175-55-15 vrs 165-55-15

[BoilerAnimal]

Going to get a set of Vredestein Quatrac tires for the front of our RT. It seems that most are getting 175-55-15 instead of the 165-55-15 that is the OEM size. I was wondering what the advantages or reasons were for the bigger size.

 

[UtahPete]

I think it's due to availability. You won't notice any difference.

 

[h0gr1der]

Going to get a set of Vredestein Quatrac tires for the front of our RT. It seems that most are getting 175-55-15 instead of the 165-55-15 that is the OEM size. I was wondering what the advantages or reasons were for the bigger size.

I dabbled with the numbers, and came up with this. Purely speculation, of course. If (a big IF) the Nanny cares about front/rear wheel rotation speed as it pertains to taking a corrective action, then keeping the ratio of change from the OEM sizes to the new sizes as close to the same should make this less likely to happen. I went with a 205/60R16 Vredestein on the back, and due to availability as UtahPete says, the 175/55R15 on front. The 205 rear is slightly larger than stock, hence the slightly larger roll-out on the front. As I calculated it, this combination overall is only 1.4% different than OEM. As a perk, it corrected 50% of the speedometer error. I'm only 1 MPH off at 70 now. As an aside, I have no rubbing on the new style fenders.

 

[BLUEKNIGHT911]

In reality the NANNY is not as sensitive about this difference as some seem to think it might be …. Spyders in general are very limited in tire sizes that will fit either Front or Rear...… In fact, I don't believe there is any combination of sizes that will / can trigger the Nanny, for this reason ….. Mike hyea:

 

[Purple Guy]

I've been riding on 175/55/15 for 2 years now.
Quite happy with them and didn't notice any difference.
As UtahPete mentioned, trying to find 165's in Canada is near impossible, bought and had blanced the 175's less than 1 mile from my home.

 

[BoilerAnimal]

I didn't know if there was a reason that I might have missed in one of the many tire discussions or what. I would imagine that the difference between the two sizes would have little effect regarding hydroplaning. That was my main area of concern.

Thanks for the replies!

 

[BLUEKNIGHT911]

I didn't know if there was a reason that I might have missed in one of the many tire discussions or what. I would imagine that the difference between the two sizes would have little effect regarding hydroplaning. That was my main area of concern.

Thanks for the replies!

The size difference 10mm is less than 1/2 inch …. on a race track in a race it be a concern ( a very small one tho ) …. but for us it won't be noticeable ………….. Mikehyea:

 

[BoilerAnimal]

The size difference 10mm is less than 1/2 inch …. on a race track in a race it be a concern ( a very small one tho ) …. but for us it won't be noticeable ………….. Mikehyea:

Per tire or total of both?

 

[BLUEKNIGHT911]

Per tire or total of both?

Per tire ….. Mike hyea:

 

[dondje]

Going to get a set of Vredestein Quatrac tires for the front of our RT. It seems that most are getting 175-55-15 instead of the 165-55-15 that is the OEM size. I was wondering what the advantages or reasons were for the bigger size.

The 175 is .39" wider and the sidewall is .215" taller. So there could be a slight hydroplaning and sidewall flex disadvantage with the 175. Some might consider more sidewall flex an advantage. But that depends on driving style.

Regards,

Don

 

[Baron14y]

The 175 is .39" wider and the sidewall is .215" taller. So there could be a slight hydroplaning and sidewall flex disadvantage with the 175. Some might consider more sidewall flex an advantage. But that depends on driving style.

Regards,

Don

The flex could also be a function of the construction. If it were a Kenda of that size, yes more flex. Another brand, ???.

 

[UtahPete]

I think it's due to availability. You won't notice any difference.

 

[BLUEKNIGHT911]

The 175 is .39" wider and the sidewall is .215" taller. So there could be a slight hydroplaning and sidewall flex disadvantage with the 175. Some might consider more sidewall flex an advantage. But that depends on driving style.

Regards,

Don

When you say " SLIGHT " disadvantage …… as a percentage I would est. - .002 % difference …….. That's really barely measurable , so the effect would not be felt …..jmho ….. Mike hyea:

 

[canamjhb]

Going to get a set of Vredestein Quatrac tires for the front of our RT. It seems that most are getting 175-55-15 instead of the 165-55-15 that is the OEM size. I was wondering what the advantages or reasons were for the bigger size.

Because the bigger ones look better. See Petes' post #12..... Jim

 

[FlyBoy2121]

Hello everyone

Is there a Spyder that rolls with Arachenid tires, may have OEM size.

FlyBoy2121

 

[dondje]

When you say " SLIGHT " disadvantage …… as a percentage I would est. - .002 % difference …….. That's really barely measurable , so the effect would not be felt …..jmho ….. Mike hyea:

Mike...

You seem to underestimate the difference a 6% larger contact patch can make when it comes to PSI (pressure) on the road, and the area that water has to be dispersed from under the tire to prevent hydroplaning. Given standard variables it is probably more like 2-3%. But hey, you were only off by (3) decimal places. And yes, that difference can be felt by those that regularly drive in heavy water/slush conditions.

Regards,

Don

 

[BoilerAnimal]

Seeing as how the Quatrac 5 is asymmetrical, has anyone had their tires mounted backwards or has anybody checked? I was at a dealer two summers ago and I discreetly pointed out that they had the tires mounted backwards on a brand new Spyder.

The reason I ask is that the difference is not glaringly obvious and could be overlooked if the person mounting the tires was not paying attention.

 

[BLUEKNIGHT911]

Mike...

You seem to underestimate the difference a 6% larger contact patch can make when it comes to PSI (pressure) on the road, and the area that water has to be dispersed from under the tire to prevent hydroplaning. Given standard variables it is probably more like 2-3%. But hey, you were only off by (3) decimal places. And yes, that difference can be felt by those that regularly drive in heavy water/slush conditions.

Regards,

Don

Don ….. I believe you are " Overestimating " the actual REAL - life effects of the above mentioned differences, for operating a Spyder during adverse weather conditions..... I am not a Typist and to give you a technically correct answer is way beyond my typing ability and time ( I'm 72 and don't have time to spare ) …… that being said, here's a question for you or anyone else reading this ….. Do you think it's possible to determine the speed or time difference in estimating when a 175/55-15 tire will aquaplane Vs. a 165/55-15 …. also do you think it matters ?????? ………….. Thanks for your above post ….. Mike hyea:

 

[Baron14y]

I have an OEM size Arachnid on the back. Good or bad? I have nothing to compare it to.

 

[BLUEKNIGHT911]

I have an OEM size Arachnid on the back. Good or bad? I have nothing to compare it to.

From a LOT of folks who tried the Arachnid ….. this tire may be WORSE than the garbage Kenda's …… When it wears out consider getting an Auto tire ….. either a 215/60-15 or 205/55-15 …… Mike hyea: