Need new underwear and a windshield

[russperry]

Unrelated aside re: flying through thick plastic:

The designed emergency egress from the A6 Intruder I flew in combat was to eject directly through the plexiglass canopy. The normal opening method of the canopy was a rearward sliding motion, so the designers decided they didn't want to try and blow the canopy rearward - if something were to hangup during that sequence, the solid metal frame would be placed right above your head and the rocket motor would blow the crew (victims) directly into a thick band of solid steel.

Now consider that the canopy is designed to withstand high pressurization so it was quite thick. Several A-6 crew members I know of were injured on the jagged plexiglass edges, usually puncture wounds to hands, wrists and arms or in one tricky case, tore open a guy's dry suit prior to him entering the North Sea with water temp at about 40F. Luckily it was daylight and right near the ship so he was picked up by helo quickly, otherwise he would have been a popsicle within minutes.

With that said, I'm going to stick with plastic screws in the windscreen - now back to the thread.....

 

[semongtaulie]

If memory serves me correctly it was the +3 tall and +4 wide. In all fairness to the shield I did not take the torque wrench to the plastic screws however they were definitely tight when I installed the shield. I've only had a MC for about five years but spent my whole life around tools, shops, etc. so I made sure all fasteners were tight.

I can't seem to master posting pics anymore but the strange thing about what happened is the studs of the screws are still sticking out of the tuning blocks. Only the heads sheared off. I just find that strange that all the screws failed in the same way.

In the past three years I've had a Calsci large, V-stream, Yamaha Touring shield, Cee Baileys short screen and the OEM screen. Now that I think about, I've always used the same screws. Maybe there is a "shelf life" for those plastic screws or they get weakened from repeated tightening.

 

[RichDoyle]

Ok...Brodie's was a good example, but the windshield did not contribute to his injuries. In over 17 years at this job, and riding since I was 8, I have NEVER, not once, seen someone injured by a broken shield. My VTX shield was secured with large allen screws and metal framework. Since I rode more 'in' that bike than 'on' it like the FJR, I would have been way more likely to hit that Memphis Shades shield than any I've seen on an FJR.
Physics says that a sudden-stop front end collision, like Brodie's, is either gonna push me into the tank and up, or up as the front of the bike is pushed downward. Both scenarios move the person away from the shield. This idea that we are going to fly 'through' the shield is far fetched at best. Sort of like car tires causing flaming aluminum and plastic deaths.

So someone, anyone, please post up a link to ANY MC crash where a rider or passenger, was cut, disemboweled, butchered, dismembered, gashed, beheaded, or otherwise injured by a jagged windshield. Police report, newspaper article, magazine article, forum thread, whatever. The forum thread or a personal story has to be a firsthand account. The person who wrote it had to be there and see it firsthand. This is to avoid the story about a cousin's friend's sister's fiancé's mother's coworker's son who was mangled by a windshield.

I totally get the reasoning behind the screws shearing and saving the mechanism, W-piece or shield itself, but I wanna see proof of all the claims of supposed added injury due to a shield that was mounted without plastic screws.

Not trying to be a ****. I'm seriously wondering if anyone has ever really seen this happen or if it's all conjecture. Anything with an almost, could have, should have, will not count, so if someone was totally lucky, it skews the result.

Actually, I received a puncture wound from the broken windshield when I crashed my '03 ST1300. The windshield did not pop off. I think it went like this: Right boot broke off the top of the windshield and the resultant jagged point punctured the skin on my right knee right below and outside the patella. Now this was a minor injury. It barely bled and hardly hurt. I put a bandaid on it when I got home and that was that. FWIW it was a Rifle. But it was definitely a nasty-looking pointy thing I wouldn't want to have encountered with my abdomen or neck.

I also suspect over-tightening of the bolts is a factor here. My Gen III is built a bit differently. I have had several brands of windshield on it and the instructions for EVERY SINGLE ONE cautioned against over-tightening. I believe they all gave a recommended torque setting but acknowledged no one has torque wrenches that read this low. The suggestions tended to be the tightness used to re-close the cap on a water bottle or soda bottle.

It's also possible that the Rifle, being angled the way it is, may actually be in a state of "lift", rather than being pushed back on while riding. Radial engine cowlings on aircraft are like this. Counterintuitively, if they come loose, they are pulled forward toward the propeller. In a case like this, rather than the plastic bolts being under shear forces, they are in tension, putting a lot of strain on the bolt-heads. In shear there is isn't much force, if any, on those heads.

 

[HotRodZilla]

Thanks Rich and John.

John, were the guys that went through the shields injured by them? I could see it happening, I just don't think it's likely.

