Author Topic: Front Flat at Speed and Bobby Almost Bought It  (Read 4247 times)

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Offline BobbyR

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Re: Front Flat at Speed and Bobby Almost Bought It
« Reply #25 on: August 03, 2012, 05:37:47 PM »
I have a double problem, I have spoked wheels, which may have a worse configuration for setting a bead than the Comstars. I think I have used up my luck at this point in my life. 
Dedicated to Sgt. Howard Bruckner 1950 - 1969. KIA LONG KHANH.

But we were boys, and boys will be boys, and so they will. To us, everything was dangerous, but what of that? Had we not been made to live forever?

Offline heffay

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Re: Front Flat at Speed and Bobby Almost Bought It
« Reply #26 on: August 03, 2012, 06:24:13 PM »
If you wanted to convince us, maybe you should have exaggerated that a bit.   :D ;)

I've never ever heard a single story about a tire coming off the wheel because it wasn't marked tubeless. I've put a few hunred highways miles on my bike with out a single issue. Others on this site have ran this setup for years with out a problem, but if it scares you don't do it. I know I'm going to keep running my comstars tubeless.
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Offline Lamp

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Re: Front Flat at Speed and Bobby Almost Bought It
« Reply #27 on: August 03, 2012, 07:01:32 PM »
Haha I know. I just finished the bike about a month ago. I'll be sure to let you guys know when I have a tire fly off a wheel though. ;D
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Offline TwoTired

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Re: Front Flat at Speed and Bobby Almost Bought It
« Reply #28 on: August 03, 2012, 11:40:23 PM »
Haha I know. I just finished the bike about a month ago. I'll be sure to let you guys know when I have a tire fly off a wheel though. ;D

I know you've made up your mind.  But, for others reading...

Consider a tubeless tire on a tubeless rim which locks the bead to the rim.  If tire pressures get low from a puncture, slow leak, other neglect, or even if total air loss occurs, then the tire stays in position on the rim, if a bit wobbly.

A tubeless tire on a Tube type rim has no bead lock mechanism.  Only air pressure holds it in place.  Low pressure and road bump and the bead shifts with sudden total air loss, and the tire then wanders sideways on the rim.  I prefer my skin on my body rather than the roadway, and will gladly add the required tube to tube type rims.  (Even if I do run old tires, at times.)

Anyway, if a tire shop knows what they are doing or if their insurance company is paying attention, they will not accept the risk of such known and previously identified failures mechanisms.  Professionals know this is wrong.

Because you haven't seen it happen, doesn't mean you aren't playing against the odds.  Because 100 examples have yet lost air, doesn't mean it cannot happen.  Riding is risky enough without adding more unnecessarily.  Did I mention, I'm getting a new tire?

Cheers,
Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

Those that learn from history are doomed to repeat it by those that don't learn from history.

Offline lostmykeys

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Re: Front Flat at Speed and Bobby Almost Bought It
« Reply #29 on: August 04, 2012, 01:29:30 AM »
 Bobby R,
 Did you try using your rear brake and the momentum of the bike at that moment to try to cool things down abit?
 I have had the same thing happen to me at very high speeds..130mph+
 I know I'm a the guy that cant spell, but use your rear brake next time to steer your bike.
 They dont teach you this in motorcycle class by the way.

Offline dave500

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Re: Front Flat at Speed and Bobby Almost Bought It
« Reply #30 on: August 04, 2012, 05:29:39 AM »
spelling has never been taught at motorcycle riding courses,but in your case they will make an exception.

Offline BobbyR

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Re: Front Flat at Speed and Bobby Almost Bought It
« Reply #31 on: August 04, 2012, 06:48:36 AM »
Bobby R,
 Did you try using your rear brake and the momentum of the bike at that moment to try to cool things down abit?
 I have had the same thing happen to me at very high speeds..130mph+
 I know I'm a the guy that cant spell, but use your rear brake next time to steer your bike.
 They dont teach you this in motorcycle class by the way.

