Going to the Dark Side

[HotRodZilla]

Another scenario: now let's say you are on Day 9 of the Iron Butt Rally, and you've been running so hard the past nine days, at this point you barely know your own name. Let's say it's 2am and you are descending down from the bonus at the summit of Pike's Peak, because you have to get north of Denver for a 4AM bonus window. You start down the mountain, initially on dirt/gravel, so the sliding sensations you detect as you begin your descent, you think it's due to dirt or gravel, but it's not... it's because your cracked rim has finally deflated your CT. Mind you, you don't have the same sharp wits Doug still had as he started down Hwy 38 from Big Bear, and neither do you have a riding partner to point out your flat.... you just think it's cause you're on dirt/gravel. You glance at the clock and realize you had better be moving right on down the road to make that Denver bonus window, so you pick up the pace even further.

Then you hit the paved portion of the road.... and realize something is indeed amiss with the rear of the bike. Can you get stopped in time before Something Way Bad happens? :huh:

So...Anyone else see a problem with this scenario? The most dangerous thing listed in it is not the car tire...It is the RIDER. To date car tires on motorcycles have not been listed as the main contributing factor in any fatal crashes. However, fatigued drivers are at the top of the list; especially on rural freeways.

You said it yourself. The problem is not the car tire going flat and the bike acting differently. The problem is the rider being so fatigued that he doesn't notice that the tire is flat and ends up in trouble. Just like the rider may be so fatigued he doesn't notice the decreasing radius turn he's entering. Or the stop light, or the family in the minivan, or the herd of dear, or...Well, you get the picture right?

So a group of guys who champion for the right to ride 10,000+ miles in a 10 day period are now going to preach motorcycle safety to the rest of us? These same guys who jump on their bikes for an excessive number of hours with minimal sleep just to prove they can do it? These same guys that admit they ride above the speed limit in fatigued states on the edge of consciousness? I think it was WC that stated back at the beginning of this cracked rim saga that if this was the FAA, they would shut the CT program down. Well, I've got news...If the FCC or the DOT was in charge of the IBR, they would shut it down too.

As far as civil liability goes, proving someone was so tired they should not have been operating a motorcycle is not that hard. When someone not involved in the IBR gets hurt, the victim or the victim's family is going to sue the shit out of the rider and entire project and they're gonna win. The same may be true for CT users, but so far, car tires on bikes are responsible for zero deaths, and driver fatigue and innatention caused by fatigue are number one or two on the list.

So...Bash against car tires all you want. There's no proof that they caused a rim to split, and certainly no proof that they are going to cause motorcycles to careen down the road and kill people. At this point, all we have is your opinion, and until I see you petitioning to end the IBR due to rider's and other drivers' safety, you opinion holds no water.

Edit: Added a couple smileys so that others know I am just bantering and picking on WC because he is older than me and bald. I am NOT going to go to his house and attempt to kick him in the balls. :assassin:

Is that better??

 

[phroenips]

Another scenario: now let's say you are on Day 9 of the Iron Butt Rally, and you've been running so hard the past nine days, at this point you barely know your own name. Let's say it's 2am and you are descending down from the bonus at the summit of Pike's Peak, because you have to get north of Denver for a 4AM bonus window. You start down the mountain, initially on dirt/gravel, so the sliding sensations you detect as you begin your descent, you think it's due to dirt or gravel, but it's not... it's because your cracked rim has finally deflated your CT. Mind you, you don't have the same sharp wits Doug still had as he started down Hwy 38 from Big Bear, and neither do you have a riding partner to point out your flat.... you just think it's cause you're on dirt/gravel. You glance at the clock and realize you had better be moving right on down the road to make that Denver bonus window, so you pick up the pace even further.

Then you hit the paved portion of the road.... and realize something is indeed amiss with the rear of the bike. Can you get stopped in time before Something Way Bad happens? :huh:

So...Anyone else see a problem with this scenario?

Yes, the Pike's Peak road is not open at 2am!

 

[Gene-ST1300]

I would think for rider saftey the IBA would have already outlawed the use of ct's in santioned rides if they were as dangerous as some say .

 

[HotRodZilla]

Another scenario: now let's say you are on Day 9 of the Iron Butt Rally, and you've been running so hard the past nine days, at this point you barely know your own name. Let's say it's 2am and you are descending down from the bonus at the summit of Pike's Peak, because you have to get north of Denver for a 4AM bonus window. You start down the mountain, initially on dirt/gravel, so the sliding sensations you detect as you begin your descent, you think it's due to dirt or gravel, but it's not... it's because your cracked rim has finally deflated your CT. Mind you, you don't have the same sharp wits Doug still had as he started down Hwy 38 from Big Bear, and neither do you have a riding partner to point out your flat.... you just think it's cause you're on dirt/gravel. You glance at the clock and realize you had better be moving right on down the road to make that Denver bonus window, so you pick up the pace even further.

