radial vs bias

[flavor]

I"ve seen talk about radial vs bias ply tires. What is the benefit of one over the other on motorcycles? I know you're not supposed to mix them.......

You can run a radial on the back and a bias on the front but not the other way around

[cactusjack]

My ME-880 180/70x16 rear tire is a radial, and the ME-880 150/80x16 front is a bias. No problemo.

.......OK......................................... .......Not OK

Crossply front, crossply rear.......... Radial front, crossply rear
Radial front, radial rear.................. Bias belt front, crossply rear
Bias belt front, bias belt rear..........Radial front, bias belt rear
Crossply front, radial rear .
Bias belt front, radial rear




http://www.bikesafe.co.uk/Bikesafe/ATS/selecting.html

[flavor]

Thanks Nico. The site you directed me to gave what, I'm guessing lists the safe combinations. For the Nomad is it better to run radials over combinations? I haven't seen anything that spells that out.

[oledawg]

The difference between radial & bias ply tires is in the construction.
For simplicity's sake, Radial tires heat up more quickly and therefore are at maximum performance quicker. Also do to the quicker heat up the quicker wear. The bias ply heats up slower, slower wear & does not work as well or as quickly as a radial. http://s2.images.proboards.com/cool.gif

[blowndodge]

Radial construction is like wrapping wire around a donut going through the hole and bias is like wrapping a wire around a donut around the circumference. Got the image???

BD, I don't believe that's entirely accurate, or in other words I get the image, but it's not quite all there.

On a belted bias ply tire there's a belt of cords running around the circumfrence. There is on a belted radial as well. (Virtually all tires are belted nowadays.)

But on any bias ply tire the cords which form the carcass are in layers, laminated one over the other, and each layer runs 45 ^o to the left or 45 ^o to the right in an alternating pattern. When cloth is layed out with the weave at 45 ^o, it's called laying it "on the bias", hence the name bias ply.

A bias tire is supposed to generate more heat and wear faster because the plys flex against the "grain" of each other, causing internal friction. Radial plys do dot rub perpendicular to each other as they flex, essentially running all in the same direction. Or approximately in the same direction as each one runs along a radius or radial line (hence the name).

Oh, yeah. What's the bennefit?

Good question when it comes to motorcycles. From what I read lots of people don't like the radials on a bike, while othes do.

I've never bought radial bike tires myself.

[rlfaubion]

I run radials front & rear..... all's well

[flavor]

Thanks for the info guys. Interesting and informative. Am I correct insaying most bikes come stock with radials? Nomads in particular.

Thanks for the info guys. Interesting and informative. Am I correct insaying most bikes come stock with radials? Nomads in particular.

Just the opposite...... a lot of sport and sport touring bikes come stock with radials... most cruisers come with bias or bias belted.. :)

[flavor]

Nico:

And I thought I knew everything.

It just goes to show.............

Thanks

http://s2.images.proboards.com/grin.gif http://s2.images.proboards.com/grin.gif http://s2.images.proboards.com/grin.gif

[blowndodge]

BD, I don't believe that's entirely accurate, or in other words I get the image, but it's not quite all there.

On a belted bias ply tire there's a belt of cords running around the circumfrence. There is on a belted radial as well. (Virtually all tires are belted nowadays.)

But on any bias ply tire the cords which form the carcass are in layers, laminated one over the other, and each layer runs 45 ^o to the left or 45 ^o to the right in an alternating pattern. When cloth is layed out with the weave at 45 ^o, it's called laying it "on the bias", hence the name bias ply.

A bias tire is supposed to generate more heat and wear faster because the plys flex against the "grain" of each other, causing internal friction. Radial plys do dot rub perpendicular to each other as they flex, essentially running all in the same direction. Or approximately in the same direction as each one runs along a radius or radial line (hence the name).

No cadd I didn't say it was "entirely" correct. I was only trying to imprint the directional construction method difference between radial and bias. I know throwing a disertation statement would bore people to tears. Short and sweet, just like Nico http://s2.images.proboards.com/grin.gif

No cadd I didn't say it was "entirely" correct. I was only trying to imprint the directional construction method difference between radial and bias. I know throwing a disertation statement would bore people to tears. Short and sweet, just like Nico http://s2.images.proboards.com/grin.gif

*sigh*

I'd give you the shortest possible version of this, but it would sound mighty harsh.

Now here's the long and comprehensive version if you'll please stick around to read it. Doing so would show great respect for the effort taken to write it.

First, I don't want to start a fight here buddy. I really don't (and I use the word "buddy" with sincere affection.) But did you really read any of my post? From your reply I suspect you might not have.

"Bias" means a specific thing, and it ain't "circumferential", which is what you described. The circumferential cords comprise the belt, which can occur on either type of tire, and has absolutely nothing to do with whether it's a radial or bias.

