Looking into getting a set of weld magnum imports for my hatch but I'm not too sure wich backspacing to go with 4'' or 5''. I searched but no solid answer. I have a 93 hatch but integra hubs/brakes. Which one will work or work best for my car and if anyone has a link of how to learn more about backspacing that would be great so I can read up and learn. Oh and I am getting the 13''x8''

 

Now that vendors can openly speak about stuff like this, I'll do a write up on how to choose backspacing on drag wheels soon.

As far as your setup, on a 13x8 either backspacing will work. It all depends on how far you want the wheel/tire to stick out. On an 8" wide wheel, it doesn't really stick out that much so 4 and 5" looks about normal for our cars. But like I was saying its more of preference if you want the tire inside the fender more or if you dont mind it sticking out a bit more.

Also FYI:
13" drag wheels have a maximum of 5" backspacing for our Hondas.
15" drag wheels have a maximum of 6" backspacing for our Hondas.
The difference in backspacing is due to the curve of the knuckle. The knuckle is closer to the hub at the lower part so that limits the clearance for the wheel with the 13" wheel. It curves farther out at the higher part so thats why the 15" has a little more clearance.

You can actually go a little more but since most drag wheels go by 1" increments, you wont clear another full inch backspacing on either a 13" or 15" wheel.

Once you start going with a beadlock setup, the calculations change a bit more since the beadlock ring adds to the edge of the rim and changes the clearance. More on that later or if you need answers on that, just email me at sales@exospeed.com

I hope that answers your questions. Enjoy your Weld Wheels.

 

fwiw i just got my 3 peice star 8s 13x9 5'' b/s they fit awsome,so i would say 4'' b/s on the 8'' wheel imo.

 

That info helps a lot I searched around and found different opinions. Still the 5'' b/s will get the wheel further away from the spindle so it doesn't rub on a 13x8 correct? I had to use a small spacer on my lensos which was fine but since I'm buying a whole new set of wheels just trying to get away without having to use spacers if I can.

 

i have dx brakes on my drag car, i have 13x9 with 5" back spacing and dont require spacers. Looks great, no pokage.

 

Now that you bring up spacers. Spacers change the whole "backspace" measurement as well. Some wheels will require spacers since they do not clear certain caliper sizes. You have to look at the Center face design and how the spokes curve out to clear the calipers. Some wheel designs are either flat on the back so that they Always require spacers and some don't curve out enough to clear the caliper.

So there's 2 things to consider if you are concerned with spacers.

1. Center design has enough curve on the spoke to clear the calipers.
2. Choosing the proper backspacing to have tire clearance on the spindle.

The other reason of using a spacer to bring out the wheel further out is due to tire rubbing on the spindle. That can either be caused by a tire that just "bubbles" out alot past the edge of the wheel. Such as 9" wide on 8" wide rims or like a 9"wide tire on a 7" wide rim. The tire will interfere with the spindle if you have a backspace that puts the wheel closed to the inside more.
So to prevent this, you can either choose the backspace that will bring the wheel away from the spindle more or you can choose the spacer route.
The clearance on the tire/spindle also depends on the Rim width and the tire width combination. If lets say you have a 9" wide rim on a 9" wide tire, you wont get that "bubble" as you would if that same tire was on a 7.5" wide rim.

I cannot speak for other wheels but on our Forged STAR8 wheels, we designed the centers to specifically clear the Honda calipers without using spacers. As far as tire clearance, that is all dependent on the tire being used and the rim width combination.

I hope that helped understand a bit. I can go on forever with other stuff regarding this.

 

OK let me clear this up since some are confusing the idea of backspacing. You have the idea opposite actually.

Backspace is the distance from the center of the wheel where it mounts up to the rotor to the backside edge lip of the wheel.

(5" vs 4" backspace) on an 8" wide wheel
The more backspace you have, the more the wheel sits inside the fender. The less backspace you have, the more it sticks outside the fender.
So in comparison, if you are wanting the wheel away from the spindle. You get the less backspace(4").

Did you have to use a spacer on the lenso to clear the caliper? or to clear the tire on the spindle. Also when you pick the wheel you are going to get. Not all drag wheels are spacer free. You have to get the one with the Center/spoke design that will curve enough to clear the caliper. Some have a totally flat backpad(the part of the wheel center that mounts against the rotor) so you will still need a spacer to clear the caliper. Just keep that in mind.

Also how far it sticks out the fender is all dependent on the width of the wheel also. I have some diagrams I was working on to explain this further.

 

I drew up some quick drawings to help explain it a little better. (excuse the crappy drawings)


On this diagram, the GREEN line is the spindle, Red is the rotor/hub where the wheel mounts against, and teal line is where the fender line is to show how much it can stick out the fender.

The sample diagram is a 13x8 wheel.

Notice that on a 4" backspace, there is quite a bit of clearance on the wheel to the spindle.
As you get more backspace with the 5" bs, the wheel gets closer to the spindle but the lip is less and it actually sticks inside the fender more.

