Question 1

What size fenders do I need for my bike?

Accepted Answer

Fenders are sized to two things: wheel diameter and tire width. Read your tire sidewall - something like "700x32c" or "27.5 x 2.1" tells you both numbers. Match the wheel diameter exactly (700c, 26", 27.5"/650b, 29", or 12-20" for kids bikes) and pick a fender rated for at least 8-10 mm wider than your tire so the fender clears mud build-up. A 700c × 45 mm fender, for example, suits 700c wheels with tires up to about 38 mm; for wider gravel tires you want a 53 mm or 65 mm fender.

Question 2

What's the difference between full-coverage and clip-on fenders?

Accepted Answer

Full-coverage (or full-wrap) fenders bolt to your frame and fork at three points per wheel and cover roughly 60% of the wheel, including a mudflap that drops down near the ground. They give the most spray protection, are quietest, and are the right answer for daily commuters and dedicated rain bikes - but they need a frame with fender eyelets. Clip-on (or strap-on) fenders use rubber straps or P-clips around the seatpost, downtube, and fork legs. They install in minutes without tools, work on bikes that lack eyelets, but cover less of the wheel and tend to shift or rattle over time. Race-style "ass-savers" are a third tier - they only protect your saddle area and are best thought of as emergency-only gear.

Question 3

Do I need eyelets on my frame to fit fenders?

Accepted Answer

For full-wrap fenders, yes - you need three mounting points per wheel (fork crown, fork dropout, and chainstay/seatstay bridge). Most touring, commuter, gravel, and many hybrid bikes ship with eyelets; race-oriented road bikes and many full-suspension MTBs do not. If your bike has no eyelets you have two options: use P-clips (small metal clips that wrap around the seatstays and fork legs to create a mounting point - a workable but noisier compromise), or skip full fenders and run a clip-on / strap-on system instead. Some clip-on fenders, like SKS Raceblades or Topeak DeFenders, are specifically designed for eyelet-free road bikes.

Question 4

Are there fenders that work on gravel bikes and mountain bikes?

Accepted Answer

Yes, but they're a different breed than road fenders. Gravel bikes need wider fenders (53-65 mm) to clear knobby 38-50 mm tires and shed mud rather than trap it; SKS Bluemels and Planet Bike Cascadia both make gravel-specific full-wrap sets. Mountain bikes - especially full-suspension models - usually run dedicated MTB guards like the Mucky Nutz Face Fender (front, zip-tied to fork arch) and Bender (rear, mounted to seat rails or seatpost). These are not designed to keep you dry the way commuter fenders are; they exist to keep mud and trail spray out of your eyes and off your shock seals. Hardtail MTBs with rack mounts can also run full-wrap fenders if the frame has enough tire clearance.

Question 5

How do I fit fenders to a kids bike?

Accepted Answer

Kids fenders are wheel-size specific - a 16" set will not fit an 18" or 20" bike, so check your child's wheel diameter before buying (it's usually printed on the tire). Most kids fenders are plastic, ship as front-and-rear pairs, and mount using the bike's existing brake-bolt and rear-dropout hardware rather than dedicated eyelets. Installation typically takes 10-15 minutes with a single Allen key. RoyalBaby, Schwinn, and Huffy all sell wheel-size-matched sets for their own bikes; aftermarket kits from generic brands also fit well as long as the wheel diameter matches.

Question 6

Can I install fenders only for winter and remove them in summer?

Accepted Answer

Absolutely, and this is the case for using a clip-on system on a fair-weather bike. Strap-on fenders like the SKS Raceblade Pro or Topeak DeFender XC come on and off in 2-3 minutes per fender with no tools. Full-wrap fenders take longer (10-20 minutes) and require the right Allen keys, but they're still removable; if you go this route, take a photo of the cable routing and stay positioning before you take them off so reinstall is easier. Some riders keep a dedicated rain bike with permanent fenders and ride a separate fender-free bike when it's dry - there's no wrong answer.

Question 7

Why are my fenders rattling, and how do I stop it?

Accepted Answer

Fender rattle is almost always caused by one of three things. First, loose mounting bolts - torque the fender stays at fork dropout, chainstay bridge, and fork crown to manufacturer spec (usually 4-6 Nm); a thread of blue Loctite helps if they keep backing out. Second, a stay that is touching the tire or rim - bend the stay slightly outward so the fender sits 8-12 mm clear of the tire on each side. Third, plastic-on-plastic vibration where the stay enters the fender body - a small piece of electrical tape or a rubber grommet at that joint kills the buzz. Premium fenders like SKS Chromoplastic use a metal core specifically to reduce this kind of resonance.

Question 8

Are fenders worth it for road riding?

Accepted Answer

If you ride year-round in any climate that sees rain, yes - wet roads soak you faster than rain falling from the sky, because tires throw a constant rooster tail of water and grit at your back, your drivetrain, and the rider behind you. A clip-on set like the SKS Raceblade Pro or Topeak DeFender weighs about 300 grams and adds maybe 5 watts of drag at speed - a tiny price for staying dry. The traditional argument against fenders on road bikes is aesthetic; functionally, every winter-training group ride in northern Europe and the US Pacific Northwest mandates them for a reason. Pure summer riders or riders in dry climates can skip them without missing much.

Bike Fender Sizing & Buying Guide

Top fenders & mudguards picks

RoyalBaby Rear & Front Fenders for 20" Bicycle

Syncros Trail Fender

Syncros Trail 34SC Fender

Syncros Trail Fender Squad

Sizing & fit guidance

What to look for when buying

Frequently Asked Questions

Keep planning your build

Sizing calculators

Sizing guides by rider

Buying guide

Fenders & Mudguards by rider type

Sizing your bike first?