Oh, and for the OP, McMastercar has those plastic screws by the bag. I don't have the link, but my brother used to work there. Unless I have some kind of issue, I'll stay with my plastic screws. Hell, I still have the OEM screen mounted, BUT, if I needed one in a hurry, I wouldn't worry about replacing it with the first metal screw I found. Then I'd prolly forget about it.

 

[bigjohnsd]

The Harley guy didn't appear to be injured by the windscreen, there was no blood on what remained of it.

The employee on the VFR wasn't injured by his windscreen, the state patrol surmised that the broken collar bone came from a one point landing on his shoulder. Helmet was quite pavement scarred but was intact, visor was scratched but intact. Jacket had no perforations. Pants and jacket had significant rash and were cut off in the ambulance enroute to ER.

 

[Slardy]

Fred W,

you said you bought a bag of Nylon Screws? Nylon is not the same as plastic. Are you thinking strength-wise, Nylon is somewhere in between metal and plastic and that's OK?

Slardy

 

[Fred W]

That may very well be true. Not knowing what the actual material was from the factory (I only had the bling blue screws), and having some experience using nylon screws in my line of work, I figured that the nylon would work just fine, break away at the required times, and maybe not be quite as brittle as a hard plastic, especially in the cold of New England.

I just went out and located my bag of screws. As it turns out I don't thik that I did get them from McMaster Carr, They were made by Small Parts, Inc, and they are M5 x .8P x 20mm L. , their part number MNFP-50807-C. But it doesn't appear that you can order from them directly on-line, so maybe I found them on Amazon.com?

With just a little google foo, I turned up some black (preferred color) nylon, philips head screws for $11.38 for a pack of 100 here.

By the way, does anyone know what the Yamaha screws are made of? Here's a chart that compares the tensile strength of various plastics, including nylon. They are all relatively close.

 

[LgFJR]

Mcmaster Carr does have the black plastic screws.........bag of 100 for $8.57

pack
92492A328
Metric Nylon Pan Head Phillips Machine Screw, Black, M5 Size, 20 mm Length, 0.8 mm Pitch, packs of 100

#90451A328 I ordered one of these a few years back and still have some........
today $8.57 pack 8.57

 

[Slardy]

Fred,

that chart convinced me. I am out to buy a bag. I just bought a bag.

I will send the first 5 people that email me with their addresses, 7 screws, free. I figure that at age 73, 50 ought to last me until.......

Thanks

Slardy

 

[RiderCoach Lar]

Ok...Brodie's was a good example, but the windshield did not contribute to his injuries. In over 17 years at this job, and riding since I was 8, I have NEVER, not once, seen someone injured by a broken shield. My VTX shield was secured with large allen screws and metal framework. Since I rode more 'in' that bike than 'on' it like the FJR, I would have been way more likely to hit that Memphis Shades shield than any I've seen on an FJR.
Physics says that a sudden-stop front end collision, like Brodie's, is either gonna push me into the tank and up, or up as the front of the bike is pushed downward. Both scenarios move the person away from the shield. This idea that we are going to fly 'through' the shield is far fetched at best. Sort of like car tires causing flaming aluminum and plastic deaths.

So someone, anyone, please post up a link to ANY MC crash where a rider or passenger, was cut, disemboweled, butchered, dismembered, gashed, beheaded, or otherwise injured by a jagged windshield. Police report, newspaper article, magazine article, forum thread, whatever. The forum thread or a personal story has to be a firsthand account. The person who wrote it had to be there and see it firsthand. This is to avoid the story about a cousin's friend's sister's fiancé's mother's coworker's son who was mangled by a windshield.

I totally get the reasoning behind the screws shearing and saving the mechanism, W-piece or shield itself, but I wanna see proof of all the claims of supposed added injury due to a shield that was mounted without plastic screws.

Not trying to be a ****. I'm seriously wondering if anyone has ever really seen this happen or if it's all conjecture. Anything with an almost, could have, should have, will not count, so if someone was totally lucky, it skews the result.

During several discussions with a friend of mine, Tony Sanfelipo, certified EMT, founder and former Director of ABATE of Wisconsin, an accident investigator for the past twenty one years, and a lead instructor for Accident Scene Management for the past seventeen years, we've talked about numerous injuries from motorcycle crashes as well as likely causes of those injuries. Tony has stated on numerous occaisions that he has treated and/or documented various punctures and lacerations, especially lower body, that appeared to be from objects such as broken control levers, shattered windscreens, even pointed bar ends after a high-side motorcycle crash. Of course no one can ever know 100% what causes specific cuts and bruises during a crash. They can only identify the most likely cause(s).

Unfortunately, there are an INFINITE number of trajectories...not just the two stated...that a body can follow during a sudden-stop front end motorcycle collision. And while the rider may escape the threat of a broken shield (or any other protrusion), a passenger may not be as fortunate. While I've personally never witness such an injury, I have seen photos of numerous bikes that have crashed and cannot recall very many where the windscreen remained intact.

