Between 2 Triangles: The MTB Tech That’s Newly and No Longer Notable

Things mountain bike reviewers no longer note: disc brakes, a 1x drivetrain, and Boost spacing, to name a few. Today, it's all about that seat angle, dropper travel, and external cable routing.
External or internal dropper routing? With most modern frames this isn’t a detail we need to mention.

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The first electronic ignition was installed in an automobile in 1896, and we haven’t since mentioned the original knuckle-busting hand cranks. Similarly, we don’t call out the touch screen on smartphones anymore, as it’s expected across the board. What’s a rotary?

There are loads of mountain bike characteristics that riders and journalists alike no longer need to mention when describing a new bike, like whether it has disc or rim brakes and if the stem and headset are threaded or threadless. How does a quill stem work again?

For the sake of amusement and posterity, we gathered up many of the mountain bike related terms and phrases that are no longer worthy of note, alongside those that have become obsolete over the past ten-or-so years. In the process, we also kicked up a cloud of bike qualities and components that we focus on today that didn’t exist or weren’t of interest a few years prior. To keep this from growing off the page we’ll stick to bike components, leaving wearables and other gear alone, and try to remain in the past decade-ish of shreddy machines.

Again, this is largely an exercise in amusement, and it’s not intended as a comprehensive document. While manufacturers and marketing executives will still call out some of these details, we rarely do. There are a few missing pieces that we hope readers will share in the comments below.

Does the bike have a 1x or 2x drivetrain? Bike characteristics that we no longer note.

No front derailleur mount, no problem.

While loads of well-built older bikes and components are still out there making smiles, many of the terms we used to describe them have been archived. To start with the frame, it’s now expected that the head tube on any new bike is compatible with a fork’s tapered steerer tube, usually rotating in one of two different threadless headset standards. We no longer note tapered steerer tubes nor threadless headsets on new bikes, and instead, expect those as standard characteristics. Slacker head tube angles and longer reach measurements have also eliminated toe-overlap and the need for curved downtubes. Before headtubes leaned beyond the 69° mark on long travel bikes, some smaller frames had to use curved down tubes to give the front tire somewhere to go as the fork compressed. Riders on size small and medium bikes would often hit their toes on the front tire in sharp corners, forcing them to strategically relocate the cranks prior to turning. Thankfully, that time has passed.

Moving back to the seat tube, which thankfully is now tilted to a much steeper angle than the head tube, we no longer use this tube length as the defacto size of a bike. Seat tubes are now as short as possible, allowing shorter-legged riders to select longer frames if they like. The tube angle also grows steeper with every new model, making those longer, modern reach measurements feel more manageable while pedaling.

Once handlebars stretched to about the 750mm-wide mark they became too wide to pair with bar ends, and bars have continued to widen to 800mm since. While many riders cut their bars down to better suit their trails and shoulder widths, new bikes haven’t come with bar ends mounted for a hot minute. Most stock bars today use similar back- and up-sweep geometry, leaving only their carbon or alloy composition to note.

Wheels have seen some significant advancements since losing their shiny braking track and gaining 6-bolt or Centerlock disc hubs. Wider rear axle spacing has allowed for a full rearrangement at the back of the bike, and asymmetrically-drilled rims help to center everything and add strength to our hoops. However, those asymmetrical rims are rarely mentioned in new bike news, similar to how we don’t have to talk about tubeless rims and tires. For a brief time, there were a couple of systems, like UST from Maxxis, that were called out as notable features. These days we can expect that any new bike worth riding will include tubeless-ready rims and tires.

At the center of it all, hubs have changed width from 130mm to 135, then 142, and finally, boost 148 on most bikes. Right, and 150mm on downhill sleds. The only time hub spacing is mentioned in a bike release today is when it’s super-sized to 157mm with frames by Pivot, Devinci, and a few others.

