New front tires are sticking out @1/2 inch. Now what?
03-26-2012, 03:57 PM
#31
Captain Obvious
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03-26-2012, 04:05 PM
#32
Three Wheelin'
Thread Starter
So it seems. They came with the car and the PO bought them from 928 Specialists. Guess that doesn't mean they were the proper ET for a 928. They look great and a few hundred bucks in inner swaps seems to be able to fix the problem. As I just bought expensive new Dunlops, I'm happy that they wont go to waste. Seems they are good regardless of any width change I decide to make.
03-26-2012, 04:17 PM
#33
Chronic Tool Dropper
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The interference looks a lot more severe in your latest pictures than I was seeing in the early pictures. 
"Sandwiched" vs. "Non-Sandwiched" probably refers to the assembly method of the three pieces. In a sandwiched assembly, the center is between the inner and outer bowls.
The vendor suggests that you swap the inner section for something narrower/shallower. I think this will move the tire out further rather than inward. I think you only want the outer section changed for a narrower piece.
In the "stranger thngs have happened at tire shops" category, verify that there are no spacers added on the front wheels.
It might be worth a call to Dave Roberts at 928 Specialists. He worked hard with Kinesis at getting the fitment just right for 928 applications. He may not visit RL as regularly as he sometimes did, and may have some insight to share on your issue.
"Sandwiched" vs. "Non-Sandwiched" probably refers to the assembly method of the three pieces. In a sandwiched assembly, the center is between the inner and outer bowls.
The vendor suggests that you swap the inner section for something narrower/shallower. I think this will move the tire out further rather than inward. I think you only want the outer section changed for a narrower piece.
In the "stranger thngs have happened at tire shops" category, verify that there are no spacers added on the front wheels.
It might be worth a call to Dave Roberts at 928 Specialists. He worked hard with Kinesis at getting the fitment just right for 928 applications. He may not visit RL as regularly as he sometimes did, and may have some insight to share on your issue.
03-26-2012, 04:54 PM
#34
Three Wheelin'
Thread Starter
The interference looks a lot more severe in your latest pictures than I was seeing in the early pictures.
"Sandwiched" vs. "Non-Sandwiched" probably refers to the assembly method of the three pieces. In a sandwiched assembly, the center is between the inner and outer bowls.
The vendor suggests that you swap the inner section for something narrower/shallower. I think this will move the tire out further rather than inward. I think you only want the outer section changed for a narrower piece.
In the "stranger thngs have happened at tire shops" category, verify that there are no spacers added on the front wheels.
It might be worth a call to Dave Roberts at 928 Specialists. He worked hard with Kinesis at getting the fitment just right for 928 applications. He may not visit RL as regularly as he sometimes did, and may have some insight to share on your issue.
"Sandwiched" vs. "Non-Sandwiched" probably refers to the assembly method of the three pieces. In a sandwiched assembly, the center is between the inner and outer bowls.
The vendor suggests that you swap the inner section for something narrower/shallower. I think this will move the tire out further rather than inward. I think you only want the outer section changed for a narrower piece.
In the "stranger thngs have happened at tire shops" category, verify that there are no spacers added on the front wheels.
It might be worth a call to Dave Roberts at 928 Specialists. He worked hard with Kinesis at getting the fitment just right for 928 applications. He may not visit RL as regularly as he sometimes did, and may have some insight to share on your issue.
The tires don't stick out as much as the newest pictures imply. The best gauge was the earlier picture -- as you can see about a half inch sticking out past the fenders. (Re-posted here)
I double checked with the shop and there's no spacers on the fronts.
I agree, I'm baffled as I don't recall any problem with the Kumho's I was running for four years.
I called 928 Specialists and got voice mail and left a msg.
According to the vendor, I have the thinnest outters available. I can't change them. My only option is the inners.
03-26-2012, 05:27 PM
#35
Many of the aftermarket rims sold for 928s were not the proper offset but simply what was available in a semicustom wheel at reasonable prices. They worked for most of the people most of the time but when pushing the envelope trying to fit the widest rims and tires possible sometimes they will hit the fender lips.
03-26-2012, 06:40 PM
#36
Drifting
It's pretty simple. Those are 911 front offsets. Any pre-made 3-pc wheels are going to be 911 offsets up front, which are just plain wrong for the 928 (unfortunately). The only 3-pc wheels in 928 offsets are custom-made wheels from the custom guys (Fikse, old Kinesis, BBS customs, Kodiak, Simmons, etc).