Then you hit the paved portion of the road.... and realize something is indeed amiss with the rear of the bike. Can you get stopped in time before Something Way Bad happens? :huh:

So...Anyone else see a problem with this scenario?

Yes, the Pike's Peak road is not open at 2am!

Well, there you go. Don't we all look like a bunch of jackasses now.

 

[charismaticmegafauna]

...The most dangerous thing listed in it is not the car tire...It is the RIDER. To date car tires on motorcycles have not been listed as the main contributing factor in any fatal crashes. However, fatigued drivers are at the top of the list; especially on rural freeways....the rider may be so fatigued he doesn't notice the decreasing radius turn he's entering. Or the stop light, or the family in the minivan, or the herd of dear, or...

...so far, car tires on bikes are responsible for zero deaths, and driver fatigue and innatention caused by fatigue are number one or two on the list.

The number one motorcycle crash statistic, historically, is another vehicle colliding with the motorcycle while that other vehicle is making a left turn in an intersection.

The number one, single vehicle, motorcycle crash statistic (historically) is the motorcycle running wide on a turn and leaving the roadway -- often colliding with a fixed object.

CTs on motorcycles, statistically, are a very small percentage -- far, far, more of these statistics were garnered from motorcycles shod with motorcycle tires.

I think we need more info... :huh:

 

[HotRodZilla]

...The most dangerous thing listed in it is not the car tire...It is the RIDER. To date car tires on motorcycles have not been listed as the main contributing factor in any fatal crashes. However, fatigued drivers are at the top of the list; especially on rural freeways....the rider may be so fatigued he doesn't notice the decreasing radius turn he's entering. Or the stop light, or the family in the minivan, or the herd of dear, or...

...so far, car tires on bikes are responsible for zero deaths, and driver fatigue and innatention caused by fatigue are number one or two on the list.

The number one motorcycle crash statistic, historically, is another vehicle colliding with the motorcycle while that other vehicle is making a left turn in an intersection.

The number one, single vehicle, motorcycle crash statistic (historically) is the motorcycle running wide on a turn and leaving the roadway -- often colliding with a fixed object.

CTs on motorcycles, statistically, are a very small percentage -- far, far, more of these statistics were garnered from motorcycles shod with motorcycle tires.

I think we need more info... :huh:

Haha...I wasn't referencing just MC crashes. I was referencing all MV crashes in general. But you are right, we need more data. Maybe everyone on this forum should be required to run a car tire for a period of time to see just how many die from something other than VD. :blink:

Goddammit, I forgot the smileys again.

 

[64Y80]

Oh what the heck, allow me to add my uneducated opinion to this. I am not a darksider, never will be, I don't ride enough to entertain the idea, but I don't think it's a necessarily bad idea. The reasons people are trying it make perfect sense to me, increased mileage, reduced cost, etc. The fact that on paper it looks like a bad idea is trumped by the fact that the people have actually done it and found it works acceptably well. Remember, it's been proven on paper that a bumble bee can't fly.

Now putting a car tire on the front I am quite sure would be a bad idea. Being a retired automotive suspension designer I see big problems with that idea. A car tire has what we referred to as a center of contact patch. The contact patch, as you might guess, is the area of the tire in contact with the road at any given moment. Theoretically the center of this patch would always lie on the centerline of the tire as viewed from the front or rear. Unfortunately there is a little thing called manufacturing tolerances to consider. In real life this center of contact wanders some from side to side. Now on the front the relationship of this point with the steering axis is very important, if this point is to the left of the steering axis it would try and turn the wheel to the left, on the right to the right. I'm willing to bet a car tire on the front would yield a tank slapper of biblical proportions. However on the rear, no steering axis no real problemo.

 

[user 213]

IOW, there is no point to mounting a CT on the front. It meets no realistic goals whatsoever. It's just some numbnut's attempt to make Darksiding look foolish.

People did and do think you are foolish. But you did it anyway...

True enough Rushes. I give you that sir. So, what's the goal here? Just to do it? Or to advance some other hopeful benefits? I had a set of goals in mind for the rear CT and stipulated some parameters that would indicate a FAIL as well.

Anything is possible. I'm just not seeing a productive point to the front CT, aside from winning a bet perhaps.

Hell, you didn't even specify that the front wheel had to have brakes. Someone could find a smaller wheel with the same axle dia., fab some spacers and remove the front brakes and fender and slap that puppy on there and go ride 500 miles just to win the bet. I'd shave the corners down to allow some possibility of actual turn in, but still, it's not something that would work for long term use, or have any benefits, that I can identify. Am I missing something?

 

[carlson_mn]

 

[doctorJ]

Well shucks. My other bike is an ST1300 and now there is a move on the ST-Owners forum to use a Hankook K111 205/50/17 and more and more peeps going to it. Apparently the measurements on that specific tire allow it to be used where others won't fit the swingarm. Now I've got to go read all that thread too. Sheesh, I was gonna leave my ST alone with a MT but if this Hankook handles pretty well and wears well, I may experiment with that too down the road. The sky is falling I say. Oh well, changes take place in many things.

doctorj

 

[rushes]

So, what's the goal here? Just to do it?

