Question about 20" rims... ???

[Hazieview]

I have a question about putting 20" rims on our chevy trucks. If you put 20" rims on lets say a stock '87 chevy pickup wouldn't you have to upgrade your brakes or no? I know it all depends on weight but I am sure that a of 20" rim would weigh a considerable amount more than a 15" steel wheel which the brakes where designed for right?

Just wondering because if I decided to spend a couple grand on 20's I hate to find out I have to spend another grand on brakes. Any help would be appreciated. Thanks!

[bigblock73]

I bet a 20" alum wheel will weight less than a 15" steel...the 20" tire might weigh more than the 15"...but when all said and done...I bet it is a wash.

I don't think any guys on here with 20's or larger upgraded their brakes...if they did, it was more than likely for looks/appearance thru the wheels and not for function.

[CLASSIC87']

I haven't had any problems running with the original brake equipment.

Anthony

[C-10volvo]

I was a bit concerned with my brakes as well when i was upgrading to 20's. What Jeff said is just about right. A one piece forged wheel is just about the same as a 15 inch steelies. There are a lot of variables in wheel design and whatnot, but for any simple 5 or 6 spoke wheel its just about nuts on. The same goes for the tires too. But what may throw it all off is where all that weight is distributed on the wheel.

On a 20'' wheel, you must take into account all the rotational mass that is put further away from the hub. Even if the tire itself is the same weight, its on the last 15 or 20% of the total wheel hight. If anyone can explain it better, go ahead, its early.

The first thing i tested after getting 20's was the brakes. I am running 255 in front with 285 in back and it will still lock them up with ease.

[kevinr1970]

I think a relevant part of this question is what is the outer diameter of the 20" tire going to be compared to the outer diameter of the 15" tires you are running now?
If its the same +/- a little then wouldn't the "mass" of the tire be less for the 20" tire as it has less sidewall? I suppose tire width would have to be considered too.

When I took the stock 17" steel rims off my '06 GMC and replaced them with 17" Denali aluminum rims I swear the denali rims with tires mounted were lighter than just the 17" steel rim.

[Hazieview]

So do we all agree that it is about the same for both rims and that it probably wont affect your breaks at all?


Thanks guys!