What’s the point of larger and longer aerobar pads? Greater surface area means better weight distribution where your arms meet the pads. In other words – you’ll feel less pressure and less pain over long periods of aero-position-riding. There’s a limit for how far this extra length can extend rearward (i.e. closer to your body), because you’ll bang your knees into the back of the pad holders. So, bar makers placed the extra pad area out front, putting more material under your forearms.

Vision’s latest product in this category is called the TFE Pro, and we’ll dive in to the details.

The TFE Pro is made to fit the existing TFA and SI 013 aerobars, as an aftermarket upgrade.

If you know those bars, you’ll recognize the grid system above. This style of attachment is becoming more and more common, allowing for better micro adjustment in all directions.

The TFE Pro also allows for up to 13 degrees of angular adjustment. Combined with the stacking spacers of the TFA and SI 013, these bars can potentially turn an ill-fitting or wrong-sized bike into something that works for you (of course, consult a bike fitting professional to help do the math before plunking down your cash).

Large rubber inserts cover up the huge voids left by the bolt hole grids.

Are S-bend extensions dead? The newer ergonomic extension shape has become a favorite among Slowtwitchers and triathletes in general. Vision even claims that the TFE Pro extensions are 8% more aero than the stock TFA extensions, resulting in a 9.4 second savings over 40km (calculated with CFD simulations).

My measurements put the fore-aft length of the arm pads at 160mm. This is about 50% longer than typical pads, but less than some competitors with lengths of 200mm or more.

A slot underneath the extension allows for wire routing and management. We anticipate that most bikes using these bars will have electronic shifting.

Vision provides detailed measurements, including comparisons to the stock extensions that come with the compatible base bars. Three sizes are available – Small (265mm), Medium (285mm), and Large (305mm).

The TFE Pro Aerobar Extensions come in at a quoted weight of 360 grams per pair, and a US MSRP of $419.

FSAProShop.com

The post Vision TFE Pro Aerobar Extensions first appeared on Slowtwitch News.

Many high-end wheel companies now offer a product continuum for drop bar bikes, with an aerodynamic choice at one end, an all-rounder in the middle, and a gravel option at the other end of the spectrum. DT Swiss does this with their ARC, ERC, and GR lines, while ENVE’s system includes SES, AR, and G Series. The aero-focused choices typically have narrower and deeper rim profiles, fewer spokes, and a focus on light weight over maximum durability. The gravel-focused wheels have shallower and wider rims, more spokes, and beefier overall construction. The all-rounded wheels like the ERC shoot for a ‘best-of-all-worlds’ design, and are typically marketed for road bike use on pavement and smooth dirt.

DT offers the ERC line in two levels: 1100 and 1400. The 1100 level ($3,240/pair) represents the highest-end product, with light spokes and ceramic bearings in top-end 180 model hubs, while the 1400 level ($2,655/pair) opts for heavier spokes and steel bearings in 240 model hubs.

The ERC line includes 35mm and 45mm rim depth options at both price points. Both feature a 22mm internal rim width, up 3mm from the previous generation wheels. The 35mm rim can be had in 700c and 650b diameter, while the 45mm rim comes in 700c only. Complete wheel weights come in at 1,391g (ERC 1100 DICUT 35), 1,442g (ERC 1100 DICUT 45), 1,468g (ERC 1400 DICUT 35), and 1,519g (ERC 1400 DICUT 45).

Both rim models are fully tubeless compatible and feature bead hooks. DT Swiss appears committed to bead hooks, offering the following reasoning:

Thus far, the market remains mixed, with few manufacturers fully committing to hookless – at least for now.

DT Swiss prefers internal spoke nipples; a somewhat controversial choice. Internal nipples improve rim strength (because they require smaller spoke holes to be drilled), along with a small potential aerodynamic gain. The downside is that they make spoke replacement and adjustment more difficult and time intensive.

Wheel stability remains a huge topic for most wheel manufacturers. In short, they seek to design wheels that create minimal steering input (though, in my experience, this has less impact on handling than side force – which is mostly a function of rim depth).

DT offers the competitive analysis above, along with this explanation of their ERC wheels’ stability:

”The chart displays the steering moment of different wheels in Nm at yaw angles between -20 and +20 degrees. The closer the curve to the x-axis at any given yaw angle, the lower the steering moment, which results in a favorable wheelset.

Based on their respective weighted steering moments, the ERC 1100 DICUT 35 and the ERC 1100 DICUT 45 both feature a generally low and linear progression of the steering moment curve, as well as a smooth stall. All three characteristics combined benefit the rider with good handling and predictable steering behavior of the wheel under crosswind conditions.”

What about aerodynamic drag? DT offered the graph above, along with this analysis:

“The ERC 1100 DICUT 35, despite having the lowest rim height among the tested wheels of 35 mm, demonstrates the second lowest drag value across relevant yaw angles in weighted drag of 13.1 W and an improved drag performance of around 1 watt when compared to the next best competing product.

