I have read in some PDF specification that rotors and caliper holder very depending on the wheel size. The brake caliper and pads stay the same. 300mm rotors for 16” and 320mm rotors for 17”. It doesn’t mention 18” wheels.
I have 16” wheels and was hoping to eventually upgrade to 17 or 18” wheels.

What’s the difference between the caliper holder and the caliper itself?
How important is this when upgrading? If I keep the tire diameter the same why would brakes have different rotor requirements?
Do I have to change the entire brake assembly + wheels + tires? It seems that it would get pretty pricy.
If any one has some thought on that let me know…THANKS

Greg :wacko:

Maybe Im reading wrong, but what is your goal? Are u upgrading the wheels, or brakes or both?

If u keep the wheel diameter the same, the brakes are not a concern. If your just upgrading the wheels, the brakes are still not a concern as long as u research and get wheels that fit your car.

If your upgrading both, I would get the wheels first. Then u can address getting brakes that will look good with larger wheels.

But there are different kinds of brake upgrade kits. U can get larger diameter rotors and keep the stock caliper. In this case, u need a bracket that will relocate the caliper. This bracket should come with the kit. And get upgraded pads also.

Then u can get the larger diameter rotor with an upgraded caliper. U will still likely need a relocation bracket for the caliper. Im sure this goes without saying, but with either of these make sure they will fit inside the wheel, including the caliper.

The caliper actually presses the pad to the rotor. Im assuming that the caliper holder u talked about is the relocation bracket.


And no, u dont have to change the brakes/wheels at the same time

S60R,

Yes, I’m not trying to change the brake assembly just the wheels and tires. I guess Volvo must use a larger tire size on their 17” wheels they offer with a new car or what would be the reason for the larger rotors.
We are talking about 20 mm over all on the rotor diameter. Does it really make a big difference?
I have 205/55/16 tires which gives me a 24.9” tire diameter. Lets say I would put a 205/50/17 tires which would give me 25.1” tire diameter, could I keep my brake setup? How about a 215/55/17 = 26.3” tire diameter? What’s the limit and how do I know which tire would feet? What’s the danger of over sizing the tires with my 300mm rotors? Longer braking distance perhaps but what are we talking here?
Too many questions here sorry…

Greg
:beer:

Well, first of all, who told u u need larger diameter rotors? Going from 16" to 17" or larger wheels, has no bearing on the brakes. The only concern would be going to smaller wheels, which your not.

Plus size the wheel/tire package all u want, your only concern will be, for example if u went to 24" wheels, is fitting in the wheel well.

So if u just want to plus size the wheels/tires, get the larger brakes out of your mind...dont even think of larger brakes because U DONT NEED THEM ( just getting the point across) :) for larger wheels.

Ive done wheel/tire upgrades seperate from brake upgrades on my cars, so I know from experience. One example...I had 17" wheels (stock wheel with winter tires ) and went to aftermarket 18" wheels (with summer tires). Then I got a brake upgrade. With the stock wheels and the brake upgrade, it required a spacer for the wheel to clear the caliper. The spacer was not needed with the aftermarket wheels.

Now, obviously the stock wheels did not have a spacer. Prior to the brake upgrade, neither did the aftermarket wheels.

Go to a reputable tire place, or call wheel manufaturers if your worried about wheel/tire fitment, but --not be redundant--u dont need larger brakes for larger wheels.



On a differant note, keep the overall tire diameter as close as possible to stock. 24.9 to 25.1 is fine. I would not go with 26.3, IMO. Generally, if u plus size one inch, the aspect ratio will be 5% less. U were good with;
205/55/16 to 205/50/17, or even 205/45/18

If a tire place says 215 will fit, then fine, but go with 215/50/17, not 215/55/17.

That's cool, I think I got the message on the brakes :thumbsup:
But if go with larger...just kidding.

My next step will be looking in what width tire/wheels fit on my S40 T5.
I'm not crazy about the idea of adding spacers.

Do they have a stop calibration to get maximum front wheel turning circle without running into anything?

Greg

Im not sure what u mean by stop calibration, but if u got to tirerack.com or tires.com, they have fittment guides. And dont forget Evolve and Heico for wheels for our cars. Im sure those companies have lists of tires that fit with aftermarket wheels.

Good luck :beer:

I just meant a mechanical adjustment to limit the turning circle of the car in order to stop wider tires from running into walls inside the car with all the suspension clearance required...

That's great; I didn't know they had fitment guides on these sites... I'll go there and take a look.
Thanks S60R...

Greg

WARNING: If you install the kit on the steering rack you will need 5 blocks for a U turn instead of 3 blocks.

:lol: :lol: :amen:

That's what I'm taking about!
That's cool guys. Thanks for the tips... :beer:
If I get somewhere I'll let you know.

