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Made by Monkeys

Harley Hindered by Lower Belt Guard

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Beth Stackpole
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Nice catch
Beth Stackpole   12/7/2011 7:27:37 AM
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Wow, that's one scary possible outcome from one very small design flaw. Just goes to show how important every component can be and why design for failure mode and effects analysis needs to be a critical part of the development workflow.

Alexander Wolfe
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Re: Nice catch
Alexander Wolfe   12/7/2011 9:46:57 AM
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That's why bikes used to use chains. Seriously, though, this column points to a common design flaw found in many products, where there's a single point of failure. And when I say point, I mean it literally, in that it often comes down to a single screw or fastener. Further, when that fastener comes loose (and usually not in the way it was intended; i.e., it comes out violently), you often get a stripped, ripped, or otherwise broken mounting point, which makes repair difficult.

Charles Murray
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Re: Nice catch
Charles Murray   12/7/2011 3:22:38 PM
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I second what Alex said: It's hard to imagine that the belt guard has a single point of failure. Even the most insignificant components on many machines have some form of redundancy. Looks like someone decided the belt guard was too insignificant for redundancy. How scary.

twinpeaks
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Re: Nice catch
twinpeaks   12/11/2011 5:03:17 AM
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"That's why bikes used to use chains." (?) LOL! I fail to see what a "chain" has to do with that screw coming loose or how it could have prevented it. I'm loving this thread and the unintentional humor. It really shows the ilk of this new breed of riders today. 

David12345
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Platinum
Re: Nice catch
David12345   12/12/2011 9:04:36 AM
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And the ilk of . . . what are you? 

Are YOU a biker today (when you have your bike is out of the garage all tighened-up with fresh super thread-locker)?

And are YOU a mechanical engineer?

I would like to know more about you; so that, I can hire the guy that never made a mistake, and "knows it all" about what constitutes good design.  L.O.L.

twinpeaks
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Iron
Re: Nice catch
twinpeaks   12/13/2011 4:46:25 AM
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"And the ilk of . . . what are you? "

 

 

LOL! Not yours is all I can say. 


Stuart21
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Silver
Lawyered by Monkeys
Stuart21   12/9/2011 7:35:55 AM
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Whatever you do don't use the name Harley Davidson!

Harley own it and you are not even allowed to think it!

Used to be a 'Harley Bar' near here. Place was a temple to Harley Davidson! Harley stuff, bikes posters etc, everywhere. 'n hawg riders, of course.

Long comes letter from Harley lawyers - place promptly closes down, now no more. It was suggested that they change their name to 'Gold Wing Bar'.

I heard that City Council renamed the road outside Harley Davidson factory 'Harley Davidson Road' - long comes a letter from Harleys sh.t for brains lawyers, ordering council to change the name back!

Not only made by Monkeys, but lawyered by them too!

twinpeaks
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Re: Lawyered by Monkeys
twinpeaks   12/9/2011 6:18:26 PM
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Really? This "tale" of biker bars and Harley lawyers has been circulating since before most of you were born. They only litigate when someone uses the name HD or the bar and shield logo in thier name or on their main sign out front - and rightly so, otherwise "Harley" bars are great for their business. This internet is nothing more than a glorified Inquirer.

 

cptjam
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Re: Nice catch
cptjam   12/19/2011 9:30:31 PM
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not an issue. I know of no failures. 

David12345
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Re: Really, This Gets Published
David12345   12/20/2011 12:34:06 PM
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It sounds like you're the designer.  Who else would EXPECT that they would know of ANY issues? 

This belt guard did have at least one failure.  The design of the CVO belt guard is different.  It looks to me like the less attractive black plastic belt guard is designed so that it would not wedge between the belt and pulley; even if, the screw fell-out allowing the guard to drop onto the belt.

I don't know the CVO V-Rod production numbers with this metal lower belt guard, but even one total failure could constitute a fairly significant MTBF for the number of years the CVO V-Rod has been built.  How many times did this start to fail when the owner or shop caught it and tightened it?  The V-Rod came out in 2001.  The CVO V-Rod came out in 2005.

I work in the medical equipment industry.  Not hearing of a field failure does not prove or guarantee that no problem exists.