Pretty much. I would never run car tires on a bike.

But for some, if it could be done, it might be just what you've been looking for. And as a machinist, I love challenges and building things others might not consider.

What got me thinking is I remember an old VW bug my sister had. The tires had rounded off to a pretty smooth radius. It would never handle like a mc tire, but it might do well enough going down the highway. I just think it'd be fun to try it if I had time.

 

[mattster31]

So, what's the goal here? Just to do it?

Pretty much. I would never run car tires on a bike.

But for some, if it could be done, it might be just what you've been looking for. And as a machinist, I love challenges and building things others might not consider.

What got me thinking is I remember an old VW bug my sister had. The tires had rounded off to a pretty smooth radius. It would never handle like a mc tire, but it might do well enough going down the highway. I just think it'd be fun to try it if I had time.

All I can say is my bike handles WAY better now that I put a new PR2 on the front. I had been running an old D220 (Exalto rear - see avatar) just to get the last few km's out of it, and it handled OK (it was almost showing cord BTW), but with the new PR2 on I would swear I just put a MT on the back. This is truly an exceptional combination. Yes, I realize I should not let my tires get to the point of cord showing, but I am a cheap bastard or I'm just lazy and I don't like changing tires.......

 

[user 213]

So, what's the goal here? Just to do it?

Pretty much. I would never run car tires on a bike.

But for some, if it could be done, it might be just what you've been looking for. And as a machinist, I love challenges and building things others might not consider.

What got me thinking is I remember an old VW bug my sister had. The tires had rounded off to a pretty smooth radius. It would never handle like a mc tire, but it might do well enough going down the highway. I just think it'd be fun to try it if I had time.

Emphasis added by me in your quote. Actually, it did handle like a motorcycle tire. I rode one of those Michelin, rounded profile car tires that normally fit VW Bugs on a '52 panhead. Very little difference from the rear moto tires of the day. Ahh, the memories. Remember when Goodyear made motorcycle tires?

While I applaud your desire to see if the front CT can be done, how much time & money are you willing to spend to do it? And all for a lark. The rear CT was cost effective to begin with. FWIW, those old bug tires were 165/85-15 if memory serves. I don't think they are even available now with that profile. Technology marches on and the flater profile was found to increase mpg and tread life.

 

[SkooterG]

A car tire has what we referred to as a center of contact patch. The contact patch, as you might guess, is the area of the tire in contact with the road at any given moment. Theoretically the center of this patch would always lie on the centerline of the tire as viewed from the front or rear. Unfortunately there is a little thing called manufacturing tolerances to consider. In real life this center of contact wanders some from side to side. Now on the front the relationship of this point with the steering axis is very important, if this point is to the left of the steering axis it would try and turn the wheel to the left, on the right to the right. I'm willing to bet a car tire on the front would yield a tank slapper of biblical proportions. However on the rear, no steering axis no real problemo.

I :wub: the Fart Smellers on this forum. You learn the darndest things.

 

[Spud]

If someone does take the bet to ride the dual CT setup, I'm hoping we get video for proof. I think a run to at least 100mph is mandatory.

Say, can you rent those airbag suits the GP guys are getting?

 

[charismaticmegafauna]

...Actually, it did handle like a motorcycle tire. Very little difference from the rear moto tires of the day.

Yes, but very different from modern m/c tires.

I rode one of those Michelin, rounded profile car tires that normally fit VW Bugs on a '52 panhead.

I doubt anyone would want their FJR to handle like a '52 panhead?

FWIW, those old bug tires were 165/85-15 if memory serves.

You must've laced a 15" rim to that old Harley?

You've been doing this sort'a thing for a long time...

 

[rushes]

The Michelin looks to have a better radius profile,(kinda expensive)

https://www.carpartjim.com/servlet/the-2068/155HR15-MICHELIN-XAS-RADIAL/Detail

but I like the dimensions of this one. The edges could be trimmed off, and air it up pretty hard.

And for a rim I'm thinking one of those lightweight spun aluminum spares from a late 80's Mustang. They're 15x4". Cut out the center and build a hub.

It might all fit without building new triple clamps.

Jus drinkin an thinkin....

 

[wfooshee]

That's EXACTLY what I want!!!! A 650-pound bike with 140+ horsepower and no front brakes!!!!

 

[exskibum]

Ahh, the memories. Remember when Goodyear made motorcycle tires?

Yep -- with the raised lettering in white -- Goodyear "Eagles"? I had them on a '75 Kawasaki Z1, and before that, on a chopped '69 BSA 650 Thunderbolt whose 40 spoke rear hub was laced to a 40 spoke 16" chrome Harley rim off an old cop bike.

 

[user 213]

You must've laced a 15" rim to that old Harley?You've been doing this sort'a thing for a long time...

It has been a coupe of years, but I rode the '40 knucklehead after that, and it had a 15" rear wheel too. Sort of common back in the day of steel wheels and tube tires.