Caution! Fenders are Death!

mason_man is doing it right, he's using Wald fenders

I'm also an advocate for fenders. Every one of my daily rides has had em for the last 25 years. I only use Walds or Planetbike polycarbonate.

Generic fenders just don't have the same quality.

I check the fittings every morning on my ride THAT HAS FULL FENDERS I have secured all fittings with stainless brackets and use locktite on all my nylock fittings aswell I have secured every bolt with small rubber washers to prevent vibration and only once have I had an issue BEFORE I FITTED ALL OF THESE MEASURES ,since I've never had any issues ,it's all about checking and double checking ,every ride I take the fender in my hand and give it a good tug and twist , they havnt moved in over 1000 miles
Still I will call it a gamble though ,but as long as the checks are done properly and all checks pass the chances are minimal ,besides that I'm more likely to be killed or hurt from an irresponsible driver ( of which 9 out of 10 here are ) .
IMHO cracking or breaking fenders or any part of a chinagirl kit is due to a lack of checking for faults and not bothering to correctly identify an issue .
Run your fingers over your frame or a joint ,you may not see a hairline fracture but you will feel it ,every few weeks remove the fender and check for potential damage or failure ,tighten every fitting and then check it ,and recheck it , look at potential areas with an attitude like it's going to fail and treat it as such ,yes it may be time consuming but what is that time worth ? Your safety and well being .
I am one of thos e who is pedantic about checking Christ I'd almost consider myself OCD , yes I have had near failures but have stepped in and secured the problem before it became an accident .

Regards Hen

2door said:

Sorry Hen but being a victim of a crash that was essentially unavoidable, I take exception to your assumption that I, or anyone injured in an accident of that nature were "lazy". I take safety very seriously, always have and always will.

Tom

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I think the intention of my post was mistaken and lazy wasn't the best wording to use ,my apologies if any offence was taken Tom.

More so I was trying to convey if checks are done on a daily basis then one should be able to pick up on any issue before it becomes a safety consern and take action to rectify this ,and don't get me wrong I'm sometimes lazy when it comes to checking and each and every time I have done this it has resulted in the issue becoming a safety consern .

Alas. You are right lazy is a resentful word so I will edit my post accordingly
Thanks for bringing it to my attention mate

Regards hen

Yes, poor wording, but motorcycle factories have been putting fenders on vibrating frames for over a hundred years - why couldn't we?

Went thru this in 60s & 70s trying to get fenders to stay on choppers with nice hidden mounts - just took some work is all.

The 2 most important things to learn before doing much with these bikes are:

do not get in a hurry

do not get lazy

if something doesn't seem right, take it all apart and redo it (sometimes over & over again) until it does seem right

in the end. you can't blame crappy kit parts or crappy chinese bicycle parts for the work YOU did - if you can't deal with those parts, then use others or don't do this work

</end old fart rant>

How do they do it on motorcycles?
With m8 bolts, that's how. Big beefy bolts.

They certainly don't use cheap, wonky rivets or crappy bent brackets made out of pot-metal.

There are very few pedal bikes out there that are overbuilt enough to withstand what we put a bike through.

Fact is, most bikes purchased at walmart only get ridden one or two dozen times, then spend the rest if their lives stuffed in a garage or shed. For most owners, poprivets and potmetal work just fine.

So as motorbicycle builders we have two choices and the spectrum between them.

1) Buy cheap and spend time, money and sweat trying to upgrade weaknesses.

2) buy ultra expensive high quality bikes, like downhill bikes and build from there.

Of course, for most of us the answer is somewhere between those choices.
Decide where you want to be and modify properly from there.

The mentioned problems really did happen and I do have pics. My happy time is an old "revered" one too, a "Starfire" from Nantong Jalie. One of the best. It never quit running, it always started up and ran great. Here is the front mount. Nice and solid with a stack of 1/8" aluminum bars and a SBC mount. Good thing too eh?



Almost a 1/8" offset in the mount radius on the crankcase halves. On the outside of the motor where God and everyone can just see it easy. Don't even need a mic, don't need any gauges, don't need a surface plate, eyeballs are good enough.

Guess what? This ain't good enough. This is crap. They shipped it and it runs great.

I will never ever buy another one. The life I save is my own -

Everyone wants to go fast for cheap. Don't have much dough. Tough economy. I know. I understand. But if you don't know, hospital time is much more expensive than anything (even cars) than you can imagine. Trust me, I know. Thousands of dollars a day. You could buy a car for 1 day in the hospital.

These motors are so bad the Chinese don't even use them anymore. They have gone electric.

Fenders aren't unsafe ...anymore than handlebars or seats are.....use inferior parts though or pieces designed around a cruise to the store pedaling and made different.. Motorize em and find out I guess.
Pre checks of flimsy just means flimsy is attached still....better parts are needed and for most of the builds I've seen,a whizzer fender and braces is an improvement and aren't hard to find.
I can't ever remember one of the hundreds of mopeds I've seen ever tossing a fender either..they have wound up two smokes shaking away too..and what shakes more then a Harley? They have fenders

Tips with pics on how I build/prep fenders can be found in my safe fender album. You guys are scaring me to death with this fender failure talk... I do pay close and special attention to my fenders every day. Thanks All!