Dave Palmer
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Riding without belt guard
Dave Palmer   12/7/2011 11:30:17 AM
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Glancing briefly at Harley owner fourms, I couldn't find any mentions of this problem.  On the other hand, there were a lot of comments from people who take the belt guard off because they don't like the way it looks.  Apparently, they prefer to take their chances with stones and gravel possibly taking out a belt! So it's possible that Harley is careless about the fastening strategy because they assume owners will just remove the part anyway.

Hopefully someone from Harley is reading this, because this sounds like a very risky bit of carelessness.

Ann R. Thryft
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Re: Riding without belt guard
Ann R. Thryft   12/7/2011 1:23:44 PM
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If there's no mention of this problem on user forums, I wonder if this is a recent "innovation" in Harley bike designs and what led to the change?


Rob Spiegel
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Re: Riding without belt guard
Rob Spiegel   12/7/2011 3:09:04 PM
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Good observation, Ann. I checked the forums as well, just to see if the problem was widespread. I couldn't find anything. I went back to David for more info. Sure enough, there seems to be a design flaw.

Rob Spiegel
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Re: Riding without belt guard
Rob Spiegel   12/7/2011 3:12:08 PM
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That is strange there is no screaming about this flaw in forums. I looked at quite a few. It could be that not many of the belt guards are actually falling off even with the design flaw.

ZooKeeper
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Iron
Re: Riding without belt guard
ZooKeeper   12/7/2011 3:36:24 PM
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acommontraitofharley-davidsonistoinstalllessthanpleasingcomponentsasstockappointments,atleastontheestheticoptions.theirtheoryseemstobethatownerswillopttotrade-uptomoreexpenseadd-onsthattheywouldn'tchosetobuyasanoriginalequipmentpackage.isupposethisallowsforamoreaffordablebuy-inpricepointaswellasfuelingtheirverylucrativereplacementpartssaleschannel.
beinganh-downersincetheamfdays,i’veneverseennorheardofanythingthislifethreateningonanyoftheirmodels.there’sgenerallyamoreappealing,betterperforming,highlypolishedchromereplacementformoststockitemsbutnotbecausetheoriginalwaspronetocatastrophicfailure.still,themoststringentfmeamightnotbeexercisedonapartthath-dexpectedtobereplacedwithinthefirst1kmilesorso.

Rob Spiegel
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Re: Riding without belt guard
Rob Spiegel   12/7/2011 3:38:28 PM
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Hi ZooKeeper,

You seem to be having some technical problems with your post. Did you copy it from another format? Usually this systems works fine if you type directly into the comment window. We would like to hear what you have to say.

ZooKeeper
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Re: Riding without belt guard
ZooKeeper   12/7/2011 3:52:26 PM
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A common trait of Harley-Davidson is to install less than pleasing components as stock appointments, at least on the esthetics option. Their theory seems to be that owners will trade-up to more expensive add-ons that they wouldn't chose to buy as an original equipment package. I suppose this allows for a more affordable buy-in price point as well as fueling their very lucrative replacement parts sales channel.

Being an H-D owner since the AMF days, I've never seen or heard of anything this life threatening from any of their models. There's generally a more appealing, better performing, highly polished chrome replacement but not because the original was prone to catastrophic failure. Still, the most stringent FMEA might not be exercised on a part that H-D expected to be replaced with the first 1k miles or so.

I'm not attempting any sort of justification, only explaining my perspective.

Thanks fo the gentle nudge. Yes, I did copy-n-paste; no spacing was the result.

Rob Spiegel
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Re: Riding without belt guard
Rob Spiegel   12/7/2011 3:57:02 PM
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This posting came out much better, ZooKeeper. Thanks.

I agree it seem an odd flaw for a company that is not usually associated with spectacular design flaws. Makes you wonder if the company caught the error and changed the design. Even so, you would think they would send out a recall to fix the error. Doesn't make sense.

TJ McDermott
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How tiny is tiny?
TJ McDermott   12/7/2011 3:32:26 PM
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What size is the screw?  Tiny like #10-32?  Tiny like 1/4-20?

How heavy is the cover?  If the cover is supported and constrained, a single fastener might make sense, if it had a reasonably good locking mechanism.

Even if it had two screws, losing one could cause a cover to pivot about the other for similar results.