The ERC 1100 DICUT 45, with 12.2 W in weighted drag, distinctively displays the lowest base drag (drag at 0º yaw angle) of all tested wheels. Within the range of relevant yaw angles the drag performance of the wheel is better by around 2 watts when compared to the next best competing product. A late detachment of the airflow from the rim at a yaw angle of about 15º further shows its excellent aerodynamic behavior.“

DT opts for T-head spokes to reduce spoke twist and frontal profile, along with new 36t Ratchet EXP internals.

These are disc-brake-only wheels. Note that the 180-level hubs even remove sections of Center Lock splines to save a few grams.

DT includes tubeless valves and factory-installed tubeless rim tape. There are no restrictions listed on tire brand, model, or type (i.e. you can use any clincher tire you’d like, so long as it’s at least 25mm wide). DT recommends 28mm tires as the best all-around choice for performance and comfort.

We haven’t had a chance to ride the new ERC wheels yet, so we can’t share our hands-on impressions. I’ve had great experiences in general with DT Swiss wheels over the past 20 years, so it’s hard to expect anything less from these new offerings. The only downside big downside is price, making it hard to recommend the 1100 series wheels (at $3,200+ per pair) unless cost is no object for you. If I had the scratch, I’d likely opt for the 1400 model with 45mm rims and ~32mm tires for my local dirt roads.

The post DT Redesigns All-Rounder ERC Carbon Wheels first appeared on Slowtwitch News.

You might not know it, but Vision (the aero sub-brand of FSA) has been selling their own three spoke wheel for several years now. They currently sell it in clincher, tubular, and tubeless-ready versions. However, the most recent (and perhaps most noteworthy) update is a disc brake version. The only competition that we’re aware of includes a disc brake trispoke from Corima, and a 5-spoke from Xentis – both of which can be hard to come by in the United States.

How do you know if a three spoke wheel is right for you? Every manufacturer of such wheels that I’ve spoken to has expressed that they’re intended for professionals and top amateurs, riding at high speeds. I take this to mean that they perform best at low yaw angles and with narrower tires than us less-speedy folks might use (I haven’t received any explanation or direction beyond this from the manufacturers). This is neither good nor bad; it’s just the design intent of the product. In short, if you are in the middle or back-of-the-pack, a more typical wheel with metal spokes will likely be a faster choice for you.

Like most competitors, the Vision 3 Spoke has an asymmetric design, meaning that it must be installed to your bike in a specific direction. If you look closely at the blade profile…

…you can see that one edge is sharp, while the other is more rounded. And of course, since this is a disc brake wheel, there is only one direction you can install it… at least if you want the ability to stop.

As for the basic specs of the wheel, the tubeless clincher version we received is listed at a weight of 860 grams. It has an internal width of 18mm, an external width of 24.8mm, and a rim depth of 55mm. Vision also sells a tubular version weighing in at 723 grams. We received a front wheel only, but their website shows information regarding freehub compatibility – suggesting that they may be working on a rear wheel version.

Vision did not provide us with a minimum, maximum, or recommended tire size, but a warning sticker on the wheel states a maximum tire pressure of 103 psi (7 bar) with a 25mm tire.

The rim edges have hooks, and Vision doesn’t list any restrictions on tire brand or model (i.e. as far as we’re aware, you can run any clincher or tubeless clincher tire that you’d like).

Interestingly, Vision placed the valve hole near one of the spokes… perhaps to allow the protruding valve to catch a draft?

Our test wheel came with the Shimano Center Lock disc brake mounting system (their website also shows a 6-bolt version, though no available inventory). It’s interesting to note that you must unthread and remove the bearing preload cap in order to install your Center Lock rotor. Also note that it requires Vision’s lockring that’s specific to their axle design.

Vision also sent along their own 140mm Center Lock rotor (160mm is also available).

Vision carbon wheels include rim coverings. They're a nice touch intended to protect from scratches or other light damage when storing your wheels.

They also offer a more robust wheel bag for $81. It holds two road wheels, and includes a shoulder strap and internal pockets.

The Vision 3 Spoke Disc comes equipped with a 12mm axle. They also include a kit with 15mm axle and quick release end caps, covering all possible options currently available in 2021.

Just how fast is this thing? Vision provided the chart above to show drag savings, along with the following translation into 40k time trial performance (at 30mph average speed):

-Vision 3-spoke V2 with 23mm tire averaged 18.4sec faster than Metron 40 with 23mm tire.

-Vision 3-spoke V2 with 25mm tire averaged 16.8sec faster than Metron 40 with 25mm tire.

The Vision Metron 3 Spoke Disc Brake is available now for $1,339 (front wheel only).

FSAProShop.com

The post Vision Metron 3 Spoke Disc Brake first appeared on Slowtwitch News.

Slowtwitch: How was your year in 2020, dealing with the pandemic and all that it brought? What was the toughest aspect, and were there any silver linings?

Chris Leiferman: I think I fared a lot better than others. It gave me an opportunity to work on other aspects of my fitness as well as tinker around on the house. The toughest aspect was staying relevant, as an athlete to the social media crowd, but the silver lining is that I got to go camping and hang out with the family more than I ever get to do in a normal race year.

ST: Describe your back-to-back wins in Florida at the end of 2020.

