I Updated My Wheels To 17'' From 15'', I'M Feeling That My Brakes Are Not As Efficient As Before

[JohanBKK]

Hello,

I upgraded my wheels to 17'' from 15'', i'm feeling that my brakes are not as efficient as before.

Should i change my brakes also ? What budget for sport brakes ?

Maybe i'm only feeling like this for nothing, maybe my brakes are just fine, any idea ?

Thanks.

[kawapower]

Your brakes are fine don't go so fast!!

[transam]

Noooooo, not necessarily, if you have the same overall tyre circumference then there is no difference, if you have increased the circumference then you might. Tyre pressures for the tyres are very important for handling and BRAKING.

[culicine]

This makes for an interesting read;

http://www.mazda3forums.com/index.php?topic=10243.0

Braking performance could be reduced if your overall tire/wheel weights are much more than stock - note I didn't really notice any difference when I went from 15" to 17" on my car.

[Riley'sLife]

As Transam says it's usual to fit low-profile tyres when you increase wheel size to maintain overall dimensions.

However, the whole practice would seem pointless in Thailand as the road conditions could result in damaged wheelrims.

I used to own a lightweight, lowered, wide-bodied AMG 320CE in the west and even there I had to replace rear tyres every 2/3 months (damned traction control!) and the occasional wheel as a result of impact damage - which always meant also replacing the tyre as the sidewall or tread would be compromised.

I can't imagine driving anything but a truck in Thailand, with high ride position and plenty of rubber on the tarmac.

[arthurwait]

From what to what profile/width ? is it that much of a difference ?

It shouldn't really make a difference but here's a load of theory:

Are they wider as in too wide for the unsmooth roads here ?

If the overall circumference isn't the same...

Have you lowered the car ? As in are the wheels now at a different camber angle than they should with less contact patch ?

The larger wheels will have a higher torque, inertia (weight further from the centre) which should in theory mean the brakes have to work harder to slow them down quickly.

If the overall circumfernece is bigger then you will have raised the centre of graivty of the car meaning slightly longer braking distances.

If you are using different tyres they may not be as good as your old ones for braking.

You will have most likely raised the unsprung weight again it's small.

Did you change brakes at the same time and not bed them in ?

[KeyserSoze01]

Step on the brake pedal harder or upgrade you brake pads to a higher performance material.

[kartman]

What make/model were the15" tyres and what are the 17" ones.

[thailoht]

..... I can't imagine driving anything but a truck in Thailand, with high ride position and plenty of rubber on the tarmac.

I whole-heartedly agree ... and especially with the first two points of that statement!

Step on the brake pedal harder or upgrade your brake pads to a higher performance material.

JohanBKK, firstly, you should decide for yourself, unequivocally, whether or not your brakes feel efficient or not with your new 17" wheels because in the event of an emergency braking situation, it will be too late: ie., .... one of the four passengers on the motorbike ahead of you falls off.....

There are a few different ways that you can upgrade your car's brakes and improve its stopping power.

1) Installing to better brake pads

2) Upgrading to larger size rotors (discs)

3) Upgrading to better calipers

4) Any combo of or all of the above

I did this upgrade, (#4), on my SUV and that piece of mind feeling that I felt when I hit my brakes right after the brake upgrade work was done is indescribable, (then again, my O.E. MU-7 is the poster child for inefficient brake and wheel combo, in my estimation).

If your braking system is top notch, there would be no question in your mind's eye, whatsoever, the very fact that you posted this thread indicates to me that this isn't the case and that you should, at the very least, do #2 or #3.

Runstop Brakes did excellent work for me and 2Unique.

[JeffreyMcCollum]

It's the weight of the new tire wheels that will increase the stopping distance

[Spoonman]

I swapped out the 17" wheels on my new Ranger for the 20" rims off my Colorado and it made zero difference to the braking performance however when I swapped the 15" rims on the Colorado for the 20" rims the brake performance diminished dramatically and was dangerous at best, a set of 320mm front rotors from Runstop fixed it though.

[bdw]

You'll probably notice your gas mileage has suffered too.

[Spoonman]

You'll probably notice your gas mileage has suffered too.

I put the 20's on when it had less than 100km on the clock, I got 810km from the first tank of fuel.

[thailoht]

You'll probably notice your gas mileage has suffered too.

It depends on the characteristics of the new tires, but gas mileage shouldn't be a consideration when it comes to the ability to (and quality of) safely stopping.

I swapped out the 17" wheels on my new Ranger for the 20" rims off my Colorado and it made zero difference to the braking performance however when I swapped the 15" rims on the Colorado for the 20" rims the brake performance diminished dramatically and was dangerous at best, a set of 320mm front rotors from Runstop fixed it though.

Exactly!