Moving forward from that rear hub, we no longer mention if a bike has a 1x drivetrain, and the style of the chainring, for example, “Narrow-Wide,” is no longer illuminated in new bike reveals. Thanks to the massive gearing-range of contemporary cassettes, frame designers no longer need to think about front derailleurs and how to fit more than one chainring while making space for large tires and short chainstays. The end of front derailleurs brought a collective sigh of relief for every home mechanic, and no true trail-loving company has attempted to revive that ugly contraption since. There’s also no need to mention the clutch on a rear derailleur these days, as they all have one.

Disc brakes have been fairly standard for more than ten years, and we don’t have to mention pad rub too often anymore. Also, there’s no need to note hydraulic actuation as a feature over mechanically-actuated calipers, nor to state whether the plunger on one side is stationary or if both sides move in tandem.

Apart from true XC race components, it’s rare that a fork or shock comes with a remote lockout these days. Also, even the least expensive suspension typically includes external rebound and compression adjusters, leaving little to report there. For a long time it was necessary to call out tapered vs. straight steerer tubes and boost or 100mm dropouts, but those too are now commonplace.

Where does this front derailleur go? Obsolete or nearly-fossilized terms and phrases.

Trek is one of the few brands keeping the “plus” in tires and the “elevated” in chainstays. Photo: Trek Bikes

Around the time that fat bikes had their popularity explosion, 27.5+ tires, aka mid-fat, also started popping up on every brand’s trail and all-mountain lineup. The bulbous 3″ tires were said to add grip and squish in ways never imagined before. The trouble was that in order to reach a reasonable weight with the wider profile the tires had to be fairly thin, resulting in an unacceptable amount of punctures and spooky sidewall squirm. After about two years on the scene, 27.5+ and 29+ tires have largely been relegated to a few backcountry adventure platforms and the rear wheel of many new e-bikes. On a heavy e-bike setup the added space between tire and rim reduces punctures somewhat and the motor’s assistance makes weight less of a concern.

One of those 29+ bikes that is still in production is the Trek Stash. This massive adventure-rig rolls on 29 x 3.0″ balloons, and keeps the chain quiet with elevated chainstays. The higher chainstay position was popular for quite some time, on full suspension frames and hardtails alike. It allows for short chainstays, large chainrings, and wide tires, all in on the same bike. Trek is one of the very few industry-leading brands to continue with the design.

A good majority of antiquated terms remain relevant in one area or another. Take quick release skewers for example. While all new bikes (barring those designed for Rohloff hubs) use bolt-through axles, some companies call their through-axle a QR, as the lever folds similarly. Likewise, while almost all tubeless MTB tires use a folding bead, wire bead tires are still produced for downhill and commuter applications, keeping the wire alive — for the moment.

One component and term that has died entirely is the square-taper bottom bracket. Sure, some bargain bikes do come with the massive steel spindle, and brands like California’s White Industries still make square taper BBs and cranks, but you won’t see a decent new mountain bike build specced with anything but an external BSA or maybe a pressfit BB if the brand is based in a dry climate.

What’s the reach measurement? Things we now call out that were rarely or never mentioned ten years ago.

Image: Norco Bikes

Gravel is the new enduro, and soon enough both will be replaced with the coming cool. As bike tech improves and new genres of bikes find their place, there are different aspects to focus on. Between those two beloved triangles, geometry has become the hot topic across all types of bikes. Consumers today often know the geo of their last bike, and have a rough idea what they want to be longer or slacker on their next setup. Even the tallest riders can now have long enough frames with matching stack measurements, and shorter folks are stoked on decreased seat tube lengths across every size run. Ten years ago most of those same riders would have simply walked into their local bike shop and asked to see the 16″, 18″, or 21″ options. Now they can crunch the numbers online, and often times buy a bike on the same website.

Inside those tubes of varying lengths, internal and external cable routing remains an important distinction for some folks. While a lot of home mechanics and tinkerers prefer the ease of external routing, others dig the clean automotive-look of naked tubes that a fully internal setup creates. A decade ago most cable routing on mountain bikes was external, and now it’s often called out because brands know it’s an important element for their customers.

