Why would you want fenders on a city commuter or touring bike?
There is basically one reason: cleanliness. And I don’t mean hygiene.
A big difference between a commuting or touring bike and a sport bike for day trips is choice. Choice about whether or not you go out riding. For a day trip, you can choose whether or not to go riding and which bike you’ll ride — the beater or the good bike. But for commuters or tourers, you’re stuck. Rain or shine, you’re out there. If you’re touring, you can either sit out a rainy day and miss your next stop, or try and ride between the rain drops when it rains in the middle of a day, or you can go out and ride in the rain to the next hotel or campsite on your itinerary. If you’re commuting, either you ride to work, or back home, or you figure out some other way of getting there. Subway? (Gross.) Car? (Gross.) Bus? (Sick.) Helicopter? (Noisy.)
There are other choices too. Ride through a puddle or damp spot on the road, or not. Ride down a dirt road, or not. Do, or don’t do; your choice.
What fenders do, is to keep the water, mud and dirt that might be flung up from the tires away from the bike and the rider. But how much does it matter? Is it worth the fuss?
What can get messy?……..Does it matter?
Rider…………………..You decide. Wearing nice clothes? (Matters.) Is it cold out and you don’t want cold water flung up on you? (Matters.) Don’t want particles thrown up into your eyes? (Matters.) Letting someone else take their first bent ride on your bike in their best clothes? (Matters.) Don’t care if you get dirty and muddy? (Doesn’t matter.)
Other Riders…………Matters. It’s a real drag to be riding behind someone who doesn’t have fenders when they go through a puddle or it’s raining. Fluid is thrown up off the back wheel into your face and onto your clothes and bike. So, simply for being considerate of others, fenders matter.
Chain…………………..Are you in a dry environment with a good dry lube? (Doesn’t matter as much.) Wet, dirty, sandy roads? (Matters, since your chain will work better and require more infrequent replacement if you keep it clean. Likewise, this diminishes wear on the chain rings and cassette.) Do you simply like having a clean chain so your leg doesn’t get as greasy while you ride? Or so your hands don’t get as greasy when you lock up the bike? (Matters.)
The Bike………………You decide. Of course, you may prolong the pretty paint if you keep dirt and grime off the bike or if you gently clean it after every ride. Generally easier to just use fenders.
The Headset……………Grunge off the front wheel is thrown up against the bottom of the headset. Slowly but surely it creeps in through the gaps and creeps into the bearings. (This matters.) This dirt will slowly and surely wear down your headset. Bad news because not only is this a critical component, but it’s also an expensive one. Of course, with periodic disassembly and cleaning, you can keep the headset clean. With fenders, and less periodic cleaning, you can also keep it clean and lasting for a long time.
Care about speed?
I’ve read on the internet somewhere (so it might be absurd) that a tightly fitting fender would decrease wind resistance at the top of a tire by shielding the contrary motion of the top of the tire from the headwind. (The top of your tire is moving at high speed in the opposite direction of the bike.) This sounds reasonable. It also stands to reason that if one shields this part of the tire, especially if it’s a treaded tire, there will be a lower energy expenditure to maintain a given speed. But it seems the fender would need to fit well or else it could create additional wind resistance. And by logic it seems the fender would need to extend along the front of the wheel to give this advantage. If one is concerned specifically with this, one may be better off using smooth tires as being the easier option. Of course, carefully crafted fenders would be even better.
Care about weight?
Fenders add weight. There are lightweight fenders available. HP Velotechnik makes carbon fiber fenders for the Scorpion series trikes.
The problem with fenders in a race is that if they fall or break off, it could cause a significant accident.
The best thing about fenders?
You can put them on and take them off to your heart’s content. It’s especially easy if your bike is designed for them.