There are a few excellent manufacturers out there who are making aftermarket fat tire forks and if you are planning on getting one for your Surly steed there are a few things you should know.
White Brothers makes a fork called the Snowpack and it’s available in two different lengths, 450mm and 468mm (we would recommend 450mm for our bikes). It has carbon fiber legs (if you’re into that sort of thing though we say a Surly rejects carbon fiber like a cat rejects hairballs) and is designed around a 135mm front disc spaced hub. White Brothers has the tire clearance listed at 4.96”. Here is where you want to pay close attention. Our forks and front 135mm hub use rear disc spacing. The Snowpack will not work as an out of the box replacement unless you are using a Phil Wood or Paul Components hub.
Salsa also makes a fat tire adventure fork called the Enabler. The Enabler is designed to work with the 135mm rear disc spacing hubs (like Surly) and Salsa lists the tire clearance at 4” of adventure on an 82mm wide rim. The length of the Enabler is 468mm axle to crown. Our fat forks have a listed length of 447mm axle to crown; that’s what the frame was designed for. Got it? So if you are adventurous and you are thinking about putting this on a Pugsley be prepared for the front end to adventure up significantly-which technically voids your Surly frame warranty, be warned you adventurers’.
9:ZERO:7 manufacturers an Aluminum fat tire fork that is available in two different lengths, 450mm and 468mm (once again, we recommend the 450mm). 9:ZERO:7 has a tire clearance listed at 4” with their 100mm rim (called the FlatTop). This fork is designed to work with 135mm rear disc spaced hubs (like Surly) so this fork should work fine on our Pugsley. I say should because I have no idea of what type of tire, rim, fender, rack, light-system, gun mount, or other random ass shit you have on your bike. Make sense?
I’m not even going to bother getting into fat front suspension forks. In my humble opinion there is just not enough information available yet. Do you need a fork with travel on a fat tire rig? Maybe you think you do. Who knows, I’m just not that adventurous.
Update:
Adam was kind enough to supply me with some more information.
I mentioned the difference between our front 135 hubs [with rear rotor spacing] and the Paul/Phil front 135 hubs [with front rotor spacing], but it is also worth mentioning the offset wheel builds. For example, the 450mm 9:ZERO:7 fork would fit fine on the Pugsley, as the ATC and rotor spacing match, but the fork is designed for a symmetric wheel build, where as the Pugsley has an offset wheel/fork. If a customer has a stock Pug complete, they would need their wheel rebuilt.
The other consideration is the disc caliper adaptor. The Pugsley uses a rear disc adaptor, where as the Moonlander and the Enabler forks use front rotor adaptors. This is a bit confusing, so one more time for clarity. Pugsley, Moonlander, and Enabler forks all use the rear 135mm rotor offset, but the Pugsley uses rear caliper adaptors, Moonlander and Enabler use front caliper adaptors. The Snowpack fork uses the front caliper adaptor standard, and I could not find the specs on the 9:ZERO:7 fork.
As always please, feel free to call us or send us an email and we’d be more than happy to answer your questions.
Random creepy bastard
Stay Surly.
BoB