Drifter57
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Does Harley Davidson know?
Drifter57   12/7/2011 4:37:03 PM
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Uh, guys... This is an EXTREMELY dangerous possible failure!  As noted, the rear tire locking at speed is a potentially LETHAL situation! "Hopefully someone from Harley is reading this..." HUH?  How about one of YOU highly educated engineer types actually CONTACTING HD and suggesting a safety upgrade here?  Blogging and laughing at HD for a safety oversight as dangerous as this is hardly a constructive exercise.  Come on, let's move into the realm of real life.  The possibility of dead riders over this is not a joke!

I for one will be sending HD a letter with this posting attached.  They need to know about this issue, prevalent or not.

PS.  Having been an avid Harley rider for decades, I can tell you that the first thing you do with a new bike is locate, torque and Loctite all of the critical screws and bolts.  I prefer Afterloc myself.  Vibration is an evil and capricious mistress baby.

David12345
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Re: Does Harley Davidson know?
David12345   12/7/2011 5:22:17 PM
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This is still a fairly recent occurance. I did discuss this problem with the dealership as I purchased replacement parts.  I still plan to follow-up with a formal letter to the factory. 

This is not typical of my experience with Harley products.  I currently own two Harleys and ride with many friends on various brands including many Harleys.  This entry was not intended to slam Harley, but rather to highlight how small an oversight could have such hazardous potential.  I guess I'm still a little shaken about it, and wanting others to take rattles (from any vehicle) with similar seriousness.

It could be this lack of appearance on discussion boards is related to the fact that this chrome belt guard is only a CVO part so the standard V-rods have a plastic belt guard.  There are fewer CVOs on the road. I am also embarassed that I didn't catch this loosening hardware upon examination, when it was giving a telltale rattle. Perhaps, most CVO owners are more attentive to these details?

How small a screw?  I'm not sure the exact metric size, but I believe it is 4mm x 13mm long fully threaded.  Pretty small.

Matt916
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Re: Does Harley Davidson know?
Matt916   12/8/2011 10:29:08 AM
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Glad to hear you're okay, David.  I have forwarded this article to my contact at Harley-Davidson Motor Company.

Ann R. Thryft
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Re: Does Harley Davidson know?
Ann R. Thryft   12/8/2011 12:27:40 PM
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Like others, I'm really surprised that a company associated for so long with high quality, especially having to do with bike and biker safety, would make such an oversight. Is HD starting to source their designs differently? Is offshoring of design, as well as materials and parts, becoming a trend in motorcycles?


Rob Spiegel
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Re: Does Harley Davidson know?
Rob Spiegel   12/8/2011 12:42:18 PM
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Thanks for sending it to HD, Matt. Surprisingly, many of the products discussed in these comments do make it to the manufacturer. I often receive requests from manufacturers asking for the email address for the person who sent in the story for posting. In that case, I just forward the manufacturer's request to the person who posted. 

Dave Palmer
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Re: Does Harley Davidson know?
Dave Palmer   12/7/2011 5:57:25 PM
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@Drifter57: Nobody's laughing.  Unfortunately, I don't know anybody at Harley, but I am trying to find out who to send this to.

William K.
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Platinum
Harley Hindered by lower belt guard
William K.   12/7/2011 11:42:55 PM
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Some biker a few years back defined "a real motorcycle" as one where you could not remove any one part and still ride it safely. 

Where this fits with your tale of woe is that you should have investigated that rattle as soon as you heard it, because all parts of a "real" motorcycle are critical.

I had a more exciting version of that experience happen to me many years ago. I had my bike with a freshly rebuilt engine just bolted in place and hooked up. I started the engine and started out to see how it ran. I was just coming off the line, and had only gone about five feet or so when the connecting rod disconnected from the crank and the engine locked. The clutch did not slip at all,  and the chain did not break. Verly fortunately I had a good grip, and so I was up on the bars looking down at the front tire. It slid to a stop, and then I rcovered. I was uninjured, but the engine lower casting and the connecting rod were "all used up". The bad news is that the replacement engine never put out as much power or ran as good, not for quite a few thousand miles.

No, that bike was not a Harley. IT had neither an upper or lower chain guard.