[JohanBKK]

Hi again,

I checked the wheels and tires.

Car brand : Honda Accord G7

New : Sports Tourer My-01 215/55/R17 94V

Old : Turanza GR-80 205/65/R15 94V

Should i upgrade my brakes ? I will go on Tuesday for my tinted windows, so it would be nice to take a decision before that day.

[Spoonman]

Better to go for the 215/50/17 as this is a close match your OE tyre rolling diametre.

[thailoht]

Hi again,

I checked the wheels and tires.

Car brand : Honda Accord G7

New : Sports Tourer My-01 215/55/R17 94V

Old : Turanza GR-80 205/65/R15 94V

Should i upgrade my brakes ? I will go on Tuesday for my tinted windows, so it would be nice to take a decision before that day.

Better to go for the 215/50/17 as this is a close match your OE tyre rolling diametre.

The OP apparently has already installed and is driving on his 215/55/R17 Sports Tourer tires, thus the cause of the loss of efficient braking that he is experiencing and the reason for his posting this thread.

JohanBKK, the above chart says it all and you most definitely, IMHO, should quickly have a brake upgrade done.

[transam]

Sorry, not convinced this minor difference in circumference/radius will cause a major braking problem IF the correct air pressure for the new tyres is adhered too for the ride.

[Spoonman]

Sorry, not convinced this minor difference in circumference/radius will cause a major braking problem IF the correct air pressure for the new tyres is adhered too for the ride.

Interesting disclaimer from the website that I do my tyre size calculations on, in this instance selecting a 205/65/15 vs a 215/55/17.

http://www.1010tires...eCalculator.asp

Edited August 26, 2012 by Spoonman

[thailoht]

Sorry, not convinced this minor difference in circumference/radius will cause a major braking problem IF the correct air pressure for the new tyres is adhered too for the ride.

With the OP c/o his brakes not feeling as efficient after his tire size upgrade coupled with the fact that said upgrade surpasses a brake expert's brake malfunction criteria, it seems crystal. On top of the theoretical red line criteria, I am also speaking from experience (and testimony from 2 other owners who had similar upgrades) in that I briefly drove my vehicle after a wheel / tire size upgrade that resulted in an increase of > 3.05% in the tires diameter. It's that lack of brake control experience that drove me (pun intended) to follow the recommendations of this motor forum's expert posters to 'upgrade' my brakes. They were right!

The quality of my braking now, is unsurpassed, in my estimation!

[JohanBKK]

Ok, so what kind of brake should i buy and what is the estimated budget for this change ? Can i order directly at Honda or do i need to go elsewhere ?

Thanks.

[transam]

Any brake upgrade WILL improve stuff, even over stock wheels and tyres. I do not agree that the slight increase in wheel diameter is a problem. Correct tyre pressures is the key as tyre wall ''give'' has been altered with the lower profile tyres. BUT, if the OP wants to spend cash, for sure there will be an improvement.

[Spoonman]

Any brake upgrade WILL improve stuff, even over stock wheels and tyres. I do not agree that the slight increase in wheel diameter is a problem. Correct tyre pressures is the key as tyre wall ''give'' has been altered with the lower profile tyres. BUT, if the OP wants to spend cash, for sure there will be an improvement.

Sorry mate but you talk shit.

If you increase the rolling diametre too much it will affect the braking performance, I experienced this going from 15" rims on my Colorado to 20" rims. I increased the rolling diametre by more than 3 % and the brakes were useless.

when I put the same rims/tyres on my Ranger the increase was under .5 % and it is fine.

When I put on the 22" rims and "off road" tyres it is another story hence I will throw on 380mm rotors and 4 pot calipers.

[transam]

Any brake upgrade WILL improve stuff, even over stock wheels and tyres. I do not agree that the slight increase in wheel diameter is a problem. Correct tyre pressures is the key as tyre wall ''give'' has been altered with the lower profile tyres. BUT, if the OP wants to spend cash, for sure there will be an improvement.

Sorry mate but you talk shit.

If you increase the rolling diametre too much it will affect the braking performance, I experienced this going from 15" rims on my Colorado to 20" rims. I increased the rolling diametre by more than 3 % and the brakes were useless.

when I put the same rims/tyres on my Ranger the increase was under .5 % and it is fine.

When I put on the 22" rims and "off road" tyres it is another story hence I will throw on 380mm rotors and 4 pot calipers.

Hmmmmmmmm, look at the circumference/diameter he has increased it by. I might add, l brush my teeth twice a day racer.

[Spoonman]

Any brake upgrade WILL improve stuff, even over stock wheels and tyres. I do not agree that the slight increase in wheel diameter is a problem. Correct tyre pressures is the key as tyre wall ''give'' has been altered with the lower profile tyres. BUT, if the OP wants to spend cash, for sure there will be an improvement.

