MTB Fork FAQ

Our general rule of thumb (and many bike manufacturers' warranty policy will be in line with this) is that going up or down 10mm of fork travel on any bike is just fine, assuming you're interested in altering the geometry of the bike a little bit. A 20mm change in travel can sometimes make sense, but anything more than that is something I'd advise against since it will dramatically change the way the bike handles.

Adding 10mm of travel is going to raise the bottom bracket slightly (preventing pedal strikes, but also raising your center of gravity slightly, most noticeable in cornering) as well as slack out your headtube angle giving the bike an all around slightly more "aggressive" feel. So not only will you have a little bit more travel, but you'll find that the bike is a little bit more stable/confidence inspiring at higher speeds and/or when pointed downhill, but sacrificing some slower speed/uphill handling. If that sounds interesting to you, then I'd say go for it.  

Your frame manufacturer will generally recommend a range of fork offsets that your frame was designed around. We recommend staying within that range, and most riders prefer a shorter offset than a longer one. A short offset will help you find front wheel grip and also help with stability at high speed, but makes it tougher to engage turns. We generally recommend riders get a short offset fork.

Unless you’re riding two different offset forks back to back, it is very difficult to identify their nuances on the trail.

It depends! If your new fork uses a different post mount size than your last fork, then yes. To figure out what size brake adapter you need, you need to know your fork’s post mount size and your desired brake rotor size. For example, let’s say you want to use a 200mm rotor with your Fox 38. A Fox 38 uses a 180mm post mount, so you’ll need a 20mm adapter to make up the difference between 180mm and 200mm. If you want to use a 200mm rotor with a RockShox ZEB, you don’t need an adapter, because the ZEB uses 200mm post mounts.

When upgrading your fork, you need to use the same hub spacing as your previous fork. That way, it will be completely compatible with your front wheel.

All modern single crown bikes use 15x110 boost spacing. This means your axle is 15mm in diameter, and your hub is 110mm wide.

All modern dual crown forks use 20x110 boost spacing, and use a more robust 20mm axle to offer more security when taking bigger hits.

There are other standards, such as 15x100, 12x100 QR, and 20x110 non boost, and you just need to make sure that your front hub and fork use the exact same spacing to ensure compatibility.

No, you do not need an eMTB specific fork for your eMTB. Luckily, our modern enduro forks are perfectly designed for both eMTBs and normal mountain bikes. Fox used to offer eMTB specific forks, but they’ve gotten rid of them and condensed their lineup because we’ve learned that eMTBs experience pretty much the same forces as normal mountain bikes. Sure, there’s a little extra weight in the system, but it’s nothing that we need to design a whole new fork chassis around.

There are two steerer tube sizes these days, with clear differences between their use cases. All forks use either a 1.5” tapered steerer tube, or a 1 ⅛” straight streerer tube.

Single crown forks use a 1.5” tapered steerer tube. Just about all modern mountain bikes are built around a 1.5” tapered steerer tube, but some bikes from department stores like Walmart will still use a straight 1 ⅛” steerer. There are also some steel bikes that use a straight steerer, but 99% of bikes built today use a 1.5” tapered steerer tube. All high performance single crown forks we sell are built around a tapered 1.5” steerer tube.

Dual crown forks use a 1 ⅛” straight steerer tube. All modern downhill bikes and forks use the 1 ⅛” steerer tube, and there are no other options for dual crown forks or downhill bikes.

No matter what kind of fork you use, your steerer tube will be long enough. All riders will use a hack saw or pipe cutter to trim their steerer tubes down before final installation.

It depends if you’re trying to win the MTB fashion contest. If you are, then yes, they do need to match. If you’re not worried about dominating the runway, then no, your fork does not need to match your shock brand. We recommend that your fork and shock match in their intended use, but beyond that, go crazy.

Every shock pump will work with every fork, so get whichever one is in your budget and has the features you’re looking for! You need to choose between an analog and a digital shock pump, and here in the shop, we use both the Fox Digital Pump and RockShox Digital Pump. Both of these digital pumps offer amazing accuracy, and are our shock pumps of choice.

It’s true! If you bust out the measuring tape and look at your new Fox or Marzocchi fork, you’ll find that your 150mm fork isn’t exactly 150mm in length. You’ll measure about 158mm, but your fork will only compress 150mm when it bottoms out. Don’t worry, all of their forks are like this, and there’s nothing wrong with your fork. When you bottom out your fork, your o-ring won’t get quite to the top of the stanchion, and that’s by design.

With your new fork, you’ll find a star nut, an axle, a couple of volume spacers, and plenty of light reading on the legality of your fork. RockShox also includes a mud guard in the box, while Fox does not.