I have SKS plastic fenders on one of my bikes and probably an SKS rear fender only on another bike. Both bikes have been used for multi-modal commuting with bus.

On the bus, the bikes ride in a rack up on front of the bus, out in the elements.

Both rear fenders have broken. The breaks start as cracks transversely across the fender. Other than the break, there are several cracks across the fenders.

I believe they are cracking and breaking due to the the constant wind loads they endure while on the bus. The bus commute includes approx 33 miles each way (66 miles per day) on an interstate with posted speed of 65 mph. I'm sure the bike is subjected to a lot of buffeting while riding on the front of the bus.

Does anyone else ride a bus at distances and speeds as this?

Would aluminum fenders hold up better, or not?

Suggestions?

Thanks.

1. Remove the fenders.
2. Ride the bike.

That's not much of a sales pitch for SKS fenders . I use planet bike ATB plastic fenders, and I throw my bike on the bus for a 15 mile 65mph interstate journey every morning. I was initially worried about the fenders breaking, since the bus rack retaining arm comes down on top of my front fender and bends it down to my tire. No breakage in 3+ years, road tested from -23°F to + 85°F.

I just ordered a replacement set of SKS longboard fenders as my rear broke in half. I don't ride the bus and just think the fenders aren't very durable.

I have had road style fenders with the wire stays, and their biggest enemies seemed to be sunlight and cold. They usually lasted a couple years and then shattered during the winter. The brand was Bluemels, IIRC. It was 20+ years ago, riding year-round in South Bend IN.

Now two of the bikes under my care have Zefal "Classic" MTB fenders that seem to be made from a tougher material, and have no stays. They don't offer the same coverage as road fenders, but are wider and have held up through multiple winters, including getting banged around in bike racks.

Interesting. I didn't think you could have fenders on a bike while using the front rack on a bus. If anything, the OP might have to commute without a front fender. The rear fender doesn't have to take any pressure from the retaining arm.

The retaining arm is the only problem I've had using my 'fendered' bike on the bus. I had Crud/Roadracer fenders, but wound up removing the front fender because it didn't cooperate well with the retaining arm on the bus rack. I've changed to a downtube fender, which doesn't work as well, but does offer some protection and works better with the bus rack.

Does SKS still have lifetime warranties on their fenders? My Raceblades do (I've gotten a new rear fender twice due to breakage.)

My vote? Properly set-up aluminum/steel fenders and never worry about them again.

I snagged an ancient Raleigh frame with steel fenders that I got for free. I'm considering snagging the fenders for a project, then scrapping the frame. Anyway, steel is, of course, subject to denting, but shouldn't fall apart like your plastic.

Split metal fenders up front might be practical although it might be a custom fabrication job. If there's any damage to the front from the bus' restraining bar or wind it wouldn't be necessary to replace the entire fender.

I'm considering a downtube splash guard instead of a front fender since I occasionally use the bus rack and the restraining bar would break a plastic fender. But I'm leaning toward a plastic fender for the rear since I occasionally ride off-road and am a little concerned about sticks or debris jamming. My rear rack already blocks quite a bit of splatter but needs a little help near the saddle.

My Planet Bike fenders are going strong after 8 years. The only thing that broke off was the rubber flap, the fenders itself are in perfect condition.

Would a front rack work on the bus to keep the retentionarm off the wheels?

I didn't have much luck with SKS fenders, either. After a couple of breaks, I switched to Planet Bike and haven't looked back. I'd recommend giving another fender manufacturer a shot.

OP here...
I will give Planet Bike fenders a look.
By the way, I have removed the broken fenders, as one suggested, and I keep riding. But I would like the protection I get from the fenders restored on my commuting bikes.

Another item: I have no problems with the front fender (only one of the two commuting bikes have a front fender) and the bus. I place the rack retention arm on the tire, immediately in front of the fender and not on the fender itself.

As for warranty on the SKS fenders: I don't know about that. I started a modification of the fender after it broke and haven't completed it. I placed a couple of layers of fiberglass cloth on the underside of the fender to mend it, but I haven't reinstalled it yet. Not only did the plastic fender break, but the stainless steel bridge for the rear wire stays also broke. I've started, but didn't finish, fabricating a new metal bridge. I doubt SKS would warranty a fender that now has fiberglass on it.

The bike that had only the rear fender came that way. I don't know if any of the previous owners had a front fender on it. It's a mid 1980's model Peugeot that has been converted to a single speed bike. The rear fender broke just as I started a ride that turned into a 53 mile Saturday cruise through the country and I listened to the maddening noise of the fender rubbing on the tire for about 52.5 miles. Since it wasn't going to do anything more than make noise, I didn't turn around and go home and get another bike...

I don't know, I'd ask. All they wanted me to do was send in a picture of the broken fender. A week later they sent me an almost complete set of new fenders (even the majority of the pieces that didn't break.) When they sent me new ones I mended the old ones by using small piece of aluminum on the outside of the fender (bent to match the curvature) and then I covered the inside and outside with epoxy (after roughing up the plastic with some sandpaper.) It's still holding 1.5 years later. (In fact the part covered with epoxy is probably stronger than the fender itself.) However, that experience led me to buy aluminum fenders for my most recent commuting bike. They're so strong I can lift the bike by them and they don't even budge.

Because of the shape, It would have to resemble a tire, arched to take the Hook ..

so maybe a reinforced steel Wald Mudguards with a Hoop like a Low rider supporting the front.



a mudguard that comes no further forward than over the front Axle should be fine

Retention-arm pulling down on just Tire.

I'd be more worried about the clamp on the front fender (as the others above) than the aerodynamic loads... maybe if your fenders are too far from the tires, wind might be an issue. Metal fenders would hold up to being clamped than plastic ones.

On my bike the bus retaining hook fits in between the front of the fender and the tire. I shove it under the fender a few inches, it stays put. My fenders are stainless steel. There's no way the hook will extend far enough to grab the upper side of the fender.

Interesting.

I use cascadia's on my big ogre and do not have issues with this, I generally do not put the retaining arm from the bus all the way to the fork bridge I put it just in front of the fender on the tire and this holds the bike fine. I do not do the everyday bus though so that has a lot to do with it I am sure.

Actually, Ray, this is a sign that you need to stop taking the bus ride all the way to work.
(Yes, I know how long your commute is.)

The bus ride is on an "express" route meaning there are limited stops. Sometimes, it also means the bus can move "expressly" along the interstate. Sometimes, the bus is at a crawl in afternoon traffic.

As for a shorter bus ride: Ain't gonna happen. Most of the commute is the 33 mile part on the interstate and there are no stops there! There's no way to shorten that part. And the "in-town" part of the commute is short and on 35 mph roads. I doubt that is causing any problems.

One way to probably fix it: Let us bring the bikes on board the bus, like they do in Belgium and probably other countries. It would be an interesting test to see if the fenders kept breaking if they were shielded from the buffeting they get out on front of the bus on the interstate.