Commuting - Fenders slow you down?

I am somewhat curious. Does adding a full fender set slow you down in any significant way? My commute is about 23mi, (80min ride). I usually avg around 16+mph. Just curious if they make a differance in aerodynamics etc. Just wondering if anyone noticed a differance when they added theirs (a few mins).

Aerodynamics don't really come into play until about 20+ mph.

I suppose if I dropped my fendered bike out of an airplane they would shave off a few mph from it's decent :rolleyes:

I regularly run over 20mph on the flats. I know it sounds a bit silly, but that's kind of why I'm asking.

I've never noticed fenders effecting my average or max speed and I'm up above 20mph for a good portion of my ride.

Fenders actually are an aerodynamic advantage, that's why they're banned from racing.

never really noticed them... i notice no extra drag or change in handling.

i think if you got the type of bike that can fit fenders (not some 14 lb anroexic roadie)the extra little weight isn't going to make a bit of difference.

IMHO: if you've only got one bike you are gonna ride everyday, it should have fenders!

IMHO: if you've only got one bike you are gonna ride everyday, it should have fenders!


I second that, if you don't have fenders on a 23 mi commute, it is going to seem like a very slow ride indeed.

Fenders actually are an aerodynamic advantage, that's why they're banned from racing.
True certin types of fenders could help aerodynamicly, but the type we use on our commuter bikes aren't that type. The type we use do in fact create a drag in the air, so they do slow you down. The question is weather or not this slow down is acceptable to you or not. You could ask: does the amount it slows me down out weigh the convience? You could ask: Do I want to build up my leg muscles to compensate for the slower times that fenders cause me? Many in this group actually LIKE having more weight and more drag as it gives them more strength in the long run. There are some variables in your question that only you can provide an answer to.

No.

Just get the fenders and save on dry cleaning.

Just my opinion. Any slowing caused by fenders is far outweighed by their functionality. It's a commute, not a race.

Fenders do indeed add drag. The wider the fender and the further from the tire it is the more drag it will cause. However on a touring or cyclocross type bike it probably won't affect you more than 1mph average. Record 10 round trips each way and see if you can measure the difference.
Craig

True certin types of fenders could help aerodynamicly, but the type we use on our commuter bikes aren't that type. .

What type could help? Where is the data supporting the gain?

Full recumbent fairing would qualify as a fender

Not noticable for commuting purposes IMO. I put full fenders on my commuter for the winter season, and I can't notice the the difference in cruising speed or ET. My commute is 10 miles each way.

My commute is 18 miles, each way with an average speed around 16mph.

I've never noticed a difference in speed with full fenders.

I have noticed that I'm a lot cleaner though. ;)

Now that I have used them, I wouldn't have a commuter without fenders.

What type could help? Where is the data supporting the gain?
here: http://72.14.207.104/search?q=cache:ezHKvGzZbvcJ:www.bikesarefun.org/ihpva/Human_Power/FullText/hp54-2003.pdf+unfaired+record+breaking+bicycle&hl=en&gl=us&ct=clnk&cd=34
Most people wouldn't stop with the fenders, they'd build a fairing for the whole bike if they were going for aerodynamic gain. But this is a commuter discussion, so I doubt that is the goal.

My commute is 18 miles, each way with an average speed around 16mph.

I've never noticed a difference in speed with full fenders.

I have noticed that I'm a lot cleaner though. ;)

Now that I have used them, I wouldn't have a commuter without fenders.


What he said +1

Fenders actually are an aerodynamic advantage, that's why they're banned from racing.


More fenders = more aero ..... right?

Prepare to be dropped like a ton of bricks. :)

Fenders give me a real advantage. Without them I slow waaaay down to keep from getting sprayed.

here: http://72.14.207.104/search?q=cache:ezHKvGzZbvcJ:www.bikesarefun.org/ihpva/Human_Power/FullText/hp54-2003.pdf+unfaired+record+breaking+bicycle&hl=en&gl=us&ct=clnk&cd=34
Most people wouldn't stop with the fenders, they'd build a fairing for the whole bike if they were going for aerodynamic gain. But this is a commuter discussion, so I doubt that is the goal.

Huh, "fender" is not in source document. http://www.ihpva.org/HParchive/PDF/hp54-2003.pdf
Fairings, yes, but I don't see anything about fenders.