Rob Spiegel
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Re: Harley Hindered by lower belt guard
Rob Spiegel   12/16/2011 12:09:38 PM
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Hi William K,

I'd like to use this story as a Made by Monkeys posting. Would you be willing to add a bit more detail and send it to rob.spiegel@ubm.com

We'd love to run it. Thanks.

mikec711
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Silver
Glad you caught it, and I am equally guilty
mikec711   12/8/2011 10:39:18 AM
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I hear rattles on my Sportster all the time (although with a lot less torque ... I probably have fewer dangers.  Your article has me determined to do a head to toe inspection this weekEnd.  I think my Sportee is fine, but it's a 2003 ... so if yours was fixed after the fact, mine won't be fixed.  And issues on 2 wheels can be much more dangerous.  Thanks for the reminder and reality check.

elusive.motorcycle.parts
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Iron
vrod's lower belt guard issue
elusive.motorcycle.parts   12/8/2011 11:50:10 AM
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I own 2 vrods and am concerned of the lower belt guard issue. I've ridden over 100.000 miles without checking the belt guard screw.

Yet one way Harlay Davidson can avoid litigation or recall is to warn vrod owners to perform a walk around SAFETY CHECK and check your lower belt guard SCREW before each ride. What a PITA!

twinpeaks
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Re: vrod's lower belt guard issue
twinpeaks   12/9/2011 5:28:12 AM
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Case in point right here. Elusive ahd done 100,000 miles and never did a single bolt check. Holy Crap

Then again might prove this is a non-issue.

twinpeaks
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Iron
Really? This gets Published?
twinpeaks   12/9/2011 5:25:40 AM
I would like to question this "rider" when the last time he performed a visual inspection of his bike or did a "bolt check". Or if ever. My guess is never, My guess is he doesn't even change his own oil. My guess is his 6 year old bike has never been attended to since it was made. Anyone with any common senese knows that even the most refined motorcycle vibrates things loose. Anyone with the least amount of experience knows that MC's regardless of suspension takes the road conditions harder than a car. THINGS COME LOOSE and it's our job to keep an eye on them. PERIOD. Made by Monkees? More like ridden by an idiot and published by same?

David12345
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Re: Really? This gets Published?
David12345   12/9/2011 11:42:21 AM
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Well, I'm the "rider". Arguably an idiot.  Arguably, this is not the only problem here.

I sometimes do my own oil changes and install accessories; however, you're right, lately I usually pay a professional mechanic to complete most of my bike maintenance. Is that incompetant? I don't think so.  I am a professional engineer, have hot-roded bikes and cars since the mid-1970's. I have built a V8 conversion to a hot-rodded Corvair in the 1970's from the ground up. Was this loose guard partially my error? Absolutely. Have YOU ever made an error? I don't know you, but I presume so.

I had done a visual and hands on inspection several days before and again that day. (Remember I was concerned about the rattle too.)  Do you tear down your bike and retorque it daily?  Not if it's a daily rider, instead of in racing.

Obviously, I missed the "root cause" problem.  I have 20-20 hindsight too.  It is embarrassing that A) I am a contributing factor to the problem of the belt guard falling down and getting jammed between the belt and pulley.

However, I believe B) the mechanic that performed my state vehicle inspection two weeks earlier was a contributing factor, and C) the original design is flawed to have no redundancy to mitigate this risk. Critical fasteners should have redundant locks or clips when possible. 

Is that the only maintenance since the V-Rod was built 6 years ago? Absolutely not.  This bike has over 19,000 miles and has been ridden from PA to NM and back. My Dresser has over 49,000 miles since 1999.  They both get regular service.  The soft Z-rated V-rod tires wear-out in around every 5,000 miles, so those wheels come off-and-on AT LEAST that often.

This WAS a maintenance issue that was more critical BECAUSE of a higher-risk design.  This can easily be argued as a design FLAW; even though, it is subtle. As engineers and designers, we should be responsible to conduct DFMEA analysis and mitigate high-risk areas when practical. In my opinion, this focus is the real value of this discussion in Design News.  I don't like about this column being called "Designed by Monkeys", after all I am also an engineer trying to make good design choices which are sometimes a trade-off.

