There used to be some stigma against riding a bike “out of the box.” Why would you let some soulless corporation decide how powerful your brakes need to be? Or which headset defines you as a person? But now, for the most part, you can’t really go wrong buying off the shelf. The top drivetrains on the market are pretty dialed. Same for the leading brakes and suspension. Just swap the touchpoints for ones that suit you, and that’s as bespoke as your spec needs to get.
But the urge to customize has not disappeared. If anything, it’s turned into something deeper. Something more essential. We can now choose a frame size based on our riding style, not our inseam length. We can add or remove volume spacers to make our suspension’s behavior complement our behavior. Or, if that’s just not enough, there is the fascinating world of aftermarket linkage components. The fanfiction of the frame-design world, aftermarket linkage components reimagine a given bike as it might have been. In an alternate universe, Pivot could have built the Switchblade with more travel. Or Specialized could have made the Stumpjumper Evo ramp up earlier and more drastically. When it comes to dreaming up these parallel realities, Washington state’s Cascade Components seems to have the most active imagination.
In early 2019, Jimmy Davis, the engineer behind Cascade’s linkage designs, was waiting on a Santa Cruz Nomad rear triangle to replace the one he had just broken. That, combined with the blizzard Seattle was then enduring, gave Davis the time to design and manufacture a link that would make for a more progressive leverage rate. After some positive feedback from fellow riders, this became Cascade’s first link. Their catalog has since expanded to offer 39 products for 14 bike brands (at the time of writing). They’re most often meant to produce more progressive leverage-rate curves, and they usually also add some travel. And according to the policies of most bike brands, a Cascade Components link also might void your frame warranty.
There are plenty of reasons why that is, and some are as simple as whether the modifications will safely fit the frame. Pivot Cycles founder and all-around bike brainiac, Chris Cocalis, knows that struggle all too well. “When we design a frame for a certain amount of travel, we typically run up to the limit for tire clearance at bottom out.” In engineering around demands for things like wider rubber and deeper seatpost insertion, bike brands tend not to leave any excess room on the table. Cascade, of course, tests for this, usually by machining a working prototype straight away. 3D-printed dummy links can suffer from flex and imperfections that prevent them from seeing the whole picture. Still, as Davis explains, Cascade admits there are variables. “When Santa Cruz changed the shock stroke on the Hightower to 55 millimeters, that did create some seat buzz on smaller-size frames. But on the Hightower that we originally designed it around, that wasn’t a thing.” As a result, instead of discontinuing or redesigning either of their Hightower links, Cascade simply explained the small-frame seat-buzz issue on the Hightower link product pages, and you can take it or leave it. This is rather unprecedented in our world. The sudden growth has left brands unsure of how to react, and most are playing it safe.
Specialized’s trail and gravity product manager, Steve Saletnik, sums up what I heard from nearly all of the bike manufacturers I checked in with. “We test all of the frame components in our labs as a system. This simulates years of riding, and of course, if you change a component in that system, there are various stresses that can transfer into other parts based on the differences of that component. And there’s no way that the team in the lab can keep up with the number of these aftermarket components or the speed at which they’re coming to market.”
Cascade’s answer to unseen frame stress made perfect sense to a layperson like myself. As Davis explains, “Realistically speaking, the thing that’s going to break your frame is a harsh bottom out. You’re reducing the severity and the frequency of those instances.” What that means on a carbon frame, though, may be different from what it means on an alloy frame. “Carbon doesn’t really fatigue, so you don’t have to worry too much about what the cycles are, just what the max stresses are.” On an alloy frame where fatigue does matter, Davis admits it’s a little less clearcut. “It decreases the maximum stress applied, but it increases the average stress. As far as fatigue goes, that’s kind of an even tradeoff.” Assuming you’re riding hard enough to take advantage of a more progressive leverage-rate curve, Cascade’s approach doesn’t pose any risks you aren’t already taking if you’re at that level. Seems legit.
