# Will wheel size affect brakes?



## HBLevine (May 20, 2005)

I'm putting 19 x 8.5s on my 2005 2.5s (ABS). A friend told me that I might have to get larger brakes. 

Anyone have any issues with the larger wheels/tires? 

Why would he be concerne?

Also - I had decided not to go with 20's because driving on NY roads, I'd sooner or later wind up with cracked rims. Any adivce on that?


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## L J Walker (Aug 3, 2005)

HBLevine said:


> I'm putting 19 x 8.5s on my 2005 2.5s (ABS). A friend told me that I might have to get larger brakes.
> 
> Anyone have any issues with the larger wheels/tires?
> 
> ...


It is not the WHEEL [metal rim] diameter that will affect braking performance, it is the overall diameter of the wheel and tire assembly that will have an effect on braking performance. Rule of thumb is: The greater the overall diameter of tire/wheel assembly, the less effective your brakes would be in stopping the vehicle. However, if you can still fit the wheel/tire combination of your choice onto the vehicle without any rubbing or clearance of the wheel wells and/or fenders, your brakes would remain as effective as with stock size wheels/tires. Before you would become aware of a decrease in the performance of your brakes due to your wheel/tire size being too tall, you would be sick of the decrease in your acceleration!!! The effect of wheel/tire diameter works both ways!! The taller the wheel/tire, the slower your acceleration will be. [if all other parameters of vehicle remain unchanged] 
The total weight of the vehicle is more of a concern in regards to the performance of the brake system than anything else you will encounter. The heavier the total weight, the harder it is to stop. Same thing on acceleration! The heavier the total weight, the harder is is to get up to speed. So, you should be more concerned with how many heavy passengers you have than the size of the wheel.
In response to the part about the roads and cracked wheels: The air pressure in your tires and cornering speeds will contribute as much risk of wheel cracking as any other factor [again, weight is high on the list]
Cast alloy wheels are more prone to cracking than stamped steel wheels. A heavy vehicle with large diameter, cast alloy wheels with under-inflated low profile tires, cornering at high relative speeds on rough roads is more likely to suffer wheel cracking than a light-weight vehicle with stock wheels and tires, properly inflated, cornering at low speeds on smooth roads. Everything else falls somewhere between these extremes. No matter what you have between the axles and the road, check your tires and wheels often for cracks, loose lugs, foreign object punctures, etc.


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## Alti9 (Apr 13, 2005)

HBLevine said:


> A friend told me that I might have to get larger brakes.


Your friends an idiot. Find new freinds and dont ever let him work on your car.


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## blitzboi (Apr 13, 2004)

Alti9 said:


> Your friends an idiot. Find new freinds and dont ever let him work on your car.


Actually, his friend is right in theory. Increasing the size of the wheel pushes the majority of the mass of the wheel/tire combination outwards. Remember that wheels generally weigh more than tires, and that most of the wheel's weight is around the rim portion, as opposed to the spokes and hub. The net effect of pushing this weight outward is that it then requires more torque to start or stop the entire assembly, which reduces both acceleration and the effectiveness of the brakes.

Theoretically, in a race between two identical vehicles, one with 17" wheels and tires, and one with 19" wheels and tires (both of the same overall weight), the car with smaller wheels would be able to both accelerate and stop faster. In practise, some of this advantage is offset by the fact that larger wheels generally wear wider tires, thus increasing road grip, and the fact that lower profile tires generally increase handling performance.


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## Alti9 (Apr 13, 2005)

Yes, but the fact remains he does not need to upgrade the brakes on his street car to put bigger wheels on it, theory aside.


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## Zac (Mar 10, 2004)

Upgrading pads is never a bad idea although you will not need to upgrade your brakes at all to run large wheels. Now, I would consider the quality of ride proir to purchasing such large wheels...what profile tyre would you run?


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## HBLevine (May 20, 2005)

I put them on last Friday. They look great. Giovanni Brakes. 
19 x 8.5

http://www.wheelsnext.com/prod_imgs/img-1927-large.jpg


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## Alti9 (Apr 13, 2005)

wow, that has got to be the .............nevermind, to each his own.


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## blitzboi (Apr 13, 2004)

Alti9 said:


> Yes, but the fact remains he does not need to upgrade the brakes on his street car to put bigger wheels on it, theory aside.


I think you're missing the point here. The fact that one could "make do" with the stock brakes following a wheel and tire upgrade is irrlevant. After all, who strives simply for adequacy?

To bolster my point, please notice that Nissan chose to upgrade the brakes on the Altima SE-R, which only comes with 18" wheels and tires. Do you honestly think they would do that if it weren't absolutely necessary, given that car companies are cheap as hell and cut corners everywhere they can?

Frankly, I find the brakes on my Altima 3.5SE lacking even without larger wheels and tires on the car. My company car, a 2003 Mazda Protege5 can easily out-stop my Altima, its rotors have yet to warp, and the pedal is easier to modulate, to boot.

I stand by my opinion that anybody going with a larger and heavier wheel/tire combo would be wise to upgrade their brakes, even if just with a more performance-oriented pad. Aparently the rotors from previous-generation Maxima will fit on the L31 Altimas, although I don't know what other mods are necessary to accomodate that.

