Jim’s Tech Talk
By Jim Langley
We’ll get to the main topic in a minute. First, I want to point out a few more tips about chain cleaning and waxing from last week’s comments since waxing is such a popular practice. We spent the last couple of Tech Talks on it actually.
If you missed them here’s part 1 and 2: Product Review: Effetto Mariposa’s Mangiacatena Chain Cleaner Tool & Allpine EXTRA Biodegradable Chain Degreaser and Game-Changing New-Chain Cleaner & Waxer From Silca.
First, a tip of the helmet goes to reader Ron Neher who was kind enough to provide a link to a thorough document he prepared on his process of cleaning and waxing chains. Ron uses an ultrasonic cleaner. I especially enjoyed his process flow chart. He also provides links to places that will provide the cleaning and waxing for you.
Next, reader Harvey Miller asked how MSpeedWax compares. I have not tried their wax products so I don’t know. But it’s helpful to hear about other companies providing wax, chains, quick links, ultrasonic cleaners and knowledge about waxing. As far as I can tell they do not sell a kit like Silca’s cleaner & waxer.. yet, anyway.
Then reader Rick Ankrum pointed out that Cyclowax does have something resembling Silca’s waxer with their Cyclowax Chain Starter Kit. It comes with a wax pot and chain hanger similar to the Silca’s yet Cyclowax does not have a treatment to turn factory chain lube into a wax compatible lube the way the Silca system works.
And I can’t leave out eagle-eyed Brian Nystrom who shared “I found what appears to be the same melting pot that Silca sells on Amazon for less than $30.” Here’s the link: https://amzn.to/3SV9UDq
It’s great to have more waxing resources and knowledge! Thanks Ron, Harvey, Rick and Brian!
This Week’s Big Story on Hookless Rims
If you follow pro road racing, you probably saw the headlines about Thomas De Gendt’s crash at the UAE Tour, which was initially blamed on a tubeless tire blowing off of a hookless rim. He was riding a Zipp wheelset with Vittoria tires. The Zipp rims are a hookless design.
As a result of this accident the governing body of cycling, the UCI are investigating the safety of hookless road tubeless rims. The whole thing is quite an uproar and I thought it would be good to go over some basics of hookless tubeless rims especially if you’re concerned about yours.
Two Types of Rims
In case you’re not familiar with the terminology, there are two basic types of rims in common use today, ones with bead hooks and hookless ones (without bead hooks).
Rims with Bead Hooks
Hopefully you can see the shape of the walls/sides of the rims in these photos. The first shows a rim with bead hooks. A bead hook is shaped like a P with a rolled edge at the top (on the right rim wall/side the P would be reversed with the bump facing in). The beads molded into the sides of all tires sit below the rolled edges that form the bead hooks.
The bead hooks and tire beads work together to help keep tires on rims. This system came out as a result of issues with some hookless rims not holding tires on the rim. That was in the 1970s when hookless rims were common and way before tubeless tires came along.
Hookless Rims
With the introduction of tubeless tire technology, the industry returned to hookless rims, which are easier to manufacture. Plus they’re improved over the hookless rims of old and designed for use with tubeless tires.
The difference between rims with bead hooks and hookless is that the latter have straight walls/sides, there’s no hook at the top. Hookless rim walls/sides are straight. With modern hookless rims the thing that keeps the tires on is a proper fit between the tire and rim.
What makes it work is the tire’s diameter matches the bead seat diameter of the rim, which is a significantly smaller diameter than the rim’s largest diameter. So the tire would have to find a way to expand or stretch in order to come off, which can happen with a sudden loss of air if the tire goes into the middle of the rim (the smallest diameter).
For further reading, here’s a nice article by Enve Components about hookless tubeless rims.
What Actually Happened to Thomas De Gendt’s Wheel?
According to Vittoria, the tire blowing off the rim was caused by De Gent striking a rock and breaking his rim. That would definitely explain how the tire could come off because it would be a sudden loss of air and sealant, which acts as a lubricant when tires come off.
My Take on It
I worked for a company that designs and manufactures road and mountain hookless rims in aluminum and carbon. I set up many tubeless tires on these rims for my own bikes and for everyone working there, plus many of our product testers.
Six years ago I wrote a story about the only blow-off incident I experienced with our rims. What caused that failure was over inflation. Due to faulty reasoning, I put 90 psi in a tire designed for 75 psi. You can read about the sonic boom and my hearing loss as a result here: https://www.roadbikerider.com/overinflation-explosion-a-cautionary-tale-about-very-wide-tires/.