I have sent Harley Davidson a letter documenting this specific concern.  I am not trying to disrespect Harley Davidson, sue them, or otherwise injure them.  However as actuarial studies will statistically support over time, time high-risk areas will fail and lead to fatalities if not addressed.  As a reputable company, I trust that they will address this issue when the best solution is defined. 

Rob Spiegel
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Re: Really? This gets Published?
Rob Spiegel   12/9/2011 4:05:10 PM
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Seems to me this is the kind of malfunction that can oly be seen in hindsight. I'm not sure you can second-guess everything. When the belt guard falls off, you notice, there is only one screw. Not something you would go looking for.

David12345
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Platinum
Re: Really? This gets Published?
David12345   12/9/2011 4:26:19 PM
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For clarification, there are two screws, but the front screw secures a rubber bushing that an open ended slot on the guard slides onto.

It only took the one back screw vibrating-out for the guard to drop-off.

The design is not terrible, but it shouldn't stop there.  It is too easy to create a secondary hardware lock on a critical fastener as in this design. 

Rob Spiegel
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Re: Really? This gets Published?
Rob Spiegel   12/12/2011 10:50:43 AM
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Hmmm, David,

That's all the more reason a quick check of the bike before riding would not turn up anything alarming. I can't imagine how you could suspect trouble given multiple screws. Tricky problem.

 

David12345
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Platinum
Re: Really? This gets Published?
David12345   12/12/2011 11:31:05 AM
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It is a tricky problem.  I will be interested to see what change, if any, that Harley Davidson comes up with, in response to this belt guard concern. 

In the meantime, I will keep locktite blue (or equivallent) on both of these lower belt guard screws (it is virtually assured the guard will fall onto the belt if the rear screw falls-out, but may be possible for it to sag enough to violently rip-out the back screw if the front screw is lost.), and keep a close eye on them both staying tight.  I have also gotten SS mesh for the radiator cowl to keep rattling stones out.  I will install this mesh before the next time I ride this bike.

For the future, A) I will see about getting Socket Head Cap Screws (SHCS) drilled for stainless steel safety wire installation on these independently safety-critical points.  B) I will also scope out the bike for other safety-critical fasteners to use safety wire, or a cotter pin back-up.  (I notice that Harley Davidson already has a redundant C-clip back-up on the V-Rod rear axle retaining the axle nut.)

Drifter57
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Re: Really? This gets Published?
Drifter57   12/13/2011 8:09:21 PM
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Well Dave, I'm glad you're all right, and that the bike gave you a heads up BEFORE it tried to kill you.  Scary stuff bolts coming off.

I fly some as well as ride, and have adopted a "flight check" mentality before I get on my bike.  Check all the lights, levers, cables, switches, axle bolts, shock bolts, brakes, exhaust system, linkages, hoses, even the mirror attachments, windshield bolts, and check the oil and tire pressure.  Takes a few minutes, but I kind of like coming home at night.  Got one more thing to add to the list now.

I'm also an aircraft engineer, and am aware I must be triple careful in my engineering decisions.  Can't exactly pull an aircraft over on the nearest cloud if something breaks or falls off.  If I goof, very likely people WILL die.  Have a lot of tried and practiced engineering policies and requirements to avoid oversights of this nature.  "New" is always the most terrifying design.

-Experience is something you rarely get, until just after you need it.

cptjam
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Re: Really? This gets Published?
cptjam   12/16/2011 1:17:42 AM
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The design is fine. Any part that hangs on for "a few days" WITHOUT A BOLT is a superb design! You ride 13 miles each way each day AFTER you hear a rattle? The gromet up front does the holding. It took that long to work its way aft to finally rattle a bit. Then took a few more days to fall off. Not many bike parts stay on without a bolt!

David12345
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Re: Really? This gets Published?
David12345   12/19/2011 1:17:36 PM
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This bike has historically rattled intermittantly since I bought the bike, due to stones sucked into the radiator cowl with no way out.  I talked to my dealer about it, and the other customer at the service counter joked that I needed a louder exhaust system so that I wouldn't hear that and be bothered.  I have bought a fairly open stainless steel mesh screen for these cowl openings, and plan to have them installed before I take the V-Rod back on the road.

