Wheel spacers vs. wheel bearings

[Starless]

After much searching and lots of reading I was all set to buy some 21mm wheel spacers for the rear of my SC. Then I came across a post by a senior member who stated that wheel spacers will wear out your wheel bearings. Any input on this? How fast will the bearings wear out? I don't track my car. Maybe @ 3000 miles a year. What should I do? I'm now having doubts as to if I should put them on my car or not. It was also stated that they have no effect on cornering, they just make the car look better.
I'm all ears.........

[Scooter]

I have never seen excess wear on wheel bearings from using spacers. I've read the same information as you, but it did not deter me from running spacers, nor hundreds of others.

BTW: Turbos had huge spacers from the factory.

[dos531]

As scooter said, the Turbo models came with 1" spacers from the factory with no issues whatsoever. Mine has 2" adapters on it and still no issues.

[safe]

Originally Posted by Starless

After much searching and lots of reading I was all set to buy some 21mm wheel spacers for the rear of my SC. Then I came across a post by a senior member who stated that wheel spacers will wear out your wheel bearings. Any input on this? How fast will the bearings wear out? I don't track my car. Maybe @ 3000 miles a year. What should I do? I'm now having doubts as to if I should put them on my car or not. It was also stated that they have no effect on cornering, they just make the car look better.
I'm all ears.........

Its not complete bull, but not far from it. Some increased wear is bound to be introduced and it will make the car look cooler. It does increase the track so it will also corner slightly better.

The turbos had bigger bearings, but there is a lot of wide body cars out there thats doing just fine, not to mension cars with spacers.

Somewhere up around the 150.000+ miles marker you might have to change them anyway.
Don't worry about it.

[wayner]

Mine failed but I'll bet they were original 40 year old bearings.

I'm not worried.

[NoYouRelax]

I think the bearings might fail from beating on the studs (hammer removal method) to install longer ones for spacers. I installed 21 MM spacers recently and folks on here said press out the old studs with a c-clamp.... not so easy to do.

[wildturkey]

I have heard old mechanics say larger offset wheels will wear out your wheel bearings. I say it's a myth. I am a qualified mechanic with a diploma in mechanical engineering and have modified dozens of cars over decades and I am yet to see proof of this.

Yes in theory but so miniscule it's not an issue.

Using the mythical suggestions could it be true that harder braking, larger loads or rough roads higher tyre pressures do the same damage? It's like the old school techniques of running in engines are largely irrelevant these days. As material science and manufacturing processes advance we need to adjust our understandings of service life but we don't.

The greatest factor that never gets mentioned in relation to greater wheel offset is slip angle. The further you send the centerline of you rim away from the ball joint on the front end, the greater the slip angle, tyre wear and understeer.Those RWB cars must really push a rubber plough through corners.

Do what you want with spacers. If you maintain your car well. Wheel bearings are cheap.

[safe]

Originally Posted by NoYouRelax

I think the bearings might fail from beating on the studs (hammer removal method) to install longer ones for spacers. I installed 21 MM spacers recently and folks on here said press out the old studs with a c-clamp.... not so easy to do.

With 21mm spacers I would choose bolted spacers and keep the orignal studs in place.

[Starless]

Originally Posted by safe

With 21mm spacers I would choose bolted spacers and keep the orignal studs in place.

Thanks for all the replies, spacers it is. And yes, I was planning on getting the bolted ones to avoid banging out the old studs and keeping it simple. One last question, would 23mm or 28mm look odd on a stock SC? I've seen pics of cars with 23's and kind of like the look, just don't want to over do it.

[safe]

Originally Posted by Starless

Thanks for all the replies, spacers it is. And yes, I was planning on getting the bolted ones to avoid banging out the old studs and keeping it simple. One last question, would 23mm or 28mm look odd on a stock SC? I've seen pics of cars with 23's and kind of like the look, just don't want to over do it.

Not sure how much spacer you can add. It depends on rim size, tire size, ride height, camber and driving style (for example tracking or getting an ice cream on Sundays).

I like to borrow spacers from friends to try them out, then buy custom spacers to my exact dimensions, but that might not be possible for you.
You can always buy 21 mm spacers and then add a 7 mm (maximum without changing studs) spacer behind it.

[Bill Verburg]

Originally Posted by Starless

Thanks for all the replies, spacers it is. And yes, I was planning on getting the bolted ones to avoid banging out the old studs and keeping it simple. One last question, would 23mm or 28mm look odd on a stock SC? I've seen pics of cars with 23's and kind of like the look, just don't want to over do it.

