lankeeyankee
Banned
Ya could also perform this mod Bling Bling.
I went to the Darkside - AKA, car tire on the bike
- Thread starter jphilipson
- Start date
lankeeyankee
Banned
Just messing with ya.. 
I installed a Good Year 215/60/15
I did the same but with a VMAX.. found a pic of the beast! Beast it was and handled worse then a loaded dump truck and to make it more exciting installed a wet nitrous system. It would do some wild roll on burn outs in all gears. fun ride but very dangerous. I sold it to a builder after turning down 15+ kids wanting it.
I installed a Good Year 215/60/15
I did the same but with a VMAX.. found a pic of the beast! Beast it was and handled worse then a loaded dump truck and to make it more exciting installed a wet nitrous system. It would do some wild roll on burn outs in all gears. fun ride but very dangerous. I sold it to a builder after turning down 15+ kids wanting it.
GNBRETT
Registered
you didnt hydroplane. you may have lost traction due to the wet surface but you wern't hydroplaning. vehicles with round profile tires like bicycles and motorcycles virtually never suffer from hydroplaning in normal road use when the road is wet.
the area of contact with the road is a canoe-shaped patch which effectively squeezes or forces water out of the way. you would have to be going around 200 mph or more to achieve hydroplaning on a narrow round profiled tire.
voodoolord
Registered
Its funny this post came up because I was thinking the other night about what it would be like to put dirt tires on the Busa and taking it in the woods. Who knows if Obama gets elected again we may all be making our Busas into offroad warriors. Just need to figure out the machine gun mount for the front. All kidding aside Im interested in seeing how it works out and hoping you dont end up in the obits.
isiahstites
Registered
Ok I will do my best to relay a conversation I had with my friend who is a motorcycle accident reenactment investigator....I expect to do him no justice but here we go.
Car tires rely on stability from 3 other tires, caster, camber and toe all working together to give the car stabilty.
Motorcycle tires get stability from slip angle coeffiecient the left pushing to the right and the right pushing to the left. They also work together to give you stability. The front working with the back and the back working with the front. With a car tire on the back and a mc tire on the front the stabilty may be there but it's compromised and the ability for the rear to take a different track than the front can happen.
Car tires have basketball shaped contact patches and mc tires have football shaped contact patches. On a MC tire at lean angle the contact patch is almost identical as straight up, both front and rear have similar shapes and work together to give stability even at full lean angle. Add a flat bottom car tire with a basketball shaped contact patch to the rear and you now have two very different types of contact patches and keep in mind the rear contact patch gets smaller and smaller with the car tires when you lean as it was not designed to used on its edge it was designed to sit flat. So the more you lean the MC you get the same regular contact patch in the front and a decreasing contact patch in the rear.
I have talked with him at length about this in the past and completely trust him 100%.....I am not trying to change anyones minds just offering up some insight from a knowledgable friend that I have a ton of respect for.
Scott
Car tires rely on stability from 3 other tires, caster, camber and toe all working together to give the car stabilty.
Motorcycle tires get stability from slip angle coeffiecient the left pushing to the right and the right pushing to the left. They also work together to give you stability. The front working with the back and the back working with the front. With a car tire on the back and a mc tire on the front the stabilty may be there but it's compromised and the ability for the rear to take a different track than the front can happen.
Car tires have basketball shaped contact patches and mc tires have football shaped contact patches. On a MC tire at lean angle the contact patch is almost identical as straight up, both front and rear have similar shapes and work together to give stability even at full lean angle. Add a flat bottom car tire with a basketball shaped contact patch to the rear and you now have two very different types of contact patches and keep in mind the rear contact patch gets smaller and smaller with the car tires when you lean as it was not designed to used on its edge it was designed to sit flat. So the more you lean the MC you get the same regular contact patch in the front and a decreasing contact patch in the rear.
I have talked with him at length about this in the past and completely trust him 100%.....I am not trying to change anyones minds just offering up some insight from a knowledgable friend that I have a ton of respect for.
Scott
voodoolord
Registered
So what your saying isiahstites is we need to have a car tire on the back and the front then were all good right? Woot we have a big wheel busa!
Woot we have a big wheel busa!
Wish I could get 7k out of a rear bike tire...
lil charlie
Registered
All of this makes sense is theory but the reality is that it just doesn’t completely hold water. When you put a car tire on the back of a motorcycle and lean into a turn the tire flexes with you and the bottom of the tire rolls so you still get the same amount of contact patch as you do when you are driving straight. Just like you said…left pushes right and right pushes left. When you make a left hand turn that tire flexes to the right keeping a very nice size of contact patch on the road. All you have to do is ride behind someone with a set up like this and I guaranty that you will be amazed watch what that car tire will do!
lil charlie
Registered
I also forgot to mention that with the grip of a car tire does to your rear breaking ability. It's 5x better than what it is with a MC tire. I know with sports bikes we dont use our rear breaks that often but the only way I can describe how much better it made the rear brake on my Honda VTX was to compair it to how much better a Gen I stops after you put SS lines on and EBC pro pads with wave rotors. A car tire really does make that rear break stop like the front does.
isiahstites
Registered
I do not believe this statement to be true as you can see in all of the photos that the flat portion of the tire is up off of the road and you are riding on the "corner" of the tire. I believe you when you say it handles good or you have contact patch, but not the same amount. There is to much surface area when the tire is flat on the ground for you to have the same amount when cornering.
And I believe this statement about the breaking proves my point. The reason the braking is much better is because you have a huge contact patch while driving straight. I do not know but I would tend to believe that the rear braking on a MC with a car tire at any type of lean angle would be a scary thing.
Scott
lil charlie
Registered
You are right by saying you have more contact patch while riding in a straight line vs while in a lean but you are wrong if you think that you are riding on nothing but the corner of the car tire while in a lean. What I meant to say is that the car tire flexs and rolls that contact patch. When you lean you are not on the corner or the car tire like you are on a MC tire, it rolls that tread around and you still have a large contact patch of tread with the ground. You have more contact patch with a car tire in a lean than you do with a MC tire in a lean..I didn’t mean to come off sound like you have the same amount of contact patch in a lean as you do while going straight, just that its more contact patch than with a MC tire. If it is something that you have not seen for yourself then it is not something that you can sit here and say isn't true. I’ve had a dark side bike and have spent many hours riding behind my father’s dark side bike and have seen with my own two eyes what that tire does in very hard leans up and down mountain roads.
isiahstites
Registered
I never said it was untrue, I am just asking questions, stating things I believe to be true and trying to understand this dark side madness.
Really hard for me to wrap my mind around the idea of a car tire on a bike. Reason being a car tire was designed to be flat on the ground not rolled on it's edge. I know you say it rolls and you still have big contact patch, but until I see it myself I will always raise questions in my mind.
jphilipson
Registered
Did you look at the video I posted in my initial post? That shows the tire rolling pretty well.
And again, I'm not trying to sell this as the "right thing to do", but simply as an option that works.
houstonbussa
Registered
The video from page one showed that the car tire had a lot more contact than I would have expected too. Very interested in learning more, so please update as you get a few K on that tire.
lil charlie
Registered
I was the very same way. My dad did his bike 1st and I rode his around and followed behind him on several trips before i did mine. Its all about how much and what type of riding you do. If you commute a lot on nothing but slabs you chew up MC tires left and right. Because you are never on the side of a MC tire when slabing it you will wear out a tire every 3 or 4K miles. If you commute a lot thats a tire every 6 weeks or so. My dad did his because he was eating about 7 rear MC tires a year...at $150 a pop thats $1000 a year if you take the tire off yourself. A car tire does great for slab riding and you are looking at (1) tire every few years. Like I said before, I got my tire shipped to my door for around $50 plus another $10 to have a shop mount it on my MC rim. That comes to a total cost of $2,000 worth of MC tires to one $60 car tire. This is why it is popular amoung the heavy crusier guys. This is the 1st I've seen of someone doing it on a lighter sports bike so Im very egar to see how it works for him.
stock busa rim? i wonder what the contact patch is like at higher speeds? whats the speed rating of the tire?
jphilipson
Registered
Yeap - that size car tire is typicall rated for a 5.5 to 7.5 inch rim, so it fits perfectly on the Busa's 6 Inch rim. Speed rating is V (150 mph). It's a performance all season tire.
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