Tires - what speed rating, H or T?

[Longtimer]

What tire rate are you using. Tires rated at. T.or rated at H. I know H is rated at 130mph and t is rated at 118mph but which one ?? It looks like you can get the Altima in either. Thanks

 

[BLUEKNIGHT911]

What tire rate are you using. Tires rated at. T.or rated at H. I know H is rated at 130mph and t is rated at 118mph but which one ?? It looks like you can get the Altima in either. Thanks

Either one will be fine ...... When they test tires at those speeds they do it for I think 8 hrs..... how often do you think you will operate your Spyder at those speeds ????? ..... JMHO..... Mike :thumbup:

 

[Peter Aawen]

Here in Oz, we can use any tire that fits within the size regs just so long as it meets or exceeds the Load Index and the Speed Rating, so we just hafta make sure our tire choices have the same or a bigger number for the Load Index, and an Alpha Character that's the same or higher than the Speed Rating - T is rated for 118 mph; while H is rated for 130 mph. Kendas aren't all that great for either, so the Minimums here aren't hard to exceed - in fact, very few other auto tires go as low in either these days! :lecturef_smilie:

So if you're concerned about what it is in your neck of the woods, just goggle 'Tire Speed Rating Chart' if you want to see them all; and look for what it says is the Minimum on your Spyder's Tire Placard, usually down on the LH Swing Arm, but also in the Glovebox Manual! :thumbup:

Enjoy! :cheers:

 

[Bunson]

I was hoping someone else would say this so I wouldn't look like a dummy. But I always thought that the higher speed rating was a softer compound. ????

 

[ButterSmooth]

I was hoping someone else would say this so I wouldn't look like a dummy. But I always thought that the higher speed rating was a softer compound. ????

I always thought the speed rating was about carcass integrity and it's ability to maintain shape at higher RPM. When a tire 'balloons' at speed (like a Kenda) it not only causes uneven wear, but greatly compromises performance. Since higher speed rated tires are stiffer, ride quality can suffer. Higher speed rating usually means a lower profile (low aspect ratio), since it's easier to reduce flex with a shorter side wall. This is not something I 'know', just what I've gleaned over the years.

 

[Peter Aawen]

I was hoping someone else would say this so I wouldn't look like a dummy. But I always thought that the higher speed rating was a softer compound. ????

Yeah, that's a reasonable assumption, there was a time when it was even a 'good' assumption; but it's not neccessarily so, and these days, it's not so all that often either! :sour:

Without getting too technical or specific....(in order to keep it to a quick & shortish answer too! ) As a general thing, Heat is the enemy of tread wear, and softer tread compounds do tend to wear quicker as they get hotter.... Hard compound treads tend to need a little more heat (often achieved by running lower pressures) and take a bit longer to reach their ideal operational temperature so they can provide their best traction, but they generally don't wear as quickly once they reach that temperature; while soft tread compounds generally provide the best grip/traction they can sooner, sometimes even before the tire's really reached it's ideal operational temperature or made it to somewhere in to its ideal temperature range! However, those softer compound treads often also start to 'go off' if they get too hot, effectively just melting off the tire, and they can do this even if they get just a little bit hotter than ideal, which is something that prolonged high speed running can do very easily.... :shocked: .

So for tires that need to provide optimal traction at high speeds, and continue do this for long periods (ie. they're higher speed rated tires that need to work well without disintegrating for hours!) the tread compound needs to be soft enough to provide optimum traction at the tires operational temperature, but hard enough that they DON'T start to 'go off' too soon and basically just melt off the tire carcass if those temperatures stay high for long periods of high speed running!

This means that Tire manufacturers not only have to balance the traction needs/wants of a given tread compound with the temperatures generated as that tire rolls along flexing like mad under its rated load at/for the required speed rating, but they also have to pay a lot of attention to making sure that carcasses and sidewalls they use are constructed of materials and in a way that won't deform readily (or let the tread deform readily, like some tires that we know of! ) under the stresses of being spun at anything up to their rated speed for long periods! The sidewalls (& tread) can't flex too much so that it lets the tread deform too much or that the tire keeps on heating up instead of reaching its operational temp & effectively plateauing there providing its optimal traction; and the tread compound needs to be carefully matched to provide traction at the temperatures that the particular tire will reach if it's loaded up to spec & then run at those speeds for whatever hours are necessary to reach it's desired speed rating! And all this is even before we start talking about the tread performance needs/wants; or profiles; or All Season Sport/Performance or Ultra Sport or whatever ratings; or Winter vs Summer; or Wet vs Dry; or M&S; or 3PMSF; or Light Truck; or Passenger; or Flotation; or Lo..... :gaah:


So yeah, it's really not anywhere near as simple as saying higher speed ratings on a tire mean a soft compound tread - altho it might, but it just as easily might not! It's all in the design, the assembly, the cooking, the tread pattern, the tire pressure, and a bunch of other stuff besides! :lecturef_smilie:

Simples, really! :cheers:

 

[troop]

T rating will be just fine. Remember, when these tires are tested, they're tested under loads that far exceed the weight of a Spyder...

 

[SportsterDoc]

Good logic ButterSmooth.

For info on high speed tires, Google Goodyear Eagle Enforcer tires with a V (149) speed rating for law enforcement.

Although I have BRIEFLY checked max speed on my bikes, sustained speeds have been within 10, maybe 15 MPH of speed limit.

In Utah on interstate 15, maybe 85 for an hour in 80 MPH zone.

And if you want to chance holding 90 or even 100 in remote areas, a T rating is more than adequate.

Do either affect MPG?