With more than half of their road bikes sales now getting disc brakes, Parlee made the call to update its TTiR triathlon bike to use disc brakes, arguably becoming the first major disc-only tri/TT bike on the market. Availability of wheels from Mavic, ENVE, Zipp and HED (including a disc brake full-disc rear wheel from HED) didn’t hurt the decision, but the way they went about it is quite unique.

The new TTiR is the replacement for the prior model, so it’s now only a disc brake bike, no rim brake version will be offered. Other than water bottle bolts, it shares nothing with the prior generation…it’s a complete clean-sheet redesign to be 100% optimized for disc brakes.


Bob Parlee revised the fluted tail designed on their ESX and prior TTiR bikes to improve overall aerodynamics. They were able to obtain similar aerodynamics straight on and with shallow yaw angles, but actually improved the aerodynamics on steeper yaw angles. They proved that in the A2 Wind Tunnel in North Carolina, getting results they say will likely surprise folks that think disc brake bikes are less aero. The full unveil will be at Eurobike, where we suspect they’ll have aero drag charts to bolster these statements.

“You add a little bit of surface area at the brake, including frontal, but because the cabling is a lot cleaner and the area above the wheel is cleaner means any loss you have at the rotor is offset by gains on the rest of the bike,” Parlee’s Tom Rodi told us. You can’t just look at the additional drag at the rotor area in isolation.”


Part of their aerodynamics trickery are carbon fiber caliper covers. Rodi says they do not trap heat as they’re totally vented on the top and back sides, adding “We probably could have made them closer fitting, but we wanted to ensure universal brake compatibility. We’ve played with other versions, but we wanted to play conservatively and not spook anyone with this first iteration.”


Other gains were had by designing their own fully integrated front end, including the fork, with a select modular cockpit parts (pads, hardware and extensions) produced for them by Profile Designs.


“With the plethora of wheel options available now, and the performance offered by disc brakes, we knew this is the direction we had to go after riding (prototypes),” Rodi said. “This is it. There’s no more reason to offer one with rim brakes.”


The bike is available for pre-order through dealers for shipping in November. Retail starts at $6,299 for complete bikes, framesets should also be available. They’ll come stock in a gloss black, but Parlee’s in-house paint team can pretty much do anything you want.



  1. Veganpotter on

    Of course, no numbers from the tunnel. You’re rarely breaking in a triathlon and most TTs. Drag is what sets these bikes apart. The only thing you know for sure about this bike is that it’s heavy(the rim brake bike is a bear compared to most and I’m sure this is no better) and brakes great in the rain even though you rarely need to brake at all in a race.

    • ChrisC on

      Convergent evolution in aerodynamics is to be expected. The Parlee looks like the Felt IA, which looks like the Argon E-119, which looks like the Trek Speed Concept, which looks like the Specialized Shiv

      • Flatbiller on

        These similes are getting old and tired. That’s like saying a Ford Mustang looks like a Porsche because it has four wheels, and expecting people to take your point seriously.

        “Oh yea, you do have a point. They do look similar. The Parlee has a chainstay and…OH SNAP, the Shiv ALSO has a chainstay!!! They totally copied them!!!”

        • Antipodean_eleven on

          If you understand anything at all about car styling and aerodynamics you’ll know that this analogy is pointless.

          Vehicles designed strictly for aerodynamic purpose will all have a ‘design convergence’. That is the net effect of designing for the lowest possible CD (drag coefficient). And if you want to look at cars as an example, look at the range of early hybrid cars, where aerodynamics were a primary design concern. More than that, look at F1, Indy carts and even NASCAR cars – they all look pretty much the same for a very good reason.

          As a net result, all TT bikes WILL end up looking the same.

          • Veganpotter on

            NASCAR, and F1 cars have very strict rules that limit their differences. Again, your anaolgy is even worse after explaining it…

          • Antipodean_eleven on

            The rules dictating F1 (and I assume NASCAR) have little to do with shape and everything to do with aerodynamics, ground effect, power output, grip etc. Min ground clearance and cockpit coverage etc. are just two of these rules, that if changed, would see drastic improvements in performance; and if allowed everyone would do and guess what?

            The rules are designed to level the playing field, not control the way the car looks. So given they are all trying to achieve effectively the same thing, the cars end up looking the same. Hello UCI.

          • Gillis on

            @Veganpotter…The UCI does have rules that dictate the dimensions and design of the bike. Mostly the 3:1 tubing profilerequirement and the double-diamond frame configuration.

            I do wonder the the rear cover falls afoul of the 3:1 rule.

            Antipodean’s anology is very apt. I would say F1 and the Le Mans LMP class (because they are bespoke cars designed to rules–yet all look alike; where as Indy and NASCAR or more spec racing) are the best examples of this.

    • Haromania on

      Improvements are going to be measured in very small fractions at this point in bike evolution, and good luck designing a bike that doesn’t look a little like something that’s already been made. I would love to see it dun though, so if the urge hits you please come back and share it with us.

    • TomM on

      This makes me wonder why Parlee’s own ESX is so different from this and other TT bikes…and other companies’ aero road bikes. Besides being aesthetically ugly, the ESX just doesn’t look aero. On the other hand, I could easily imagine a variation of this new TT bike as a Parlee aero road bike. Maybe that’s coming soon too…

  2. anonymous on

    Brake fairing is interesting since the UCI already sort of allows fairings for rim brakes. Maybe this is the somewhat silly solution to people complaining about disc brake aero.

  3. th1npower on

    Silly luddites, you can pick away at everything you want, but this will be the wave of the future. Kudos for Parlee seeing the market and putting out the bike! First! This will crush at Euro bike, probably take top bike, along w/ Interbike later this year.

  4. AdamM on

    Removing the breaking surface from the wheels gives wheel designers the ability to optimise the wheel profile to minimise drag. I’m not at all surprised that they claim lower drag from a disc braked bicycle as a whole.

  5. rich hargus on

    surprise! the industry is finally answering the call of the marketing department to sell us something “new and improved”. *yawn* I dont really recall many time trialists clamoring for disc brakes options.

    • Robin on

      Not right now, but wait a few years for when disc brakes will be the dominant brake type on road bikes and will be used in the pro peloton. Of course the other option is to cling to today hoping that nothing changes in the future.

    • lak on

      Lol, are you seriously comparing an AERO tri bike to a motor assisted bike? What kind of PLEB are you??????

      The comment section on this site is atrocious.

  6. ginsu on

    There is design convergence because the companies all use the same software and get the same results from CFD and aero given the constraints imposed by outside factors.

    Aero isn’t probably ever going to get that interesting on a bike because it is all about efficiency, and a completely smooth, faired body will always be a better shape than one with ‘design flair’. Any decent aero engineer is going to make the shape simpler rather than more complicated. It’s always more expensive and doesn’t bring positive results. That’s why I really don’t like a lot of Pinarello designs, as they often compromise efficiency for design.

  7. Kernel Flickitov on

    You know this bike is a success when you see lawyers and dentists on them going for Stava segments on multi-use paths in a full aero tuck. Maybe with disc brakes now they can avoid the head-on collisions while trying to pass dog walkers around blind corners at full clip.


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