Tubeless wheels have been around for quite some time now. The early hype has been replaced with a slow, steady growth led by vocal support from those that have made the swap. On the wheel side of things, more and more companies are offering tubeless-specific wheelsets, but not until American Classic’s unveiling of their new tubeless wheelset at Eurobike last fall did someone really push the envelope.
Wheels are highlighted by American Classic’s new Black Uppercut styling with white hubs. The black and white theme is distinctive and stands out nicely on the wheels. They just look plain good.
For the most part, tubeless wheels have been sturdy, day-to-day oriented wheels. The true performance wheel hadn’t been made. The rims were solid, but lacked in some imagination.
You can guess that I’m about to say that American Classic has done something different. I don’t want to get too superlative-y, but I’m going to flat out say from the beginning that I was impressed by these wheels, so much so that I hope to get a second pair, so that Ashley and I don’t have to share.
Back to the story and the finished product – then we’ll take a closer look. Bill Shook created a aluminum tubeless wheelset with a newly designed rim shape that tips that scales at 1179 grams. 1179. While it is marketed as a race day wheel, I’ve found it impressively capable of enduring day-to-day abuse.
So What’s The Big Deal?
The rim shape, that’s what.
American Classic’s new rim design allows for tubeless and traditional tube and tire pairings. According to Shook, it’s a superior design, and one you should expect to see more of in the future. I’ll let Bill take it from here…
“If you look inside the rim at some point you will see the distance between the hook and the bead seat is very short. A lot of people see that and think the rim is a smaller diameter, but in fact the rim is the same diameter as any standard rim. It’s just that the bead seat is larger. The tires fit tighter. The bead has to stretch more before it pops into place. Then there is a shelf that supports the bead and centers it. This is the proper way to design a rim. If you look at car tires or car rims, motorcycle rims, even wheelbarrow rims, they don’t try to center the tire on a hook like a bicycle tire. That is a crazy thing to do because it will never really center. Not really. You force it up a cone and on to a shelf and yes, it really will center perfectly. Every other kind of tire in the world, except bicycles, does that. It forces the casing out of the rim a little bit further. The extra width on the rim and the extra bead seat diameter, you are able to use a tire that is rated a 20 and on our rim it will measure a 23 or 24.”
On the tubeless side of things, the result is a rim that creates a sealed environment to hold the liquid sealant without burping. I’ve heard a lot of stories about this phenomenon, but have yet to experience it myself, and with this rim shape, I highly doubt that will ever be a problem.
Ashley is a much better model than I am.
Wider Is Better, Duh
The rim width on the wheels is 22 mm. At this point, a wide rim doesn’t seem like news, as it has been adopted by many of the leading wheel companies and those that haven’t adopted it yet, likely will very soon. It should be noted, however, that American Classic were at the forefront of this.
“We were the pioneer for wider clincher, performance rims. The Hurricane was our first – it’s 22 wide. After that our Magnesium rims were 22mm wide. We have had 22mm wide road rims for quite a long time. We have been pioneering this, and it is sort of a discovery that other people have made recently. ‘Hey! This actually works and it actually supports the tire better!’ I have found is by using a 23 rated tire on the wider rims, you can corner a lot better. You can rail the corners. It takes that tire and supports it so you aren’t floating around and gives you a much better control and contact patch. You can corner that much better. It’s amazing. Performance-wise, we can lighten up the tire considerably by downsizing the casing, if we want to. The other option is to go with the same casing size, and get better cornering performance. When you downsize the tire, you do not downsize the rolling characteristics. The wider rim spreads the tire out. If you were to ride a 20 on a standard rim, you would start to notice a degradation in the performance. They just don’t roll as freely. That starts to go away about 23. That is why that is the chosen size for most tires. It is wide enough that you get the lower rolling resistance and it is the best compromise. A 23 rated tire is not a 23 on all rims. A 20 rated tire is not 20 on all rims. On our rim is it more like a 23 or 24.