CL: It was a pretty good feeling! To be the only one winning an Ironman in North America was huge! Definitely a good way to have made something out of nothing during 2020.

ST: You joined the BMC team in 2018. What is it like being part of a team?

CL: It’s amazing! Team BMC has been around for years and they have solidified the best brands in the world to sponsor the team. They take really good care of us and really leave it to us to just train and compete. Bob and Ben are fantastic managers and their credibility is something that is known around the industry.

ST: Do you have any big changes in 2021 with your equipment or bike position?

CL: I would like to work on my position and I have already made changes to raising my extensions higher and bringing my head lower. I think cleaning up my front end will make a big difference for me.

ST: Will you do any wind tunnel testing this year?

CL: I would love to. I will have to reach out to a tunnel or velodrome myself in order to make it happen.

ST: Are you on rim brakes or disc brakes this year?

CL: Disc brakes. BMC has really dialed their TM01 with the disc braking and it is a dream to ride on!

ST: What about tubed tires vs tubeless – for training and racing? What make, model, width, and pressure will you run?

CL: I have changed over to tubeless for training now, I’ve been racing tubeless for about 3 years. It’s just nice, haha, as simple as that. Smoother, more protection and faster. I have DT Swiss ARC wheels for racing and use the Hutchinson Fusion tires. I use the 25c tires since the DT Swiss wheels are wide, it places the outside bead of the tire nice and flush. I race at 95 PSI. I train a bit lower for more supple rides, but an extra 5 PSI for racing.

ST: We learned that you've been testing the new ARC 1100 disc wheel from DT Swiss. Do you plan to use this for most or all of your races? Do you ever use a deep rim rear wheel instead? What's your front wheel of choice?

CL: The new DT Swiss disc is legit! it’s extremely light and aero. They even have their own disc valve cover which, I believe, is the first ever. It ticks every box needed in a disc wheel. I will use that disc in every opportunity. It’s light enough to climb up any hill and, well, it’s just simply fast for any other style of terrain. The DT Swiss hub is top notch and with their ceramic bearings, which is stock by the way, makes it absolutely smooth. Combined with an 80mm front wheel, you are stacked with the best wheel combination on the market. I do use a rear 80mm wheel only when the race makes it mandatory like Ironman Kona or Cozumel. [In Kona I use the] 60mm front and 80mm rear.

ST: What's your drivetrain setup, including front chainring size(s) and rear cog sizes?

CL: My most standard set up is a 55/42t front with an 11/25 rear. The 55 front allows you to keep the power to the pedals on downhills and the 11/25 allows you to not miss out on that sweet spot cog in the back. sometimes the 11/28 isn’t best as it’s missing the 16 tooth. I do train with the 11/28 as in training, it’s nice to have your easy spins up hill and getting into the 42/28 is necessary. However, in a race, you are motoring through and I get by just fine with the harder gearing.

ST: What does your upcoming race schedule look like?

CL: I have the Collins Cup in August and then 70.3 Worlds, Ironman Worlds, and finally Challenge Daytona in December.

—
All images courtesy of Chris Leiferman.

The post Chris Leiferman Eyes a Strong Close to 2021 first appeared on Slowtwitch News.

Before we get too far along, allow me to explain some vocabulary for those that may be new to the sport, or less tech savvy. If you go back about ten, twenty, or thirty years, a disc wheel meant only one thing: a solid rear wheel with no spokes. These wheels are meant to be an aerodynamic upgrade over traditional wheels, because the air can slip past them without being churned up by spokes (plus they can create a sailing effect with the wind that further reduces drag).

These days, there is another piece of disc terminology that’s often thrown around – disc brakes. You may often see the word ‘disc’ attached to wheel product names, which simply denotes that it’s meant for disc brake-equipped bikes.

The new DT Swiss ARC 1100 DICUT Disc ticks both boxes. In other words, it’s an aero disc wheel that’s equipped with disc brakes. The reason I offer this preamble isn’t because DT Swiss is first to market here; it’s just a relatively rare bird even in 2021.

Side note: DT has offered some rim-brake discs in the past, but our sources say that these were made by companies such as Lightweight and Reynolds. This new wheel is, to our knowledge, the first DT-produced disc wheel.

Aero disc wheels have historically been expensive, and have always had a mystique about them. There remains folklore that they must be impossible to ride on anything but a windless day… because I know a guy that knows a guy whose cousin rode a disc wheel into a ditch and burst into flames. In reality, a deep-section front wheel is more difficult to handle than a rear disc. We’ve done our best to educate our readers in countless articles and in our reader forum, but many athletes simply will not ride a rear disc. They opt for a fast – but not as-fast – deep-section rear wheel.

The disc brake disc is even more rare. It has taken quite a while for disc brakes to migrate to triathlon bikes. This is due in part to the way triathlon wheels have been marketed, sold, and used for the last thirty years or so – as a quiver. Invest in a couple sets of good wheels, and you can use them for years and years. Upgraded your bike? No problem – just keep your fast wheels and move them over to your new bike. Many triathletes followed this logic and had a closet full of rim brake wheels. Changing to a disc brake bike requires that you buy ALL new wheels. More athletes are doing this; it’s just not something that happens overnight – especially during economic hardship (and a pandemic that cancelled racing opportunities).

