Wheel Spacers vs. Backspacing
- Thread starter Fergie
- Start date
Fergie
Expedition Leader
ntsqd said:
The users.
There are numerous arguements for both sides; I'd hoped to keep that kind of diatribe out of the thread.
It would be great if we could re-focus on the actual mechanics of the two methods, as well as the empirical data; that would suite us all better than arguing about age and experience.
michaelgroves
Explorer
ntsqd said:
The decision might be made for one person, but the discussion could still be interesting!
For example, why would aluminium be a bad material for the spacers? I.e. why would a well-made aluminium spacer be any more of a problem than a well-made aluminium wheel?
So far, it seems that apart from a dislike of spacers, the only technical disadvantage of a well-designed and manufactured spacer (compared to a wheel equivalently backspaced) is if the nuts aren't tightened properly!
If there are other issues, it would be interesting to get some facts about them.
i have been running quality 1 1/2" aircraft grade aluminum wheel spacers on my dodge ram for over 6 months, driving 120mi 5 days a week for work and have had zero problems with them. however i would stay away from ones that just slide on over the studs, since they reduce the amount of thread available on the stud.
this is an argument that will always go on just like ifs vs. sfa. however one thing to think about......if wheel spacers are so dangerous then why are they legal to run, and dot approved?
this is an argument that will always go on just like ifs vs. sfa. however one thing to think about......if wheel spacers are so dangerous then why are they legal to run, and dot approved?
In some states it is NOT LEGAL to run them. I think for what they cost $200 plus you can find a set of wheels with the right backspacing and not have to worry about 40 nuts instead of 20 that are easy to see and check. I ran them for a short time ( spidertrax) they did OK but just did not think it was worth it
michaelgroves
Explorer
tommudd said:
Which states, for example?
Fergie
Expedition Leader
2drx4 said:
I'm guessing that in aircraft manufacturing, certain grades of material are required, with these grades being established by outside firms such as the ASTM.
Without the buyer being able to run their own independent tests on the material of the spacers, they have to rely on the maker's honesty in advertising that the material is "aircraft" grade.
"Aircraft Grade" might be considered a misnomer.
ntsqd
Heretic Car Camper
Aluminum has a limited fatigue life, mild steel does not. The basic design of most spacers with offset holes and studs is a stress riser nightmare. Attached is a partial cross section of the common design of a spacer. Note that stress does NOT like sharp corners. Best visualization is that stress wants to flow like water. No sharp corners in the conductor and volumes outside of the flow path do little to aid the flow. Even using a bull or ball nosed end mill won't cure the basic problem with the design, and if there's a better design that does the same job I've yet to see it.
U.S. DOT doesn't approve anything. They publish standards and require that mfg's independently certify that their product meets and continues to meet the applicable requirements. If there is an accident whose cause points to a faulty product, the mfg had better have the documentation showing that they have done everything humanly possible to guarantee that their products consistently meet the requirements. It takes no imagination to see what would happen if they can't.
I've never seen "Aircraft Grade" used anywhere but in marketing. If it is a critical component there is a paperwork trail that leads all the way back to that particular batch of whatever alloy it is. Every entity to perform any processing on the metal has documentation on that particular piece of material. This is partly why a Gov't hammer costs $375.
U.S. DOT doesn't approve anything. They publish standards and require that mfg's independently certify that their product meets and continues to meet the applicable requirements. If there is an accident whose cause points to a faulty product, the mfg had better have the documentation showing that they have done everything humanly possible to guarantee that their products consistently meet the requirements. It takes no imagination to see what would happen if they can't.
I've never seen "Aircraft Grade" used anywhere but in marketing. If it is a critical component there is a paperwork trail that leads all the way back to that particular batch of whatever alloy it is. Every entity to perform any processing on the metal has documentation on that particular piece of material. This is partly why a Gov't hammer costs $375.
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w_b
Observer
I contend that IFS is better for some things and a solid front axle is better for others...inked33 said:
Don't buy into the "DOT Approved" stamp. I've seen it on aftermarket clear lens assemblies on the rear of vehicles for brake and turn signal lights (years before manufacturers began making vehicles with clear lenses). The lens was completely clear and made no provision to make the light a legal color (red, yellow or amber).
For what it's worth, Pennsylvania State Law 175.80, spacers over 1/4" are illegal. Oh, and they appear to be illegal in Australia.
I've been taking accident reports for 20 years here in Nevada. The current state accident form has the federally mandated reporting fields (you may know the story -- report the data or lose federal highway funds). There is no field on these reports to notate alterations to vehicles (lifts, etc.). If there's a notation to be made, it must be made by the investigating officer in the narrative portion of the report.
I'm not an accident re-constructionist, nor do I want to be however, as an investigator, I've never been to court nor have I been deposed regarding an accident involving a modified vehicle. I have made a notation in several reports regarding lifted/lowered/modified vehicles and noted how the modifications caused or contributed to the crash. In my experience, the insurance companies' lawyers argue about their clients conformity to state and local laws that were in effect at the time of the accident (right of way, speed, lights at night, etc.). In other words, the fellow that lost the rear dual into his fifth wheel may have been able to successfully sue his insurance company -- unless what he was doing was illegal.