Net-Moto :: Community :: Racing :: :: Racing Videos Sponsor :: Contact
 Forums   Features   Trackdays   Moto Crash Incidents   Race Team   CMSP Training   Sponsors      Donate   Terms of Service 
BARF - Bay Area Riders Forum  Home   UserCP   Register   Calendar   Members   FAQ   Search  AMA

Go Back   BARF - Bay Area Riders Forum > Moto > Crash Analysis


Closed Thread
 
Thread Tools Display Modes
Old 06-19-2017, 10:35 PM   #1
Dyn Blin
BARF'd
 
Dyn Blin's Avatar
 
AMA #2965147
Contributor

Join Date: Feb 2015
Location: SoCo NorCal
Motorcycles: '05 Girlie
Name: sMerk
First slow speed get-off in 20 years

Bone-headed move on my part:

Put on new rear tire, over-inflated to ensure bead had seated the night before, & didn't scrub the tire to ensure molding-release compound was cleaned off.

Figured I'd be OK going the 500 feet to the corner gas station before an early departure for a long trip this morning...

Rear wheel slipped & spun around the corner from a full foot-down stop out of my cul-de-sac, & dropped it in front of my wife, kids and neighbors.

Embarrassing lessons:
Dad is not infallible,
Don't hurry through the mental checklist in an effort to get ahead of the departure schedule,
Double check inflation- even for short trips,
Extra caution for new & cold tires.

Good reinforcement:
ATGATT was validated, even for short trips.
Dyn Blin is offline  
Old 06-20-2017, 12:29 PM   #2
dtrides
Veteran
 
dtrides's Avatar
 
Contributor ++++ + + + + 4%

Join Date: Jun 2004
Location: Eureka,Ca.
Motorcycles: Aprilia Tuono Factory for the street, Sv 650s for the track
Name: Duncan
Bummer, been there, done that.
Same situation, one block from house pulling on to main st .
Wife and riding friends right behind me to watch it happen.

Driver rolled by while I was on the ground, rolled down window and yelled at me to slow down..

So, first off, tire manufactures claim they no longer use release compounds in the process.
That doesn't mean your new tire isn't slick. They micro polish the tire mold (instead of using release compounds) to ensure a easy release. That leaves your new tire's surface super smooth, aka: not grippy right out of the gate.
When this happened to me it spooked me for quite a while with new tires.
I bought a can of 'racing tire cleaner' and just do a quick wipe down with a clean cotton rag.
Never had a issue since but I think most of that is just in my head.
DT
__________________
TPF-PM
dtrides is offline  
Old 06-20-2017, 05:15 PM   #3
Dyn Blin
BARF'd
 
Dyn Blin's Avatar
 
AMA #2965147
Contributor

Join Date: Feb 2015
Location: SoCo NorCal
Motorcycles: '05 Girlie
Name: sMerk
Good to know I'm not alone in my self-inflicted humiliation. I appreciate it.

I was pleasantly surprised by the reaction of passing drivers, the 3 that passed by all stopped to help me get the bike back up.

I was curious about the release compound, too, I had heard no one uses it anymore, but the manufacturer mentions it on their site.

Great tip on the racing cleaner, even if it's in my head, I'm going to use it from now on. Thanks.

Last edited by Dyn Blin; 06-20-2017 at 05:22 PM..
Dyn Blin is offline  
Old 06-22-2017, 10:11 PM   #4
tzrider
Write Only User
 
tzrider's Avatar
 
BARF Admin
Contributor +

Join Date: Feb 2003
Location: Pleasanton, CA
Motorcycles: Kaw N1K
Name: Andy
Dyn, the tire inflation is a big deal. Personally, I'd focus more on that than being concerned about release compound.

