bias tire raidal tire

[oldviolin501]

i have a new bias 150 70 17 rear tire and just bought a new 120 70 17 raidal front for my 96 kat... good or bad or ok???

[loudnlow7484]

I've heard that it's bad to mix radial and bias tires. I rode on a mismatched set for a couple hundred miles, and never noticed anything odd, but then I didn't really push it either.

I recommend grabbing a radial back tire to match, but the bike isn't going to explode or anything in the meantime.

[oldviolin501]

Yeah I've heard that befor to but it was always for trucks and cars something that needs 4 tires. I don't see where the problem would come in unless I were racing or doing some super serious hard riding. My Kay is just a comuter to work and home. She rairly hits 65mph. Just wondering if I'm gonna have serious issues. The bias tire I have is a bridgestone battlax bt45v 150/70 17. Front is a conti motion sport raidal 120/70 17.

[thetable]

Bias ply bad, not fire bad, but just not as good as a radial, bad. They wear faster, run hotter, and failure mode leans towards more catastrophic than a radial.

[05RedKat600]

Not to mention if they sit for a while they get a flat spot in them.

[cintidude04]

Not to mention if they sit for a while they get a flat spot in them.

So do radials don't they?...
It's calling cupping the tire.

[Kreylyn]

So do radials don't they?...
It's calling cupping the tire.

Not the same thing.

"cupping" is generally a repetative variance in the surface of the tire... Think "wave" shape instead of continuious even curvature.

(some good info with pics on it...) http://www.rattlebars.com/tirewear/index.html

A flat spot is just that... a single flat spot. Radials are really resistant against that due to the belting preventing it by helping to keep the shape.

Krey

[oldviolin501]

All good to know. I went ahead and bought a new raidal rear tire just to be safe.

[05RedKat600]

So do radials don't they?...
It's calling cupping the tire.

Not the same.

Not the same thing.

"cupping" is generally a repetative variance in the surface of the tire... Think "wave" shape instead of continuious even curvature.

(some good info with pics on it...) http://www.rattlebars.com/tirewear/index.html

A flat spot is just that... a single flat spot. Radials are really resistant against that due to the belting preventing it by helping to keep the shape.

Krey

What he said.

[hardlydangerous]

the reason they claim not to use bias/radial mix is simply because the tire designs allow them to react differently as well as warm up at much different speeds.

most people think the back tire is where the grip is.... thats 100% incorrect. the front tire is alway the most important and should always be the softer compound and the tire that needs to be brought up to temp.

the big issue with a bias on one end and radial on the other is the bias tires will heat up quickly compared to the radial. if the bias is on the front you will have good grip in a turn but can easily spin the rear exiting the turn if it has not had time to warm up properly.
OR if you have a bias on the rear and radial on the front you may forget your front tire is not up to temps yet and come in too hot on a cold tire and lose the front end.

Once up to temp it makes no difference really I know guys that prefer to track bikes with mixed bias/radials or just on bias tires. With bias tires they ballon out of shape at speeds more but seem to wear more evenly and work well in most wet conditions. The down side is they ride harder and dont provide as much feed back. Many are heavy and dont last to long and often harder compounds.
The GREAT thing about radial tires is the profiles. The radial design allows them to shape the profile for better traction, larger footprint at extreme angles and maintain this profile regardless of speed. The down side is they flat top quickly and wear out the center super fast if your doing a lot of touring. Other then that I cant think of any downsides to a radial.

a good exa mple of this is look at a Michelin Pilot power and a Pilot activ the active is a round profile where the road is more /\ shaped

I ran bias on both ends
I ran an pilot active bias rear and road radial front
Ive also run bias up front and radial in the rear
currently running both radials.

Just remember it will take longer for the front tire to get up to temp for max grip. the rear bias tire may give you a faulse sence of security because its up to temp and providing full grip. For touring and comuting the bias tires are perfectly fine. If you ride hard you will likely be better off with radials.