If there are not narrower outer halves available, I wouldn't mess with taking the wheels apart. Sandwiching the centers doesn't sound like a good idea to me, but I guess I could be wrong there. You aren't going to gain much by sandwiching the center anyway; all you will gain is the lack of thickness of one barrel at the mounting flange, which I find hard to believe is 5mm. More like 3mm. That's a negligible difference, and sounds like a big PITA to be right back where you are now--and with a set of bastardized wheels that no one will want with a sandwiched center.
I'd leave it as-is, get narrower front tires, or move on to another set of wheels. I'm refinishing a set of 17" Fikse Mach Vs in 928 offsets, but you'd need spacers in the back, as they were intended for an "S" 928 with the 21mm rear spacers.
If there are not narrower outer halves available, I wouldn't mess with taking the wheels apart. Sandwiching the centers doesn't sound like a good idea to me, but I guess I could be wrong there. You aren't going to gain much by sandwiching the center anyway; all you will gain is the lack of thickness of one barrel at the mounting flange, which I find hard to believe is 5mm. More like 3mm. That's a negligible difference, and sounds like a big PITA to be right back where you are now--and with a set of bastardized wheels that no one will want with a sandwiched center.
I'd leave it as-is, get narrower front tires, or move on to another set of wheels. I'm refinishing a set of 17" Fikse Mach Vs in 928 offsets, but you'd need spacers in the back, as they were intended for an "S" 928 with the 21mm rear spacers.
03-26-2012, 07:02 PM
#37
Nordschleife Master
in order to properly fit these, you need to pull an inch off the outer shell and put it to the inner.
Or try it with just 1" off the outside.
However another inch on the inside will require 2.5" coil springs, and more rack stops.
Or try it with just 1" off the outside.
However another inch on the inside will require 2.5" coil springs, and more rack stops.
03-26-2012, 08:23 PM
#38
Rennlist Member
Taking width off the inner will not do anything to modify where the outer rim sits in regard to the edge of your fender, and as was stated earlier, it might actually allow the outer portion of the tire to be a mm or more FURTHER out. IF David R. had these mfg for a 928, then they should be the proper offsets. I had a set of these Kinesis wheels I bought from Dave about 8 years ago on two different '88's, and they do look nice - they are 3.6 turbo knock offs.
I'd drive them for a while and see if you hear any rubbing - start driving non-agressively with regard to cornering and bumps, then slowly increase speeds, etc.
Gary Knox
I'd drive them for a while and see if you hear any rubbing - start driving non-agressively with regard to cornering and bumps, then slowly increase speeds, etc.
Gary Knox
Last edited by Gary Knox; 03-27-2012 at 09:31 AM.
03-26-2012, 09:28 PM
#39
Chronic Tool Dropper
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Many of the aftermarket rims sold for 928s were not the proper offset but simply what was available in a semicustom wheel at reasonable prices. They worked for most of the people most of the time but when pushing the envelope trying to fit the widest rims and tires possible sometimes they will hit the fender lips.
It's pretty simple. Those are 911 front offsets. Any pre-made 3-pc wheels are going to be 911 offsets up front, which are just plain wrong for the 928 (unfortunately). The only 3-pc wheels in 928 offsets are custom-made wheels from the custom guys (Fikse, old Kinesis, BBS customs, Kodiak, Simmons, etc).
If there are not narrower outer halves available, I wouldn't mess with taking the wheels apart. Sandwiching the centers doesn't sound like a good idea to me, but I guess I could be wrong there. You aren't going to gain much by sandwiching the center anyway; all you will gain is the lack of thickness of one barrel at the mounting flange, which I find hard to believe is 5mm. More like 3mm. That's a negligible difference, and sounds like a big PITA to be right back where you are now--and with a set of bastardized wheels that no one will want with a sandwiched center.
I'd leave it as-is, get narrower front tires, or move on to another set of wheels. I'm refinishing a set of 17" Fikse Mach Vs in 928 offsets, but you'd need spacers in the back, as they were intended for an "S" 928 with the 21mm rear spacers.
If there are not narrower outer halves available, I wouldn't mess with taking the wheels apart. Sandwiching the centers doesn't sound like a good idea to me, but I guess I could be wrong there. You aren't going to gain much by sandwiching the center anyway; all you will gain is the lack of thickness of one barrel at the mounting flange, which I find hard to believe is 5mm. More like 3mm. That's a negligible difference, and sounds like a big PITA to be right back where you are now--and with a set of bastardized wheels that no one will want with a sandwiched center.
