Ultimate Guide to Fat Bike Maintenance
We all know that regular mountain bike maintenance is a necessary evil, but when you have a fat bike in your quiver that’s capable of riding in all four seasons, it becomes even more necessary and requires that you perform it at regular intervals all year.
This is your rig for riding on sand, snow and loose terrain where good grip may only be had with fat tires, and these conditions are typically the worst for all the other parts of your bike. While we all get a little lazy during the dry summer season and just roll our bikes in and out with barely a spot of chain lube to keep things rolling, you can’t expect to get off so easily all year.
It makes sense then, that for your safety and the longevity and smooth operation of your all-terrain ride, you should have to take extra care of your buxom beauty. Wet, muddy spring and fall riding can be rough on your bike’s moving parts, but the winter throws extra harsh conditions at them – snow, slush, salt, and sometimes extreme cold.
The general wisdom has always been to do a thorough clean and tune of your bike before you put it away for the season, but if you’re riding your fatty all year or just pulling it out for the upcoming snow season, it’s best to do the same before winter sets in. If noted polymath and founding father Benjamin Franklin were a bike mechanic (it’s possible) he might have famously said that “an ounce of preventative maintenance is worth a pound of repair.”
Take a good look at your fat bike
While you’re giving your bike a thorough clean and tune, it’s a great time to do a careful visual inspection. Start with your fork – whether you’re running a suspension fork or an RSD carbon fork, you’ll want to check for damaged or dirty seals, excess oil on the stanchions, or any chips, cracks, or peeling layers of carbon.
For suspension forks specifically, always refer to the manufacturer’s recommended service intervals for the timing of a service or rebuild. Despite regular service, you may find that in very cold temps, the rebound is slower and compression is harder due to oil thickening, and some riders are OCD enough to swap oils for a thinner viscosity during winter.
You can also mitigate the effect of extreme cold on your suspension by backing off your rebound and compression damping to wide open settings so that forks or shocks don’t pack up due to the thickness of cold, heavy oil. If you run hydraulic brakes and you’re concerned about the cold on their performance, it’s worth noting that DOT 4 – a common mountain bike brake fluid – is rated to -230°C, so you’re good at least until heck freezes over. Extreme cold may also have an adverse effect on greasy freehubs, as cold, thick grease will prevent the instant engagement of pawls, but this condition probably won’t persist for long enough during a cold snap to be worth the effort of removing grease and then replacing it when temps warm up again.
Generally speaking, the cold should not affect your fat bike’s frame and parts adversely, since most of the materials used to make bikes come from the aircraft industry, and most aircraft fly at altitudes in these temperatures all time, without any issues.
Continue your inspection to include all parts of your frame, especially high-stress areas like chain stays and seat stays, bottom bracket junction, head tube junction, and dropouts. Look closely for cracks and chips while you’ve got your bike clean and grime-free, as you’ll never get a clearer view and a closer look than when you’re giving your fat bike a good scrub.
While you’re at it, why not check all of your bolts and fasteners, too – you don’t wanna lose any of those in the muck or snow, or risk running components with over- or under-tightened clamps on frame or bars – metals can expand or contract with changing temperatures, and like carbon, there’s a very slight chance that they can become brittle in extreme cold, so regular inspections are a good habit to get into and can reduce the amount of actual maintenance that you need to do to keep your fat bike in fighting shape.
Fat bike drivetrain care
First up, it’s important to replace shifter cables and housing if they’re worn, but also because water and grime can infiltrate them over time, and colder temps will surely worsen shifting (and mechanical braking) if they freeze up, too. Don’t forget to lube new cable or housing when installing.
Speaking of lube, it’s best to use silicone-based wet lube as opposed to teflon-based dry lube, as it’s thicker, stickier and water-resistant, for the wet winter months. Wet lubes are used in all weather conditions but really excel when riding in autumn and winter as they won’t get washed off easily in puddles, snow or slush, or during storms, if you’re hardy (or unlucky) enough to be riding in one. As an important added bonus, wet lubes will resist salt corrosion, and they’re also really good at reducing drivetrain noise.
Of course, wet lube attracts more dirt and grime, and if it’s left to accumulate, it can act like a grinding paste to wear out components more rapidly. Wiping down your chain, chainring, cogs and derailleur after each ride is definitely a good idea, and weekly scrubbing of your chain and drivetrain with solvent or de-greaser is also recommended. And it should go without saying, but…
Never put your fat bike away WET
Big rigs will pick up more debris and moisture than skinny single-speeders, so unless you’re cool with puddles of thaw around your bike, you’re gonna wanna wipe that baby down! If you’re still using rim brakes on any of your bikes, give those rims ago with the towel, but make sure to wipe down disc rotors too, as these will build up with grime from hard-wearing brake pads and deep snow. Check those brake pads while you’re at it, too.
If you commute, or your trail ride involves some road riding to get to the trailhead and back, road salt can also be a huge problem. This is true even for the highway drive while your bike is up on a roof or hitch rack. If you’re not a van guy or gal or don’t have a truck with a covered rear, maybe you should work out a barter deal with your riding buddy who is, or does. Free maintenance maybe, or post-ride beers? 🤔
Fend off the splashes
There are several choices on the market now to fit plus- and fat bike wheels and tires, ranging from off-the-shelf Surface604 or Portland Design Works fenders, to baller custom titanium ones from Kelpie Cycles or custom wooden jobs from MK or Woody’s. DIY’ers can also hack store-bought guards and fenders to fit a fatty just fine.
The next couple of tips are more about you than your bike, but they’ll definitely help you enjoy riding your fat bike or plus bike more if you’re into all-season riding.
Late fall to early spring is darker days, and in the dead of winter, you may not be able to get much of a daytime ride at all, so a good set of lights is key to enjoying a ride session without having to worry about navigating in the dark. Generally, the best set-up is some bar-mounted lights and a unit for your helmet too, as this will illuminate the trail ahead of your bike, and also down-trail towards wherever your head is turned and looking. The Gloworms we’ve been using are insanely bright and very light, highly recommendable.
Foot out, flat out
When you’re getting loose and rowdy and trail conditions are slippy and sloppy, it helps to be able to throw a foot out in a split second if you need to. If you normally ride clipped in, it might be best to swap your clipless pedals for platforms. They’re easier to clean, have less moving parts, and don’t pack up with snow and ice as easily.
Your choice of footwear also expands greatly to anything you’re warm and comfortable enough in that’ll still grip your pins. If you’re gonna stick with SPDs, we’ve found that the 45NRTH Wolvhammer is as good as it gets for a cold-weather riding boot.
A good pair of durable merino wool socks will keep your dogs comfortable while you hammer away, and if your extremities take a while to get up to nice cozy temperatures when riding in the cold, maybe bring along a few sets of boot and hand warmers. Popping these in at the trailhead on a frigid day will make you very happy, and having spares for your mates will also make you very popular at the apres festivities 🍻
And of course, always keep the rubber side down!
Disclaimer – While we have a lot of friends in the industry that make great stuff we like to use, none of the products mentioned in this post are being endorsed for a fee or kickback of any kind. Also, any permanent mods you might make to your RSD frame can potentially void your warranty.