They Aren’t Aero, But…
The Tubeless rim is only 21mm deep, but employs an almost half-circle round profile, which strengthens the rim quite nicely, but also helps cut a better swath through the wind. This is no wind cheating wheel by any means, but it’s also not your traditional box section rim either. They feel marvelously quick to spin up to speed (of course, at only 1179 grams), but roll well at speed, which is a very nice, unexpected feeling with such a low profile rim.
The rim shape is a bit different that normal – it’s not a box section rim, it’s not an aero rim – it’s a kind of semi-circle, if you will.
“The reason for that is to give it a kind of stiffness. Torsional stiffness. It is more like a tube. If you think of it in engineering terms if you find where the center of gravity is or try to increase the inertia on the cross-section of the rim, at the same time reduce the mass, what you end up doing is trying to move the mass as far away from the center as you can. The perfect shape is a tube. The thinner and further you get that material away from the center, the stiffer it gets for the weight, mass. That ratio of mass to stiffness is what you’re fighting all the time. What I have done is use more of that tubular shape to try to gain stiffness without increasing the mass. It is almost like a semi-circle. That successfully made the rim stiffer and lighter.”
A Pretty Good Trick
Moving away from the rim, we center our attention on the spokes. The rear wheel uses only 24 spokes, which isn’t that notable, but the lacing is: 16 drive side, 8 non-drive side.
“We have done it before. We have been doing that for quite a while now. The theory behind that is that I’m trying to stiffen up the read wheel without increasing the number of spokes. I realized that the limiting factor on the rear wheel is the disc angle on the drive-side spoke. It is a nasty situation. You have to get all ten or eleven gears in there, and it pushes the spoke angle to be so steep that you don’t have a lot of power to keep the rim from flexing side to side. You can only tighten the spokes so much. You have to loosen the non-drive spokes to keep from pulling the rim out of dish. You’ve got all the drive side spokes doing all the work. The non-drive side spokes just go along for the ride. Just sort of doing the balancing act to keep the rim on center. A lot of weight not being used. By going to a pattern where I have two spokes on the drive side opposed to one spoke on the non-drive, and then adjusting the position of the non-drive side flange so that the force vector on the non-drive side is twice the force vector on the drive side. If all the spokes then are the same tension, it’s a balanced system. I have two force vectors on the drive side opposed to one force vector on the non-drive. the two on the drive side are half the one of the non-drive side. It is completely balanced when all the spokes are at the same tension. Did you follow that?
Let me back up. There are 24 spokes on the rear wheel. The rear wheel is a stiff as a 32 spoke wheel. Here is the reason why. On the drive side I have 16 spokes. The same as a 32 spoke wheel. That is why the drive side is the same stiffness as a 32 spoke wheel, but on the non-drive side I only have 8 spokes. Those 8 spokes have to do the job of 16 spokes on a 32 spoke wheel. What I have done is increase the bracing angle so that they have more power. One spoke with an increased bracing angle can do the job of two spokes with a reduced bracing angle. The bracing angle, since I can move that non-drive side flange where ever I want, I chose to put it where the tension in that non-drive side spoke will be equal to the tension in the drive side spoke. I adjusted the bracing angle to make it so.
Now all the spokes in the read wheel are equal tension. The wheel is as stiff as a 32 spoke wheel, but it only has 24 spokes. That is not a new trick. Ford Model A’s have spoked wheels with a 2:1 lacing pattern also. For the same reason. They had to deal with a bracing angle difference. It’s an old, old trick, but boy does it work. We applied it to the bicycle wheels. We did that a number of years ago with the 420’s, and it really worked great.”
Traditional spokes are the order of the day here – easy to tune, easy to replace. They do the job, and they do it well.
Return To Disco
Beyond the fact that the wheels are absurdly light, the first feature of the wheels that caught my eye was the braking surface. Braking surface is different than most that you’ll come across. It doesn’t have the typical machining. Shook comments on this but starts first with – how old are you? Somewhat taken aback, I respond – 29…
“You have to go back further than that to find brake surfaces like that. It starts life as just raw, anodized aluminum. We did not cut the brake surface. It is very difficult to make an absolute minimum rim thickness, then you have to cut the brake surface on it, it is uncontrollable. You will leave thickness variations behind. I chose to not do anything to the brake surface and leave it as-is. We anodized the rim silver. The anodization will wear off very quickly and then you will be down to the raw aluminum. That is the way rims used to be, back in the ’70’s. That is what we had. We had colored rims, but it was all colored anodized and the brake surface was also anodized and that colored anodized would wear off very quickly, but unevenly because the spoke tension would make stiffness difference between the spokes. It would wear off more quickly at the stiff spots. That will happen with that rim too, but it won’t change the braking characteristics at all.
