The most popular MTB fork you (probably) know nothing about

This is the SR Suntour XCT30 mountain bike suspension fork, and this is its cousin, the XEM series. Together, these are the most popular suspension forks in the observable universe. They're also the suspension forks that people replace the most. In other words, people are ripping these off their bikes and replacing them with better ones. However, there is more to both of these than what meets the eye, and today I'm going to deep dive into the XCT and XEM series and tell you all about them. First of all, where are you likely to find these suspension forks? Well, mountain bikes price between $500 and $1,000. That's the entry level. They're usually spec'd with these. Nine out of 10 times, you're going to find one of these two forks on those bikes. They're even available on cheaper bikes like the Kent True Vale and Ozark Trail Ridge, which are available at Walmart. Why is that? Why are these so ubiquitous at the entry level? To a bike company, there's just no other option that has a better mix of safety, durability, neglect tolerance, performance, and of course, pricing. There's really not even a close second. Let's start with safety. Well, for a fly-by-night bike brand, safety might not be that important at all, but if you want to do business for more than a few years, you don't want your customers getting hurt, and you certainly don't want to get sued. And given the fact that anything can break, they make sure that these break slowly. And that's precisely what you want. You want a suspension fork to die a slow and painful death where it's cursing at you, talking about your sister. What you don't want is an instantaneous catastrophic failure. Everything on this fork from the top of the steer tube all the way to the bottom of the stanchions is made of steel, more steel than is actually needed, and it bends. Now the lowers are actually made of a stiffer aluminum alloy, and so when this fork fails, it's going to happen right here, slowly. But it sure does take a lot to make it do that. Here's a video that Kyle Warner took of a kid having way too much fun. Now it does say right here to kind of take it easy on this fork, but that is precisely what 12 and 14 year olds don't do. Despite that warning sticker, these are actually tested to the same ISO 4210 standards as other suspension forks, so they can take a lot of abuse. How do they make it that strong for that price? They throw metal at it. Nobody has ever accused a Suntour coil fork of being lightweight. That's why a lot of people replace these. You can replace it with basically any air fork and save two pounds off the total weight of your bike, but you can't make something durable and cost effective without a trade-off. But these are also durable in other ways. I've actually ridden cheap suspension forks to the point of failure after just a few minutes of hard descending. I've ridden these way harder with no failure whatsoever. And just like you can't guarantee that a beginner is going to take it easy on their Suntour coil fork, you most certainly can't guarantee that they're going to service it. And so let me ask you, what do you suppose the service interval is on a Suntour XCT30? I don't know either. Different variations of this fork have been around since the mid-2000s, and I'd venture to guess that maybe 5% of them have even been taken apart. They're easy to service. You can replace the seals and the bushings in this fork in just a couple of minutes, but nobody ever does. And if you just leave it, it tends to degrade and then plateau pretty much indefinitely. Beyond replacing these seals and bushings, all you have to do with this fork is clean it. You drop the lowers, you wipe them off, you clean off the springs, and then you put new grease on it and put it back together. There's not much you have to do to maintain a coil fork in general. But safety, durability, and neglect tolerance are far from the only reasons why manufacturers spec these forks so often. They're also available in a dizzying variety of configurations. First of all, they're available in all different wheel sizes, 27.5, 29, 26, 24, but also hub widths, travel, axle type, and even straight and tapered steerer tubes, but it doesn't end there. They actually come in different spring rates, and so a bike company might put a heavier spring on a size large than they would on a size small. But there's more. When you compress a suspension fork fully, it is considered bottomed out. Now the opposite is called topping out, and if you've ever gone off a jump on a cheap fork and it extends, sometimes it feels kind of violent, almost like a slide hammer. Little known fact, XCM forks actually have a negative spring that stops that from happening, much like a high-end fork would. But in every version of both suspension forks, this rubber cylinder inside one of the springs is known as rebound rubber. I don't know if that's the official term, but yeah, they call it rebound rubber because as the spring decompresses, it actually gets a little bit narrower and clamps down around the rubber and slows the extension of the