I do periodically check over the bike and seek-out anything that's not right.  Obviously using my wonderful 20/20 hindsight, it was the lower belt guard loose, not stones in the radiator cowl.  I do not believe the front rubber grommet held the part on for ANY appreciable time after the rear screw fell out.  I can only presume the front grommet and the loose rear screw held it wedged and tight enough during my pre-start inspections to evade detection.  Although, it rattled a few times while riding on the road a few days before it fell into the belt, I obviously did not find the correct root cause immediately.

The rear fastener is hidden enough that a secondary clip, folded tab, or safety wire will also be hidden; except for, inspection on your knees with a mirror.

Harley Davidson's engineering department has talked to me three times so far as a follow-up of my letter.  Clearly, the fact that it was loose after over 19,000 miles and multiple tire changes was NOT a factory assembly issue.  However, I still contend that the design contributed to the problem and I intend to have this fastener lock-tighted AND safety wired on MY BIKE before I take this bike back out on the road.  Harley Davidson is still evaluated this concern and has not told me what their response will be.

CL0511
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Re: Really? This gets Published?
CL0511   12/19/2011 4:36:39 PM
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David,

 

One thing to consider for the safety of all riders, is that you can post an issue on the NHTSA website.  Sending a copy of this to Harley may assist with getting some response from their team.

I was one of the lucky few that purchased a 2006 VRSCR Street Rod.  In my first 3/4 mile ride, my jeans caught on fire, causing some decent 2nd/3rd degree burns.  Within a week of posting on NHTSA, sending a copy to Harley and the dealership, I had a heat-shield installed, and eventually a recall ensued.  Luckily I was not riding at 60mph, as fire usually causes panic, and panic causes accidents.

Glad to hear your V-Rod issue didn't cause injury or worse.  It's my opinion that the V-Rod models, although beautiful and a great concept, have been very poorly executed from an engineering standpoint.

David12345
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Platinum
Re: Pictures Requested
David12345   12/19/2011 6:53:51 PM
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  I have pictures of the physical part and downloads of the Service Manual page showing the drawing of how it mounts.  I can transform this into DOC, PDF, JPG, HTM, or other formats; however, this post does not seem to allow anything other than TXT format which strips the graphics from the file.

I have tried to post the Service Manual drawing in this video comment upload.  We'll see if it works.

 

David12345
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Platinum
Re: Pictures Requested
David12345   12/19/2011 6:57:32 PM
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Video Comment


Rob Spiegel
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Re: Pictures Requested
Rob Spiegel   12/20/2011 4:00:15 PM
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Hi David,

I'm getting a message that "this video is not available." Not sure if it's becuase of my browser or whether everyone is barred from viewing the video. Please check it out.

Thanks.

David12345
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Platinum
Re: Pictures Requested
David12345   12/20/2011 4:50:50 PM
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Rob,

No, I was having an upload issue . . . the file did not load correctly.   I was trying to share a drawing of the "belt contamination guard" application that I later attached as a PDF to an E-mail to you.

That video comment should be deleted as it has never worked, but I don't know a way to do that in your software.

Rob Spiegel
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Re: Pictures Requested
Rob Spiegel   12/21/2011 1:28:06 PM
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Thanks Dave,

I'll see what I can do about fixing the video. 

jccubs
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Silver
Re: Pictures Requested
jccubs   2/16/2012 10:17:28 AM
Had a friend in college that had his rear wheel shredded when the license plate bracket came loose on his Honda Magna.  Again, not typically what you would look for as far as safety, but on a motorcycle EVERYTHING can be a problem.

twinpeaks
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Iron
Re: Really? This gets Published?
twinpeaks   12/9/2011 6:10:52 PM
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Rob - 2 screws, thank you, and no screw or bolt is insignificant.

 

David, it would seem you're "engineering background" was not mechanical? 

 

John
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Gold
Locktite Everywhere
John   12/13/2011 9:01:43 AM
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I am not a motorcyclist and some pictures of the guard and or area would have been nice to view.  I don't see how it's Harley or the riders fault.  Harleys have radical cams and sometimes high compression.  Thus they are rough idling and I wouldn't expect the rider to make visual inspection for loose screws and bolts every time you want to go for a ride.  Not very practical or reliable.  I am sure HD uses locktite all over the place since wires and folded corners of plates wouldn't look good next to chrome.