Hi ya'll, new here.. I like your forum a lot, lots of technical info to be gathered here!
The fenders are worrisome, I'll take them off til the mounts are redone. My cheep wallyworld genesis bike has an aluminum stem with a thin aluminum boss where the handlebar is clamped on..
I worry I'll be buzzing along and the bars will break off.
Talk about eating the curb! I've crashed motorcycles before but I was a lot younger then, and always walked away from them.
I'm too old to go bouncing down the street on my face, so I guess I'm in the market for a steel stem.
Are there broken stem stories out there? (Hope not!)

couple weeks ago I bought a bike which had only a coaster brake when the kid rode down a really long, really steep hill - he pushed the front forks right back to the frame & broke the aluminum quill (first time in 50 years, I got to use that huge extractor in the 'ace extractor set' getting that mashed aluminum piece out of the stem)

replaced fork with v-brake fork & quill with steel

Thanks for the reply, man. When you say quill, do you mean the handlebar mount part of the stem?
My bike has steel forks but an alloy adjustable stem that lets you move the bars higher or further forward, hinged with an allen head lock bolt. It feels stout, but head butting asphalt really sucks.

I haven't really started on it yet, so everything is up in the air, so to speak.
I think I need a steel stem.
Whoops- thread drift, I'll chuttup.

I think we assume a certain amount of risk just getting out of bed in the morning. Everything we do in life has some degree of risk that comes with it. I have a motorized bicycle with fenders, I race go karts, fly and race model airplanes, target shoot, do some boating and fishing, etc. etc. etc. All of these hobbies that bring so much joy to my life also each carry with them a certain amount of risk and each has potential hazards to watch for.

Sitting at home watching the world pass me by due to fear of something bad happening is NOT an option. So the best we can do is to let our fellow hobbiest know about a potential problem and together try to find ways to minimize the potential hazards associated with a particular hobby. However...not participating in the hobby is not an option. Sometimes we can do our best to try to minimize hazards and still experience a failure that results in damage or loss, but everything we do in life we learn to accept a certain of degree of risk even when we know the potential hazards.

I would never tell someone that they should not buy cheap engine kits or cheap bikes because perhaps there may be some higher percentage chance of something failing. What I would tell someone is that if you are aware that there may be more risk associated with some of the cheaper engine kits and bikes suffering a potential failure and are willing to try to find ways to minimize that risk...then I say good luck with your project and I hope you are able to get many miles without suffering a failure, but just like all the Fords, Chevys and Dodges I have owned......everything has the potential to break or fail no matter how much we try to minimize that chance or how much quality we thought we were buying by spending a boat load of money.

I run the fenders on my bike and have added reinforcement because the good folks on this forum have warned of the potential problem. Does it mean that they will never fail and that I may never suffer skinned knees or broken leg like Tom or maybe even worse? The logical answer is no, but I have done my best to try to minimize the chance of failure, and if they do fail....I have modified them to a point where I can accept the risk that may still exist even after modification. I also appreciate my fellow riders bringing the potential risk to my attention so I can decide whether it is a risk I want to take or not.

Dan said:

Thats good advice, Cti.

But the main problem with fenders are not that the fasteners loosen, but that the brackets themselves fail and let go. Often with the nuts, bolts, rivets still secured to them.

Very often it is just an L bracket that is just bent. That causes a weak spot at the outside of the bend. So with the vibrations, it wiggles it self to death.

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Well there's something very wrong with the bending job on those "L" brackets. At least with aftermarket style, plastic or plastic-aluminum sandwiched, bike shop quality fenders, like the Esge's, Mt Zephal's and Bike Planet's, the L brackets are made of a thick bit of stainless steel with proper radiused bends so as to not cause a stress riser in the sharpest part of the "L" bend.

They also often times have more than one pair of stays, this tends to keep from allowing bad cyclic vibration from certain ranges of the RPM band. This is something I've fought with my present friction drive bike. Sometimes adding a bit of rubber isolation at the fork or chainstay crosspiece damps this out, or, makes it worse.

They can still have issues with the of the stay bits and and "L" bracket riveting to the fender and sometimes the plastic can crack, but they tend to stay attached at the stays and fork attachment points even with cracked plastic.

I'd be more inclined to replace these suspect "L" brackets with custom made 12 gauge or thicker stainless steel L brackets cut from old rack mounting hardware, that you've taken the time to bend with at least an 1/8" or larger radiused bend. These brackets can be really tough to bend sometimes and will require a good vise and cutting tools to shape.

Gonna have beg to differ, Buddy. For a motorized bicycle fender. I would not use an "L" bracket at all and stainless, while corrosion resistant, is kinda brittle for this application.

Just chat and am sure I am a little gun shy. It really did freak me out during a fender related crash that Carol would end-up spoon feeding me.

Obviously you have spent considerable time on this and I don't mean to disagree. I am more erring on the side of caution.

LOL, and bolting the heck out of em. If I had more room, there would be 3 ubolts

Where's a good place to buy some Death Fenders? I might like to put some on my bike.

biknut said:

Where's a good place to buy some Death Fenders? I might like to put some on my bike.

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2door said:

Try your local Nirve Switchblade dealer.

Tom

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Anti zombie, flame throwing, chariot like DEATH FENDERS!
(Patent pending)

Accept no cheap imitations!

You guys are bummin my trip.. I bought my stupid bike because I liked the long, narrow fall-offy fenders of death and now I have to live in abject terror of being torn to bloody shreds, dashed to bits on the cruel pavement because of them.

Oh well, we all got to go sometime. Could be worse, I could die on the crapper like Elvis.