Indeed, the smooth braking surface works just fine. What more can I say about a braking surface? I apply the brakes, the bike stops quickly. Thumbs up!
To The Center Of Things
I’ll admit it, I’m not much of a tech guy alongside someone like Charles. I know what works, I know what I like, but I don’t know the innards of everything I touch. I do know that I’ve always found American Classic hubs to be excellent, long lasting, and super smooth. Bill, bless his heart, helped me out with a little lesson on the inner workings of his special hubs.
The cassette body is American Classic’s tried and true…
“We have a steel-faced cassette body. The gears don’t chew up the lightweight aluminum cassette body. We have our cam-actuated six pawl drive mechanism to make sure that all the pawls work every time. That is unlike all of our competition. We are the only ones that can do that because it’s a patented system.” Many pawls engaging at the same time – that’s a good thing – especially considering that other pair of nameless wheels where I destroyed each and every one of the pawls.
“We also use a split-sleeve technology to fasten the bearings securely onto the axle and still be able to adjust the bearings. All other manufactures have to make a choice: if they want to adjust the bearings, then they have to be able to move on the axle. What we have found is that this is not really a good thing because then the bearing races will squirm around on the axle and shorten the bearing life. It is probably better to fix the inner races on the axle. For most people that means giving up adjustability, but for us, what I did was create a split-sleeve. It’s like having two bushings with a giant spring in the middle. We were able to crush it enough to be able to adjust the bearings. It puts out so much power that it really does fix the inner-races of the bearings on the axle so they don’t move around under load. It increased the bearing life tremendously. It reduced rolling resistance.
All of those technologies are in that rear hub. Plus, more. There is so much hidden technology in there that is just good, solid engineering. Using vices and shapes that work right. It is a very lightweight hub. 205 grams for the rear hub. It really, really works. They hold up a long time.”
The white hubs with black logos are appealing when you look down while riding. It’s not something that one normally gives kudos to in a review, but I like the look, so I’m giving it a thumbs up.
From this chat – I took away – long-lasting, high quality, adjustability and light from that conversation. On the road, I didn’t notice a thing other than silky smooth and a really quiet, soothing click whilst freewheeling. That’s what I want from my hubs – light, smooth, sturdy, long-lasting, and a good tune to enjoy when not pedaling.
A Wheel For The Future
Mr. Shook takes the mic…
I was really thinking into the future of what tubeless could and should be. On the mountain bike side it started with the UST tires that are thick in order to be air tight and heavy, and as a result don’t roll extremely well There is a lot of internal friction in the tire, and it’s heavy.
Then people sort of rejected those in favor of the tube type tires and started putting sealant in them. Then there is always the race for making it lighter and putting sealant in it and make it work. That is true to a point, with mountain bike tires, and it works with mountain bike tires because they are lower pressure. The real racers are using lower pressure to get traction and they are using very, very lightweight tires so that they don’t consume a lot of energy when they are flexing. They are looking for very supple casing that don’t have a lot of internal friction when they are being flexed. They are depending on the sealant to do the job of the tube or sealing the tire. For the most part it works very well on the mountain bikes. Looking at this and seeing where we are currently with the road bike side of things. It is a little different with road bikes because we absolutely need higher pressure to get the rolling resistance down. When you do that, the beads that are provided for tube type tires are inadequate. They stretch too much and the tires will pop off the rims. In order to run a tire tubeless, you have to have a tubeless specific bead on the tire. For road that is a big difference.
Shook thinks that tubeless tire technology is still only in its infancy – someday, these wheels will be even better when they get an able rubber mate.