On to the wheel itself, the ARC 1100 DICUT Disc is impressive on paper. It is slightly lighter and pricier than the Zipp Super-9 Carbon Tubeless Disc-Brake Disc, perhaps its closest competitor. It has a 20mm internal rim width (compared to 18mm for the Zipp), and is fully tubeless compatible.

DT lists a tire width range of 25 – 32mm, with 28mm as their optimal recommended choice.

The rim features bead hooks, which act as a failsafe for tire retention at high pressure (and is a requirement for using standard clincher tires – which have beads that are not as stout or inflexible as tubeless tires). DT lists no limitations on tire brand or model with their ARC series wheels. On the topic of rim bead hooks, DT offered the following quote:

“We are convinced that hooked rims are technically the optimal rim construction in terms of safety for bikes that require a relatively high pressure in combination with relatively wide tires.”

The hub internals are DT’s latest 180 DICUT with Ratchet EXP system and ceramic SINC bearings. Note that the disc brake mounting surface uses the Shimano Center Lock standard.

The carbon disc surface was designed in conjunction with DT’s aerodynamic partner, Swiss Side. It includes eight glued carbon pieces of equal size, aligned symmetrically. The overall wheel shape is asymmetric right-to-left, with a flat right side (to make room for the cassette) and slightly convex left side.

DT includes a very cool carbon cover for the valve hole, which opens and closes without tools.

The wheel comes with standard red DT Swiss decals. If red isn’t your thing, they also include gold, black, and chrome stickers with every wheel.

DT performed wind tunnel testing at the GST wind tunnel in Immenstaad to put some numbers behind their product. The wheels were mounted in a 2021 Canyon Speedmax (size M). DT provided these additional details:

“For the analysis of the wheels in the wind tunnel, we use a weighting system based on extensive real-world measurements and statistical evaluations of weather data. It takes into account that frontal airflow (0°yaw) occurs more frequently and is weighted more strongly than crosswind (up to 20 degrees yaw). This weighting system is very similar to the weighting system used by the leading European cycling magazines in their product tests.”

DT Swiss claims an improvement of 1.8 watts for the disc wheel over their own ARC 1100 DICUT 80. When compared to the Zipp Super 9 Disc, they quote an improvement of 2 watts.

Is the ARC 1100 DICUT Disc for you? I haven’t had a chance to ride the wheel, and it’s light-years out of my price range, so it’s hard to say. On paper, it ticks just about all of the boxes I’d look for, if I had to choose one disc-brake-disc. I like the 20mm internal rim width, the lack of tire restrictions, the weight, the brake compatibility (Center Lock), and DT’s typically very high build quality. If that’s what you’re looking for, I think it would be hard to find something better.

DTSwiss.com

The post DT Swiss ARC 1100 DICUT Disc first appeared on Slowtwitch News.

The 6D is an all-carbon bar/stem combination, with a UD carbon finish. It features a compact 125mm drop and 80mm reach; dimensions that are more-or-less in the ballpark of what I’d call “standard” for road riding these days.

Those drops include a 5mm offset, which I personally call “squiggle shape”. While originally reserved for gravel and cyclocross bikes, flared drops are quickly becoming standard for road.

Similar to other aero-shaped bars, the 6D includes a molded-in “suggestion” of where you ought to stop wrapping your bars, to leave as much un-taped area as possible on the tops.

Size options for the 6D include:

-6 x L90 x W400 mm (c-c)
-6 x L100 x W400, 420 mm (c-c)
-6 x L110 x W420 mm (c-c)
-6 x L120 x W420 mm (c-c)
-6 x L130 x W420, 440 mm (c-c)

All that carbon beauty comes at a cost – a hefty $625 USD.

The weight of the 6D comes in at 395 grams (100×400mm size). This is certainly not heavy, but light weight isn’t the purpose of this product. For comparison, you can purchase an FSA SL-K Compact carbon bar ($242, 210 grams) along with their Energy SCR alloy stem ($104, 113g) for a savings of $279 and 72 grams.

The 6D comes pre-routed with guides for internal cable routing to assist with the installation process.

The underside of the stem area has attachment points for accessories, along with a Di2 junction box compartment.

Yes, even the stem is full carbon. It appears to be fairly beefy, to handle the high forces that a stem must deal with.

Vision includes a full kit of headset accessories, along with mount options for a standard computer or a Garmin head unit.

Aero headset spacers round out the package to dial in handlebar height.

As far as performance claims go, Vision states that the 6D is “The stiffest and most aero integrated handlebar and stem system.” We requested information to back the claim, but haven't received any data as of yet.

Note that Vision also offers a similar bar called the 5D, which features a 10-degree forward sweep. They tell us that this is often chosen by the climbers on their sponsored professional road teams, who prefer the comfort of the forward-swept bar tops.

VisionTechUSA.com

The post Vision Metron 6D Integrated Handlebar first appeared on Slowtwitch News.