In my case I would think carrying a set of fully loaded panniers would be far worse than my set of fenders. Plus, I would rather slow down slightly than be soaking wet.

I had a fully faired trike with the wheels sticking out thru the shell. I got soaked with water and sand everytime I road in the wet or snow. A fairing works if the wheels are outside the hull. In the winter the windshield fogger/froze over and in the summer I got heat stressed. Stick with fenders.

Theoretically, the slight added weight and scoop effect of the front fender should slow a cyclist down minimally. However, the advantages of having dry feet & the absence of the stripe up the back far out wieghs its disadvantages IMO.

More fenders = more aero ..... right?

Prepare to be dropped like a ton of bricks. :)


Hey 2many... How did you attach that front fender???
I have yet find anything that will work with my Manitou Mach 5 fork. I use a "Grunge Guard" attached to the Frame:

http://harleyzone.tenmagazines.com/gallery/Walkafire/109646.jpg

These fenders don't slow me at all!

You could always get the SKS Raceblade quick release fenders. I use these. I pull them off when the weather is nice. It's not so much for aerodynamics though as it is for looks :D

--Illah

I don't notice any slowdown on my 520, which has close fitting fenders. On group rides I can usually be found near the front. On the 830, they might slow me up a little. The fenders are for 2.125 tires. I'm using 1.5's. You can almost step through the gap and I've installed flaps that will suck small animals into the wheels. That's the purpose of the clearance.

Mighty dry and clean, though.

You could always get the SKS Raceblade quick release fenders.

you COULD but they wouldn't keep you as dry as a nice full set of fenders.

you COULD but they wouldn't keep you as dry as a nice full set of fenders.

Maybe so, but they will get you 99% of the way there. I know they keep me sufficiently dry.

Patriot,
I haven't noticed any appreciable difference in my speed when riding with fenders. I commute 10 miles each way and am usually over 20 mph. The standard full fenders from SKS work great, they are light weight, come in sizes to fit your tire (wider/narrower) and are easy to install.

Like me, you live in the NW west of the Cascades so there really shouldn't be any question if you need fenders or not. You do, stay dry and clean!

You can get a set of removable fenders.

I don't have a dedicated commuting bike so I use these:

Headland Quickslide Fender (http://www.nashbar.com/profile.cfm?category=&subcategory=&brand=&sku=8575&storetype=&estoreid=&pagename=)

Headland Backslide Fender (http://www.nashbar.com/profile.cfm?category=&subcategory=&brand=&sku=8574&storetype=&estoreid=&pagename=)

I can get both of these on in about a minute and they offer good coverage.

Hey 2many... How did you attach that front fender???
I have yet find anything that will work with my Manitou Mach 5 fork. I use a "Grunge Guard" attached to the Frame:

Have you tried zip ties? Use regular ones on the fork bridge and these on the fork legs:
http://www.homedepot.com/prel80/HDUS/EN_US/jsearch/product.jsp?pn=300427

You could also look into a set of these:
http://www.planetbike.com/pop/7015-17.html

Hey 2many... How did you attach that front fender???
I have yet find anything that will work with my Manitou Mach 5 fork. I use a "Grunge Guard" attached to the Frame:These fenders don't slow me at all!

It's a Topeak DeFender. It has a bracket going under the bottom of the steerer tube and an expansion plug that goes up into the tube from the bottom. Then I just added other fender pieces I had.

I had a fully faired trike with the wheels sticking out thru the shell. I got soaked with water and sand everytime I road in the wet or snow. A fairing works if the wheels are outside the hull. In the winter the windshield fogger/froze over and in the summer I got heat stressed. Stick with fenders.

Did you get one of the ones now on the market?

I don't think the fenders on either of my bikes with fenders slow me down significantly, as I don't slow down in order to avoid face-spray and butt-stripes when I am riding either of those bikes, but when I am caught in the rain on my fenderless bike, I am liable to ride much more conservatively to avoid having to spit grit.

I second that, if you don't have fenders on a 23 mi commute, it is going to seem like a very slow ride indeed.
If you are not concerned about the effects of NOT using fenders on a 23 mile commute in wet conditions, then by all means don't use them.

Otherwise, IMO only a dingbat speed ball or masochistic roadie wouldn't opt for fenders no matter what the alleged areo effect.

More fenders = more aero ..... right?

Prepare to be dropped like a ton of bricks. :)

That IS a ton of bricks...

