. Blow offs are almost always attributed to the tire not the rim.

  15. #15
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    Quote Originally Posted by beanbag View Post
    In response to Derby, I still think hookless rims are a bad idea. On the point that hooks are needed for 65+ psi : That is 65 psi on a road tire. The hoop stress, or the force that the tire sidewall tries to pull upwards on the bead, is proportional to both pressure and tire diameter. So the sidewall upwards pulling force for a 2" 32 psi mtb tire is the same as that of a 1" tire at 65 psi.

    Obviously, the hookless design has no protection at all from preventing the tire bead from lifting upwards slightly. This is critically important because if it lift upwards even slightly, you lose the sealing effect of the bead against the rim bed, and air can get underneath the bead, contributing to an additional upwards as well as inwards force. (Running a tube would prevent this, btw.)

    So the hookless design is even worse than Stan's in that it totally relies on circumferential bead tension to keep the tire tightly against the rim. How do you know it is enough under high cornering forces where there is additional tugging on the tire?

    UST rim and UST tire is a very good combination because the bead hook is at exactly the right height to keep the tire bead pressed down against the rim. Further, in the case of a tire bead or sidewall failure, or when using a tube-full tire, you can still use an inner tube, and the bead hooks will still keep the tire on.
    Good point about the relative tire pressures to tire size and bead stretching force pulling the bead up from the rim, for those needing high tire pressures. Is the pulling pressure 1:1 rate to tire diameter, same rim width?

    Yes, agree, bead hooks are only useful with an inner tube and higher pressures, or tubeless only if UST bead or TR bead with UST rim.

    I time time will soon tell. The Specialized hookless rims are not UST. They are pretty light in weight. I imagine many will use them with light 2.0 tires and higher pressures than 32 psi for XC racing, tubeless and with tubes, repeating failures would be broadcast soon. Although Specialized probably did test with high pressures before investing major dollars in these rims.

  16. #16
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    In the last video Specialized uploaded of the last WC they said that the new roval wheels are bead hook-less!!

    I don't think Specialized will install on s-works bikes and in the market around the world a Roval wheels that are useless or won't work!!
    They didn't say anything about new tires or special tires with this new system they are using the sworks 2bliss tires!!

    I will buy the 2014 SW stumpy and I'm scared too that this new rim could fail in races I use my tires with very low pressure 25-26 psi but I just trust in the brand!!!!

  17. #17
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    Quote Originally Posted by PainkillerSPE View Post
    No need for hookless ready tires. I have been using the new Roval rims with Rocket Rons for a few rides now and have yet to have an issue with them. Even when I sliced a side wall and the tire was loosing air it stayed on. I know several people that have been using the rims with zero issues as well.

    Very east to set up tubeless too. I experienced absolutely zero leaks from around the bead.
    Well you are the first person who have tested the new wheels!!!
    Cool!! Are they 1370 g like they said?? I will use sworks tires hope this new system works perfect in all conditions!!

  18. #18
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    Quote Originally Posted by andresco50 View Post
    Well you are the first person who have tested the new wheels!!!
    Cool!! Are they 1370 g like they said?? I will use sworks tires hope this new system works perfect in all conditions!!
    Mine are the heavier Roval Control Carbons. But in terms of the hookless rim, don't worry about it at all. I have over 6 months of constant use on mine and not a single problem. I run my tires around 21-23 PSI. I completely trust the wheelset and have won several races with them.

    Both wheels are still going strong and have never needed truing, despite several really bad wrecks. It's a very solid dependable wheelset that's worth every penny.

  19. #19
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    Hook-less is fine as long as the tire is designed for it. The tire needs a strong enough and small enough bead so that it will not stretch off the rim. Ideally there should be a max pressure listed for this combination with a significant safety factor. Low pressure is ideal for this. Notubes rims are basically hook-less and they also have a much shorter sidewall than the Specialized rims. Notubes rims work for most people at low pressure, but at higher pressures with larger riders tires have been known to blow off the rim.