It's a good idea to wear in a new tire by going easy on the throttle and lean angle at first. Find a series of turns and ride them at progressively greater lean angles until the tire is fully scuffed. The changes in lean angle should be small enough that you always have some scuffed surface on the asphalt as well as new surface. It doesn't take long; a couple of miles of twisty road will do it.
__________________
"Rudeness is the weak man's imitation of strength." - Eric Hoffer

California Superbike School tzrider's blog
tzrider is offline  
Old 06-22-2017, 10:39 PM   #5
dtrides
Veteran
 
dtrides's Avatar
 
Contributor ++++ + + + + 4%

Join Date: Jun 2004
Location: Eureka,Ca.
Motorcycles: Aprilia Tuono Factory for the street, Sv 650s for the track
Name: Duncan
Those are words of wisdom TZ, but hard to implement if you are down at the end of your block as you turn at the first street....
Sometimes sh*t happens....even with proper inflation...lol
DT
__________________
TPF-PM
dtrides is offline  
Old 06-23-2017, 07:29 AM   #6
tzrider
Write Only User
 
tzrider's Avatar
 
BARF Admin
Contributor +

Join Date: Feb 2003
Location: Pleasanton, CA
Motorcycles: Kaw N1K
Name: Andy
Quote:
Originally Posted by dtrides View Post
Sometimes sh*t happens....even with proper inflation...lol
DT
Hoping the takeaway is not that shit happens. None of us would want to see it happen again, I think we can agree.

At the Superbike School, we have a contraption called the Slide Bike. Part of the setup is to over-inflate the rear to make it easier to slide. Even at that, it's not trivial to make the tire slide, but it's considerably easier. With a little too much throttle and lean angle one can spin up even a scuffed in tire.

New tires are a little slicker and need to be treated carefully for the first little bit. No tire I've used in the last decade has had mold release on it, though there is no telling what gets on a tire during shipping. Personally, I'd rather not treat a tire with a chemical if progressive scuffing will clean it up. Either way, it is wise to be careful about throttle and lean angle for the first few miles.
__________________
"Rudeness is the weak man's imitation of strength." - Eric Hoffer

California Superbike School tzrider's blog

Last edited by tzrider; 06-23-2017 at 07:31 AM..
tzrider is offline  
Old 06-23-2017, 08:11 AM   #7
dtrides
Veteran
 
dtrides's Avatar
 
Contributor ++++ + + + + 4%

Join Date: Jun 2004
Location: Eureka,Ca.
Motorcycles: Aprilia Tuono Factory for the street, Sv 650s for the track
Name: Duncan
Well, sorry, sometimes all the prep in the world can't prevent finding one's self on your ass.
I , like the OP, have decades of riding under my belt. Dirt bike, road, schools such as CSS, etc.
I go through about 3 sets of tires a year. I check my tire pressure before every ride.
I check my chain for pretty exacting tension and cleanliness every other ride.
So, in other words my bikes are in better than average nick.
To this day I have no idea why the rear let go.
Brand new tires, one block from house, gently making a left on to the main street and I was down in a flash.
It was a clear dry summer morning. Nothing to speak of on the road.
A turn from a complete stop I had taken a hundred of times. The only differentiation was brand new tires.
As far as the tire treatment, in the way I administer it, I cant see any real damage being done by a quick wipe of the surface.
I do agree it doesn't NEED to be done.
But it did leave me with the knowledge that there wasn't any foreign substance left on the tire from the manufacture, shipping or the tire installer.
This was just peace of mind in my case after a confidence sapping fall.
Once I make it past that first corner I follow the easy does it on adding lean angle .
I also use the brakes and acceleration in a controlled method while in a straight line to create heat in brand new tires as recommended by tire manufactures (vs the weaving I see folks do).
As always, YRMV.
DT
__________________
TPF-PM

Last edited by dtrides; 06-23-2017 at 08:15 AM..
dtrides is offline  
Old 06-23-2017, 08:39 AM   #8
Kawikiwi
Veteran
 
Kawikiwi's Avatar
 
Contributor + 2%

Join Date: Apr 2016
Location: Somewhere in a garage, a hangar, or across the world
Motorcycles: Gotta ride 'em all!
Name: Victor
Was there any road hazard that may have contributed? The release compund thing is a myth, that's been done away with years before I started even thinking about motorcycles, as stated by others. Glad it's a bruised ego and nothing serious OP; sometimes we have learning days so be thankful the world has educated you
Kawikiwi is offline  
Old 08-26-2017, 12:32 PM   #9
captainpanda
Newbie
 
captainpanda's Avatar
 

Join Date: Dec 2015
Location: Berkeley
Motorcycles: GSXR600
Name:
Wish I had come across this thread yesterday

... Just had the exact same thing happen to me, literally two blocks from the tire shop getting onto the freeway....Completely ate s**t turning onto the onramp. Bike's okay. Obvious fairing damage but all cosmetic and my Shoei has a nice set of DEEP gouges in the visor, so much so that you couldn't even see through half of it anymore. No injuries, just some bruises.

