Guest Anonymous Posted January 11, 2002 Share Posted January 11, 2002 This is one of those times where I think I know a good deal about cars and I have to ask a basic, no-brainer.... I'm looking at various project cars trying to make my decision on a donor for a rebody project. I would like fairly flush faced wheels. Seems the common way to do this is with "wheel spacers" or "wheel adapters". However, the concern I have is that I have heard nothing but negative opinion about using these from a performance standpoint. So, I am wondering just how bad are they? What do they affect adversely? How are they dangerous (I've heard people say they can be unsafe). Thanks, Andrew Quote Link to comment Share on other sites More sharing options...
CruxGNZ Posted January 11, 2002 Share Posted January 11, 2002 Here, check out this thread. Just trying to help. http://www.hybridz.org//ubb/ultimatebb.php?ubb=get_topic&f=6&t=000946 !M! Quote Link to comment Share on other sites More sharing options...
johnc Posted January 11, 2002 Share Posted January 11, 2002 As with any product sold in the automotive aftermarket, there are good ones, bad ones, and dangerous ones. Generally, a well made wheel spacer is safe and effective. When you start combining a wheel spacer with an adapter (4 lug to 5 lug) or purchase an "all in one" piece then the quality of design and manufacturing becomes critical, so expect to pay a lot more for a safe and effective product. I suggest that you avoid any wheel spacer/adapter that is designed to work on more than one vehicle. Universal fit pieces univerally fit every vehicle poorly. Quote Link to comment Share on other sites More sharing options...
Tim240z Posted January 11, 2002 Share Posted January 11, 2002 I have always been told that spacing the wheel outwards, either by extreme offsets or large spacers, puts a lot more stress on the wheel bearings, severely shortening their life and function. This would logically make sense, since the leverage effect of putting the wheel further out would effect bearing loads. I guess by using a wheel with a flush face and large 'inside' offset, this should not be an issue. I am open to being corrected!! Tim Quote Link to comment Share on other sites More sharing options...
blueovalz Posted January 11, 2002 Share Posted January 11, 2002 from the bearings point of view, yes, the highly offset wheels toward the hub would negate the stresses on the bearings. However, large spacers using long studs has a separate issue of the stresses upon the studs themselves. Very well designed spacers with tight fits around the studs and or hub will help relieve this somewhat. I would say the worst kind of spacer is one that uses long studs thru holes in the spacer, and depends on the wheel to hold them all tight, and the best design is one that uses two sets of studs (one to attach spacer to hub, and another set to attach wheel to spacer). Another issue that should be taken into consideration with wheel offset, it the amount of static camber. A wheel with excessive negative offset (spaced outward) can "feel" as though it has less offset by the use of camber to bring the contact patch of the tire back inboard toward the zero offset point. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted January 11, 2002 Share Posted January 11, 2002 If it's any help, I was wanting to run something like a 8" or 9" wide rim, so I'm not trying to go as extreme as some of the 12" and 14" rims I've seen Fieros running when trying to make up the width of a 512TR or Lamborghini in wide-rims alone... Quote Link to comment Share on other sites More sharing options...
pparaska Posted January 12, 2002 Share Posted January 12, 2002 The issue of spacers, large offset wheels, and increased loads on wheel bearings is a bit tricky. You have to consider only one thing here: If you keep the center (across the tire) of the tire in the same place in relation to the hub flange, everything is fine as you've not offset the center of the tire tread from it's original location. If this relationship is kept as stock, the bearings will be loaded as stock, and all is fine with them. In this case, all you are doing is in effect adding a spacer to the wheel mounting surface of the wheel to move it towards the center of the car so as to keep the center of the tire in the correct side-to-side location with respect to the wheel mounting surface on the hub. That's the wheel bearing issue anyway. Wheel studs: The only issue I can see is that whatever studs you have on the car do not get overloaded. Adding very long studs and using a thick slip on wheel spacer is asking for trouble. If it's only a 1/2" thickslip on adapter, I'd not worry too much. Much more than that and I think that you need to move to a bolt on adapter that is heald to the hub with the stock studs and nuts and has another set of studs protruding from it to mount the wheels onto. For this type of arrangement (bolt on adapter), the length of the studs and more importantly the length that the bending loads on the studs act at away from the surface they protrude from on the hub or the adapter is near stock and they should be fine, if good quality hardware is used. Of course, a good strong material and good structural design of the adapter is important as well. Pete Paraska Master of Science, Mechanical Engineering, (Solid Mechanics concentration) (in case you were wondering if I had any qualifications to be making the above claims) Quote Link to comment Share on other sites More sharing options...
Modern Motorsports Ltd Posted January 13, 2002 Share Posted January 13, 2002 "Adding very long studs and using a thick slip on wheel spacer is asking for trouble" Haven't had time to wade in here yet but here's a start..... -I think most important points are all made above, high quality machining/material and purposebuilt for your car/setup. -Pete, why is a slip on setup over long(standard 2.5" ARPs) studs undesirable? My front set are out of aircraft grade aluminum (which is really a total non-issue/all compression, petrified would might work ), hubcentric and with a lip to match my wheels (very snug fit/matched by machinist) and studs pass thru snug fit again holes. As long as it all stays tight (as with most fasteners) then what is the issue? Center hub/adaptor is locked in by friction/compression so can't spin or change position so no bending is induced on studs that are torqued up in compression correct? To suit all preferences/desires I have either custom built for each order and use 6061 aluminum and use metric 10.9 or sae grade 8 studs of the customers spec. FWIW I use 1.25" slipons up front (over 1/2 studs) and 1.5" bolt ons out back (new OEM studs). I personally rec'd 1/2" studs with thicker slipons just to err on the safe side. Most bad rep's on spacers have IMO come from some of the very cheap crap out their, some made of inferior alloys and been sold by transdapt as well as others. Personally I prefer slipons as it's 1/2 as many fasteners and it's easy to check and make sure they're all torqued since there's no inner set, but I've never had a lug nut come loose either so perhaps the anal engineer in me. Quote Link to comment Share on other sites More sharing options...
blueovalz Posted January 13, 2002 Share Posted January 13, 2002 Ross, I quess the key to successful pass-thru spacers is a very snug and well machined bolt pattern. Any amount of play could result in high tension loads on the studs if any of the components slip even a small amount. Kept tight, I can't see any problems. Can't help thinking what an inadvertent bump to a curb or pot-hole could do to a less-than-ideal torquing of the nuts though. Quote Link to comment Share on other sites More sharing options...
pparaska Posted January 13, 2002 Share Posted January 13, 2002 Ross, Terry, It's not the tension loads that worry me. It's the bending loads. Slip on spacers, no matter how nice, can spin on the hub, unless they are put on so tight as to stretch the lug bolt. Friction to keep things put is not good high load design, IMO. The US Navy practices taught me that. I agree that adding the concentric lip at the outboard end is good, as is having a nice fit around the hub pilot diameter, as this will limit slippage. On the front, this is probably o.k. On the rear, I'd not try it. If you have the room (thick spacer), I'd prefer seeing a bolt on set up. This way the bending loads are lower since the lugs are relatively short. Having a 4 inch lug for a 2.5" spacer (just pulling numbers out of the air) is just un-nerving to me. If the spacer slips (counting on friction here seems risky to me) by spinning (at the drive wheels) then the lugs bend over a long moment arm (from the nut to the hub) and lug failure can result. On the front (non-drive wheels) this lug bending can't occur with good concentric slip-ons. Quote Link to comment Share on other sites More sharing options...
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