Two Absolutes with Hookless Tubeless Rims and Tires
Know Your Pressure and Never Over Inflate
Suffice to say that it was a huge mistake to over inflate the tire. And that’s one important rule with hookless tubeless rims and tires. You have to know what the maximum recommended pressure is and stick to it, never exceed it. This means having an accurate way to inflate tires and doing the research to find out if the tire and rim specs aren’t printed on the tire and rim.
Only Run Tires Compatible with Your Hookless Tubeless Rims
The other thing with hookless rims is that manufacturers often provide a list of specs for tires to use with their rims. You want to choose a tire that is sure to work with that rim. For example, here’s how Enve handles it: https://enve.com/pages/tire-compatibility.
Summing Up
I understand that the UCI is acting in the interest of rider safety, which is a good thing, but I don’t believe the hookless rims were to blame for De Gendt’s crash or the tire blow-off. And apart from my mistake of over inflating a tire on a hookless tubeless rim, I haven’t experienced issues with the rims on my own bikes or on customers’ bikes that I could blame on the rims. So to answer my question in the title, I don’t believe there’s anything to be afraid of with hookless tubeless rims.
Your Turn
But, it would be interesting to hear what you think and what you’ve experienced with hookless tubeless rims. Please share your thoughts, tips and stories in a comment.
Jim Langley is RBR’s Technical Editor. A pro mechanic & cycling writer for more than 40 years, he’s the author of Your Home Bicycle Workshop in the RBR eBookstore. Tune in to Jim’s popular YouTube channel for wheel building & bike repair how-to’s. Jim’s also known for his cycling streak that ended in February 2022 with a total of 10,269 consecutive daily rides (28 years, 1 month and 11 days of never missing a ride). Click to read Jim’s full bio.
Peter Wimberg says
I have ten road bikes and I’m not using tubeless on any of them. I ride 12,000+ miles per year and given the free number of flats I found the tubeless tires and rims just another hassle in what should be a simple cycling world. I can replace or repair a tube in minutes. When I did have a bike with tubeless tires and flated, it was a long walk or call for a ride. And that sealant is a pain in the you know what to deal with. I’ll leave well enough alone and use tubes.
George Straznitskas says
Our stories are exactly the same Peter. (Was beginning to think I was the only one)😉
Curtis Potter says
Same for me. I was an early adopter of tubeless MTB tires and really I liked them. I tried it on my road bike and found that I got the same number of flats as with tubes. The difference was the road tubeless would seal at 30 lbs pod pressure and when I aired them up to finished my ride they would leak until it got back down to 30ish lbs. in goes the tube and I finish my ride then I have patch the tire remove the tube until the next flat. I gave up and went back to tubes. I would rather not spend my time messing with a tubeless road set up. I do run tubeless on my gravel bikes, it works much better because of the lower pressures.
Aaro Paavo Heinonen says
My story is the same, except I never even tried the tubeless because so many people I rode with had the flat, then called for a ride after trying to fix it for 30 minutes. In addition to leave well enough alone, I still prefer 15mm inner width of my hooked rims and use 23c tires, which of course, usually measure 24 to 24.5. I have too many wheels and bikes to mess with disc squeaks and expensive parts. Been cycling a long time, rarely flat and can change it with out tools. Nice simple world of cycling. Ride on.
syborg says
I’ve used tubeless on road bikes with 23mm – 32mm tires. My findings are that going tubeless with high pressure, low volume tires is a crapshoot. For me, 28mm is marginal and I’ve had good success with 30mm and 32mm. I like to ride 32mm with ~45psi in front and ~65psi in the rear. I have no problems with the tires sealing with this combo.
YMMV depending on the tire volume and the pressure you use.
Bruce Lulu says
32 mm does seem to be the road sweet spot. Some of the top end road (not gravel) bikes can fit a 32.
Robert Ray says
Agreed. I went tubeless for a couple of years and have switched back to tubeless. Tubeless is messy, when you have problems, and you will, it becomes a much more difficult problem to fix. Most of the tubeless tires require pumping before each ride. Sealant plugging the valve is also common, etc. Just not worth the hassle. Tubes work fine.
J Mokhtar says
“So to answer my question in the title, I don’t believe there’s anything to be afraid of with hookless tubeless rims.”