Look, I get long-winded a lot of the time. I know this, but it is never without reason. To be correctly understood, technical things often need exact and complete description. Part of my job as an engineer is to describe things exactly, so please forgive me if I am at times a stickler at it.

Yes, some people will get bored and quit reading as soon as they see the length of my posts. I'm not writing for the benefit of those people. I'm writing for the benefit of people that really want to know all the whys and wherefores, and I'm doing it as concisely as I possibly can and still be accurate and unambiguous. This is important stuff to me so I do not treat these things trivially, even though to many they may appear to be mere trivia compared to really important sh*t like football.

Nico to the rescue!!!


A pic is worth 1000 words! (or in Cadd's case, 100,000 words!!)


Here it is Noobs!!!!


http://www.bikernet.com/news/images/PhotoID21166.jpg


You are welcome!!!

Sir Nico

Thanks a bunch, Nico.

You'll notice from the pictures that there was something I DID feel it too wordy to mention previously, and it is this:

While the belts themselves are circumferential, the cords in them are actually slightly biased. I let that inaccuracy slip through in my dissertations as I truly did want them to be manageable in length.

[blowndodge]

No problem cadd. The reason I was pointing it out in the construction was that if you could get a "mental" view of the construction and understand that lateral loads transferred through the tire would be different then you'd understand why manufactures don't recommend mixing the two. Radial vs. Bias have different side lateral load reflexes or rollover dynamics.

Wasn't trying to pretend I'm an expert by any means in tires but I'm willing to bet 95% of the motorcycle riders have heard that you not suppose to mix radials with bias without really understanding the rational behind it. Was just trying to simplify it.

You have to know the audience with which you speak to. I didn't feel they needed to think beyond the example. Guess its my bad.

Some things are definately better said (and understood!) through pictures. That's one reason our firm cranks out over 300 sheets of drawings a month.

Imagine trying to build even a simple building from written instructions alone.
http://s2.images.proboards.com/shocked.gif ::) http://s2.images.proboards.com/shocked.gif

[skeeter]

It is my understanding, and you will correct me if I'm wrong, that the bias tire is a stiffer tire especially in the side to side action. The radial has a bit of flexiblity or mush to the side allowing more tread to stay in contact with the road surface in curves.

It's OK to have the bias (stiffer) on front with a radial on back even though it mushes a bit. Your steering is not affected that much.

With radial front and back, you get the same mush front to back. still in control.

With a bias tire on the rear you have a more solid feel which does seem to mix well with a mushy radial in the front. It a wobble we can do without in the twistys.

When I was a teen, I had new radials on the rear of my truck and the old bias on the front. I'm still too poor to by 4 new tires. I switched them out to see what the big deal was. I didn't have power steering. I switched them back in a hurry.

Stiffness of the sidewalls also depends on the number of plys, but all things being equal the radial has more flex in the sidewalls.

[ells]

I've noticed that load ratings tend to run a little higher for bias tires compared to otherwise similar radials. Any confirmation or explanation on that?

I've noticed that load ratings tend to run a little higher for bias tires compared to otherwise similar radials. Any confirmation or explanation on that?

That is true.... partly because they are made for Sport Tourers as a rule... I'll bet the higher heat factor comes into play as well....

I'm sure Cadd &/or BD will elaborate!! ::) http://s2.images.proboards.com/shocked.gif http://s2.images.proboards.com/grin.gif ;)

[reflush2]

I'm new to the board and I couldn't help but wonder about the radial and bias mix of tires discussion.

To know just about anything and everything about MC tires try

http://www.dunlopmotorcycle.com/infocenter_tiretips.asp?id=2#tip

There's an enormous amount of info there just for looking...

Works for me,

reflush2

[audiogooroo]

Thanks for the link, and welcome to the forum from Colorado!

[radco]

I'm new to the board and I couldn't help but wonder about the radial and bias mix of tires discussion.

To know just about anything and everything about MC tires try

http://www.dunlopmotorcycle.com/infocenter_tiretips.asp?id=2#tip

There's an enormous amount of info there just for looking...

Works for me,

reflush2

FIRST WELCOME to the Forums,, GREAT link http://s2.images.proboards.com/grin.gif THANKs,,Rich

[bigdog]

Well, not having ever run radials on the nomad, sounds like a good question that I'm not sure I saw an answer to, but I probably just missed it.
Is there an advantage to one type over the other on a motorcycle?

[skeeter]

Hey Big Dog! Glad to see ya here.
I'm trying the radials cuz some said they got more miles out of them and they liked the way they handled.
On longevity- the rider, the roads, and the rubber all have to be considered.
On handling- all the above have to be considered plus tread design.

It will all boil down to how I feel about the tires whether I'll try them again.
I didn't really answer any questions, I was just saying Hey to Big Dog.
See ya on the 27th

[aj]

I like the radials, feels better on the road.

And Nico I work with engineers all day, they are a misunderstood bunch so there is a karma going your way.

[aj]

thats a + Karma!!