Greg

When I bought my S70 GLT SE, the SE package had the larger diameter wheels and the lower profile, wider tires. Having had similar tires before, I wanted no part of this "upgrade." The lower profile tires ride harder, wear out sooner (softer rubber to regain lost traction due to wider tires=lower loading per square inch on the road) and cost a lot more to replace than the "stock" high speed, high weight rated Michelins. I had the dealer swap out the high-end wheels and tires for the more "standard" wheels and tires before I would take delivery. I had gotten a great deal on the car and, as far as I was concerned, the dealer could resell the high end wheels and tires to another buyer for a profit to the dealership.

As an aside, another dealer wanted to charge me $500 to swap out the the wheels and tires and do the "downgrade" on my car. I told him I would think about it and never came back. Anyway, the dealer who sold me the car took about 15 minutes to swap the wheels and tires at no charge to me. I assume that in the 15 minutes the job took, they did not swap out any brake components. They did do an adjustment in the computer so speedo would read correctly.

Car has stopped nicely since the day I bought it. It is time to think about new rotors so I guess I'll need to take out the tape measure and measure what is on it before I order replacements.

I mention all of this to say that it doesn't make much difference. I guess the larger diameter rotors might last a bit longer given that they have more swept area and they might stay a bit cooler in a road race (I'm getting too old for that), but, on other hand, the larger rotors would have more unsprung weight giving a less controlled ride.

You bring a lot of good points there. I actually like very much the 16" wheels I have and the Michelin V rated tires are good over all.

One thing that I don't hear too much is that some wheels are easier to clean than other and I like the one I have in that respect as well.

I'm much more used to the car since last August so I handle it better even with 16" push by the T5. This said, I also like the look of the 17 or 18". It's a question of proportion in comparison to the car volume. I also like the idea of more rubber on the road and more cornering stability.

However as you mention it's more expensive overall especially considering the life of the tires as well. The S40 has a stiffer ride than most of its competition so I'm note necessarily sure I want that all year long.
I'll see what I do later and one option I could consider is buying a set of 17" wheel with summer tires and a set of winter tires to use with my current 16".

Thank for the feed back. Cool to see that not every one is chasing the sporting performance. :grin:

Greg

I've enjoyed reading the posts on this topic, interesting comments by experienced & expert Volvoers.

I'm far from being an expert but wholeheartedly agree with you S60R, i.e. increasing wheel diameter should be accompanied by reducing the aspect ratio of the tyre.

I had a choice of 3 wheel sizes on my company car & the bigger the wheel, the lower the aspect ratio of the tyre they fitted. However, all of these choices carried the same disk (rotor) & caliper size.

I believe I understand from my motorbike riding days the principles involved with the larger disks & calipers you now won't be fitting, Gregoire! Imagine lifting a pedal cycle wheel off of the ground & spinning it really fast. Then try to stop the wheel turning by applying pressure to the spokes with your hand, as close to the wheel hub as possible. It's hard work & takes a while to stop the wheel. Spin the wheel again then do the same pressure thing, but this time apply pressure to the spokes a few inches from the wheel rim. Much easier & the wheel stops almost straight away.

Bigger disk with relocated same-size caliper will increase braking power because of the principle above, but a proportionally bigger caliper (bigger, more powerful hand) will make full use of the increased surface area of the disk.

Another Volvoer posted the following site's address re the effect on speedos of increasing wheelsize, unless you also get the speedo/software re-calibrated:

http://www.miata.net/garage/tirecalc.html

Happy & safe Volvoing.

BB :grin:

Thanks Black Beauty 4 (feels funny to spell this out has a name :P ) for your input although I already new all this principals. I'm sure it is still good for others to know as your example is well illustrated.

I think the missing puzzle I had was that Volvo does specify different rotor size on new model that has the 17" wheel. And I don't know if it is because they used larger tires (overall diameter) or because they think (with T5 models) that better tires + suspension = better handling = more power = higher risk!

I'm sure if it is because the tire diameter is larger with new 17" wheels new model it should be easy to check online. Otherwise they may have more complicated performance reasons or they just want to give customers more breaking power with higher end models.

I think one of the most valuable thing I've eared, and not to reiterate too much, is that: let say the larger tire can fit with no problems and your wheeling to get a hit in braking power (which wouldn't be too smart), changing the tire size would probably mess up the speedometer. And I think that is a really neat notion :grin: .

Any-way I'm not too sorry with the tires and wheels I have. Doesn't look to bad and since today it started to snow, I'm eager (not) to see how it behaves for the first winter of my new Volvo :banana:

Thank a lot for participating in this discussion which I think is quite interesting too :thumbsup:

Greg