2016 Cervelo R3 Disc Ultegra disc brake road bike

With the UCI allowing teams to test disc brake road bikes in two races this fall, Cervelo needed something for Team MTN Qubeka to ride.

The all-new Cervelo R3 Disc is that bike, and it’s both very similar and completely different than the standard rim brake model bearing the same name.

They wanted to keep the race geometry and handling since it’s going to be tested at the highest level under MTN Qubeka. The problem was, they had to widen the chainstays to fit the 135mm rear hub spacing that disc brake hubs use. And that can throw off the chainline. Most other brands simply extend their chainstays to accommodate the wider axle spacing, which is usually necessary to maintain proper shifting. There are specific recommendations from Shimano regarding the amount of chain deflection from chainring to cog. If it’s too much, the chain can start to pick up the chainring ramps too early, potentially limiting the number of usable gears or negatively impacting drivetrain performance.

Cervelo found a way to keep the chainstay length exactly the same…

2016 Cervelo R3 Disc Ultegra disc brake road bike

The 5mm extra hub width was split evenly from left to right. Where Cannondale has shifted the extra width to the driveside on some bikes, that requires a specially dished or offset wheel lacing. Cervelo wanted to keep the bike compatible with high end wheels you may already own, though.

2016 Cervelo R3 Disc Ultegra disc brake road bike

The solution was simple – move the crank arm outboard by 2.5mm on the driveside, lining everything up perfectly. They had plenty of room to work. The bike uses their 79mm wide BBright standard, which splits the difference between BB30 and BB90 (no, the numbers don’t all refer to the same thing, but BBright’s spindle width is exactly in the middle of those two. That kept the chainline correct without lengthening the stays, but to get the rear brake caliper inside the rear triangle, they had to loop the left seatstay further out a bit and use flat mount brake calipers.

2016 Cervelo R3 Disc Ultegra disc brake road bike

Note how the non-drive seatstay sticks further back than the driveside? That’s what opens up the dropout area so the brake caliper can fit inside. This official pic also shows the correct graphics color for the FSA SL-K crankset that’ll come stock…no red graphics like what’s on the display bike. SL-K bar, stem and seatpost are also used.

2016 Cervelo R3 Disc Ultegra disc brake road bike

The R3 Disc makes the move to 12mm thru axles front and rear. For now, they’re using a standard threaded design with QR lever, but they may switch to their sister company Focus’ thru axle system in the future.

2016 Cervelo R3 Disc Ultegra disc brake road bike

Not content with simply drilling dropout holes from one side of the frame to the other, Cervelo came up with a semi-floating design to ensure perfect alignment. Thru axles require very tight concentric tolerances, which they say is very hard to do in mass manufacturing. So, the rear derailleur hanger is floating in the frame, given a few millimeters to wander when placed there on it’s own.

To line everything up and install it with perfect precision, you’d then slide the wheel in, thread in the thru-axle and then thread the nut on the outside of the driveside dropout. By putting the axle in while the hanger is a little loose, it can be perfectly aligned from side to side. Then by tightening the bolt on the driveside, everything is locked into place. That removes any binding from the thru axle and ensures perfect alignment and shifting.

2016 Cervelo R3 Disc Ultegra disc brake road bike

Claimed clearance for 700×25 tires, but depending on the rim and tire combo, you may be able to get a slim 27 in there. The chainstay clearance is the limiter. BB stiffness increases at least 25%, mainly thanks to different layup, the seatstay’s wider stance and switching to thru axles.

Frame weight is claimed around 950g depending on size. On sale in October. It’s their first disc brake bike, but it won’t be their last…

The rest of the bike’s spec is Shimano BR-RS805 hydraulic disc brakes, 140mm rotors, Ultegra mechanical group, Fizik Antares saddle, HED Ardennes GP+ Disc and Continental Grand Prix Race (700×25).

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In addition to the R3, they have a few team replica colorways available to first come, first served. There are only a few of the Tour de France MTN Qubeka team bikes left, and each one purchased sends a Buffalo Bike to Africa to help keep that economy moving along.

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They also have a Bigla pro women’s team frameset (left) and Velocio team replica in an R5.

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The P3 gets a mostly white with aqua blue color hits throughout. It also gets a Di2 Shimano group rather than mechanical, which meant they left off the hydraulic Magura TT brakes. They did this because the customer for the P3 wants/needs the additional shift buttons by the brake levers, and Magura’s hydraulic TT levers make no concessions for Di2 button shifters.