This is true only if the two absolutes you mention – never overinflate and only run compatible tires – are adhered to.
Therein lies the issue.
1. Nothing is stopping end users from making the faulty decision you made regarding inflation pressure.
2. Nothing is stopping end users from installing tires that are incompatible with the new hookless rims they just spent thousands of dollars on.
Until all rim manufacturers, tire manufacturers and retailers actively educate their customers about the two absolutes you mention, and this requires more than just an online compatibility list, there will be safety issues with hookless rims.
Rex Brewer says
I agree with J Mokhtar above, over inflation and incompatible tires may create safety issues. I strongly prefer the firm connection of a hook bead tire securely held on by a hook bead rim, where tire fit and tire pressure don’t need to be exactly right to keep the tire on the wheel. There’s a lot more room for inevitable errors and unforeseen circumstances with a hook bead tire and wheel.
BigBob says
Cycling is an inherently dangerous activity; doesn’t the rider bear some responsibility for ensuring he/she is operating their equipment within manufacturer’s guidelines and recommendations?
Brian Nystrom says
As you said Jim, hookless rims were common back in the 70’s and 80’s, and they worked just fine with the 90 psi 1″ (25mm) and 1 1/8″ (28mm) tires that were available at the time. There’s no reason that they shouldn’t be completely safe now. My understanding is that hookless rim beads are substantially stronger than hooked beads and much less prone to impact damage, plus they’re often lighter. That seems like a winning combination.
John C Tonetti says
I have seven bikes I ride regularly. One has the tubeless/hookless combination. I run it at a pressure I wouldn’t have believed possible a few years ago (PSI 58F/60R). I’ve had no problems with these wheels. But TBH, I think tubeless is a bit of a solution in search of a problem. I’ve had no issues with tubes, and like Peter (above), I find changing a tubeless tire is a much bigger hassle and almost creates the same type of mess for which I abandoned tubulars years ago.
Bob says
As a recreational cardio training cyclist I can’t think of any meaningful advantage to me of hookless rims. My basic TCR is set up tubeless and I ride it that way with tubeless Continental 5000 tires and it works well. I’m not looking forward to my first road flat. My cheapo Florida bike, I run with cheaper Continental 5000s and latex tubes. Since I learned to reduce the pressure after every ride the flat’s I was getting from poor manufacturing/design have stopped. Why I should accept the risk from hookless I don’t know. Good tires make both bikes dramatically better to ride
Richard Handler says
Both failures were with 28mm tires mounted on 25mm internal width rims which cuts the margin of safety and violates rules, depending on which set of rules you read.
Albert Dalia says
I’m wondering if hitting a rock with hooked rims and tubes would have resulted in the same catastrophic failure that De Gendt experienced.
Kerry Irons says
Jan Heine of Rene Herse Cycles has a really good article about hookless rims and tubeless: renehersecycles.com/journal/
Jim Langley says
Thanks a lot for the link Kerry. I missed that one. Jan covers a lot of ground – great to read. Thank you!
Jim
Rich G says
Jan Heine is selling tires.
Bruce Lulu says
He sells many things related to bicycles, some items made to his specifications. He is a mechanical engineer who has contributed to the renaissance of classical steel bicycles. Also an owner of many bicycles: steel, carbon, titanium,…aluminum rims, carbon rims (hooked and hookless). Worth reading,
Rich G says
The point is a simple one: As much as Jan Heine has contributed to the discussion about tire pressure, he is not disinterested. He has written pieces advocating for hookless rims. These benefit his business. Always think about the incentives someone faces when they are expressing an opinion, especially an opinion that could benefit them. I will never buy or knowingly ride hookless rims. The benefit is de minimis; the potential for a bad outcome might be small but could be catastrophic.
Reed Hart says
I run tubeless on my gravel bike (38’s) and road bike (32’s). Advantage is that low pressures enabled are sooo comfortable. Never flatted, but did have a sidewall hole that sealed well enough to ride home and replace the tire. Road Bike has hookless rims. In hindsight I probably would have bought hooked cause tire choice is somewhat limited, but with pressure in the low 40’s have no concerns about blowouts.
Don Haller says
I believe there are so many hooked rim designs and manufacturers to choose from other than ENVE and ZIPP, that there is no real reason to use their options (at least for me, that is). I also agree that I’d rather not be bothered with the whole tubeless/hookless hassles. I changed over to TPU tubes on my good ol’ hooked carbon rims and they work perfectly for me.
