Frame builder pet peeves: Cannondale

American cycling brand Cannondale is beloved by many, sometimes with a fanaticism not obvious from other large marques. However, having started cycling well after the brand had established itself as a mass-production juggernaut, I’m afraid I don’t really see what the fuss is about.

While Cannondale is rightly applauded for stubbornly sticking to its aluminum alloy guns, there are quite a few reasons why I can’t really support the brand with my own cash.

BB30…

In a bid to increase the stiffness of cranks while making them lightweight, Cannondale introduced the use of aluminum in the crank spindles. Due to the lower density of the material versus steel, they increased the spindle diameter to 30 mm, which required creating a bottom bracket shell to house this new spindle and the bearings it spins within. Lo and behold, the press-fit standard called BB30 was born, and Cannondale opened it up for other frame builders to use in 2006.

Instead of screw threads, BB30 uses bare cartridge bearings pressed into a bottom bracket shell that’s ever so slightly smaller, held in place by a circlip on the inside. By keeping the bearings close together (spaced 68 mm apart for road bikes, and 73 mm for mountain bikes), a bike with a BB30 shell keeps a narrow Q-factor, which is a personal-preference bike fit metric that determines how widely set apart your legs and feet are while pedaling. Couple that with a light yet stiff crank, and you get power, comfort, and control.

A PF30 bottom bracket getting pressed into a frame. Unlike BB30, PF30 uses nylon cups (in black) to take up any slack or bad tolerances between bearings and frame.

For BB30 to work right, it relies on the bottom bracket shells being machined to very exacting tolerances. Done correctly, a press-fit bottom bracket system like BB30 should not be problematic. However, this is where it starts to fall on its face. Opening up the standard to other framebuilders, those with less manufacturing precision, may have jeopardized the popularity and engineering soundness of BB30, as loose tolerances and poor bearing alignment can cause the dreaded creaking. Worse, the bare metal cartridge bearings don’t have a cup they sit in to take up the slack.

…AND ITS CHILDREN

Yes, BB30 begat children. BB30A was released in 2014, and BB30-83Ai in 2017.

The 2014 Synapse frameset introduced BB30A to the world in 2014.

I understand that BB30A and BB30-83Ai each introduce engineering solutions to problems. BB30A extends the 68 mm BB30 shell and adds 5 mm, much like on a mountain bike. However, unlike on mountain bikes, it adds all of this 5 mm on just one side – the non-drive side – hence the “A” designation for “asymmetric.”

BB30-83Ai is similar in concept. Remember the narrow Q-factor benefit promised by BB30 and its 68 mm bearing spacing? That’s proven short-sighted and very restricting for cyclocross and gravel bikes, which require the capability to fit ever wider tires. Cannondale ended up widening the bottom bracket shell to 83 mm, giving them more room to attach the chainstays while increasing tire clearance at the rear and keeping stiffness good.

Released in a time when bikes already have way too many bottom bracket standards for the average consumer to keep track of, perhaps this is Cannondale simply being inconsiderate IMHO. Both BB30A and BB30-83Ai require new-ish cranks to work; older BB30 units will simply be too short. Add to that their known inconsistencies and bad tolerances, and you’d think Cannondale would have learned their lesson by now…especially when BB386EVO/BB392EVO, a bottom bracket standard designed to be as compatible as possible with everything else short of reintroducing screw threads, already exists.

INCONSISTENT MANUFACTURING?

That would have been enough to end, but it’s a different story altogether when it’s Cannondale themselves that have bad manufacturing tolerances. Hambini, a small British engineering firm which specializes in fanatically built bottom brackets, has a video showing just how sloppy and inconsistent Cannondale’s manufacturing has gotten – in some cases, even worse than Chinese “own brand” frame makers which have a lot less name recall in the West.

Below is Hambini’s box-and-whiskers plot of bottom bracket diameters and tolerances, which he constructed by measuring the bottom bracket shells of a large number of frames, across a number of manufacturers. As not all of these frame builders use the same bottom bracket standards (e.g. both Trek and Giant don’t use BB30), he normalized the chart for the 6806 bearings used in a typical BB30 system for comparison purposes. The larger the figure, the worse the consistency of manufacturing. Ideally for a manufacturer of BB30 bikes, you’d be close to the BB30 specification of 41.96-41.98 mm.