It is also theoretically possible to make a very lightweight tire with an adequate bead for tubeless application and run it with the liquid sealants without a tube, and reduce your weight by eliminating the tube and reduce the rolling resistance because you haven’t got a tube. That is what I’m thinking. That probably is the future of high performance tires. I’m building one of the first rims available to support those new, high-performance racing tires that don’t exist yet.
Having said that, where are we with the road tire development? I’d say we’re still back at the UST stage, where all the road tubeless tires are going through the same growing pains as the original tubeless mountain bike tires. They are all back at the UST thinking stage where everything is heavy, air tight, it is going to be aired up once and for the rest of its life has to hold air, because you know darn well the consumer is never going to put air in it again. It has to last a billion miles. It is not high performance thinking. Unless your performance definition is different. For racing, for ultimate racing performance, you are willing to take some risk as far as flats go to gain lower rolling resistance and lower inertia. So that you can, in fact, increase your competitive advantage. It is always this tradeoff. How scary light can you go and still finish the race?
They haven’t gotten there yet with the tires. They are still back in the fumbling around stage that the mountain bike tires went through. They will catch on eventually. I have provided a platform for the tire makers to start to work with. In the past it has been “Well, the tires are heavy. Why make a super lightweight tubeless ready wheel? For what tire?” Somebody has to take the first step.
And that’s a step American Classic have taken with these wheels – an impressive one.
Getting The Wheels Ready For The Road
Going with a tubeless setup brings in some new requirements – tubeless tires, tubeless sealant, and the mounting process. It’s not just tire, tube, inflate.
Shook highly discourages using tire levers on the rims. All tires can and should be mounted entirely by hand. Shook recommends scrubbing the tires with soapy water. Finding it too slippery? Throw a towel over the top and roll the tire on – does the trick just fine.
Valve stems are an important part of the tubeless setup – bad valve stem, no chance at holding air. American Classic has made their very own – they look good and work just fine.
Wheels come with American Classic’s new rim tape installed (nice plus!)
They even poke the valve hole for you.
Armed with the knowledge that this would be a job best left to my hands, I headed straight to the bike shop. I do not trust myself with bike things.
I opted for Stan’s NoTubes sealant. It’s the industry standard, and it works great.
Hutchinson has been at the forefront of tubeless tires so far, so it didn’t take much coaxing to go with their new all-around Fusion 3 tires. They were a bit hard to start with, but some road time has softened them up to a very nice point. I like the road feel very much with these tires.
Just put in the valve, screw in the top, put your tire on…
Clean, tidy, works great.
The tire mounting process was pretty easy. It was especially easy for me, because I went to my local bike shop, The Hub in Athens, Georgia, and had Patrick put his iron thumbs to work. Easy.
Getting the tire to seat on Shook’s special rim shape took a little extra doing, but let me emphasize LITTLE. I found that pressurized air worked best. Put some in, let part of the tire seat, take it out, put it back in, back out…until after a minute or two of working on it, the tire seated perfectly, and there it has stayed.
Add sealant…rotate the wheel a bit, let it sit, then go!
The wheels have been rock solid so far. I was warned that I shouldn’t be too ruthless with them, as no matter how you slice it – they’re sub-1200 gram wheels.
To the touch, they’re almost unbelievably light. I’ve never touched an aluminum wheel that weighed so little. It’s disconcerting at first. Of course, I passed them around to everyone within arm’s reach, and since I did most of this at a bike shop, they passed through a lot of hands, all with the same reaction – whaaaaat? That’s crazy!
It’s hard not to think of them as fragile. I’m particularly mean to equipment, and I’d say I can apply a reasonable amount of force to wheels, so I wasn’t holding my breath on the wheels riding in noodle-like fashion.
Shook admits as much and says that, understandably, the wheels require a slightly delicate touch.
“This is the ultimate lightweight aluminum high-performance rim. It is extremely thin. To the point of almost being fragile. If it’s treated properly, it is not a problem. It gets its stiffness from the fact that it is sort of a larger diameter and very, very thin walls. You have to be careful not to dent those thin walls. It’s sort of like a bike frame. You can make bike frames very, very stiff and lightweight, but the tubing gets very thin. It’s stiff and lightweight and high-performance, but you have to take care of it. You can dent it.”