The basic setup for the day included a wind speed of 45 kph, measuring at both zero and ten degrees of yaw.

Simmonds’ Canyon bike features Shimano hydraulic disc brakes and a Shimano drivetrain.

In addition to this wind tunnel test, Simmonds also took part in a track test one week prior. Key tests surrounded cockpit height and angles, looking to maintain aerodynamics for her future in long distance racing.

At only 28 years of age, Simmonds is already putting pressure on top competition, with very strong bike performances at 70.3 Dubai and Challenge St Polten earlier this year.

Simmonds is using what appears to be the Canyon Speedmax Armrest Upgrade Kit, with vastly increased surface area over the stock arm pads.

Wind tunnel tests can be long and exhausting… requiring breaks for comic relief.

A sleeved skinsuit and short-tail helmet round out the equipment choices for the day.

Above image © TRIATHLONPRESS Germany, Ingo Kutsche

Simmonds will put these aerodynamic changes to the test in the 2021 racing season.

Above image © TRIATHLONPRESS Germany, Ingo Kutsche

Follow Imogen Simmonds on Instagram and Facebook to keep up with her latest results.

The post In the Wind Tunnel with Imogen Simmonds first appeared on Slowtwitch News.

Looking at bicycle gearing from about ten years ago, it appeared that gearing options were disappearing. We could buy standard 53/39 chainrings, or compact 50/34 chainrings. That was pretty much it, at least from major manufacturers. Triple cranksets were steadily removed from product offerings. SRAM campaigned to kill the front derailleur entirely (at least for mountain bikes), and offered a single cassette size of 10-42. We were being given fewer and fewer options.

However, since that time, gearing options have reversed course – sometimes in strange ways. Single chainring systems have spread to road, but are far from having universal adoption. We have mid-compact 52/36 chainrings as the arguable standard. There are chainrings of many different shapes and styles. We now have some 12-speed road systems, in addition to 11, 10, 9, and even 8-speed systems still being offered. Campagnolo and Rotor even offer 13-speeds! It’s also worth mentioning that the addition of more cassette cogs has been accompanied by wider gear range, with 10 and even 9-tooth small cogs (which have had further implications for chainring sizing).

In short, there’s a myriad of options. Choices are good, but can also cause overwhelm and decision fatigue. We’ll do our best to clear the air.

Super-Compact Cranks

I can’t get us out of the gearing quagmire in a single article, so today I’ll focus on an interesting trend that appears to have staying power: Super-compact chainrings. They debuted about five years ago, and while they don’t have wide-spread adoption, they have a secure foothold.

There’s no official definition for what qualifies as super-compact, but the general agreement seems to include anything smaller that a 50-tooth large chainring and a 34-tooth small chainring. 50/34 is the “standard” compact crank size, and is typically built on a crank with a bolt circle diameter (BCD) of 110mm. At the time of its debut, nobody seemed to think that we’d need a small ring with less than 34 teeth (which is the smallest size that fits to a 110mm BCD crank). If you needed low gearing lower than that, the sentiment was that you should get fitter, or resign yourself to using an “unfashionable” triple crank with 30-tooth small ring.

Over time, we realized that some of us do need that ultra-low gearing. We’re not all fit 150-pound bike racers. We often use road-focused components for riding gravel, which can often include terrain more fit for a mountain bike (and its super-low gearing). Triple cranks are almost non-existent in 2021 (save entry-level components like Shimano Claris), so the only solution was to make new double cranks with a smaller bolt circle diameter, and really small chainrings – i.e. super-compact!

The most common options you’ll see today are 48/32 and 46/30 (the latter matching “granny gear” size on most road triple cranks). If you are new to super-compact and aren’t sure what you need, I suggest erring on the smaller side. If your current cranks are 50/34 and you don’t find this is enough to climb your local hills, dropping two teeth per chainring isn’t very much. Go for 46/30.

What About Front Derailleurs?

Back when compact cranks debuted, front derailleur performance was a legitimate concern. Derailleurs of the time simply weren’t designed for that 50/34 chainring size, so shifting suffered. Shimano went as far as designing a compact-specific front derailleur.

Over time, this issue has been eliminated, and modern front derailleurs are designed to work with both compact and standard chainring sizes. As far as super-compact chainrings are concerned, I don’t have enough experience with enough combinations of derailleurs and cranks to say for certain, but it appears that shifting isn’t compromised, and you can use your normal front derailleur, provided it’s less than 10 years old (give or take).

What’s Out There?

There are a handful of options for super-compact cranks. FSA was a pioneer in original compact cranks, providing pro cyclist Tyler Hamilton with a 52/36 crank for his harrowing efforts at the Tour de France. We just took delivery of their latest K-FORCE Light Modular BB386EVO cranks with 48/32 rings, which will work with a variety of different frame and bottom-bracket designs. They also offer 46/30, though they were out of stock when I ordered – likely due to high demand of the smaller size.

FSA solves the bolt circle diameter issue by mounting the small ring to the big ring, and the big ring to the crankarms. This keeps weight low and makes both rings replaceable – which is music to this mechanic’s ears.

