2014 Calfee Manta Pro custom carbon endurance road bike

When we first spotted the new Calfee Manta Pro road bike on our Factory Tour, it was still in prototype form. Now, the design is final, and it gets some interesting tweaks to the frame and component spec.

Key changes include structural elements around the bottom bracket to change the flex point via stiffening struts. They also added more carbon material within the chainstays and where they meet the bottom bracket, as well as in the area around the suspension at the top of the seatstay wishbone under the brake caliper. That was done to reduce pedaling influence on the vertical flex and add strength to the system.

They also tweaked the cable entry at the front of the bike. The prototype had a gorgeous port letting the rear brake cable come into the front of the headtube. In practice, though, it wanted to turn the wheel a little, making it less stable when riding with hands off the bar. So, they moved it a bit further back.

2014 Calfee Manta Pro custom carbon endurance road bike

Calfee’s known for their paint, too, and this show bike certainly didn’t disappoint.

2014 Calfee Manta Pro custom carbon endurance road bike

The 65mm ID bottom bracket shell is designed around the Look ZED2 crankset. They did that to be able to fit a modified Campagnolo EPS battery into the downtube, and because the one-piece crankset is wicked light. They’re running Praxis chainrings. Note the color coordinated Look logo on the inside crank arm.

2014 Calfee Manta Pro custom carbon endurance road bike

Now for the big change: Two struts are added to suspension models, connecting the BB shell to the chainstays, meeting about halfway toward the rear axle. The struts have 200,000 individual strands of carbon pulled through each stainless steel rod, with the metal there simply to protect the strands. Total added weight for both struts is just 35g, but they were critical to proper function of the bike. They stiffen the chainstays so the rear wheel remains in plane with the frame because the seatstay is not as much of a structural element once the suspension is added. The male end of the suspension is round, which reduced stiction versus a keyed or square design. But, leverage from the wheel could rotate it, and Calfee’s Michael Moore says the rear ended up feeling sluggish in the corners. Basically, the additional stiffness there had to make up for the suspension integrated into the seat stays.

2014 Calfee Manta Pro custom carbon endurance road bike

Curious about whether the chainstays are really up to the task? They took a Cervelo with their infamously thin seatstays and massive chainstays and cut the seatstays off. They rode it and tested it, and it did just fine. That was the proof of concept that suggested stiffening up the chainstays would solve the problem…and it did.

So, why add struts rather than just beef up the chainstays? Because Calfee also offers a rigid Manta Pro, and the thinner stays on the rigid bike keep the ride quality smooth and comfortable. But the rigid bikes are retrofittable to the suspension model, so being able to simply add struts along with the suspension was the best overall solution.

They can also make it with disc brakes, and Moore says they’re building about 3:1 rim to disc brakes. They can even build it as a cyclocross or adventure bike. Aaaah, the beauty of custom. Wanna see all the options? Hit their website to kill some time. Retail starts at $4,795 for the frame, and $5,995 for the module with complete crankset, Chris King Inset 7 headset and Easton or ENVE tapered fork.


  1. “But the rigid bikes are retrofittable to the suspension model, so being able to simply add struts along with the suspension was the best overall solution.” I’m going to have to call BS on this. Those struts are a just stupid hack to avoid having to tool up new chainstays and BB after they found out their original design wasn’t up to par.

  2. Brandon it says they used the 65mm bb “to be able to fit a modified Campagnolo EPS battery into the downtube” not, this bike has a campy battery.

  3. I’d definitely take the non-suspension model. I agree that the struts would work to stiffen up the rear end, but I just don’t like the compromise in looks over beefing up the chain stays.

    Would like to see what this one looks like with discs…

  4. i’ve been waiting for Craig to beef up tube diameters for years now. ditch the suspension and give me an appropriately sized/tapered chain-stay and i’m in.

  5. Why is it that when you see a Calfee out on the road, it is always some older dude, about 6′ 5″ tall with a scraigly beard wearing a t-shirt tucked in to black lycra shorts going an average of about 6 mph? It never fails.

  6. @Matt – Were do you live? That is not the case were I live.

    Calfee has unparalleled customer service and attention to detail. Nice to be able to have your bike not come out of a box, shipped from somewhere else in the world.

  7. I don’t own a car
    every day is bike day
    I’d put the rest of my bikes to the side, and ride this one daily for a year
    run a blog on it and see what happens over 10,000 miles.
    The Mantra Year

  8. No offense taken – I got used to negative comments with carbon fiber in the 80’s and bamboo in the 90’s. But I should explain the struts a bit: The 1st obvious solution of running larger/taller chainstays that taper quickly to the virtual pivot point would be heavier – if we maintained a thick enough wall that avoids the serious problem of minor chainsuck causing a rather quick and dangerous failure on what is now a leaf spring. We’ve seen enough gouged, thin wall chainstays in our repair service that the stainless steel covered “tendon” is very confidence inspiring. And it is convenient for adding the suspension to a non suspended version as more people realize that the traction enhancement results in significantly faster climbing.

  9. @Matt – I’m a USAC Cat 1 and UCI Professional MTB licensed rider. I race on a custom Calfee DFly. Most people say I’m pretty good at riding a bicycle. Bring your taiwanese, monocoque wonder ride you spent $10,000 on to NorCal sometime and ride with me, maybe you’ll feel differently.

  10. Matt, I don’t have a beard and usually hit at least 8 mph. But I do love my Calfees. Craig put couplers in a 1999 model Tetra a couple of years ago & I’ve ridden it all over world. Must have close to 40,000 miles on it. Have another uncoupled that I love. Rode PBP on a Calfee Tandem with a pal (his bike.) Don’t even like tandems and loved it. Always incredible service from Craig. I still suck but these are sweet rides. Love to try a Mantra.

What do you think?