When you say take care of it – what do you mean? “Be a little more careful with it. You can’t throw it around or press tire levers into the side of the rim because it will dent it. You’ve got to be a little more gentle with it. In order to get that weight down, it is thin and it is a little more delicate. It is very, very lightweight and as a result it is very high-performance.”
This made me a bit nervous, and while the rims do feel delicate, I can assure you, they’re plenty sturdy.
I was distinctly surprised and happy to find the wheels plenty sturdy. I got the wheels right around the New Year, and I had two months of hard riding to put them through their paces. I rode about 140 hours and did a bit over 4000 kilometers in that time. Of that total, at least 500 kilometers were on dirt roads.
I tried to be gentle with them, but when I get to training, everything becomes a tool, no matter how awesome the piece of equipment might be. I reverted to my typical harsh ways with my bike and wheels, and the wheels came out the other side in perfect condition. This includes the hole in the earth I hit around the midway point in the testing – I thought I might fall through the earth to Mongolia on the other side. It was an impressive whack…but no problems at all.
Making The Switch Tubeless
A lot of positives are cited as reasons to run tubeless – lower rolling resistance, lower tire pressures, no more pinch flats, etc. For me, it’s all about flat protection and the ability to run lower tire pressures. I ride my bike a lot. I ride my bike a lot on bad roads. Ergo, my rides are typically bumpy, and I flat a lot. Typically, when I’m hitting the dirt roads pretty hard, I’ll flat at least once a week.
This being me, I somehow managed to flat a tubeless set-up. I had run tubeless for many thousands of kilometers before these wheels but never flatted – not once. This was one of those moments where there was little doubting it though – I managed to nail a large rock, right along the sidewall. I flatted on a particularly nasty stretch of gravelly dirt road and finally got a chance to enjoy the magic of tubeless. I thought that might be the end of the tire, but thankfully for me (and much to the chagrin of Shook), tubeless tires are sturdy.
I rotated the wheel so that the sidewall puncture was at six o’clock and waited…a couple minutes later, the significant, hissing puncture was sealed. I added some air, and away I went.
I suffered some lesser punctures as well that didn’t even require a re-pumping or a few moments to re-seal. I pulled a staple right out of the tire at one point with no ill-effects.
Being able to ride at lower pressures is a welcome plus if you’re spending hours and hours on the bike. It might not be the fastest, but if it’s just you out on the road collecting hours, kilometers, miles, tiredness, fitness, whatever – why not enjoy a cushier ride? Being the experimentalist, I’ve run the tires between 50-110 psi with no problems. Of course, 50 is a bit low, but I wanted to try it anyway. Just because I could.
The wheels are understandably quick, but in two particular areas, I found them surprising – at speed and in corners. The rim design and its bulbous shape gives that little bit of extra zing in the fast moments, but as I’ve mentioned a lot – these rims are light – so I was a bit nervous about really hitting them hard through turns, so of course, I did. They were quite nice.
“I think that’s 20 mm rim. Some people have tried to make rims lighter by taking depth away from them and what happens is that they get very compliant. Even if they maintain the width, they become too compliant and they are almost scary in a corner. The rim will flex too much. You go into a corner and it will understeer, understeer, and then catch and oversteer. When the tire digs and catches and then the rim instead of being flexed out and goes flexing in to the corner and you’ve been pushing trying to get it to corner harder because you are not going where you want to go and then all of the sudden it catches and bites. You are trying to make that correction fast enough so that you don’t high-side it. It can be scary. Those rims don’t do that. They are stiff enough.”
They are indeed – more than stiff enough, plenty durable, incredibly light, smooth riding…these are my go to wheels for pretty much everything but the cobbles of Flanders.
24/24 front and rear spokes
519 grams front
660 grams rear
1179 grams total
Rim width: 22mm
Rim depth: 21 mm
Rider weight limit: 200lbs/91kg
MSRP: $US1399.00 dollars
For more info – head over to www.AMClassic.com!