fork. It's almost like a rebound damper that's really cheap and can never break. But if a manufacturer wants to, they can spec an XCT or XCM fork with a rebound cartridge. These you can actually buy on Suntour's website and upgrade your own fork. It's a fixed rebound damper that you can't adjust from the outside. It's just in there, and so you would never know that the fork was spec'd with it unless you physically tested it or took it apart. This is not a feature that would actually help sell a bike since most consumers don't even know it's there, so it's something a bike company would add to actually make the fork better. And to a bike company, these upgrades might only cost a couple of extra bucks, and at the $700 to $1,000 range, you can spend an extra $10 or $15 to make the bike better. But at the lowest price points, every dollar counts and they have the cheaper forks with no options to make it work. I don't have exact numbers, but I estimate that large bike companies are paying somewhere below $50 for these forks. And of course it goes up from there as you add things like dampers and lockouts. I've even messed around with some forks from Amazon and AliExpress, and yeah, for the money they can be pretty lightweight, have some impressive features, and even perform well, but in my experience the performance degrades very quickly over time and the quality can be inconsistent. And from a performance standpoint, these work. I've ridden far too many bikes with XCT and XCM forks, and I can say from experience you are better off with one than without one. If these are such a great balance of performance and quality, why are so many people removing them and replacing them with better forks? Well because they're heavy and they're not very adjustable, a high-end suspension fork can cost you a thousand dollars or more, but you can get a pretty decent entry-level air fork for $250 and save two pounds off of one of these. And so for many consumers who purchase entry-level bikes and then progress, they want something they can set the sag on, adjust the rebound damping, they want the weight savings, and for them $250 is well worth it for the upgrade. But in my opinion, on the list of upgrades you should be doing to an entry-level bike, this is pretty far down the list. On a bike like this GT you're much better off upgrading the drivetrain, the brakes, adding a dropper post, and maybe even swapping out the stem before you plunk over $250 for an air fork. But Suntour knows that these coil forks are the bare minimum and that many consumers are going to end up upgrading them, and so they lean into it. Suntour actually has an upgrade program, they'll give you a $100 discount on a newer better Suntour fork if you're upgrading from an old Suntour fork. And so one reason that a lot of people upgrade this fork is that Suntour is actually providing an incentive to do so. And much like Shimano makes low-end high-end parts, Suntour makes suspension forks like this one, and then they also make magnesium air forks like the one that Kyle Warner rides. So no matter what application or price range you're looking at, they're going to have something that fits your needs. And so, are these high performance? No, of course not. They're heavy, they don't have a lot of features, and they're not particularly beautiful, but they are safe, they're durable, and you can care for them much like you would a Philodendron, that is to say, water it like once every two months. And of course, they're very affordable and they perform well enough, and so they do find their way onto more bikes than almost any other suspension fork in the world. In researching for this video, I was fascinated to find all the differences between cheap Suntour suspension forks. This video is not sponsored by Suntour. I only say that because when I do videos featuring some kind of brand, people always accuse me of that. But no, I'm just interested in it and I want to put the information out there. These forks get a lot of hate because they are on the cheapest bikes, but that gets a lot of people into mountain biking. And when you consider the price point that the manufacturer is trying to reach, and the types of people that are going to buy the bike, these do a lot of good in the world, and they're actually very well engineered for what they are. I wrote this article about why experts have a difficult time getting through to beginners. This article and many other articles written by some of the most interesting voices in mountain biking are available on my Substack. Not only that, but you'll get the video you just watched two weeks early with no ads. Get interesting articles, ad-free early videos, discussions, and help me break free from the algorithm on Substack. I hope you enjoyed this deep dive into entry-level Suntour coil forks. I hope you learned something, and if you didn't, I hope you at least found this entertaining. Thanks for riding with me today, and I'll see you next time. Okay, buddy. Okay. It's okay. It's gonna be okay. Everything's gonna be okay, Oscar. It's all gonna be okay. Yeah. Okay. Get away from the grease, please. Okay. Disaster.