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1988 gl1500 someone installed a bias on the rear and radial on the front. i ordered another bias matching the new rear. just wondering if it's safe to run to different type tires on the bike or does it matter at all. it will be a trike soon so not worried about longevity just the handling until i trike in a 2 months.

rode about 100 miles today and it did seem a little twitchy on the interstate. at 75.
 

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skoto1 wrote:
1988 gl1500 someone installed a bias on the rear and radial on the front. i ordered another bias matching the new rear. just wondering if it's safe to run to different type tires on the bike or does it matter at all. it will be a trike soon so not worried about longevity just the handling until i trike in a 2 months.

rode about 100 miles today and it did seem a little twitchy on the interstate. at 75.
All is well as long as you only do 74 :badgrin:

I've had bias on the front and radial on the rear. Now both are radials.
Mixed tires I noticed no difference even at 122 nor hauling my trailer.
BUT it was bias up front not a radial.

2 months? Live longer, "Let's be careful out there". (H.S.B.)
 

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I have no idea about safety but on the GL1800 a know of darksiders that run a radial CT on back and a bias ply rear-MC tire on front and swear by it.

I run a CT on back but so far have stuck t the E3 on front.
 

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Two of the main differences between bias and radial are:

Bias

Bias tires can have either nylon or steel belt plies that run at a 40 degree angle to the crown starting at one bead and running under the tread to the other bead. Generally there at least 6 plies but that depends on the tire manufacturer. With plies running from bead to bead and being more plies, it makes for stiff sidewalls.

Radial:

Radial car tires have steel belts (plies) that run at a 20 degree angle to the crown ONLY under the tread area. Depending on the manufacturer, the amount of plies can range from 4-6 with four being the most common. The sidewalls of CT normally only have two plies of cords that run from bead to bead and run perpendicular to the thread and sidewall to give the sidewall room to flex and give a softer ride. Note: that MT that is of the radial design has 4-6 plies run from bead to bead to give a stiffer sidewall that a MT requires.

The radial tire design is to give a softer ride than the bias ply tire.
 

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I am not a tire expert but I read that principle advantages of Radial over bias include;

Good high speed capacity
Longer lasting and Longer tread life (Up to30%- 50% longer)
Steel Belted - Results in tougher overall construction
Better floatation ,larger contact area wider footprint
Low heat build-up or run cooler
Lower rolling resistance
Better Fuel Economy
Better stability
Wear resistant
Smoother, more quiet ride


Disadvantage of radial tire over a bias tire:
More prone to puncturing at side walls
Side wall bulging
More difficult to repair
Higher purchase price

Source: http://wiki.answers.com/Q/What_is_the_difference_between_bias_and_radial_tires

If you somehow think the sidewalls on a 195/55R16-ZP CT are less stiff than on a Dunlop E3 MT, - Wrong. The sideways on my CT are very stiff, far stiffer than the MT it replaced. You can remove the air from the tire, ride your motorcycle 55mph on the interstate - I have done it. Try that with your motorcycle tires.

Radials also for certain run cooler on the same road, same speed, my radials run 25°F cooler than the GL1500 with bias ply running behind me.
 

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i prefer radials but the po had already put a new bias on the rear so i bought one to match it. they'll all come off soon anyway.
 

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I am no engineer but I wonder why mixing tires is a known no-no on cars but seems to be ok on a motorcycle? Maybe someone here can explain that to me?
 

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The only time it will matter is IF you mix the type of tire on the SAME axle.

I have yet to try a radial tire on a bike but would not be concerned if there was one of each type. If the tread is good and the tire pressure is right, off I go and enjoy.
 

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the rims of the 1500 are made for bias tires not radial.

I dont really know enough, to say that using radial may create a safety issue, but Hondas recommendation for the 1500 is bias tires, so i would humbly suggest, that bias may be a the right option.
 

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A friend of mine got 1 radial accidentally put on his 1500 when he got new tires at a bike shop... it handled so badly it nearly caused him to get into several accidents before he discovered the screw up...
 

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i thought i had read that somewhere about the 1500 where made for bias tires but could never find it again.
 

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My Sources:



TJ Tennent - Lead motorcycle tire engineer for Bridgestone\Firestone

Virginia Gallant -Tire engineer from Dunlop\Goodyear

Tire and Rim Association - Joe Pacuit

Sukoshi Fahey - LeadMotorcycle tireDeveloper from Cooper\Avon Tires

I have also received emails back from Metzler but not from anyone in particular.



Some of thereading I have done is "The Theory of Ground Vehicles" by Jo Yung Wong and "Motorcycling Handling and Chassis Design" by Tony Foale.



I have spent quite a few monthsof doing some real in depth research on howcar tires and motorcycle tires are designed and manufactured.





