Fenders on a gravel bike

[EB]

Originally Posted by benb

The internet always says this but I've been doing it for 13 years and I have had items get lodged in the fenders many times and it has absolutely never stopped the tire.

I have the SKS ones, if it's big enough the quick-release tabs pop out. What far more usually happens is the object just scrapes against the tire and fender and makes a racket and you stop and get it out.

You can worry about cleaning Fenders but it's undeniable they keep the rest of the bike cleaner.

If it's a gravel bike and you're running Fenders in dirty or wet conditions though I'm guessing you're not the "not one atom of dirt on my bike" type of rider.

Respectfully, you're just wrong. This happened to me with hammered honjos on a Scarab Paramo on a muddy March circa 2020. With the 42s I was running and Honjos - 4 to 6mm of clearance at best - mud built up on a ride in the whereabouts of the Marin watershed until the bike seized up and wouldn't move an inch. Pedals would not turn.

After pouring out the entire contents of my water bottles on the jammed sections and pushing with my fingers I was able to get the wheels to turn for another 300 meters until the bike seized again. This was not a particularly "muddy" section to look at it.

Ultimately I had to carry the bike to a paved road and a water fountain.

Moving to 1cm of clearance (which is all that I was recommending) solved this problem entirely. But the resulting paint damage on the stays was permanent.

[ridethecliche]

This seems like overkill.

Why not just use protective film on the downtube?

[johnniecakes]

This morning I rode one of the typical routes I ride. Some fire road, some big gravel, and some crushed limestone MUT sections. Compared to the almost identical ride on Monday the bike is orders of magnitude less dusty. My black bike is still mostly black, not the gray from all the dust kicked up. It will be a much quicker clean up job. This is especially true around the bottom bracket/crank area. So much better. The only thing that got stuck were a few leaves that quickly cleared themselves. For now they are staying on, I like them.

[benb]

Originally Posted by EB

Respectfully, you're just wrong. This happened to me with hammered honjos on a Scarab Paramo on a muddy March circa 2020. With the 42s I was running and Honjos - 4 to 6mm of clearance at best - mud built up on a ride in the whereabouts of the Marin watershed until the bike seized up and wouldn't move an inch. Pedals would not turn.

After pouring out the entire contents of my water bottles on the jammed sections and pushing with my fingers I was able to get the wheels to turn for another 300 meters until the bike seized again. This was not a particularly "muddy" section to look at it.

Ultimately I had to carry the bike to a paved road and a water fountain.

Moving to 1cm of clearance (which is all that I was recommending) solved this problem entirely. But the resulting paint damage on the stays was permanent.

I was referring to the claims people make about a rock/stick/acorn lodging in between the fender and the tire and instantly locking the tire if it's the rear or sending you OTB if it's the front.

Not mud buildup. Mud buildup is obviously a different thing and you didn't build up that much mud in <1 second after hitting the mud like the theoretical "fenders lock up the tire if an object lodges" stuff.

I am somewhat of the opinion that kind of buildup is going to just get you eventually with no fenders too if it's bad enough. I have had mud/snow/ice buildup lock up the whole bike with no fenders at all but it was a gradual mess, not an instantaneous one.

[CMiller]

Is there a reason the rear fender goes up to 12 and not fully to 9 o'clock?

I agree that fenders do keep things considerably cleaner and on a gravel bike I would just be sure there was plenty of clearance, I like a full centimeter.

[johnniecakes]

Originally Posted by CMiller

Is there a reason the rear fender goes up to 12 and not fully to 9 o'clock?

I agree that fenders do keep things considerably cleaner and on a gravel bike I would just be sure there was plenty of clearance, I like a full centimeter.

I cut the fender for a couple of reasons

1) I don't like how fenders look on any bike so if it can be shortened without defeating the purpose of keeping the dust down it helps me get past the appearance.

2). Having the fender longer would make it sway more over rough sections of trail. Long supports are not as good the center screw where the brake bridge would be.

3). In case rear wheel has to be removed a longer fender gets in the way.

4). Weight. (Not really, a couple of extra grams is not a concern)

[Mark Davison]

I run fenders on my gravel and all-road bikes. They serve well on the mix of rail-trail and wet roads that we encounter around Seattle, where there is very little mud.

On recent rides in Montana the fluted French (copy) fenders on my MAP randonneur bike were a mixed success. In particular:

a) they were great for negotiating the very wet, long tunnel on the Path of the Hiawatha rail trail. In spite of dry, dusty conditions on the trail, the tunnel seems to have perpetual rain, and the top surface of the trail was slurpy, slippery wet clay. Full fenders were welcome.

b) the fenders bogged down in the muddy sections of the Cino route from Kila to Hot Springs MT. The mud was sticky and wedged in between the fenders and the chain stays. I had to clear the mud out with a stick on several occasions to free up the rear wheel. (The mud was so sticky that I had to clean out my SPD cleats just to get them to engage.) I made the problem worse by not removing the plastic mud flaps.

c) the fenders were great riding wet paved roads in Glacier National Park during rain showers. They keep water off of your shoes and the front derailleur.

It would be great if someone invented effective fenders that could be easily removed for passage through mud, and folded up so you could store them on the bike. Fluted French style fenders definitely do not qualify--I had to take the front fender off to store my bike inside my RAV4, and NHAero can attest to the obnoxious chore of unbolting the two nuts that held the front fender to the daruma and mini-rack, plus the bolts attaching the stays to the fork. It became a running joke on our trip.

[Mark Davison]

Earlier this year Bob Freeman rode through the first long tunnel at the top of the Path of the Hiawatha trail without fenders, and here's what he got for his efforts:

Bob Freeman with mud.jpg

[marciero]

Originally Posted by Mark Davison

b) the fenders bogged down in the muddy sections of the Cino route from Kila to Hot Springs MT. The mud was sticky and wedged in between the fenders and the chain stays. I had to clear the mud out with a stick on several occasions to free up the rear wheel. (The mud was so sticky that I had to clean out my SPD cleats just to get them to engage.) I made the problem worse by not removing the plastic mud flaps.

With very sticky mud this can happen with or without fenders, and I am not convinced fenders even make it worse.

I have permanent fenders on two bikes that get heavy gravel use, and have never suffered any negative effects. I cant remember the last time, or if I have ever gotten, for example, a twig stuck on those bikes.

On the other hand, on bikes with long front mudflaps, picking up twigs or
other debris is a frequent occurrence depending on the terrain.