The effects of different backspacing changes:

1. The clearance between the spindle.
2. How much it will stick out the fender.
3. How much lip the wheel will have.

 

Here is another effect of backspacing and width of the rim.

Explanation is underneath the drawings.



I always get the question of how can backspacing affect the clearance on different wheel widths.

The backspacing is not affected by changes on the rim width.
As shown on the diagram, if you have different wheel widths but have the same backspace, it will always be the same clearance on the backside. The only thing will change with different wheel widths are how much it will end up sticking outside the fender.

 

get 5 inch backspace............ and a 1/4 inch spacer or take your front brakes off

 

good info

 

this stuff has always confused me, but those drawings help a tonnnn

 

wow, thanks for that diagram. i was always under the impression that, like offset, the backspace would change inner clearance for different wheel widths. now i see that while the two measurements are related, they are not interchangeable terms.

 

Yes correct. Backspace will always stay the same. Offset is dependent on the rim width and can change how it looks and fits on the car based on the width.

 

Hmm I have a 6" back spacing on my 13" wheels, No spacer and no rubbing.

 

Thanks for dumbing it down Wil. It's always easier to see it on paper rather than try to measure it with a jack stand and a bare wheel. lol

 

What about a 3.5" backspace wheel for an RSX-S. Most 15" wheels do not clear the calipers. I'm currently running the only aftermarket wheel I know of that clears the calipers with a 15" rim without spacers and shaving the ish out of the calipers but I'm looking for more of a drag rim.

 

Really. Is there any way you would post up closeup pictures of caliper and how close to the spindle it is? How wide are the rims and are you running a 9'' wide tire?

 

Another FYI: The caliper wouldnt be the issue on backspacing. Backspace has nothing to do with caliper clearance. That is more on the center face design.

Back to what nonvtecaallmotor was saying. A 6" does clear on a 13" rim but the edge of the rim is like 1/8" from the spindle. If you're running a tire that is just as wide or even less than the rim width, you can get away with this. I guess you can call it the stretched tire look. Like 10" wide rim on 9" wide tire. The reason it can work in this setup is that the tire protrudes less out of the rim compared to what we've been using for years such as a 8" rim on 9" wide tire(and with MTs they are more than 9" from what we've measured). Its only recently that we've been using 9-10" wide rims with these wide tires so you can play around with backspace some more.

I would only recommend getting that close of a backspace if the person know what they are expecting and know what they are doing. To play it safe, I would give yourself the clearance on the spindle for tire clearance if you are planning to run a wide tire on an 8" wide rim. For the average setup, 5" would work really well. For the hardcore guys that know whats up, 6" can be an option.

Back to backspace choices:
Certain backspacing can only be achieved depending on the rim width. Like with a 8" wide rim, on our forged wheels, we're limited to 3, 4, 5" backspace due to how the rim halves are put together. You can't do a 6" backspace on an 8" rim. I'm sure its like this as well with other 3 piece drag wheels.

 

We made our 5x114 wheel centers to clear RSX calipers. On our wheel, we only set it up to go with 1" increments on backspacing. I know most other drag wheels are in 1" increments as well. ON wheels that only go by 1" increments, the only way that you can achieve 1/2" increments if you use spacers to achieve that 3.5" backspace.

Lets say you have a 15x8 and you want to get that fitment that a 4" sits too much inside and a 3" bs sticks out a little more than you want. I would just get a 4" backspace and use a 1/2" spacer to bring it out that 1/2" to make it have the 3.5" backspace look.
I know some aren't into using spacers, but thats the only way to get that 3.5" in a situation like this.

 

So with 15's what are most people using with these wide front ends? 4 or 5" BS?

 

Was there ever an answer to this? ^^^^

 

If your concerned about tucking in the tire as much as possible under the fenders, you want the most backspace as possible. Of course there will be limitations with spindle clearance so its usually 6" at mkst on a 15" wheel. I havent encountered every suspension setup but there maybe some that let u vlear a bit more. But as a general rule, 6" is the most.

Other factor is tire width, rim width, and fender width. I cant speak for all front end kits but on ours each application has its own clearance. For examplethe integra has the most clearance under the fender and the crx kits has the least.


In my opnion contact the front end manufacturer that has experience with wheel manufacturing as well to get the most thorough advice. :p

 

Well I'm leaning toward getting your front for a 2k civic. Im going to run a 15" rim with a 10" tire. Maybe a 15x8 or a 15x9.

 

With a 8 or 9" wide rim, its easier to have it flush inside the fenders with the proper backspace.. Once you get into the 10" wide, thats when the tires start sticking out past the fenders(depends on the kit). We're actually doing a revised fender sometime in May to work with our existing bumper.

Here's Cortney Greens Civic. I dont really know what his rim width is, but from what I recall he may have said it was a 9"wide rim. Don't quote me on that, I'm not 100% sure.