2006Gl1800:




I am not a tire expert but I read that principle advantages of Radial over bias include;

Good high speed capacity
Longer lasting and Longer tread life (Up to30%- 50% longer) - This depends on the chemical make up fo the tire not whether it is bias ply or a radial. A hard compound tire wears longer than a soft compound tire. With how the radial tire reacts and flexes to the road surface, the tire manufacturercan run a harder compound on radial tire than a bias ply tire.
Steel Belted - Results in tougher overall construction - Most radials use steel belts. Some bias plies use steel belts also. Depends on the manfucaturer
Better floatation ,larger contact area wider footprint - Not possible. A bias ply and a radial tire of the same size (155/60/17) will have the same contact patch.
Low heat build-up or run cooler - Again depends on the chemical make up of the tire. Harder compound tires run cooler than soft compound tires.
Lower rolling resistance
Better Fuel Economy
Better stability - For cars, yes. When corning, the side walls are designed to flex to try to keep as much of thetread in contact with the road surface. This is why the plies in the side walls run perpendicular to the tread to allow them to flex.
Wear resistant - Depends on the chemical make up of the tire. There are two major chemicals in all types of tire, carbon black and silica. The higher the level of carbon black versusa lower level of silica make a hard compound allowing for longer wear life. Conversly, the higher the level of silica versus a lower level of carbon black makes a softer compound allowing more grip and it will wear faster.
Smoother, more quiet ride - This is due to the design of the side walls. They again are designed to flex and absorb some of the road shock as not transmit it back into the chassis of the vehicles.


Disadvantage of radial tire over a bias tire:
More prone to puncturing at side walls - Due to less plies means less carcass.
Side wall bulging - This is due to the way the plies are laid up in the carcass running perpendicular to the tread versus a bias ply running diagonally.
More difficult to repair
Higher purchase price - Due to more labor intensive to build.

Source: http://wiki.answers.com/Q/What_is_the_difference_between_bias_and_radial_tires

If you somehow think the sidewalls on a 195/55R16-ZP CT are less stiff than on a Dunlop E3 MT, - Wrong. The sideways on my CT are very stiff, far stiffer than the MT it replaced. You can remove the air from the tire, ride your motorcycle 55mph on the interstate - I have done it. Try that with your motorcycle tires.

Radials also for certain run cooler on the same road, same speed, my radials run 25°F cooler than the GL1500 with bias ply running behind me.










 

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oldishwinger wrote:
the rims of the 1500 are made for bias tires not radial. - There are no design differences between a rim for bias ply or radial tire. The rim can handle either or. There are major design differences between between a car rim and a motorcycle rim.

I dont really know enough, to say that using radial may create a safety issue, but Hondas recommendation for the 1500 is bias tires, so i would humbly suggest, that bias may be a the right option.
 

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My writing was a direct quote from the listed, verifiable, source, I have no personal opinion.

I read with interest your colourful writing but I am left to wonder is there more than your conjecture (informed as it maybe)? Tires have become a significant maintenance expense in the last 10-12 years so the issue is important.

Is there any empirical evidence concerning the advantages concerning wear or safety of various tire types? I would be interested in what the listed sources have to say on the matter.

I have not before heard of design differences in rims and significant difference seems unlikely. I run a tire, supposed designed for a "car rim", a 195/55R16ZP on a rim supposedly designed for a motorcycle tire. Yet the tire performs as advertised. I have personally drained the air from it (by removing the valve stem) and ridden the motorcycle on zero air pressure and so-called "car tire" did not disconnect from the motorcycle rim. I rode only a small number of miles (2) but within a block a so-called motorcycle tire would have broken away from the rim without air pressure to support the downward force. Admittedly anecdotal evidence. The "major design differences" apparently do not prevent mZP tires from working as advertised on my GL1800 rim.

I also use a TPMS (as is recommended and even required by some rally masters) and the rear "car tire"on my GL1800 on the same road at same speed will run far cooler than a similar motorcycle tire. Motorcycle tire users at a recent long distance riding meeting indicated rear tire temperatures exceeding 180°F while even in the Mojave with air temperature at 112°F (as measured by the GL1800) my rear tire never exceeded 142°F. I am not sure what to read into this difference but it exists.
 

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Would you believe Redbaron, the moderator, on the differences between the two rims? If so, PM him and ask him about the differences. I met up with Redbaron in Madisonville, Texas after NASSIR 5. I gave him the design spec's of both the car rim and motorcycle rim so you won't have to take my word on it. He got to handle and do a side by side comparison of the two rims. He seen how the actual tires fit inside each of the rims whether it be a ct in a mc rim or a mt in a mc rimand even a mc tire in a car rim. After he seen all whatI had, he had said to me this changed his mind andwas enough to convince himnot to go darkside.



The reason why tire manufactures went away from bias ply tires is for several reasons:

1) the tire design allows for the tire to flex which again keeps more tread in contact with the road surface and helps maintain better control.

2) the tire design allows for a harder compound which allows for longer wear life.

3)allows for a softer, more luxurious ride by allowing the tire to absorb some the road shock. This allows the car manufacturer now to be able torun a softer spring rate.

These points are whatthe general public wants, a safer, longer wear life out of tireswith a softer, more quietride.
 

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On a bike you can run Radial on the rear and Bias on the front, but not vice-versa... The later causes bad handling, so I hear. I run radial and bias as mentioned.

On a car you cannot mix radial and bias on the same axle, because the radials have the freedom to flex sideways, where-as the bias do not. Hence, the bias tire would end up carrying twice the load in a turn as the radial (at least when you first enter a corner), possibly causing a skid. In contrast, having all-radial or all-bias on an axle will allow both tires on the axle to carry the same sideways loading in a turn.
 
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