I have a question regarding tire selection on a street bike (i.e. not for racing). Would there be any consequences (good or bad) of having a bias-ply front tire and a radial rear tire? Particularly considering braking and handling...

Thanks

 

You are talking about two totally different types of tires not to mention tread and compound used. It is usually best not to mix and match tires from differing brands and the same can hold true for same brand tires as well.

What two tires are we talking about?

Lance

 

Yes, it all about the grip differential between the two tires. Don't do it! Why would you even consider it?

 

We're talking about motorcycles here, right?

Mixing tires front and rear is not the same as mixing tire types on a car. When you mix bias ply and radial tires on a car you can get strange behavior like oversteer when the car would otherwise understeer with matching tires.

On a motorcycle the tire behavior is totally different. Either the front tire or the rear tire loses traction first. Generally you want the rear to go first because a rear wheel slide is much easier to correct. If the front gets less traction than the rear, you just have to ride to the traction that's available from that front tire. In the more common case where the front gets better traction than the rear, you can ride until you start to feel the rear tire giving hints that you're approaching its limits. Most sport bike riders, at least here in Northern California, go for sticky tires where they'll almost never feel either of them slipping. Personally, I use sport touring tires because they last longer and expect to occasionally feel the rear tire giving me traction signals. I had more "signals" from the Michelin 90X than the Bridgestone BT-020 rear, so now I stick with Bridgestones. They stick good enough for the type of riding that I enjoy.

Mixing different brands of tires DOES NOT seriously upset the handling of a motorcycle unless one of them gets significantly worse traction than the other. Since I generally wear out two rear tires for each front, I've had several combinations of Dunlop, Michelin, and Bridgestone tires on my bike and it has never been a problem. Note that I'm one of those riders that generally wears the tire on the middle as well as the edges. I've only had one tire, a BT-010 front where the edges were gone before the middle was worn out. The rears don't end up that way because the V-Twin power tends to keep the middle wearing along with the edges.


The more important question I would like to ask is: why would anyone want to have a bias ply tire on a motorcycle that can take a radial?

Radials get so much better traction than bias ply tires that I never want to go back to a street bike with bias tires again. The other issue is the age of the front tire you would be keeping. Any motorcycle tire more than about three years old is losing important traction that you might need sometime in an emergency.

I say don't mix them, not because mixing different tires is bad by itself, but because bias ply tires are not as good.

 

Scott,

While I agree with most of what you said, mixing two different types of tires is just not wise. Yes, you can mix tires so you can get more traction in the front. This is usually best done by buying a tire in the same family. For one, the tires are designed differently and as such, different applications. The tires behave differently as well. If the original poster was looking into keeping an existing tire and just buying one new one, that is not wise at all. Second, you have how the tires respond as well. Different tread design, construction, and compound all They would be better off buying two new tires. The tread, construction and compound all play a part in how the tires react to various road conditions. Some handle standing water better then others, others hate those tar strips, some warm up faster then others, etc. Having two totally different tires is just asking for problems.

When it comes to new tires and want to change brands, both get changed, not one. For one peace of mind, the major one is that the tires do respond differently and I don't want to have one talking Chinese and the other Spanish. Just like if I hit some water, I don't want one hydroplaneing and the other holding its own.

Lance

 

Thanks for the answers, guys. The story behind this is that an acquaintence, who has been riding for 20+ years, took his Electra Glide to the dealer to get a new rear tire. The EG was designed with Bias tires in mind, but the dealer suggested replacing the rear with a better Radial tire, and leaving the front as-is. He had an incident where he lost control in a situation that shouldn't have been a problem, and was wondering if the tire difference is what caused it.

 

My BMW cruiser comes with bias ply tires also. I understand it is for the big "fat" look. I wouldn't mix-n-match.

 

If you ride hard; Pilot race hard for summer, soft for winter. Watch cold roads w/ the hard. If your bike has a 180 like a GSXR 1000, put a 170 on and it will turn like a 600.