Praxis Works makes their Alba model down to 48/32 size. Rotor offers both 48/32 and 46/30 – in both round and oval rings (because… it’s Rotor).

And what of the two biggest drivetrain companies? SRAM ditched standard chainring sizes altogether when they debuted their latest 12-speed wireless electronic systems, offering 50/37, 48/35, and barely-super-compact 46/33. This big change was due to the fact that their new standard small cassette cog size went from eleven to ten teeth – increasing top-end gear ratio and eliminating the need for larger chainrings. Since that time they’ve added a 43/30 option for their new “Wide” drivetrain options. This is more of a gravel-focused drivetrain, pushing the chainline out wider to increase tire clearance. The Wide crank must be paired with the corresponding Wide front derailleur.

Shimano has a similar arrangement, only going as small as 50/34 for their road products. Their GRX gravel line offers 46/30 in 10-speed, and 48/31 in 11-speed – both with a wider chainline that’s gravel-specific (similar to SRAM, you must use the front derailleur that’s specific to the wider chainline).

Concerns of Small Cog Size

In my view, the key thing that can make super-compact chainrings work – or not – is the size of the smallest cassette cog. We’ve written extensively about this topic, and the gist is that the size of the small cog has a big effect on gearing. Especially for road riding, a 46 or 48-tooth chainring isn’t enough gear for many athletes, when paired with an 11-tooth small cog (i.e. you’ll run out of gear while riding fast). SRAM offers the perfect case-in-point, opting for a 10-tooth cog to increase effective gearing (note that I’m ignoring the discussion about increased drivetrain friction from smaller cassette cogs for now; this has been discussed at length in our forum, and would double the length of this already-long article). They effectively recreated the gearing of an old triple crank with ~11-27 cassette, by eliminating one chainring, and adding a couple cogs to the rear.

If you’re using your super-compact cranks for gravel riding, an 11-tooth cog may be enough, due to the tendency for lower overall bicycle speeds compared to road. This will depend on your local terrain, and whether you also use your gravel bike for road riding and/or significant downhill riding.

Super-Compact in the Real World

Who is the realistic customer for super-compact cranks? Are there ideal drivetrain configurations? What about other considerations?

I’m glad you asked.

The simple place to start is to ask yourself, “Do I need lower gearing to get up hills?” If the answer is yes, I suggest a follow-up of, “Does my rear derailleur have enough capacity to swap to a larger set of cogs?” The reason being – it’s probably cheaper and easier to install a larger cassette, rather than new cranks. If you’re maxed on cassette size and still need more gear – super-compact cranks are what you need. As previously mentioned, also keep your top-end gear ratio in mind to be sure you’ll stay happy on fast rides and going downhill.

Once you’ve decided to take the plunge, it becomes a matter of determining compatibility for both bottom bracket and chainline. Also keep in mind that not all chainrings are designed to work with all chain widths; are you running nine, ten, eleven, or twelve rear cogs? Double check that your new cranks and chainrings are compatible with your chain and will shift properly. This is why I noted that we "sort of" have an increasing number of gearing options at the beginning of this article – it all depends on the compatibility of the components, frame, and rear hub.

If this all sounds overwhelming (as can happen when trying to determine compatibility with the myriad of modern options), I suggest a trip to your local mechanic, who can help do the math and order the right parts to fulfill your big super-compact desires.

The post Are Super-Compact Cranks Here to Stay? first appeared on Slowtwitch News.

Perhaps I should clarify further that I’m talking about upper-echelon carbon wheels, which will set you back four figures or more. I’ve been involved in the high-end wheel game for over 15 years now, and have worked both as a journalist, and directly for two major carbon wheel manufacturers. I’ve toured the factories of several more. I’m not bragging here – just trying to communicate that I’ve analyzed and used more wheels than the average cycling consumer.

Every year, I receive press releases saying roughly the same thing – our new wheels are faster than our old wheels, and faster than our competitors. I’m not suggesting that innovations and improvements aren’t happening; I’m just pondering out loud whether we’ll see any meaningful improvements in the future – at least under the given rulesets of our sports.

That last point is an important one, because it has driven much of the recent evolution. I’m referring, of course, to the recent introduction of disc brakes to road and triathlon bicycles. I was an early proponent of disc brakes, and built up my first disc brake-equipped cyclocross/road/gravel/everything bike in 2007. People scoffed and laughed at me back then. Now everyone and their brother has a bike like that.

But that’s beside the real point – which is that the adoption of disc brakes and thru axles required that we buy new carbon wheels for our new bikes – and these new wheels had the opportunity to be designed differently (and potentially faster). In other words, we all generally agreed that we were reaching the limits of wheel speed, and the current focus is now on potential improvements due to the rule changes around braking systems.

The state of road and triathlon racing wheels is interesting in 2021. For the most part, wheels have gone wide. Rims from 20 years ago had internal widths of 13 – 15mm. Now they’re at 17 – 21mm. Tubeless compatibility is near-standard (which allows, but does not require, that you use tubeless tires). Some brands, such as ENVE, are moving heavily into hookless beads. Others, such as DT Swiss, are staying with hooks.