Peter Anthony Wimberg says
I agree that riders have to be responsible for their gear being in working conditions and set to the specs of the manufacturer. That being said, I feel like the industry is for the sake of generting new sales continually adding unneeded updates. Disc brakes are good for some riding but for many the rim brake works just fine and requires much less maintenance. Same with this discussion on tubeless and tires. I’ll hit 400,000 lifetime miles in the next year with touring, racing, training, endurance miles, etc and I find no need for tubeless technology. I understand the off-road benefits. I don’t do any off road riding. Same with electronic shifting. I have it on Giant Trinity and Trek Speed Concept time trial bikes. I don’t want it on a ride through Alaksa. I think I’ve had one cable fail, ever. I’ve had electronic shifting fail in a race three times. Bikes should be simple, for the most part.
Moose says
This is exactly my attitude. I am frustrated that bikes are becoming harder to maintain. My road bike has rim brakes and Campy manual shifting, and it works. It can be fixed. And it will still work 20-years from now. A phone to adjust my derailleur settings – omg. I am not against discs or e-shifting. In fact, I readily concede that electronic shifting is both smoother and more precise and that the discs on my gravel bike are necessary to allow for the larger tire sizes (even if I don’t find any appreciable difference in braking). I understand the clear benefits of low pressure tubeless when I am off pavement. But when I am far from home I really appreciate the mostly on-the-road fixable clinchers, rim brakes, and cables that old school affords (tape a spare spoke to the inside of your seat post, carry an extra cable in your handlebars, and cash makes an acceptable tire boot).
Golden says
The thing that makes me a little nervous about the tire pressure requirement for hookless, is: what about when you get a flat, add a tube or patch, and then re-inflate your tire with a C)2 cartridge (that doesn’t have a pressure gauge on it)? It’s not that hard to over-inflate the tire in that case. I guess I could carry a little tire pressure guage, or try to feel the difference between the un-flatted tire and the repaired tire. Hopefully with the tubeless setup this is a rare occurrence, but stuff happens.
Dave Minden says
The Heine article Kerry referenced identifies that the main reason for hookless rims today is that making hooked carbon rims is expensive in the manufacturing process. When hooked carbon is made, it is actually stronger than alloy hooked. Having ridden hooked rims for decades without a single failure – and none among my friends’ decades of riding – I conclude hooked is very strong. Tubed or tubeless, it makes sense to me to use hooked rims only.
Bruce Lulu says
See Peak Torque’s explanation
He is a professional mechanical engineer and bike geek
https://www.youtube.com/watch?v=bAgxTdNIOhA&t=4s
Ian says
“Plus they’re improved over the hookles rims” In what way? The only advantage is increased profit margin. Some very good videos about this on youtube (engineer Peaktorque in particular) but anyone who thinks 15psi between maximum pressure and failure is an adequate safety margin does not understand good engineering practice.
Jim Langley says
Great question Ian. The biggest “advantage” touted by proponents of hookless is that the rim walls are stronger due to more material. Proponents say that it reduces rim damage issues seen with hooked rims when you pinch the tire/bottom out the tire hitting rocks, roots, potholes etc. an important advantage for mountain bikers and now gravel riders.
Thanks!
Jim
John C Tonetti says
I’m going to respectfully disagree. I’ve yet to see any tubeless tire or hookless rim manufacturer who doesn’t warn about tire pressures greater than 72psi. Fifteen pounds overinflation is an “error” of >20%… that seems to me to be more like an uninformed or willfully negligent user.
You can’t fix stupid, or engineer it out.
Bruce Lulu says
You can very easily exceed a 15 psi safety margin if you hit a bump, pothole or rock..
John C Tonetti says
I’m not sure I understand your argument, Mr. lulu. There are lots of things that can happen if you hit a bump, hole, or rock on a bike; most are not good. I’ve rolled off tubs in a corner, had catastrophic blow outs with clinchers, etc. I’m not sure the type of tire, matters, and running at lower pressure and wider would seemingly mean that the impact is spread over a larger area, and less likely to exceed the tolerance.
Bruce Lulu says
All things being equal, hooked rims have a much larger over-pressure safety margin. As PeakTorque explains, the only advantage of hookless rims is lower manufacturing costs.