Are modern framesets killing mechanical groupsets?

Modern road and gravel bikes are highly engineered objects. It’s commonplace for their release to be accompanied by a white paper, detailing Computational Fluid Dynamics modelling, wind tunnel testing - and data - lots of data. As a result the bikes we ride today are, largely, faster and more comfortable than their predecessors.

We’ve grown accustomed to the aesthetic of the modern bike too, to the point where a bicycle with external cables and a traditional two-piece bar and stem might be deemed old-fashioned, and is often met with criticism from consumers.

However, internal cables can be a cause of great frustration when it comes time to replace them. A routing system that doesn't bypass the headset adds faff and creates confusion for the inexperienced mechanic. It also makes the once straightforward job of swapping out a stem or altering the number of headset spacers, far more involved. Unless, however, the bike is designed with an electronic groupset only in mind; an electronic-only frameset with limited to no wiring - SRAM and Campagnolo options have none whilst Shimano Di2 has just one cable - is a much easier beast to deal with.

Some of the most progressive road - and even gravel - framesets aren’t designed with mechanical shifting in mind, with brands telling us that this is dictated by consumer behaviour. The trend does, however, arguably render mechanical groupsets as being en route to obsolescence.

In the last couple of years, we’ve seen the release of the Specialized Tarmac SL8, the Gen 8 Trek Madone SLR, Pinarello Dogma F, the Factor O2 and Ostro VAM and the Canyon Aeroad CFR, all high-profile bikes created without a second thought for a mechanical groupset; the lack of any exit ports on the frame for mechanical housing means these iconic models are now ‘electronic-only’ options. Similarly, the Roval Rapide cockpit designed in conjunction with the SL8 is only compatible with electronic shifting.

“Consumer demand does influence our decision to include electronic groupsets,” says Pierre-Henri Medas, Product Marketing Manager at BMC. “It also motivates us to design our frames specifically to accommodate these technologies.”

I ask whether designing a frame that can accommodate both external and internal cables is more labour-intensive?

“Yes, designing frames compatible with multiple drivetrain types requires significant engineering effort. We consider mechanical drivetrains alongside electronic systems like Shimano Di2, SRAM AXS and Campagnolo Wireless. It’s not straightforward to determine optimal cable exit locations, sizes, and routing, whether internal or external.”

BMC chooses to match the frame material to the intended groupset, which still includes mechanical options.

“We optimize our [higher end] MPC and 01 composite carbon levels specifically to meet the requirements of electronic groupsets. Since the likelihood of mechanical groupsets being assembled on these two levels is minimal, we focus exclusively on optimizing for electronic systems,” says Medas.

“For standard-grade carbon frames used with mechanical setups, we account for all drivetrain systems. BMC remains committed to supporting mechanical shifting options and ensures they are integrated seamlessly into our frame designs.”

So is it simply down to making a choice between ease of maintenance and having the very latest in peloton-led design? Glen Whittington, of AEIGHT, thinks so.

“I think customers have to accept that if you want cutting-edge design, your maintenance fees will go up too,” he says, referencing both the cost of labour but also the cost of replacement parts; a mechanical Shimano 105 derailleur will set you back around £50/$65 vs a Di2 version at £275/$280. “Just in the same way that you probably wouldn't service your own expensive car or motorbike, unless you know what you're doing.”

He also makes the point that modern bikes with fully internal cabling require their owners to care for them well. Or risk the consequences.

“Muddy or wet bikes, which aren't properly stored, can lead to some big repair bills,” he says. “A simple headset bearing swap can easily turn into a full strip and rebuild plus parts, depending on the brand and the design.”

That said he extols the benefits of both internal routed framesets and electronic gearing. With one caveat.

“In many cases I don't see the point in mechanical groupsets. The exception to this would be expedition/touring/bikepacking bikes,” he says. “I wouldn't personally design a mechanical frame now, unless the rider was going touring or bikepacking somewhere really off grid. If that was the case I'd use mostly external cables for ease of repairs in the field.”

There is of course still the option to buy a modern road or gravel bike with externally routed cables, and mechanical compatibility built in.

Brands such as Ritchey in the US and Fairlight in the UK only sell bikes with external routed cables, and all of them are compatible with mechanical and electronic groupsets. The design choices are part of an ethos that places a premium on functionality, ease and cost of repair. And, depending on your interpretation, these bikes are no less modern when it comes to ride quality, as they too benefit from contemporary materials, geometry and tyre clearances. What they lack is the same level of system integration. If being able to repair and maintain your own bike with a minimum of fuss trumps all other requirements, and running a mechanical groupset is high on your agenda, then a bike such as this makes the most amount of sense.

To an extent, many consumers could argue that the ease of maintenance and availability of parts for top-end bikes is irrelevant to them - after all, we’re talking about bikes that in some cases are retailing for five figures, whether you’re buying in dollars or pounds. This is true, until the march of trickle-down technology is considered.

Technology made available to the most professional of bikes will, eventually, find its way onto machines purchased by those who are more frugally minded. And at that point, what we’ll need from bike manufacturers is an approach that takes into account backwards compatibility, the cost of maintenance and replacement parts, as well as a forward-facing lens on progression.