The hooked vs hookless debate is interesting. We’ve reported on it extensively (yes, extensively). To be clear, the rider won’t perceive any difference between a hooked vs hookless rim (i.e. with ride quality); its design affects tire compatibility, rim diameter control, and potential tubeless tire sealing.

And what of aerodynamics? Is there any consensus on whether modern wheels are becoming faster? Is this affected by the bead design (hooked vs hookless)? Has the move to disc brakes allowed for unique rim shapes that weren’t possible before – and which outweigh the aerodynamic cost of the brake caliper and extra spokes required to build a strong disc brake wheel? After an intense investigation into these topics, I can only respond with a resounding… ‘I don’t know.’

I truly don’t mean to be a Debbie Downer. Many of the newest wheels are outstanding. If you can afford the price tag, you can take your pick of a number of wonderful premium products. You won’t be disappointed.

I suppose what I’m getting at is that I think the time may have arrived where the debate about any continued marginal performance gains is largely not worth our time. I look at the behavior of actual consumers, which confirms my viewpoint. Even out on smooth roads and paths, I see a lot of gravel bikes. Fatter tires and wheels. Also: People choosing bikes and wheels because of the cachet, and because they just like them.

I ask people about their equipment choices, and it appears that people have been overwhelmed by tech information overload, and just end up buying what their buddy or bike shop recommended. It’s as if we’ve gone backwards in time – to a purer state of riding – and I think it’s a good thing. I’m on board. When I shop bike products today, I look for brands that I trust, backed by good people. Am I always choosing the fastest stuff? Gosh, I don’t know.

With that said, it’s been easy for me to get behind the latest efforts of DT Swiss. I haven’t had a single failure or reliability problem with any of their products in my ~20 years as a serious cyclist (and I value reliability above all else… what good are fast wheels if they can’t make it to the finish line?). We’ve reviewed their newest carbon wheels (see the link below), which performed as you’d expect from such a price point. Their new video details their design philosophy behind the renewed and refreshed ARC line.

BUT MORE IMPORTANTLY for you, the reader – they’re giving away a set of wheels! Click through to watch the video on YouTube, which has details in the video description on how to enter. May the best Slowtwitcher win!

The post Are Wheels Getting Any Faster? first appeared on Slowtwitch News.

With ENVE specifically, the story gets quite a bit more interesting, too. You see, most tire introductions sound something like this: “We looked at what’s out in the market, and saw a gap. We wanted to produce a tire that properly balances the factors of weight, rolling resistance, puncture resistance, and aerodynamics. Our product outperforms the competition when considering ALL factors.” It’s similar to how they pitch wheels to the marketplace; ”our blend of performance characteristics is better than those chumps you’ve been buying from” (my words, not ENVE’s).

Like so many other brands, ENVE does claim to have a well-rounded balance sheet of performance. But – they did want to own (and dominate) two characteristics that we rarely talk about: Bead stiffness and diameter.

We got in to the topic of tire bead stiffness and diameter during our visit to the ENVE factory in 2019. In short, ENVE tests every tire they can get their hands on, and have found a wide range of tire bead stiffness and diameter. When using inner tubes and traditional hooked clincher rims (i.e. what most of us have used for decades), this variability in tire construction is largely a non-issue. If a tire is too large or stretchy, the bead hooks of the rim act as a failsafe to keep the tire on the rim.

However, many newer rims – including several from ENVE – use a hookless design. Our own Dan Empfield has been busy writing on this topic lately. We also reported on the update of ETRTO rim standards for 2020, which now officially includes road and gravel hookless specifications (and clarifies/unifies diameter standards between these and the preexisting mountain bike hookless standard). Hookless is here, and it’s on the rise with more brands.

Why hookless for road? We’ve already written at length about hookless rims, so I’ll only provide the Cliffs Notes here. From a performance standpoint, brands like ENVE claim slightly reduced rim weight and improved impact strength. But more importantly, they cite a combination of reduced manufacturing cost and the ability to produce a rim with better diameter control due to the type of mold used. According to ENVE, tighter rim diameter control improves the installation, fit, air retention, and overall experience of using tubeless tires, making it a win. However, the lack of bead hooks exposed a safety concern with using non-tubeless road tires (with their typically stretchier beads), or any tire that doesn’t fit within their acceptable window of bead diameter and stiffness.

Circling way back – and given all of the above – ENVE thought it wise to offer their own tires. There are other tires which meet their bead stiffness and diameter specs – but none that they felt also satisfied all of the other performance characteristics they wanted (i.e. their secret sauce of aero, weight, puncture resistance, and so on).

We’ve had ENVE’s tires in our hands for several months now, and sought to find out – are they good? Are they necessary? And of course – how do they fare with the day-to-day concerns of installation ease and air retention?

Installation

ENVE sent sample tires to us in 25mm and 29mm sizes (they also make 27mm and 31mm). I received the 25mm samples first, and installed them to a set of ENVE Foundation wheels.

Above: Note that the larger tire sizes appear to have a slightly deeper tread.