  20. #20
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    Quote Originally Posted by changingleaf View Post
    Hook-less is fine as long as the tire is designed for it. The tire needs a strong enough and small enough bead so that it will not stretch off the rim. Ideally there should be a max pressure listed for this combination with a significant safety factor. Low pressure is ideal for this. Notubes rims are basically hook-less and they also have a much shorter sidewall than the Specialized rims. Notubes rims work for most people at low pressure, but at higher pressures with larger riders tires have been known to blow off the rim.
    That's totally true once I inflated a sw renegade tire with so much pressure that the tire blow off the NOTUBES rim sounded like an explosion!! and all the sealant was in the roof and in my face!!

    Now changingleaf said that low pressure is ideal for this type of rims but how much low is safe to run?!! I don't know at what pressure I'm running but maybe is about 24 25psi!!!

    I'm deciding what to do right now.. 1.-buy a complete 2014 s-works stumpy bike with this new hookless roval wheelset or 2.- Buy the frameset and install it with stans wheelset.

    Right now I have a stans ztr crest wheelset on my bike and they are really awesome no problems just perfect!!!

  21. #21
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    Quote Originally Posted by derby View Post
    Good point about the relative tire pressures to tire size and bead stretching force pulling the bead up from the rim, for those needing high tire pressures. Is the pulling pressure 1:1 rate to tire diameter, same rim width?

    Yes, agree, bead hooks are only useful with an inner tube and higher pressures, or tubeless only if UST bead or TR bead with UST rim.

    I time time will soon tell. The Specialized hookless rims are not UST. They are pretty light in weight. I imagine many will use them with light 2.0 tires and higher pressures than 32 psi for XC racing, tubeless and with tubes, repeating failures would be broadcast soon. Although Specialized probably did test with high pressures before investing major dollars in these rims.
    Derby: Right a big company needs a lot of tests to produce something!! so like u said the hook only works with high pressure like 65psi!! I'm in XC racing and use 24 psi not 30psi hope my sworks tires won't blow off the rims in the downhills

  22. #22
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    here is a great review about the 2013 hookless roval control 29 wheelset check it out

    Specialized Roval Control 29 Carbon Mountain Bike Wheels, Tested | Bicycling Magazine

    and I love this part:

    "I dropped tire pressure down as low as 16 psi on one ride. Even with so little air, the tires remained stuck to the rims and didnít burp. After the snow melted, the trails bared their teeth again and I continued to run low pressure (about 18-22 psi), but I never flatted and the tires never flinched. After weeks of hard riding, the rims emerged without cracks or dents."

    and here is a review from here mtbr!!!!!

    2013 Specialized Roval Control 29 Carbon Wheels for $1200 | Mountain Bike Review
    Last edited by andresco50; 08-17-2013 at 02:56 PM.

  23. #23
    mtbpete
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    andresco50. The bead hook was not designed to secure the tire at low pressure, it is strictly designed to keep the tire from blowing off at higher pressures (and even there you will find a limit), so go as low as you can. You will know the pressure you are running is too low if you dent your rim, or burp air on bumps or hard corners or feel the tire folding in corners.

    Even without a bead hook most modern tires will never blow off when inflated under 35psi and many will go much higher before blowing off. The bead hook then becomes just added weight so specialized removed it and other brands are making theirs smaller.

    Unless Specialized changed the inside of their rims tires do not inflate nearly as easily on them as they do on stan's rims. I good functioning rim and tire combination will allow you to inflate the tire with a floor pump. If a compressor is necessary it's not an ideal setup.

  24. #24
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    obviously the materials/ strength is different but if a street bike can use hook less rims i think we can get away with them with a properly designed tire on our bicycles.

  25. #25
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    Bead hook-less rims, are they the future?

    Quote Originally Posted by b-kul View Post
    obviously the materials/ strength is different but if a street bike can use hook less rims i think we can get away with them with a properly designed tire on our bicycles.
    Agreed, but current performance tires are not designed for hookless bead rims.
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