I'd leave it as-is, get narrower front tires, or move on to another set of wheels. I'm refinishing a set of 17" Fikse Mach Vs in 928 offsets, but you'd need spacers in the back, as they were intended for an "S" 928 with the 21mm rear spacers.
If it were me, I'd look at tire options, like offering the ones you bought for exchange for the ones you need.
03-26-2012, 09:46 PM
#40
Three Wheelin'
Thread Starter
Like I said, these were sourced by 928 specialists for a 928. They were fine for years with no rubbing. Only thing that changed was new tires. Clearly the Dunlops are wider than the NLA Kumhos Ecsta Supra tires I had previously.
Well today I took a right turn through a down hill grade and heard a rub noise. Checked the fender and no damage, but rubber residue on the fender edge.
I'm perplexed with what to do here. I love my wheels and don't want to replace them. I'm never selling my 928, so I don't care if making the wheels into 8" wide wheels will make them unresellable. But I do care if making them 8" wide won't change my offset or solve my problem.
I'm thinking maybe I should go to my local tire supplier and have them swap around some different size tires up front. Maybe I can get some improvement with ride height and tire swapping?
Sigh, this really sux. I was so happy with my new tires too. They look and feel spectacular. Too bad they dont fit for sh&t.
I'm open to any other suggestions.
Well today I took a right turn through a down hill grade and heard a rub noise. Checked the fender and no damage, but rubber residue on the fender edge.
I'm perplexed with what to do here. I love my wheels and don't want to replace them. I'm never selling my 928, so I don't care if making the wheels into 8" wide wheels will make them unresellable. But I do care if making them 8" wide won't change my offset or solve my problem.
I'm thinking maybe I should go to my local tire supplier and have them swap around some different size tires up front. Maybe I can get some improvement with ride height and tire swapping?
Sigh, this really sux. I was so happy with my new tires too. They look and feel spectacular. Too bad they dont fit for sh&t.
I'm open to any other suggestions.
03-27-2012, 01:48 PM
#41
Drifting
Guys, I'm not trying to rub you the wrong way, but I can look at a wheel and tell you it is a 911 wheel. I have a 911, I have multiple 928s, and I have had about 15 different sets of wheels--many OEM and many aftermarket. Those are 911 front offsets or darn near close. They'd be .5" narrower on the outers if they were for a 928.
Kinesis had more flexibility with their forged centers to tailor-fit the wheels to each application. The mounting of the wheel center in relation to the halves is clearly different on these wheels when compared to the Kinesis bespoke forged wheels. Kinesis also produced certain replica wheels which utilized a cast center and their own custom-spun rim halves (as is the case here, and on the Kinesis Supercup 993 replica wheels). I can elaborate more, if necessary. I've got 4 sets of 3-pc wheels in my shop right now, and each set has a different mounting/sandwich style.
As far as squeezing max rubber under the front, obviously, that is not the case. He is going to have to run a smaller tire on the wheel, in order to make it "fit." If they truly spec'd these for a 928, they were shooting for max wheel width with no regard for max rubber. 911 front wheels "fit" on a 928, with the right tires, but it is a compromise fit. I say "fit" because many have different definitions of what that means. It's not black and white. It's about what works for you and what you are looking to get out of the car, but most wheels that "fit" are not the correct fitment for the car when taking into account track width, scrub radius, tire size, and of course, the fenders.
How about this: take the front wheels off and shoot me some measurements. It's all speculation until we get some numbers. Lay the wheel face-down on something soft, put a straight edge across the tire (parallel to mounting face), then measure the distance from the mounting face to the underside of the straight edge. That will get us in the offset ballpark (have to estimate with only a backspace measurement like this, as the tire and width of the wheel half from tire mounting face to the edge of the wheel cause discrepancies from the actual backspace).
Kinesis had more flexibility with their forged centers to tailor-fit the wheels to each application. The mounting of the wheel center in relation to the halves is clearly different on these wheels when compared to the Kinesis bespoke forged wheels. Kinesis also produced certain replica wheels which utilized a cast center and their own custom-spun rim halves (as is the case here, and on the Kinesis Supercup 993 replica wheels). I can elaborate more, if necessary. I've got 4 sets of 3-pc wheels in my shop right now, and each set has a different mounting/sandwich style.