Considering they introduced BB30 to the world, Cannondale has a pretty bad showing here. The upper limits of the box plot go too far past 41.99 mm, with outliers even reaching 42.01 mm…meaning they’ve got bikes out there with pretty sloppily made bottom bracket shells.

Ever wondered why so many complaints arise in local bike groups about BB30 bikes and cranks creaking? Now you know. Perhaps this is because no Cannondales are actually made in America nowadays any more?

MORE FRAME MAKERS ARE REDISCOVERING ALUMINUM

For a long time, Cannondale’s unique selling proposition was that it could keep committing itself to making aluminum bikes that were not only good; they could even be competitively raced against carbon fiber. In recent memory, the CAAD10 and CAAD12 road bikes are proof of this; apart from material choice, these bikes share a lot of their geometry and design choices with the brand’s premier carbon fiber race bike, the SuperSix Evo.

Junction of the headtube, downtube, and top tube of a 2018 Trek Emonda ALR. Yes, this bike is made of aluminum. Photo courtesy CyclingTips

They’re not the only player any more though. Specialized has been promoting Chris D’Aluisio’s SmartWeld technology on its aluminum bikes for years now, although perhaps due to premium pricing they cannot gain the same top-of-mind traction Cannondale does. Recently, Trek has bet on next-level aluminum metal working with its second-generation Emonda ALR lightweight road bike sporting similar Invisible Weld Technology, featuring tube junctions so smooth, and welds so inconspicuous, you’d swear the bike was made of carbon fiber.

IS CANNONDALE THE BIKE EQUIVALENT OF SONY?

What do the two brands have in common? They have an unhealthy appetite for creating proprietary parts.

Now, this isn’t really a new thing, and I think proprietary parts lie on a spectrum of hassle. For example, seatposts have been proprietary for a long time; just look at any aero bike or time-trial bike. Also, more and more brands seem to be introducing their own take on a D-shaped seatpost to encourage more flex and comfort. Seatposts are relatively low on the hassle spectrum, though, especially if you take yours out every few months to avoid seizing inside your seat tube by galvanic corrosion.

To properly fit the rear dropouts of a 2018 Cannondale SuperX, a wheel must be dished asymmetrically.

Wheels and hubs, on the other hand, are just about the worst place on a bike for proprietary restriction. And this is where Cannondale played its most recent hand with their 2018 SuperX cyclocross bike, which requires its wheels’ spokes to be dished a certain way vs. normal. Okay, so it makes for a slightly stronger wheel and shorter chainstays, but all of a sudden, the wheels you used for cyclocross may no longer work if you have a SuperX or two or five on your cyclocross race bike fleet, unless you get them all re-dished to fit. If you don’t know how to true wheels or re-dish them yourself, you can imagine how high that ranks on the hassle spectrum.

Cannondale’s 2015 release of the Slate was a risky move that eventually paid off.

Had times not changed, I would have included the 2015 introduction of the Slate, Cannondale’s strange gravel bike equipped with a Lefty fork, in this point. At the time, 650B (27.5″ or 584 mm bead seat diameter), as a wheel and tire size for road bikes, was largely a fringe offering used only by randonneurs and bicycle tourers. Fortunately, Lefty forks have been around long enough that people have gotten used to their quirks. The arrival of the Slate and its reintroduction of 650B also coincided with the boom in gravel bikes, which led to a notable increase of wheel and tire options in that size and around the 47-55 mm width, as people found out that this combination yielded a smoother ride at the same effective diameter as a 700C x 22-25 mm wheel/tire combo.

CONCLUSION

At long last, a Cannondale I am finally comfortable recommending: their Topstone aluminum gravel bike.

Don’t get me wrong. I admire a lot of what Cannondale does. Their affinity for aluminum and willingness to keep developing bikes with it while pushing its metallurgical merits is exemplary. A lot of the innovations they introduced are also legitimate solutions to engineering problems. However, from a DIY maintenance perspective, I find it very hard to recommend their bikes, and I believe buying them means telling Cannondale that there is nothing wrong with their approach. Personally, I wouldn’t entertain a Cannondale unless it had a threaded bottom bracket shell…and all credit to them for finally taking notice, as evidenced by their Topstone gravel bike.

Advertisement