Sorry mate but you talk shit.

If you increase the rolling diametre too much it will affect the braking performance, I experienced this going from 15" rims on my Colorado to 20" rims. I increased the rolling diametre by more than 3 % and the brakes were useless.

when I put the same rims/tyres on my Ranger the increase was under .5 % and it is fine.

When I put on the 22" rims and "off road" tyres it is another story hence I will throw on 380mm rotors and 4 pot calipers.

Hmmmmmmmm, look at the circumference/diameter he has increased it by. I might add, l brush my teeth twice a day racer.

the online calculator says the change is an issue and will affect braking performance, do you disrepute this ?

[transam]

Any brake upgrade WILL improve stuff, even over stock wheels and tyres. I do not agree that the slight increase in wheel diameter is a problem. Correct tyre pressures is the key as tyre wall ''give'' has been altered with the lower profile tyres. BUT, if the OP wants to spend cash, for sure there will be an improvement.

Sorry mate but you talk shit.

If you increase the rolling diametre too much it will affect the braking performance, I experienced this going from 15" rims on my Colorado to 20" rims. I increased the rolling diametre by more than 3 % and the brakes were useless.

when I put the same rims/tyres on my Ranger the increase was under .5 % and it is fine.

When I put on the 22" rims and "off road" tyres it is another story hence I will throw on 380mm rotors and 4 pot calipers.

Hmmmmmmmm, look at the circumference/diameter he has increased it by. I might add, l brush my teeth twice a day racer.

the online calculator says the change is an issue and will affect braking performance, do you disrepute this ?

Know l don't, if the guy had stock tyres and wheels, had five passengers and their luggage the ride will still deal with it, it's built in. Extra driver foot pressure is required. LOOK at the minor difference in circumference, minimal. A minor increase in pedal pressure, and may l point out the servo DOES the work for the driver.

[Spoonman]

Seriously, are you saying added load requires more throttle given the extra weight of additional passengers............ go get your head read, in the context of this thread you are not even close to the mark.

[transam]

Seriously, are you saying added load requires more throttle given the extra weight of additional passengers............ go get your head read, in the context of this thread you are not even close to the mark.

Your thoughts, thats OK with me .Who mentioned throttle, not me, BUT, if you want to go there then extra load = more gas to move and more brakes to stop. Simple physics. You quote you changing wheels from stock to 22 inch and had a brake problem. Of course you had a brake problem, probably increased by 5 <deleted> inches. Not a few centimeters.

[thailoht]

Seriously, are you saying added load requires more throttle given the extra weight of additional passengers............ go get your head read, in the context of this thread you are not even close to the mark.

Seriously, are you saying added load requires more throttle given the extra weight of additional passengers............ go get your head read, in the context of this thread you are not even close to the mark.

Your thoughts, thats OK with me .Who mentioned throttle, not me, BUT, if you want to go there then extra load = more gas to move and more brakes to stop. Simple physics. You quote you changing wheels from stock to 22 inch and had a brake problem. Of course you had a brake problem, probably increased by 5 <deleted> inches. Not a few centimeters.

OK,ok, ok guys!

Instead of getting into a technical free-for-all, poor(?) JohanBKK is eating popcorn and enjoying the 'show' while waiting for some type of answer to his brake problem.

Of course Transam is theoretically correct, but, in light of the real-life loss of brake efficiency that Spoonman and I experienced after similar upgrades, it should be factored into ones final analysis. Personally, I think the O.E. rotor / caliper sizes must have been near their theoretical operational limits with the O.E. wheels and tires (to save mfg $$$). By adding our 'just-over-the-maximum' tire /wheel upgrades ..... wah-lah .... the O.E. brakes can't handle the increase 'load'...... but that's just my explanation to link what actually happened to the theoretical.

So, JohanBKK, 'run' (don't walk) to Runstop Brake shop (or any related aftermarket comp - not the dealer) get larger size rotors and/or more efficient calipers. They will show you your options .... and the cost.

[funcat]

Hi Guys...just reading this and thought that the "Tire Size Calculator" could be a good thing...but in practice,it may not actually be correct...I've upgraded my wheels on my Audi A4 some time ego and did not have this calculator handy,but the shop didn't see any problems(of course),so since I've liked them,they went on....but I've checked the calculator now and the difference in diameter should be only 24.87" to 25.08"(not going in to details 205/55/15 to 225/40/18)...now,see the photos and tell me if the calculator is right ?...the new wheels/tires look much bigger than that(sorry,but I don't have this car anymore,so can't take the measurements)...

...but interestingly,I haven't noticed a big difference in braking...actually the big tires would make a car to stop on the dime...and turning corners was a snitch...but Audi has Front and Rear disk/ABS brakes...