The installation went as I’ve come to expect from ENVE. Their rims have a deep center channel, making tire bead installation easier than most wheel brands (because the rim diameter is quite small in that center channel). The tradeoff is that I typically cannot perform the initial inflation of any tubeless tire with a floor pump – because the tire fit is loose in the channel. As an apartment dweller, I don’t have an air compressor, and use CO2 cartridges to blast the tire beads in to place. I do this operation without any sealant installed, because the cold CO2 can cause liquid sealant to solidify. So – I blast those beads into place, deflate the tire, inject liquid sealant, and then reinflate with a floor pump.

Post-installation, one of my ENVE tires had trouble holding air overnight. After much troubleshooting and many layers of new rim tape, it was determined that I had an issue with a preproduction tire (I sent it back to ENVE for analysis). A 25mm Schwalbe Pro One (2019 model) successfully held air on the same wheel; a tire that’s on ENVE’s approved list. I have had no problems with air retention on any of my new production-quality ENVE tires.

I attempted to install the 29mm set of tires onto a pair of 2019 DT Swiss ARC 1100 DICUT 62 wheels, which currently reside on my road bike. I’ve ridden these wheels tubeless with the same pair of 25mm Pro Ones as mentioned above, which had a tight, but not impossible fit (and note that I was able to inflate those tires with a floor pump). I’ve also ridden them with inner tubes and Donnelly Strada LGG clincher tires, which slipped on very easily.

Try as I might, I was not able to install the ENVE tires to these rims. I could not install either the first or second tire bead. My experience and intuition said that this was due to the depth of the dropped center channel of the rim being shallower on the DT product.

ENVE’s Jake Pantone provided the following response:

“ETRTO specification have changed a bit with the 2020 standard as it relates to tubeless rim geometry, and specifically, the drop center. [We] haven’t measured any of the latest DT rims, but some we measured from a few years back look to have had a drop center depth dimension of 2.8mm roughly. The 2020 ETRTO standard calls for a range between 2.6 – 3.4mm for hooked rim and 2.9 – 3.5mm for hookless.

So, ENVE tends to be on the deeper end of the standard to provide a little more depth for ease of installation. Specifically, the Foundation 45 or 65 are 3.3mm deep. Our tire sits right in the middle of the bead seat diameter standard. Therefore, depending on the rim, an SES tire will be easier or harder to install depending on the rim’s drop center channel depth.”

I’ll also venture a guess that the Schwalbe Pro Ones have beads that are either less stiff, or larger diameter than the ENVE tires. The Schwalbe tires worked on both sets of wheels (DT and ENVE), whereas the ENVE tire only fit on to the ENVE wheel.

Now, I don’t have every brand and model of wheel, nor the time to test ENVE’s tire on all of them. They might work just fine on your wheels. As mentioned, the key driver of the installation ease (or lack thereof) is the center channel depth. Deeper means easier initial installation, but more difficult inflation (i.e. you’ll need compressed air). If you’re riding ENVE wheels and want to ride ENVE tires – you’re good to go.

Don’t forget that rim width influences the allowable tire size for a given wheel. If a rim is too wide, it cannot safely retain a tire that’s too narrow. Above, you’ll note that the packaging for the 25mm tire says that it cannot be used on ENVE AR rims, which have a 25mm internal rim width.

The ENVE website reinforces this, showing a maximum internal rim width of 21mm for the 25mm tire size. All other tire sizes from ENVE (27mm, 29mm, 31mm) are approved for use on the wide AR rims.

Riding

So – how do the tires actually ride and feel? I must say – I was pleasantly surprised with the speed, comfort, and overall feel of the SES tires. Especially when paired with their Foundation wheels, I was cutting minutes off of my ride times, compared to some of the previous wheels and tires I was using (but to be fair, some of these were clearly not performance-oriented products). I’ll go as far as saying that in a blind test, none of you could tell the difference between ENVE’s tires and any of the common competitors, such as the Schwalbe Pro One or Conti GP5000 TL.

I don’t have the resources to verify or deny ENVE’s aerodynamic and rolling resistance claims, but my seat-of-the-pants impression after having ridden hundreds of different wheels and tires is that ENVE’s tires are legit from a performance standpoint. As a bonus, I didn’t experience any flat tires, and had about as much fun as you can riding a road bike on a mix of roads and multi-use paths.

Wrap Up

At the end of the day, ENVE has produced a tire that’s on-par performance-wise with the key competitors that you know and love, from brands like Continental, Michelin, Schwalbe, and more. Of course, you’ll have to decide which performance characteristics are most important to you – puncture resistance, rolling resistance, aerodynamics, and so on. ENVE erred the way I prefer, which is to forego the absolute fastest rolling properties in favor of more realistic durability (I can already hear the rolling resistance geeks scoff and groan). You pick your poison, I’ll pick mine. Personally, I’ve had more success installing the Schwalbe Pro Ones on more wheel brands and models, but the ENVE tire did install without trouble to their own wheels. If I had to guess, most buyers of these tires plan to install them to ENVE hookless wheels, making this largely a non-issue.

ENVE.com

The post Review: ENVE SES Road Tires first appeared on Slowtwitch News.