This maybe the barn burner, but I think the guard would be made of thin sheet metal and wouldn't do anything to wheel spokes or the belt except for maybe throw the belt off or shred it some how in a worse case scenario.

Dangela
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Bronze
chain drive
Dangela   12/16/2011 1:56:56 PM
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I was driving along a four lane road when I spotted a black line in the middle of my lane. It wasn't straight and I initially could not figure out what it was. After about 1,000 feet it lead over to a motorcycle on the side of the road. I pulled over to see what happened. The guy was standing next to the motorcycle smoking a cigarette with a noticable shake. I looked at the motorcycle which was a Kawasaki 1000 and noticed the chain wrapped around the rear axle. I was amazed he kept it upright for so long with the rear wheel locked up. So was he. He said he just installed a "Diamond" chain and was surprised it failed so soon. I'll stick with my shaft drive.

William K.
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Platinum
Harley Hindered by lower belt guard
William K.   12/16/2011 9:55:54 PM
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I also had a chain around the axle problem on the first version of my first custom "bike", a non-raked chopper. The problem was a lack of stiffness in the frame between the engine and the rear axle. Fortunately that problem happened at startup before I got moving fast. 

MY cure was two changes. I stiffened the frame a lot around the engine mounts area, and I added an idler under the bottom chain, about 4 inches in front of the rear tire. That kept chain stretch from letting the chain jump off the sprocket and get between sprocket and spokes. It was still working as designed 22 years later when I sold that "bike". The problem with a strong engine is that you also need a stronger chain.

My guess is that the guy you met put on a brand new chain and then did not tighten it enough, and did not tighten it again after a few miles. Chains do grow at the begining as the production burrs flatten out. You mustmALWAYS check a new chain a few miles after installing it.

Rob Spiegel
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Re: Harley Hindered by lower belt guard
Rob Spiegel   12/19/2011 4:02:32 PM
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Good story on the chain, William. You were fortunate to see the problem before you got started. I can understand the commener who said he decided to leave chains behind.

jadbp
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Iron
I've BEEN there!
jadbp   2/16/2012 10:16:37 AM
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I am sorry to say, I've been there.  I have had chains come loose on my bikes and lock up the rear wheel AT SPEED.  It's a scary process, and requires outstanding balance to try to stay upright (or climb on top of the sled if it falls over). 

This is no as uncommon as you might think.  While Harley's use a belt to try to smooth out their chunky engine, it is not immune to locked wheels.  More common is a broken chain or chain off gear.  The root cause is a loose chain, a worn chain, a stretched chain or an unlibricated chain.  It can come off the gear and jam, or come off the gear and break. 

Actually, the root cause is operator error.  Chains DO stretch, particularly when first installed.  It is cumbersome to tighten the chain, but it is the rider's responsibility to maintain a safe bike--including the chain. 

Rob Spiegel
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Re: I've BEEN there!
Rob Spiegel   2/16/2012 10:55:09 AM
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Thanks for the story Jadbp. It must be horrifying to run into that problem. I would imagine the solution is continue maintenance on the chain.

Tom Barker
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Iron
LocTite Thread-Locker and/or Spiralock threads
Tom Barker   2/16/2012 10:46:27 AM
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Harley, Triumph and other potato-potato/chug-chug bikes should be using these proven, decades old technologies, but they're not.  Until then, keep your wrenches handy, and tighten everything biweekly.

William K.
User Rank
Platinum
Belt guard grief and the heavy Harley.
William K.   2/16/2012 5:41:42 PM
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It is very exciting to have a rear wheel lock up. It happened to me one time just coming foo the line, when "the engine broke". 

The fundamental design flaw was putting anything inside the belt loop. If there really was a need for the guard it would be covering the loop so as to prevent anything from getting caught in the drive pulley or getting chewed by the belt teeth. When a correctly implemented belt guard falls onto the belt it will make a lot of noise and wear the belt, but never result in a loss of control.

The bike that I built had an idler that held the chainin line with the engine-end sprocket at the same time that it kept the chain adjusted correctly. It was similar in shape to a pulley, except that the edges did not taper very much. The result was that as the chain would stretch, which they certainly do, the slack was easy to adjust out, and when the limits of the adjuster were reached the chain was due to be replaced anyway. PLus, it looked good.