I think the only thing that's far-fetched when it comes to risk tolerance/acceptance and riding is believing that a threat doesn't exist because one has never witnessed it first-hand. Not trying to be a ****, either. Just providing an opinion, knowing that polycarbonate plastic isn't made to shatter into tiny fragments, break cleanly, or get itself out of your way if you're thrown against it.

 

[gixxerjasen]

Just so we are comparing apples to apples here, and for my own curiosity...those bikes mentioned that used metal screws....what did they screw into? I've had bikes before that had metal screws, but they went into one of those rubber expandy things in the holes. With those, they fit snug, but are still designed to be ripped out before the screen is smashed. So, for the sake of argument, were those bikes with metal screws screwing into some type of metal frame like the FJR or were they using the expandy things?

 

[bergmen]

Just so we are comparing apples to apples here, and for my own curiosity...those bikes mentioned that used metal screws....what did they screw into? I've had bikes before that had metal screws, but they went into one of those rubber expandy things in the holes. With those, they fit snug, but are still designed to be ripped out before the screen is smashed. So, for the sake of argument, were those bikes with metal screws screwing into some type of metal frame like the FJR or were they using the expandy things?

On the Concours, the top two screws on both sides threaded into brass inserts in the injection molded inner instrument cowling. The rest (six screws) threaded into rubber expansion inserts (commonly called "well nuts") inserted into the front of the main fairing. None of the screws threaded into metal structural members.

Dan

 

[bergmen]

Fred W,you said you bought a bag of Nylon Screws? Nylon is not the same as plastic. Are you thinking strength-wise, Nylon is somewhere in between metal and plastic and that's OK?

Slardy

Nylon (Polyamide) is a semi-crystalline thermoplastic in the same general category as the polyethylenes and polypropylenes. Polycarbonate is an amorphous thermoplastic in the same general category as ABS, PVC, etc.

Nylon is very resistant to stress (or tension) failures, it stretches quite a bit before actual failure. Polycarbonate on the other hand is extremely strong with compressive loads and is very popular as impact resistant shields (bullet "proof" windows at banks, etc.), safety glasses, face shields and windshields. PC is very weak in tensile strength. Acrylic (Plexiglass) fractures easily with impact loads (especially with thinner cross sections) and is not a good choice for motorcycle windshields or helmet face shields as a result.

Dan

 

[ionbeam]

...those bikes mentioned that used metal screws....what did they screw into? I've had bikes before that had metal screws, but they went into one of those rubber expandy things in the holes...

Well nuts. A rubber/neoprene body with a brass nut molded in, typically used as a blind fastener. The flanged body of the well nut can also be used to make a water tight (well, at least resistant) seal at the fastener hole.

 

[bigjohnsd]

https://www.coloradoplastics.com/blog-0/bid/42625/Polycarbonate-Lexan-vs-Acrylic-Lucite

 

[FJR Bill]

When I bought my CaliSci shield it came with the metal screws. Talked to the owner who said they are preferable to the plastic/nylon OEM screws at least for his shields. Seems he's not concerned about liability issues which means he's either ignorant of the possibilities or as an engineer, knows what he's talking about. Bill

 

[gixxerjasen]

Thanks guys, soon as you said "Well nuts" I was like "Oh yea, that's them!" I hate it when I can't think of the word when I need it. I suck at scrabble and wheel of fortune.

 

[TomInPA]

I'm not sure how many more pages this will go on while different folks stress about what windshield screws to use. I understand the break-away screws are mainly for a tip-over to prevent damage to the windshield mechanism. I have not seen a manufacturing or safety source that claimed it was for injury prevention. Show me the source, and I'll change my mind...

Meanwhile, I'm using chrome socket bolts that seem to do a spiffy job of never breaking and tossing the windshield at my head. Now that is a hazard I heard about first-hand in this thread and that trumps all the imagined hazards. So, I guess that puts me squarely in agreement with A.J. Scary!

 

[RadioHowie]

Wow, what a great discussion!

Now, can we move on and over-think something else?

How about how to add a supercharger to an FJR? How are we gonna drive the impeller?

I'm thinking "mount it where the airbox goes and drive it via chain or belt off the rear balancer."

Thoughts are welcomed and encouraged.

 

[palerider]

Wow, what a great discussion!
Now, can we move on and over-think something else?

How about how to add a supercharger to an FJR? How are we gonna drive the impeller?

I'm thinking "mount it where the airbox goes and drive it via chain or belt off the rear balancer."

Thoughts are welcomed and encouraged.

Perfect application for nylon screws.