Typical PSA:

Always wear a FULL FACE helmet!! This would have otherwise been a very different experience.

Holy c***p watch out for new tires! They had even told me to be cautious--and I thought I was--but clearly not enough. Didn't realize "be cautious" meant "ride like your on f***in ice".

I'm not the type of person to pass blame to others, and I don't blame the shop here necessarily, but C'MON GUYS, for the price you charge at least clean your greasy hands off the tire before you send your customers out. I got home and took a piece of 200 grit to that damn thing!!

Last edited by captainpanda; 08-26-2017 at 12:37 PM..
captainpanda is offline  
Old 08-26-2017, 02:40 PM   #10
Kawikiwi
Veteran
 
Kawikiwi's Avatar
 
Contributor + 2%

Join Date: Apr 2016
Location: Somewhere in a garage, a hangar, or across the world
Motorcycles: Gotta ride 'em all!
Name: Victor
Quote:
Originally Posted by captainpanda View Post
Wish I had come across this thread yesterday

... Just had the exact same thing happen to me, literally two blocks from the tire shop getting onto the freeway....Completely ate s**t turning onto the onramp. Bike's okay. Obvious fairing damage but all cosmetic and my Shoei has a nice set of DEEP gouges in the visor, so much so that you couldn't even see through half of it anymore. No injuries, just some bruises.

Typical PSA:

Always wear a FULL FACE helmet!! This would have otherwise been a very different experience.

Holy c***p watch out for new tires! They had even told me to be cautious--and I thought I was--but clearly not enough. Didn't realize "be cautious" meant "ride like your on f***in ice".

I'm not the type of person to pass blame to others, and I don't blame the shop here necessarily, but C'MON GUYS, for the price you charge at least clean your greasy hands off the tire before you send your customers out. I got home and took a piece of 200 grit to that damn thing!!
The greasy hands or whatever aren't the issue, it's the shape of the new rubber that gets people. You get used to the steering of your out-of-round tires, so getting on fresh rubber requires the understanding that your motorcycle will steer differently than before. 200 grit is overkill, use it for your rashed fairings when you repaint it.
Kawikiwi is offline  
Old 08-27-2017, 06:01 AM   #11
RV6John
Rookie
 

Join Date: May 2010
Location: Hendersonville, NC
Motorcycles: GSXR 750, Z1000, SXV550, DR650, KTM525SMR
Name:
Quote:
Originally Posted by Kawikiwi View Post
The greasy hands or whatever aren't the issue, it's the shape of the new rubber that gets people. You get used to the steering of your out-of-round tires, so getting on fresh rubber requires the understanding that your motorcycle will steer differently than before. 200 grit is overkill, use it for your rashed fairings when you repaint it.
Good thought about the tire shape and the change in handling and turn in qualities.

Even with mold release compounds not being an issue on just about any new tire, I've chalked up "the new tire syndrome" to the tire just being so smooth when it's new. The texture sure does change in a mile or two.
RV6John is offline  
Old 08-27-2017, 07:31 AM   #12
mototireguy
Moto Tire Veteran
 
mototireguy's Avatar
 
Valgar beer donor
Contributor +

Join Date: Mar 2004
Location: San Francisco, CA
Motorcycles: FJR13 - XR650L - Madass 125
Name: Robbie
Quote:
Originally Posted by captainpanda View Post
Wish I had come across this thread yesterday
... Just had the exact same thing happen to me, literally two blocks from the tire shop getting onto the freeway....Completely ate s**t turning onto the onramp. I got home and took a piece of 200 grit to that damn thing!!
This is why I dislike the 'scrub' in new tires metaphor. It's heat and a couple of heat cycles that breaks-in new tires, not 'scrubbing', not sandpaper. Newbies hear the word scrub-in and somehow begin to think cool I'll borrow a belt-sander for new tire break-in.