Prepare to be dropped like a ton of bricks.



That IS a ton of bricks...

What cracks me up about that bike is its aggresively treaded tires, suspension fork and seatpost, big fat fenders, and...

it looks so clean you'd think somebody wanted to eat off of it.

My bike is filthy and gonna stay filthy. :)

I am somewhat curious. Does adding a full fender set slow you down in any significant way? My commute is about 23mi, (80min ride). I usually avg around 16+mph. Just curious if they make a differance in aerodynamics etc. Just wondering if anyone noticed a differance when they added theirs (a few mins).

Percentage-wise, fenders and little to nothing to your frontal area (i.e. how big you look viewed from directly in front) and add very little to your overall weight, percentage-wise. I think it would be reasonable to assume that over an 80minute ride, you'd be somewhere between 30 seconds and 3 minutes slower if you add fenders.

You can get a set of removable fenders.

I don't have a dedicated commuting bike so I use these:

Headland Quickslide Fender (http://www.nashbar.com/profile.cfm?category=&subcategory=&brand=&sku=8575&storetype=&estoreid=&pagename=)

Headland Backslide Fender (http://www.nashbar.com/profile.cfm?category=&subcategory=&brand=&sku=8574&storetype=&estoreid=&pagename=)

I can get both of these on in about a minute and they offer good coverage.

they offer some coverage... same with them sks raceblades, i am sure they are much better than nothing but FULL fenders are still just so much better than the clip on versions. sure the clip on ones will keep you from getting spray in your face and up your back but fullfenders protect you whole body and bikefom the road grit and water (including your feet with a properly installed mudflap).

i never beleived the hype, then i got some....

I must admit that the thought of mudguards (fenders) was not one I liked when I first started commuting 18 months ago, but now I think anyone who commutes without them is mad. I will never go back to not having them on my commuter. As for aerodynamics, just try harder?

What cracks me up about that bike is its aggresively treaded tires, suspension fork and seatpost, big fat fenders, and...

it looks so clean you'd think somebody wanted to eat off of it.

My bike is filthy and gonna stay filthy. :)

Don't you use bike cleaning therapy, for stress ? :)

That IS a ton of bricks...

:lol:

I would weigh it my hanging scale, but I think I would hurt my back.... :)

More fenders = more aero ..... right?

Prepare to be dropped like a ton of bricks. :)

That bike is WAY to clean to be a commuter.

I have an 18 mile commute to work and only a 4 mile commute to school. I use an old road bike with a rear rack that has a plate on the center of it which saves my back from the wet. No fenders though. I've been commuting since September and only caught in the rain twice. I just got wet and it wasn't too bad really. Just wet. I'm on my bike for over an hour going to/from work so I think I'd get sufficiently wet being in the rain for so long that fenders wouldn't have made me any drier. Now maybe if I didn't live in Dallas where it seems to rarely rain anymore I'd want fenders more.

That bike is WAY to clean to be a commuter.

I keep the studded tires on it all the time now. It only goes out in the ice and snow.

Also the fenders work. :)

My fenders make noise when they vibrate on a ride. I perceive it as a slow down (you know, noise => poorly functioning bike => going slower), but that's just how my silly mind works. I don't think it makes much of a difference at all as far as speed is concerned. But I sure love the dryness factor...

you COULD but they wouldn't keep you as dry as a nice full set of fenders.

Just a tiny bit of splatter on the back of my leg - no big deal. The major offenders, i.e. the front of your legs from the front tire and the stripe up the back, are fully covered. Plus my fork doesn't have mounts for 'real' fenders.

--Illah

I perceive it as a slow down (you know, noise => poorly functioning bike => going slower), but that's just how my silly mind works.

I guess putting an engine on the bike would make you feel it slows you down as well then... :D

It is possible that fenders create a net aerodynamic benefit by controlling where the "dirty" turbulent air coming off the wheels goes. I saw an article in Bicycling long ago (like maybe early '80's) by Frank Berto (if I remember right) in which he did a fairly crude roll-out test and concluded that a bike with fenders was aerodynamically better (or at least no worse) than the same bike unfendered.

I don't notice any difference, and can stay up with others on high-speed downhills as well on my touring bike with fenders as I can on my road bike without fenders. The only reason I have a bike that doesn't have fenders is that it is a lot easier to put in a car trunk.