Cervelo.com

21 COMMENTS

  1. Okay, so here’s what bothers me…

    Why should Cervelo (or any frame builder) need to alter their geometry or design when Shimano (and other component makers) could probably more easily retool to build their cranksets with the chainrings 2mm further outboard?

  2. @ChrisC It’s because Shimano will obviously produce far more cranksets in total, than Cervelo will ever order. There are many more bike companies that DON’T require a different chainline. This bike will be made in tiny numbers in comparison.

    The real question is if Cervelo “knows best”, why the didn’t they just offset the entire BB shell so ALMOST ANY CRANK WOULD FIT???? Silly me, it’s because FSA cranks/chainrings have the best shifting…..

  3. FSA already dishes out their rings on some cranks. It makes sense for Shimano(and SRAM) to do this too. Not for Cervelo but for pretty much every cross bike on the market as well as touring bikes with doubles. For cross, the benefits will be small but they’ll be there

  4. FSA and SRAM offer their road cranks in a wider chainline, specifically for road discs. SRAM has some road front derailleurs that are intended for the wider positioning too, so you don’t have to adjust a standard front derailleur’s limit screws past their intended range.
    Specialized SCS is the dumbest thing Spec has come up with in a long time. That and their new Tarmac seatpost clamp hardware…

  5. I will wait a few years before I buy a disc road bike. Went everything is settled , they are still searching was it’s best , and special hubs or cranks is no solution . Next year is will be something else ..

  6. only 25c tire clearance? Possibly 27c on outmoded narrow rims? That is an issue I was really hoping would be addressed with this iteration of the R3. Having recently had experience of Compass tires 28c and 32c tires, I would hope for 28c compatibility on HED Ardennes, Pacenti 23s or Archetype rims. A supple, 28c race tire weighing ~20g more than a standard 23c tire in this bike would be incredible…

  7. This is dead on,

    “Journey Man – 08/29/15 – 2:53am

    only 25c tire clearance? Possibly 27c on outmoded narrow rims? That is an issue I was really hoping would be addressed with this iteration of the R3. Having recently had experience of Compass tires 28c and 32c tires, I would hope for 28c compatibility on HED Ardennes, Pacenti 23s or Archetype rims. A supple, 28c race tire weighing ~20g more than a standard 23c tire in this bike would be incredible…”

    I have the current gen. R3 and can’t get more than about at 25c. The new fork looks loads better, but updated molds around the chainstay/ BB junction would make the R3 a much more capable frame (regardless of the brake type).

  8. This is not Cervelo’s solution. It is FSA’s “DB” crank. This is in fact the laziest way to engineer a frame, not that inventing standards is a good thing, but it’s not clever, it’s absolutely and perfectly normal.

    Also my q-factor.

  9. Also I find it amazing how their philosophy about the dropout is that it’s too hard to do it the right way, so they’ll give you a bodge job solution, at Cervelo prices.

  10. Loops! Cervelo screwed up the front when they gambled and created a fork that will only work with a 12mm x 100 thru axle, instead of going with a fork design for the already established 15mm x 100 thru axle. Shimano is supporting the 15mm x 100 thru axle, NOT 12mm x 100.

  11. I completely agree with mudrock. The bike should just have longer chainstays and tire clearance so you run 28’s or even wider. Not being able to run Shimano cranks is a fail. As far as the P3 goes can Cervelo please switch to the internal battery? The bulky external battery hanging off the BB looks horrible.

  12. The reason Cervelo can only run 25mm tires on HED Ardennes + is because the 25mm tire on the Ardenne + rim balloons up to a 28mm outside to outside, with a narrower rim, a 28mm tire should work.

  13. I have the current R5 (same frame shapes as the R3) and am running C24’s with Hutchinson Sector 28’s. There’s a little bit of rub in the rear under high power efforts but under normal use they fit/work just fine.

  14. Will the rear chain stay hold under load or eventually weaken and brake? Had two r3s 2012s that did that. Above where the rear derailleur hanger mounts the carbon ripped apart at this weak spot one time leaving the crappy (comes stock with frame) hanger unaffected and the other time with only 200 miles on it did bend the derailleur hanger until the frame gave up and ripped apart. Just a sad customer venting.

  15. Tried this bike for a few hours at The Tour Down Under last week. I’m used to an aero frame (Merida Reacto 907) so although not quite as peppy in the acceleration (this is subjective anyway) I found the ride to be absolutely beautiful. Cracks in the road, potholes etc used to go right through my head, but this was able to bomb over stuff and maintain a high speed. Its a compact sort of frame so I’d spec something bigger than the 56 that I tried. (6’2″ rider). Very nice bike.

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