New tires from the dealer often results in the dealer inflating the tires to the 42psi maximum pressure. Max tire pressure with light-middle weight bikes often results in major derpage.

Captpanda; for your Gsxr6 I would recommend 34psi.
__________________
* Motorcycle Tire Services @ http://MotoTireGuy.com
* 1064 Revere Ave, San Francisco CA 94124
mototireguy is offline  
Old 08-27-2017, 09:40 AM   #13
captainpanda
Newbie
 
captainpanda's Avatar
 

Join Date: Dec 2015
Location: Berkeley
Motorcycles: GSXR600
Name:
I rode my last tire down to the wear bars on 42 PSI. What do you get with the lower PSI? I can't stand it when my front tire starts to get low, the steering gets very dull / heavy. Not sure how the rear would behave.

I'm sure there are more than a few factors at play here, but there is absolutely a difference in surface friction between the new tire that I had and the outgoing one. Just feeling the two surfaces, the new one was so slick my finger slips right off of it. That's more than just heat cycles, that's a surface film / residue / coating / whatever you want to call it that needs to wear away. Since asphalt is basically sand paper in that regard, it seems reasonable.

I know that there's no substitute for breaking in the tire by riding on it. I've been reading people describing the molding process and how the molds are "micro-polished" or whatever so as to result in an incredibly smooth rubber finish, which might very well be the case.

The difference in shape of old versus new is a very good point that I didn't consider also!

Last edited by captainpanda; 08-27-2017 at 09:48 AM..
captainpanda is offline  
Old 08-27-2017, 02:57 PM   #14
Hank Wong
Veteran
 

Join Date: Jan 2011
Location: Mountain View
Motorcycles: 2001 BMW R1100RS
Name:
Come on, people! Hundreds of motorcyclists get new tires every week in the Bay Area! And they don't crash leaving the shop! Put some sandpaper on the tire!!!! What other nonsense can we think of next?
Hank Wong is offline  
Old 08-27-2017, 07:49 PM   #15
Enchanter
Ghost in The Machine
 
Enchanter's Avatar
 
AMA #: 2815246
BARF Admin
Founding Member
Barfie Winner 2007, 2010, 2014, 2017
Contributor ++++++++++

Join Date: Apr 2002
Location: SF Bay Area
Motorcycles: Attack™-ed R1 & hybrid S1000rr
Name:
Captainpanda, consider the screen name of who you are responding to. That might give some insight into his recommendation regarding tire pressure.

42psi in a motorcycle tire can be done, but it reduces the traction available becaus eit prevents the tire from deforming to the road surface. The contact patch is smaller. It can also keep the tire from warming up to operating temperature (= more traction). These leaves less room for rider error.

As a reference point: I've been riding since 1981, all brands of tires, all brands of motorcycles, mainly sportbikes. You couldn't pay me enough $ to ride with 42psi in the front tire. With 42 in the rear, I'm going to try and lean as little as possible. It's not worth the risk.

As for how long your front tire lasted, I submit to you that the high(er than recommended) pressure was the least significant variable in that equation.

All this being said, if we're going to continue the discussion of recommended tire pressures, please start a new thread in General. That discussion doesn't fit the intent of Crash Analysis.
__________________
A superior rider uses superior judgment to avoid situations that require superior skill.

Quote:
Originally Posted by DataDan View Post
Be resilient. After an unpleasant surprise or close call, get your head back in the game quickly. Learn whatever lesson you can and move on.
Quote:
Originally Posted by cardinal03 View Post
The panties. Unbunch them.
Occam's Razor: The simplest explanation tends to be the right one.
Hanlon's Razor: Never attribute to malice that which is adequately explained by stupidity.


BARF Terms of Service
Enchanter is offline  
Closed Thread

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -8. The time now is 04:45 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.