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#1 (permalink) |
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Member
Join Date: Aug 2011
Location: NE Ohio
Posts: 79
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Can you mix speed ratings on the front and back tires? for instance can you
have a h speed rating on the back and a s on the front? ALSO Does the speed rating change the tread or the way a bike rides? Is there a difference in the ride between putting on radials vs bias. Can't seem to find radials for the shadow aero. |
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#2 (permalink) |
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Senior Member
Join Date: Aug 2009
Location: In your garage stealing parts off your bike
Posts: 2,138
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Speed ratings are internationally recognized maximum speeds at which the tire may be used with maximum load when the maximum listed inflation pressure is used. Maximum loads and inflation pressures are found on the sidewalls of the tires.
Your H rating has a maximum speed rating of 130mph, and your S rating is for 112mph. As for mixing the two, as long as you don't exceed the aforementioned maximums of the lower speed rated tire, the tires will be fine together. Regarding mixing radials and bias. Back when radial motorcycle tires first hit the market, tire makers strongly advised riders not to mix radial and bias tires. Radials were new and offered significantly different handling characteristics than bias rubber, and neither the bike manufacturers nor the tire companies yet had enough model-and-tire-specific data to predict how a combination of the two would affect the handling of any given motorcycle. So the best policy was to discourage mixing radials and bias tires. Fast forward to current times, radial technology has evolved dramatically, and the manufacturers have had years to develop a better understanding of the effects of mixing tire types. As a result, production bikes like the Harley-Davidson Rocker and the Yamaha Star Raider-S come from the factory equipped with a radial on the rear and a bias-ply tire on the front. The concept I believe is that you want the rear to break traction before the front, a far safer option on a bike that a front-end washout. Some good information in this link: Motorcycle Tires 101
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#4 (permalink) |
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Member
Join Date: Aug 2011
Location: NE Ohio
Posts: 79
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Thank you for the info but
I may have mis-spoke . I meant to ask if your bike originaly took radials can you change them to bias instead of radials on both the front and back? So the speed ratings don't change the tire thread patterns? |
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#5 (permalink) |
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Senior Member
Join Date: Aug 2011
Location: Sack-a-Tomatoes, CA, US
Posts: 705
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I heard, and it kinda makes sense, that the higher speed rated tires are often more perfectly round and, of course, more dimensionally stable - they have to be to meet the tests. Also, and this really makes sense, a higher speed rated tire needs to be able to withstand more heating - higher speed usually equals more heating while running.
Regarding the speed ratings of tires, usually, different rating tires are different models from the manuf, so they often do have different tread patterns, but not necessarily because of the speed ratings... I am sure there are some sites that get into more detail about the physics of tires if anyone has the inclination to do some serious research.
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Black Beast = '71 CB750 Lazarus = '86 VT1100C rescued from a salvage yard. |
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#6 (permalink) | |
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Senior Member
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Location: In your garage stealing parts off your bike
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Quote:
Back to switching out your tires. From Dunlop's FAQ center: Bias and radial tires have significantly different dynamic properties. They deflect differently, create different cornering forces, have different damping characteristics, as well as other differences. In order for radial tires to be introduced into the two-wheel market, it was necessary to change certain characteristics of the motorcycle. The introduction of the radial tire led to such things as modified frames, wider wheels, new steering geometries and suspensions. Therefore, it is recommended that a motorcycle be used with the type of tire construction that it came with originally. If a change is to be made, then it should only be done if the motorcycle or tire manufacturer has approved the change. Above all, do not mix bias ply and radial tires on the same motorcycle unless it is with the approval of the motorcycle or tire manufacturer. Now, some of that may be corporate law mumbo-jumbo, however most of it makes sense. When I was a kid, the Grand Prix racing motorcycles converted from bias ply tires to radials in the late '80s. They found the need for stiffer frames, better forks, and stronger swingarms to deal with the additional traction. The suspension components and frames that worked well enough with bias ply tires twisted too much with the newer radial tires making the bikes much harder to ride. They also found that the tires no longer overheated after ten laps, so the tires kept their initial traction much longer ... at least until they had worn off all of the good rubber. Being not a professional racer nor aggressive rider such as on a sport bike, I would assume you may not even feel a difference. As for the tread differences regarding speed ratings, I'm certain there are differences, although it's not something I've explored. Question(s): What bike do you have, and are (as you say) switching from radials to bias???
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![]() Keep the rubber side down ... unless of course you have a rubber head! My Road to Rod, 4° Advance Timing Mod, Tubeless Spokes, Walk Around Aced It ACE Service Manual: https://dl.dropbox.com/u/106488173/ACE%20Manual.pdf |
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#7 (permalink) |
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Senior Member
Join Date: Apr 2008
Location: Palatine, IL
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Speed ratings generally don't dictate tread pattern. I would not vary tread patterns too much between front and rear tire but as stated bias and radial tires can normally be mixed on a cruiser without a problem.
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#8 (permalink) |
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Member
Join Date: Aug 2011
Location: NE Ohio
Posts: 79
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2008 honda shadow aero 750,
The tires on it now are ( which need replaced) I will be replacing both tires at one time. BRIDGESTONE 120/90/R17 #G701 front BRIDGESTONE 160/80/R15 #G702 rear Problem i have is I can't find anyone that has the exact same tires. Shade tree has Bridgstone g702 160-80h-15 but is NOT a radial and has the h speed rating. Can this tire be used on my bike to replace the one that is on it . Unitl last year i haven't road for 30 years. I just don't want to make a rookie mistake and buy the wrong tires. i am new to buying tires for a bike. i don't know if any g702 bridgestone tire will be ok as long as it has least the 160/80/15 on it and other letters would just be a bonus to the tire or if the numbers should match exaclty. Last edited by bullheadpond; 12-06-2012 at 02:35 PM. |
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#9 (permalink) | |
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Senior Member
Join Date: Aug 2009
Location: In your garage stealing parts off your bike
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Quote:
Front: Bridgestone Exedra Max Front Motorcycle Tire | Motorcycle Tires | Jake Wilson Rear: Bridgestone Exedra Max Rear Motorcycle Tire | Motorcycle Tires | Jake Wilson But upon quick search your exact tires are here: Front: Rear: The front looks like it's coming from Motorcycle Superstore through Amazon. I had bad experiences with MS, but others may say otherwise.
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![]() Keep the rubber side down ... unless of course you have a rubber head! My Road to Rod, 4° Advance Timing Mod, Tubeless Spokes, Walk Around Aced It ACE Service Manual: https://dl.dropbox.com/u/106488173/ACE%20Manual.pdf |
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#10 (permalink) |
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Senior Member
Join Date: Nov 2008
Location: Visalia, CA
Posts: 4,320
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On a Shadow as long as the speed rating of both tires is above 100 you'll be good. Actually could get away with much less on a commuter bike. As said above you really don't need to worry about the rating, unless you are riding fully loaded, at full pressure and at sustained speeds above the rating. Can a Shadow exceed the rating of tires available for them? A few can, most no way.
As for Bias vs radial, as far as a Shadow is concerned, use whichever you prefer. Don't mix Radial and bias, the differences in handling can make things get squirlly. But again you might not ever feel it on the typical street ridden bike.
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