Of course, there are those who claim that "real bikes have chains", but that would be part of a different discussion.

Rob Spiegel
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Blogger
Re: Belt guard grief and the heavy Harley.
Rob Spiegel   2/17/2012 11:57:21 AM
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What are your thoughts on "real bikes have chains," William? Wouldn't a bike without a chain be safer?

David12345
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Platinum
Re: Belt guard grief and the Harley.
David12345   4/11/2012 1:40:29 PM
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William K.   "The fundamental design flaw was putting anything inside the belt loop. If there really was a need for the guard it would be covering the loop so as to prevent anything from getting caught in the drive pulley or getting chewed by the belt teeth. When a correctly implemented belt guard falls onto the belt it will make a lot of noise and wear the belt, but never result in a loss of control."

I agree with you in principle; however, the one other design consideration that I have become aware of is that rocks or sticks can be deflected by the rear tire and land in that belt loop causing a lock-up or damage to the belt and rear pulley.   This guard was designed to reduce this possibility without having the guard itself creating other problems of making frequent belt inspection impossible without partial disassembly. Design is indeed a trade-off of sometimes conflicting considerations.

I still feel that it is important to have better retention of this guard to avoid potentially lethal consequences.  Mine is now safety wired.


William K.
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Platinum
Harley Hindered by lower belt guard
William K.   2/18/2012 10:36:34 AM
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Probably a bike without a chain could be safer, but there are other things to be considered. Some motorcycles wind up being used in rather harsh terrain and in a very abusive (to the bike) manner. The result is that a bike with a drive shaft would be damaged to the point of being disabled and needing shop repair in a fairly short time, since the universal joint is a relatively fragile part, and does not generally like large changes in angle. Toothed belts are much better in that area, and are often used, but a damaged belt requires replacement, since they are not generally repairable. Chains and sprockets do wear more than belts and pulleys, but chains are field repairable, and also replacable with less effort than a normal belt replacement requires.

So the application requires consideration. In addition, a belt will chew up a leg almost as much as a chain will, if one contacts the side of either one. At least that is what I have read, but not experienced.

Rob Spiegel
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Blogger
Re: Harley Hindered by lower belt guard
Rob Spiegel   2/21/2012 11:49:24 AM
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Thanks, William. Sounds like we're not going to see any dirt bikes with drive shafts soon. I would imagine there is also a social stigma against drive shafts among some bike groups.

William K.
User Rank
Platinum
Harley Hindered by lower belt guard
William K.   2/22/2012 9:47:48 PM
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You are certainly correct about the "social stigma" associated with drive shafts.

Any manufacturer would love to have that kind of loyalty to their product. 

I suppose that it would be possible to come up with a rugged enough type of U-joint, but it would probably be heavier and I know that it would cost more, and besides that it would make field changing the driven end ratio  awhole lot more complex, at best.

William K.
User Rank
Platinum
belt grief
William K.   4/11/2012 4:01:33 PM
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Thanks for the information about the problem of stuff getting caught in the belt. That is one of the things that those touting belt drive never mention. I have not had a rock get caught up in a chain, although I did have a chain come off one time and wrap between the big sprocket and the spokes.  I came to a very squirrly stop with the rear wheel locked, fortunately I was just starting up when it happened. I learned how critical chain tension is, and a bit about chain paths. That bike got a back-side chain idler and always had correct belt tension from there on for the next 20 years.

But still it seems that there should be a way to avoid that kind of hazard with the belt guard.Safety wires on the bolt is a good approach, but redundant supports and safety wires on the support bolts would be the best way.

David12345
User Rank
Platinum
Re: belt grief
David12345   7/19/2012 3:50:34 PM
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William K. - I agree with your comments, "redundant supports and safety wires on the support bolts would be the best way."

For the record, this belt guard mount has been trouble-free, since I attached the guard screws with lock-tite blue AND the back mount also with safety wire.

The screws are small enough diameter that I am VERY careful on torque.  The front screw is a button head, so I was not able to cross-drill the head for safety wire (or I would).  I didn't replace that button head with a SHCS, because I didn't want a form that could rub or catch on the belt in any condition.

I also monitor this component (and the top belt guard) very closely now that I am more aware of their vunerability.

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