On a side note, does anybody know the actual weight of the stock wheel/tire combination? If not, I'll make sure to weigh mine come winter, when they're swapped out for my snows.

Cheers!


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## blitzboi (Apr 13, 2004)

Alti9 said:


> wow, that has got to be the .............nevermind, to each his own.


They're not my cup of tea either, but then again beauty is in the eye of the beholder I guess.

Kinda reminds me a bit of the guy down the street who put giant chrome spinners on his Mazda3 sedan... talk about U-G-L-Y. One of these days I'm gonna put an "bad taste ticket" on his car... lol


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## Alti9 (Apr 13, 2005)

blitzboi said:


> I think you're missing the point here. The fact that one could "make do" with the stock brakes following a wheel and tire upgrade is irrlevant. After all, who strives simply for adequacy?
> 
> To bolster my point, please notice that Nissan chose to upgrade the brakes on the Altima SE-R, which only comes with 18" wheels and tires. Do you honestly think they would do that if it weren't absolutely necessary, given that car companies are cheap as hell and cut corners everywhere they can?
> 
> ...


I think your missing the point here. The original questions was "a friend told me I might have to get larger brakes", and the answer is simply "no, you dont HAVE to get larger brakes."

Sure, we would all love to have a set of 6 piston brembo calipers on our rides, but the fact remains its not a cost freindly mod or even remotely necessary.

Nissan chose to upgrade the brakes on the SER to justify the extra $5K they charge for it, not because it wouldnt stop sufficiently with the standard SE brakes. And it didnt cost them anything extra, as I believe they are simply Maxima brakes.

And Mazdas have always been known for excellent brakes, Nissan on the other hand, not so much.


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## blitzboi (Apr 13, 2004)

Alti9 said:


> I think your missing the point here. The original questions was "a friend told me I might have to get larger brakes", and the answer is simply "no, you dont HAVE to get larger brakes."


That's not an answer, that's your opinion, and, contrary to your belief, there is in fact a difference between the two. I choose to not agree with your opinion, based on personal experience and a solid background in physics. I'm not sure what your opinion is based on exactly.



alti9 said:


> Sure, we would all love to have a set of 6 piston brembo calipers on our rides, but the fact remains its not a cost freindly mod or even remotely necessary.


You obviously haven't bothered to read my posts, because I never suggested that such extreme brake upgrades were necessary. In fact, I said that even a set of performance pads would help.



Alti9 said:


> Nissan chose to upgrade the brakes on the SER to justify the extra $5K they charge for it, not because it wouldnt stop sufficiently with the standard SE brakes. And it didnt cost them anything extra, as I believe they are simply Maxima brakes.


That's a lousy argument, and I think you know it.



alti9 said:


> And Mazdas have always been known for excellent brakes, Nissan on the other hand, not so much.


Exactly, which is the reason why it's prudent to upgrade them even without larger wheels or tires. You just made my point for me, thank you sir!


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## blitzboi (Apr 13, 2004)

In any case, I'm getting sick of this discussion. 

You have your opinion, and I have mine, and it's obvious we're not going to come to a consensus. So let's just agree to disagree and leave it at that, okay?


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## Alti9 (Apr 13, 2005)

I think your missing the point here. The original questions was "a friend told me I might have to get larger brakes", and the answer is simply "no, you dont HAVE to get larger brakes."

Actually, that is fact, not opinion. Maybe you should trade your physics background in for some common sense.


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## blitzboi (Apr 13, 2004)

Alti9 said:


> I think your missing the point here. The original questions was "a friend told me I might have to get larger brakes", and the answer is simply "no, you dont HAVE to get larger brakes."
> 
> Actually, that is fact, not opinion. Maybe you should trade your physics background in for some common sense.


I would strongly suggest you keep personal insults to yourself in future, as they're against the rules of this forum (quote: "No flaming, hostility, derogatory or abusive language").

All I'm trying to do here is have an intelligent, sophisticated, technical discussion on the impact of larger wheels and tires on braking performance. If you can't do the same, and leave your attitude at the door, then perhaps this forum isn't the place for you.


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## Alti9 (Apr 13, 2005)

Are you kidding me?

The guy asked if he needed larger brakes to put bigger wheels on. The answer is "NO". I cant make it any simpler for you.

If you want to have a discussion on brakes, maybe you should start your own thread with your own topic.

And save the threats...lol...well, I did need a good laugh, thanks for that.


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## blitzboi (Apr 13, 2004)

It seems as though you're intent on forcing everyone else to conform with your opinion. And just because I don't doesn't justify your use of insulting comments (paraphrased quote: "get some common sense"). I never insulted you or made any remarks about your intelligence.

As for your suggestion about starting a thread about braking systems, it's a good idea, and I might just do that.

As for my previous post, there was no threat intended, I was simply explaining the rules of this forum to you in response to your rude comment. I can attest the rules are enforced because I was locked out once myself a while back. Besides which, making threats just isn't my style.

Now, please, let's just end this discussion. You've had your say, I've had mine, and the readers can make up their own minds from there.

Cheers!


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