Perhaps something in a wide, Sir? When motorcycle designers are creating their new concept bikes and they want to make a statement or they need a tire in some odd size when they build the bike for a show, what do they do? Well, there are workshops with just that capability, ready to whip up the tire you need. This 400 tire is actually not for production but is a demonstration of what Wellings Engineering can do. Of course, with chopper tires already at the 360 mark, you know something like this won’t be far behind.
Wellings Engineering is the shop of Syd Wellings, a member of the Motorcycle Design Association and he’s located over in Birmingham, England.
Link: Motorcycle Design Association via Motoblog.it
hoyt says
no side-stand required.
aaron says
I’ll take two.
It’s hard to find a beachball that lasts a full season, plus my swiss (stability training) ball kinda looks stupid sitting next to all the moto-toys. this will blend in better.
***money-making idea***
Is anybody marketing a tire swing for obese kids yet? yet another revenue stream for Wellings Engineering….
mark says
I’m holding out for a tire that’s wider than the bike is long.
Scott says
I have been expecting these 400mm tires for about a year, since I first heard the rumour, and having just purchased two 360mm tires to build a bike around.
Skinny tire riders may shrug them off, but this IS going to be the future of motorcycles.
Dodgy says
Quote:
“Does this make my fat ass look skinny?”
doug says
there’s nothing skinny about a 180 or 190 leaned over – engineering & skill coming together.
good one, Aaron.
sfan says
I’d be curious to understand the physics and design implications of fat tired bikes where form was a result of function. Obviously fat tires could have traction advantages on an off-road bike. The Yamaha TW200 is a cautious example of this, but I have not seen a review.
More significantly, I have wondered about fat tired street/race bikes that are designed to benefit from the added traction. It seems to me the advantages would include the potential for better acceleration, braking and turning, including when road surface conditions are less than perfect. Bigger contact patch could mean harder compound rubber that lasts longer. More frontal area means increased air resistance, but this could be easily mitigated and is otherwise immaterial in the scheme of generally poor bike aerodynamics. Also increased contact friction would be overcome by the ability to handle more power. I am not sure how to assess the effects of greater unsprung & gyroscopic weight.
I remember in the 80’s there werre many sport bikes with small (
bobbio says
I wonder what ol’ Sigmund would have said about wannabe bad guys on hardtails who seem to enjoy having their their rear ends pounded by something large, round, and………
How much longer ’til skinny 21″ tires start showing up at the back of trendy edge customs?
aaron says
funny, but goldammer keeps winning world championships with the skinniest tires out there….
sfan mentions performance potential, but the tendancy of a bike to wheelie, stoppie, or ground out means that all available increases in traction mean very little to all us sub-rossi riders…
it may be the future of choppers in some peoples eyes, but the increased weight, rolling resistance, moment and gyroscopic forces, aero drag, cost, etc, will not endear it to many…
plus if you want side grip, a change in profile is needed: meaning either the same circumferance tire will run on a 12″ rim, or the tire will grow to waist height….
Alejandro Martinez says
It cracks me up to see the tires getting so wide, while being so useless. Let me explain. The actual part of the tire that is in useful contact is the tangent section contacting the road, which depending on air pressure, looks to be about only half the width of the tire. To put it another way, half the tire is useless.
How about someone designing a flat motorcycle tire that can really put the tire to the ground while also being able to lean. Something akin to that Mercedes concept vehicle that leans a specially designed unsymetrical tire during cornering, yet adapted for motorcycles. Just a thought…
Scott says
I may have missed the relevant lecture in my physics class, but it seems to me that the contact patch area must follow the “… all forces must be equal … ” rule. Simply speaking, the contact patch area will be a function of bike weight divided by the air pressure, no matter how wide or thin the tire is.
Also, if half the tire is useless, then the other half must be useful. Would it not be better to have a larger useful half than a smaller one…?
One of the biggest problems produced when fat tires are put on the rear of bikes, is that the front tire is still narrow. This causes a dramatic change in the contact patch alignments between the two tires when cornering versus the centerline of the bike. Having wider tires on both ends, or at least the same width tires on both should reduce this variance.
Alejandro Martinez says
Scott, you must have missed the relevant lecture in physics class about friction. The amount of static friction a tire, or any object can hold before sliding, is a factor of many things. (1) The coefficient of friction depends on the tire compound (2) the weight or normal force of the object and (3) the surface area in contact. That is why, everything being equal, a wider tire has more traction.
For another example, the military Hummer has an device which controls the air pressure inside each tire as the vehicle moves. In slippery conditions, you lower the air pressure to effectively spread the tire out over a larger patch, thus gaining more traction. Also, when people go off-roading you lower the air pressure. Same principal.
For maximum traction, the tank is a perfect example with an extrememly large traction patch in contact with the road / dirt.
With a big fat rounded rear tire, you can get a larger contact patch by dropping the air pressure, yet you may be at a pressure that is too low for the tire to function properly. The problem is that a round tire and a flat surface produce a very small contact area due to the natural geometry.
kk says
The contact patch does matter, however in your physics classes they taught you that it doesn’t. The surface area of the contact patch cancels out of all relevant friction equations (go check your physics book, since the normal force is divided by the surface area there is less force per unit area. The equation for static friction has nothing to do with the contact area) So in ideal conditions it wouldn’t matter if the tire was a mile or an inch wide, the friction is the same. However, this is the real world so we have to consider heat dissipation, deformation of the tire, and other things that are affected by the tire shape/ size. More contact area is better for reasons that go beyond the physics classroom and into graduate level research labs. The reason why racers run less air is because it increases tire deformation (not contact area), and more heat goes into the tire. (Ideal tire temps are usually around 170 degrees.) Also surface conditions can greatly influence the friction forces on a tire. Wider tires display a more consistent co-efficient of friction then do narrow ones. Anyway my point being wider is not always better…. Its not a simple equation you might have picked up in 5th grade.
scott says
aaron is dead on. all you other people are idiots. Even a slightly bigger rear sprocket has a huge impact on the rear wheel gyro… imagine how much larger the increase in the I value has with that huge tire. redic. Im sure moto gp riders have close to the ideal set up considering they pound out almost 300 horse power on a bike that has a smaller motor then your neighbors R1. And i dont see them using any wider tire then i have on my bike.
Chris Edmonds says
I am from North Carolina and I have seen a growing intrest in the big tire market out there. I was interest in putting a kit on my 2001 Hayabusa untill I saw the after effects on another bike. The wider tire is more of a parking lot show upgrade than performance. I saw a bike at a show with a 240 kit and the chain was rubbing the rear tire. If you go wider than 240 you must use 2 sprokets and 2 chains or jackshaft as they call it. I took a few mechanical classes in my day an that calls for loss of power through transmission and strain on components. I also noticed when the rider with the wide tire kit made turns and corners he had to go wide and slow. This cuts down your reaction time as well. If you get into a situation where you have to make a quick move. You might not be able to. The bottom line is if you are going to ride everyday and like curves it’s not for you. If you ride slow and like to show go get it.
Brad says
Ridiculous comments, the whole concept of the tire is to look friggin cool. And it does. All this talk about cornering and traction. If practicality was the real topic, I wouldn’t have spent 6k painting my bike.
Chris says
6k for a paint job. Yeah! I know a lot of guys who spent a a few grand for a paint job just for the first time effect. There are thousands of custom paint jobs and all of them are old now.lol The best custom paint is stock paint in my book.