As far as squeezing max rubber under the front, obviously, that is not the case. He is going to have to run a smaller tire on the wheel, in order to make it "fit." If they truly spec'd these for a 928, they were shooting for max wheel width with no regard for max rubber. 911 front wheels "fit" on a 928, with the right tires, but it is a compromise fit. I say "fit" because many have different definitions of what that means. It's not black and white. It's about what works for you and what you are looking to get out of the car, but most wheels that "fit" are not the correct fitment for the car when taking into account track width, scrub radius, tire size, and of course, the fenders.
How about this: take the front wheels off and shoot me some measurements. It's all speculation until we get some numbers. Lay the wheel face-down on something soft, put a straight edge across the tire (parallel to mounting face), then measure the distance from the mounting face to the underside of the straight edge. That will get us in the offset ballpark (have to estimate with only a backspace measurement like this, as the tire and width of the wheel half from tire mounting face to the edge of the wheel cause discrepancies from the actual backspace).
Last edited by Benton; 03-27-2012 at 02:09 PM.
03-27-2012, 01:59 PM
#42
Three Wheelin'
Thread Starter
Hi Mark, I only know the wheels came from 928 Specialists and were bought by the PO. I also know that my previous tires were the same size as my new tires and those fit and the new ones don't.
I'm running S4 brakes on my 79. Does offset and fender clearence differ between OB's and S4's? Meaning were these wheels a better fit on S4, GT, GTS?
This "problem" is news to me as I never expected the same size tires to be a problem. I'm running 245/40/17 up front. Dunlop offers 235/40/17. Do you think those will "fit". Do you know of any sure solution to my situation?
I do really like how the car looks and feels. I don't want damage/rubbing. I know my suspension is as low as possible and I'm willing to raise it up and swap front tires. I'd be kind of annoyed to have to totally swap all four tires, but this needs to be solved now that tire has made contact with fender last night.
Guys, Any and all help is much appreciated. I'm on a trip to LA right now so can't do much but "fret" over this. It's getting warm in NJ and I want my baby ready to roll! HEEEELLLLLP.
I'm running S4 brakes on my 79. Does offset and fender clearence differ between OB's and S4's? Meaning were these wheels a better fit on S4, GT, GTS?
This "problem" is news to me as I never expected the same size tires to be a problem. I'm running 245/40/17 up front. Dunlop offers 235/40/17. Do you think those will "fit". Do you know of any sure solution to my situation?
I do really like how the car looks and feels. I don't want damage/rubbing. I know my suspension is as low as possible and I'm willing to raise it up and swap front tires. I'd be kind of annoyed to have to totally swap all four tires, but this needs to be solved now that tire has made contact with fender last night.
Guys, Any and all help is much appreciated. I'm on a trip to LA right now so can't do much but "fret" over this. It's getting warm in NJ and I want my baby ready to roll! HEEEELLLLLP.
03-27-2012, 05:04 PM
#43
Burning Brakes
235s will probably remedy your problem, but as Mark stated, you need to MEASURE your offsets.
Rather than laying a straight edge across the tire, I'd suggest cutting something so that it will rest on the rim rather than the tire to measure the backspacing.
Without knowing the offsets all anyone can do is guess.
James
Rather than laying a straight edge across the tire, I'd suggest cutting something so that it will rest on the rim rather than the tire to measure the backspacing.
Without knowing the offsets all anyone can do is guess.
James
03-27-2012, 07:11 PM
#44
Chronic Tool Dropper
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235 will be 10mm narrower, moving the edge of the tread about 3/16". Will that be enough?
03-27-2012, 07:46 PM
#45
Nordschleife Master
Have you tried measuring the offset on the front wheels?
Remove a wheel - measure the rim outer to outer, then measure the distance from the inner of the rim to the hub, and calculate the offset (i.e. use a straight edge across the rim and measure distance from the hub mounting surface to the straight edge)
You should be able to do it with a piece of timber or similar cut to fit just inside the bead on the tire so you're measuring the actual rim, without taking a tire off a rim.
Remove a wheel - measure the rim outer to outer, then measure the distance from the inner of the rim to the hub, and calculate the offset (i.e. use a straight edge across the rim and measure distance from the hub mounting surface to the straight edge)
You should be able to do it with a piece of timber or similar cut to fit just inside the bead on the tire so you're measuring the actual rim, without taking a tire off a rim.