That is a very good point I should have mentioned I did use the rear brake to burn off speed. I may have tapped the front at some point, I don't remember. I do remember helping the bike stay upright and trying to stay upright until it was going slow enough for me to dive off and hope the jacket, helmet and gloves to do their thing.
I got it stopped in the dirt because that is where it wanted to go and I could stay upright. If I tried to force it to stay on the pavement, I think it would have dumped me on the pavement.
Dedicated to Sgt. Howard Bruckner 1950 - 1969. KIA LONG KHANH.

But we were boys, and boys will be boys, and so they will. To us, everything was dangerous, but what of that? Had we not been made to live forever?

Offline 754

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Re: Front Flat at Speed and Bobby Almost Bought It
« Reply #32 on: August 04, 2012, 09:53:56 AM »
 You can use the rear brake but your foot keeps coming off when the tire shifts left tossing it over hard right.. I think i snubbed the front gingerly..
 a tad hard to take notes, whist being puckered...

 sooo.. anyone beat my 5 flats in 10 days record?
« Last Edit: August 04, 2012, 09:57:16 AM by 754 »
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Offline BobbyR

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Re: Front Flat at Speed and Bobby Almost Bought It
« Reply #33 on: August 04, 2012, 01:01:30 PM »
You can use the rear brake but your foot keeps coming off when the tire shifts left tossing it over hard right.. I think i snubbed the front gingerly..
 a tad hard to take notes, whist being puckered...

 sooo.. anyone beat my 5 flats in 10 days record?

Nooooooooo I think everyone would like you keep that record.  ;D ;D ;D ;D ;D ;D ;D
Dedicated to Sgt. Howard Bruckner 1950 - 1969. KIA LONG KHANH.

But we were boys, and boys will be boys, and so they will. To us, everything was dangerous, but what of that? Had we not been made to live forever?

Offline the technological J

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Re: Front Flat at Speed and Bobby Almost Bought It
« Reply #34 on: August 04, 2012, 10:39:43 PM »
how far did you travel from flat to stop do you think?  or how much time did it take you to stop?


 i guess what im trying to ask is was it like.."lose control, regain control begin slowing..lose control, regain control begin slowing more" until stopped or was it like full brake until stopped and you did it in record time?
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Offline 754

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Re: Front Flat at Speed and Bobby Almost Bought It
« Reply #35 on: August 04, 2012, 11:32:10 PM »
 about 300 feet over about a minute it seems like...
Maker of the WELDLESS 750 Frame Kit
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Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline BobbyR

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Re: Front Flat at Speed and Bobby Almost Bought It
« Reply #36 on: August 05, 2012, 11:22:20 AM »
how far did you travel from flat to stop do you think?  or how much time did it take you to stop?


 i guess what im trying to ask is was it like.."lose control, regain control begin slowing..lose control, regain control begin slowing more" until stopped or was it like full brake until stopped and you did it in record time?

It was over 300 ft on a slight down slope. It probably did not last much more than a minute. It felt like forever, but probably it was a minute plus or minus.  There was no regain control as AndyCB750 said. The best I could do is try to fight bars and hold it upright.

The tire squirms on the rim and tries to violently take the bars out of your hands. I think the idea is to stay upright and let the bike go straight to keep the tire on the rim and keep the steel from hitting the pavement.

It never let's up until you come to a stop, you always know you will go down. Once I was just just down to a low enough speed to probably not get too dinged up, I just hit the rear brake and it stopped. There is no time the bars are not being whipped around, even at walking speed.

Different type of road, the outcome could have been worse. 
Dedicated to Sgt. Howard Bruckner 1950 - 1969. KIA LONG KHANH.

But we were boys, and boys will be boys, and so they will. To us, everything was dangerous, but what of that? Had we not been made to live forever?

Offline City Boy

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Re: Front Flat at Speed and Bobby Almost Bought It
« Reply #37 on: August 05, 2012, 03:55:18 PM »
Hi gang.No threat to your record 754 but reminds me of something.While wrenching at Nelson Motorcycles in Toronto we had a customer come in requesting we patch his tire tube.WELL,he had about 20 patches already including patches on patches.
  We bought him a new tube!
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Online scottly

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Re: Front Flat at Speed and Bobby Almost Bought It
« Reply #38 on: August 05, 2012, 05:35:06 PM »
But, for others reading...