One tube that we now focus loads of attention toward is the seat tube. Yes, it needs to be short, and it also needs to be steep enough to accommodate long reach measurements with a proper climbing position, tilted forward enough to make room for 2.5″ tires and short chainstays, and straight enough to hold as much dropper post as a rider needs to sink inside. That’s a lot of needs from one frame tube, and it’s all culminated in the 77° to 80° STA measurements we see on new trail and enduro bikes today. Above all, the primary benefit of steeper seat tubes, as Richard Cunningham eloquently outlined, is that they put the rider’s weight where it needs to be while climbing. No more perching uncomfortably on the nose of the saddle while trying to maneuver steep roots. All of this is why we signal the seat tube angle in every new bike release article.

The Privateer 161 has an industry leading 80° seat tube angle that helps the burly bike climb comfortably.

Inside the over-studied seat tube, the dropper post is a piece of equipment most riders didn’t own ten years ago and now wouldn’t ride without. The trusty up-downer has several elements that are regularly noted in bike news, including travel, maximum and minimum insertion, stack height, actuation type, rebuildability, remote lever styles, and more. With long-travel droppers as affordable as $99, we can all get familiar with these terms and the massive benefits of saddle-free descending.

Over to the squishy side of things, our full suspension frames and their requisite shocks and forks have improved tremendously over the past decade, and trends abound. We now highlight fork offset numbers and whether a suspension platform’s progressivity is coil-compatible or not. The glut of aftermarket suspension options has led consumers to wonder about shock stroke, length, bottom-out style, volume spacers, standard vs. trunnion mount, and the internal tune of suspension components. We now include as many of these elements as possible in our suspension and frame reviews and news.

To roll it all together, carbon and alloy rims have remained a focal point of new-bike news, and the primary elements of importance today are rim width and hub engagement. While they’re all tubeless-ready and most wheels use a similar three-cross spoke lacing pattern, discerning riders want to know what tire width a given rim has been designed for and how quickly the freehub pawls will engage on tricky technical tracks. Trail- and enduro-intended rims seem to be settling between 30mm to 35mm internal measurements, optimized for 2.35-2.6″ tires, while freehubs are all over the place with between 10° and 0.52° of engagement offered up by 3 or 6 pawls and a hub-shell full of teeth.

Glossary of newly noted, formerly noted, and outdated MTB tech terms

We asked our localized MTB hive-mind to get this glossary started, and we could use your help to augment it. Please share any terms you feel should be on these lists in the comments and we will update them accordingly.

Newly notedNo longer noted (Usually)Obsolete terms/phrases
Basically anything with the word “gravel” in it. The new-ish “so enduro.”20mm v. 15mm front axle diameterWire bead v. folding
Adjustable geometry (flip-chip)Boost/non-boostBar ends
Air or coil sprung forkClutch derailleurFront derailleur mount and routing and existence
Asymmetrical spoke holesEnglish v. Italian BSA BB threadsQuick release
Bar/stem clamp diameterFull length cable housingQuick release seat post collar
Bikepacking compatibilityHandlebar widthRaised/elevated chainstays
Coil compatibilityHydraulic or mechanical discsShock/fork lockout routing or existence
Crank lengthHydro or mechanical dropper remoteShrader v. Presta valve
Dropper post min/max insertionIncludes dropper postSquare taper BB
Dropper travel and overall lengthInfinite adjust dropperToe overlap
Electronic shiftingInternally routed dropperV-brakes and cantilevers
Environmental friendlinessLock on grips
Fork offsetSeat tube length as sizing
Four-piston or two-piston brake calipersSingle, double, or triple chainring
Frame protectionSpoke lacing pattern
Freehub spline styleTapered steer tube
Geometry measurementsThrough axle front/rear
Hub engagements and number of pawlsTubeless tires or rims
Internal/external cable routing27.5+ compatible
Is it gravel and XC approved?
Is there an e-bike version?
ISCG05 chain guide mounts
Frame warranty
Max 1x chainringring teeth
Mineral oil or DOT
Mullet compatibility
Rim width
Shock length and stroke
Shock tune
Single clamp vs. double clamp grips
Suspension kinematics
Threaded v. Press fit BB
Tire rubber compound
Trunnion or standard mount shock
The number of water bottle mounts
Trickle down tech from said brand’s e-bike