Lights: the aim matters more than the output
Fit the front light, then stand the bike facing a wall a few yards away and check where the beam lands. The brightest part should fall on the road roughly 33 ft (10 m) ahead of the wheel, not straight ahead at head height. Lights with a shaped beam, built to the German StVZO standard and sold in the US too, have a flat cut-off at the top; it only works if the light is tilted down so the cut-off sits on the road.
A light aimed level puts most of its output into oncoming faces and very little where you need it.
The rear light position
Low and unobstructed. A seatpost light is hidden by a saddle bag, and a rack-mounted light by a pannier. Check what actually blocks it with the bike loaded the way you ride it. Set it to steady rather than flashing when you ride in a group, where a strobe in front of other riders is tiring.
What the law asks for
In the US the rules are set by each state. Most require, at night, a white front light visible from about 500 ft and a red rear reflector; many also require or accept a red rear light. A rear light is worth fitting wherever you ride. Our bike light page compares the sets we cover, including the Sigma Aura 80 and Blaze set.
Fenders: the clearance figure
Tire width clearance in millimeters, stated by the fender maker. Wheel size is not the number that decides fit: a fender sized for a 700c or 28-inch wheel still rubs a wide tire. Fitting a fender also reduces the tire width your frame can take, which is a second figure, from the frame maker.
Full-length or clip-on
Full-length fenders mount to threaded eyelets at the dropouts and to a bridge behind the brake or the fork crown, and cover most of the wheel. Look for those holes before buying.
Clip-on fenders need no mounting points at all. They cover less of the wheel and are the answer for mountain bikes and suspension forks, like the RBRL set for 24 to 29 inch wheels. For a road or gravel bike, see the SKS SPEEDROCKER set.
Stopping the rattle
Almost always a stay. Fit the fender, then adjust the stays so it sits at an even distance from the tire all the way round. Trim excess stay length rather than leaving it to vibrate, and cap the cut ends.
Check for rubbing by spinning the wheel and listening, then again with your weight on the bike: clearance changes under load.
The bolts
Fender stays, light brackets and rack fixings all loosen with vibration. Check them after the first ride and then once a month. A drop of medium-strength threadlocker on the stay bolts keeps them in place.
Where to go next
All the fenders, kickstands and bells we cover are on the fender page, and the best fenders for winter commuting are in our guide. For the rest of the cold-weather setup, see setting up a bike for winter.
The questions riders ask
What decides whether a fender fits?
The tire width it clears, in millimeters, stated by the fender maker, and the space in the frame. Wheel size only narrows the choice: a fender sized for a 700c or 28-inch wheel can still rub a wide tire, and fitting one reduces the tire width the frame can take.
Where should the front light point?
At the road, roughly 33 ft (10 m) ahead. A light aimed level throws most of its output into the eyes of drivers and other riders and very little onto the surface you are riding on.
What lights does the law require at night in the US?
It varies by state, but most require a white front light visible from about 500 ft and a red rear reflector, and many also accept or require a red rear light. Check your state’s vehicle code; a rear light is worth fitting everywhere.
Can I fit fenders to a bike without eyelets?
Yes, with clip-on fenders, which attach with straps or quick-release mounts to the seatpost, down tube or fork. They cover less of the wheel than full-length fenders, but they are the usual answer for mountain bikes and suspension forks.
Last reviewed October 28, 2026