Consider a tubeless tire on a tubeless rim which locks the bead to the rim.  If tire pressures get low from a puncture, slow leak, other neglect, or even if total air loss occurs, then the tire stays in position on the rim, if a bit wobbly.

A tubeless tire on a Tube type rim has no bead lock mechanism.  Only air pressure holds it in place.
Not all tubeless rims have the inner safety beads. The third pic is a Morris wheel that, ironically, I was told could not be run tubeless. 
« Last Edit: August 05, 2012, 05:36:48 PM by scottly »
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Offline TwoTired

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Re: Front Flat at Speed and Bobby Almost Bought It
« Reply #39 on: August 05, 2012, 08:11:02 PM »
Not all tubeless rims have the inner safety beads. The third pic is a Morris wheel that, ironically, I was told could not be run tubeless.

Was the Morris wheel an aftermarket one or one that came with a production bike?  (Intended use for racing, perhaps.)  Not much liability risk for the maker there, if so.

Certainly there is good engineering and bad engineering.  And also sales and marketing types who think they are engineers and rely on labeling to sell product.

I've tested many devices that claimed compliance to a standard, but didn't.

For the first picture you posted, I'd claim that the wheel didn't really qualify for a street driven tubeless spec wheel.  If the maker claimed the wheel was approved for use on the street, and an accident occurred, they would be liable for a pretty easy to win lawsuit claim.  If they are still in business today, they wouldn't be, after the jury awarded damages, I'll bet.   ;D  If it was a tire shop that told you they could not be run tubeless, they are right not to assume the liability, as it is not built to tubeless rim specifications.

However, if you are interjecting that "buyer beware".  I'll go with you on that, easily.

Certainly, if you buy "race purpose" parts and use them on the street, then you assume liability for their proper function.

Cheers,
Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

Those that learn from history are doomed to repeat it by those that don't learn from history.

Online scottly

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Re: Front Flat at Speed and Bobby Almost Bought It
« Reply #40 on: August 05, 2012, 08:26:44 PM »
The first two pics are of an '82 Kawasaki wheel; the second pic shows the "tubeless" marking quite clearly. The Morris wheel is an aftermarket wheel, made in '77, before tubeless tires were readily available. It is stamped TL, which I've learned means tubeless. It obviously has the safety bead. The Morris wheels were also used on production models, such as the Harley Davidson CR 1000.
I would like to see pics of the bead sealing area of an early, tube-type Comstar, and the later Comstars that came fitted from Honda with tubeless tires.
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Offline RAFster122s

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Re: Front Flat at Speed and Bobby Almost Bought It
« Reply #41 on: August 05, 2012, 09:09:01 PM »
Isn't the 78 CX500 Comstar a "tubeless" design? They are a bugger to get to pop and seal initially but I've seen car rims that were the same way.

Friend here in Sierra Vista had  bad spill on her HD this spring. She was geared up to the teeth but I don't know if she had an armored jacket on..just lots of layers and a leather bike jacket.
chaps, etc
She had a double rear puncture and the rear got major squirrelly back and forth in a hurry. She held it upright as long as possible and tben bailed when it got worse. She landed striking helmet and shoulder and then the rest of her followed. Helmet had some great visual rash and gear some road rash. She was very bruised up and sore for weeks. Bike was close to a write off  but they fixed it and in doing so it exceeded the writeoff amount. She was riding in a large group to the "motorcycle blessing" and was a new rider and had taken the MSF course. She had been riding about 6 months when it happened. She did everything right and lived. Made a lot of non-helmeted cruiser riders helmet believer that day.
David- back in the desert SW!

Offline Stev-o

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Re: Front Flat at Speed and Bobby Almost Bought It
« Reply #42 on: August 05, 2012, 09:18:46 PM »
I had a rear tire go low on pressure last year, what a bad feeling it is. Luckily I was not going fast and close to the house.
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Online scottly

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Re: Front Flat at Speed and Bobby Almost Bought It
« Reply #43 on: August 05, 2012, 09:27:37 PM »
Isn't the 78 CX500 Comstar a "tubeless" design?
I'm not sure just when Honda decided the Comstar was suitable for tubeless use, but I thought it was at least as early as the '79 750s and CBX.
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