But what about the shock itself? Bike manufacturers almost always work with suspension brands to find a damping tune and air volume that suits a frame’s given kinematics. Pivot is no exception, as Cocalis points out. “Dave Weagle, Fox, and Pivot all go to great lengths to ensure that the damper and spring can handle the forces that are applied to them. Changing leverage ratio substantially on the shock that the bike was designed for could result in a poor-performing shock and/or reduced durability of the damper.” Davis acknowledges the relationship between shock tune and frame design, but compares a change in leverage ratio to a change in rider weight. Many bike brands (including Pivot) still don’t adjust their shock tune based on frame size to accommodate different-weight riders. He adds that the average leverage rate, not the particular shape of the leverage-rate curve, is what matters. Current bike suspension is not position-sensitive, and Davis asserts that nearly any shock will have the damping range to accommodate the impact that a Cascade link has on average leverage rate.
All this back and forth feels unprecedented because it usually happens behind one tightly knit engineering team’s closed doors. But there is very little communication between manufacturers like Cascade and the bike brands they outfit. Cascade is gathering its data on a bike’s stock setup through real physical measurements, not factory blueprints provided by the brands. And information is not flowing in the other direction either. Although the folks I talked to at Santa Cruz, Specialized and Pivot all stated they would welcome communication, Cascade’s operations manager, David Howell, is understandably hesitant. “We may get an email that asks, ‘We’d like to evaluate this for warranty, can you send us a link?’ And for us, we can’t just send out a part and have nothing in return, because then we’re potentially doing someone’s R&D for them. That effort that we put into the kinematics is valuable to us.”
This is a stalemate that other industries have done a better job at settling. The 1975 Manguson-Moss Warranty Act is a popular protection for those suping up their cars and trucks. Lifting your Tacoma four inches absolutely might void its warranty, but the manufacturer has to prove that any damage was caused by the modification. That’s a difficult thing to do on a mountain bike, which is subject to an immeasurable variety of stresses and impacts. And at this level, there’s just not a big enough user base to impact consumer law. The safe and simple answer is the blanket void that most brands have adopted. But most brands are also seeing this as an emerging trend, and are actively trying to find ways to address it.
Santa Cruz’s North American brand manager Garen Becker starts to explain their warranty position just like I expected, but takes a refreshing, pragmatic turn. “Yes—if we didn’t design it, we don’t officially recommend it, so it would technically void the warranty. That said, if something completely unrelated were to happen to your bike with the link installed, we’d cover that.”
Specialized is also keeping a close eye and an open mind about how to approach this. “I will note that we do have inconclusive data on claims coming in from the use of these products,” global MTB marketing manager, Kerstin Ulf carefully puts it. “So this isn’t to say there’s no data, we just don’t have enough to say it’s fine.”
Despite how it may seem, this hesitation is not about brands looking to stifle creativity in the industry. Even Pivot Cycles’ founder, Chris Cocalis, who seemed the most skeptical of the trend, was at the same time kind of excited by it. “The entire idea of really cool-looking aftermarket CNC machined linkages was really intriguing to me as a consumer and tech geek,” he says.
Santa Cruz had a similar understanding of the appeal of what a Cascade link can represent, citing the ability to reinvigorate someone’s love for their Hightower by modifying it to work with a mixed-wheel setup. And Ulf at Specialized compared what riders are achieving with Cascade Components linkages with what they themselves do every day. “We’re making eight to ten different links when we start a new bike project, figuring out what’s best and what works. This is basically riders getting to do a little slice of what we do when we develop a bike.”
This is definitely not the first time aftermarket linkages have been available. And Cascade is not the first brand to make them. But things have changed. Our tastes are more sophisticated. Our sport, and our bikes have matured over the past decade. Maybe someday, these will be choices we’ll be able to make for ourselves.
Photos: Anthony Smith
From Fall 2021