Mud De-Fender!

3 03 2011

20kms of muddy rail trail later...

I just came back from a ride on my new rando rig.  Total distance ~60kms. About 20kms of that was damp dirt trail including numerous mud puddles and another 20kms was various wet paved surfaces. We even made a couple poor routing choices and had to ride through sections of thick juicy mud…=-( I was a little horrified to subject a new bike to such treatment, but as you can see from the photo above that’s the result after splashing my way through puddle after puddle and cruising over a wet dirt trail. Luckily my bike sports full coverage Honjo metal fenders that fit the tires diameter perfectly. A bunch of that splatter isn’t even from my bike as Aaron and I kept passing one another and his rear fender was fairly short so it was shooting crap at me if I wasn’t careful about my bike positioning. I also do not have a full front mud flap on this bike yet so the fender protection factor can be improved.

Good fenders not only make wet weather riding more pleasant they drastically reduce the amount of maintenance you need to do on your bike.

The trouble with plastic fenders…

3 03 2011

Planet Bike Cascadia fenders on my Big Dummy...

I like fenders.  I was a big fan of plastic fenders for a number of years.  They work for sure, but I’ve come to realize they have some problems:

  • they mount the fender brackets inside the fender which means water hitting the bracket can’t run down the inside of the fender to the road uninterrupted and some of it sprays out the side onto you and your bike. Metal fenders wrap the strut over the back of the fender avoiding this problem.
  • the fender struts themselves don’t mount very securely to the fender compared to the how a metal fender wraps the strut around the back of the fender keeping the strut in one piece which triangulates it for stiffness. This is exacerbated by the fact plastic fenders themselves aren’t very stiff.
  • most plastic fenders are too short to provide full coverage [front fender mudflap should almost touch the ground] although this can be solved with a DIY mud flap.
  • you can’t reshape a plastic fender to perfectly fit the outline of your tire without loading it with tension like a spring.  This leads to fender failures and allows the fender to go out of adjustment easily as it tries to go back to its original shape.
  • plastic fenders don’t come forward enough past the fork crown to stop spray from the tire from coming back and hitting you from the front.
  • because the mounting systems on plastic fenders are not as stiff as on a metal fender there is a greater chance something will get stuck in the fender causing an incident. Some plastic fenders get around this with breakaway struts [ie. SKS].

Sharon's Surly Cross Check with hammered Velo Orange metal fenders...

I assumed metal fenders would be super expensive and really hard to install on a bike.  It turns out they are quite reasonably priced – $55 for PB Cascadias & $60 for VO metal fenders. My install time for Sharon’s VO metal fenders shown above was no longer than a set of plastic fenders. Although some Berthoud & Honjo fenders do require extra time to install.  Once installed they are very stiff, quiet and provide excellent protection from road spray while enhancing the look of your bike.

Planet Bike vs. Berthoud...

The Planet Bike Cascadia ATB fender and Berthoud stainless steel 60mm fender shown above are both designed to work with a 26 x 2.0 tire.  The Planet Bike fender has two sets of struts on each side vs. the single strut on the Berthoud.  Just looking at it the PB looks like a more secure mounting system.

But when you try to flex the fender struts it becomes pretty clear that the PB system is weak [I can easily touch the end of the struts together] and the Berthoud system is very stiff.  This is simply because the wrap around single stay on the Berthoud is a superior design.  Attaching a single strut rear fender to your bike is easier and the metal fender allows you to gently reshape the diameter of the fender to perfectly match your tire.  This not only looks better it means the fender is not under tension and will stay in place and will not fail as quickly as a plastic fender.  Since a plastic fender has a memory it always wants to be a specific shape. If that isn’t fitting your tire well you can bend the plastic fender into shape, but it will be under tension and want to go out of alignment to release that tension.

Inside fender detail...

You can see from the above photo that the rolled edges and external strut mount of the metal fender will keep water inside the fender running down to the road which is where you want it to go.  The PB fender has two of these interior struts on each fender and when the water inside the fender hits them some of it follows the strut mount to the side and flies out onto you and your bike. Again the metal fender strut mount is simply a superior design.

Strut mounts...

You might be thinking the plastic fenders on your bike do a reasonable job protecting you from road spray.  Of course any fender is better than no fender. A longer fender is better than a shorter fender.  A longer fender with a mudflap that goes to the ground is better than one without.  A metal fender is better than a plastic fender. A metal fender with a mudflap that goes to the ground is better than one without.  At each stage we can see a tangible improvement in protection and functionality.  I have plastic fenders on a bunch of my bikes and I won’t be replacing them all with metal fenders.  I don’t ride all my bikes in the rain a ton and so optimized protection from road spray isn’t vital on all of them. However, I do have some bikes that I want to be as perfect as possible in terms of rain riding and these bikes [like my LHT and Sharon’s CC commuter] will get metals fenders.

I appreciate the good looks of a metal fender and my geeky side appreciates the subtle design elements that make them so functional.  Should your metal fenders ever become unusable they can be recycled back into new metal products easily.