The question makes no sense w/o knowing what wheel width and o/s you are using

spacers per se aren't an issue,

changing the net ET from stock is, the smaller the net change the less of an issue
oe on an SC was
7ET23.3 or 8ET10.6

9ET15 splits the difference and also works fine

930 used a higher o/s(ET) and a bigger bearing and wider fenders to accommodate that set up

[DRACO A5OG]

I am one of those that experienced the phantom myth.I quantify this by the fact I only placed the spacer on my passenger side to even out the hand made fenders from the factory. Driver side had not failed. I agree, if allot of miles on the bearings introducing spacers will accelerate the wear but only time will tell. But in your case 3000 miles per year, I would not worry about it, mine is a daily.

Just do it and see how it goes. Replacing bearings with proper tools is a snap. +1 do not pound the bearings in, instead press them in.

As far as wider spacers you may need to adjust your camber to insure it does not rub on the lips or worse inside the wheel well.

[Starless]

Originally Posted by Bill Verburg

The question makes no sense w/o knowing what wheel width and o/s you are using

spacers per se aren't an issue,

changing the net ET from stock is, the smaller the net change the less of an issue
oe on an SC was
7ET23.3 or 8ET10.6

9ET15 splits the difference and also works fine

930 used a higher o/s(ET) and a bigger bearing and wider fenders to accommodate that set up

Agreed, my bad.

I have a stock 1980 SC Targa still set at US ride hight. 16 X 7 rear with 225-50's. I think I'll just go with 23mm. What could go wrong?

[WideRide 86]

Draco. It seems unlikely that adding a spacer to one side could cause your bearing to fail noticeably quicker. How big was the spacer? Wouldn't be more likely that the right side wore out more quickly because it's the favored drive wheel (for non LSD cars)?

These threads often refer to the monument induced forces on the bearings due to the increased offset, but these forces are not that large relative to the cornering forces and their induced moments. The cornering forces induce moments to the bearing that are actually in the opposite direction to the vertical load moments.

The point being that the bearings are designed for much greater forces than those created by the additional offset using spacers (or wider wheels).

I am one of those that experienced the phantom myth.I quantify this by the fact I only placed the spacer on my passenger side to even out the hand made fenders from the factory. Driver side had not failed. I agree, if allot of miles on the bearings introducing spacers will accelerate the wear but only time will tell. But in your case 3000 miles per year, I would not worry about it, mine is a daily.



Just do it and see how it goes. Replacing bearings with proper tools is a snap. +1 do not pound the bearings in, instead press them in.



As far as wider spacers you may need to adjust your camber to insure it does not rub on the lips or worse inside the wheel well.

[victatwin]

Here is my 100mm or 4 inch spacer in US terminology, they have been on for over 7 years, no track work ,but some very spirited road work in the windy stuff, to the point of snapping off the through the body sway bar mounting on the A arm , yes rewelded on, but shows some pretty full on pressure on all 4 wheels, no expert but I have had the car checked out (rear wheel bearings) by one of the best Porsche mech. in Australia ,Ian Hamilton,(SEMI RETIRED) who lives just 25 mins away from me, ALL GOOD, just the slightest of movement in one rear bearing to which a long bar was used to tighten it up . perfect, this was the set up of the previous owner , and like yourself, I worried about the extra pressure on the wheel bearings, DON`T worry . 1 inch will do nothing in your life time to bring about a failure.

[DRACO A5OG]

Originally Posted by WideRide 86

Draco. It seems unlikely that adding a spacer to one side could cause your bearing to fail noticeably quicker. How big was the spacer? Wouldn't be more likely that the right side wore out more quickly because it's the favored drive wheel (for non LSD cars)?

These threads often refer to the monument induced forces on the bearings due to the increased offset, but these forces are not that large relative to the cornering forces and their induced moments. The cornering forces induce moments to the bearing that are actually in the opposite direction to the vertical load moments.

The point being that the bearings are designed for much greater forces than those created by the additional offset using spacers (or wider wheels).

Actually mine is a LSD

[WideRide 86]

Actually mine is a LSD

Touché!

[gtc]

Originally Posted by Starless

Agreed, my bad.

I have a stock 1980 SC Targa still set at US ride hight. 16 X 7 rear with 225-50's. I think I'll just go with 23mm. What could go wrong?

23mm is a good plan. Might want to check your fenders after installation to see if they need to be rolled. I have 1" spacers with stock wheels & tires, and one side rubs a bit with some models of tires.

[Dan J]

Originally Posted by Bill Verburg

The question makes no sense w/o knowing what wheel width and o/s you are using

spacers per se aren't an issue,

changing the net ET from stock is, the smaller the net change the less of an issue
oe on an SC was
7ET23.3 or 8ET10.6

9ET15 splits the difference and also works fine

930 used a higher o/s(ET) and a bigger bearing and wider fenders to accommodate that set up

Bill,
You are a brainiac and a great resource for this board
That is all

[Walt Fricke]

To decide how to get a spacer which won't cause your wheel/tire combination to rub on something, just make a spacer out of wood. You don't have to drive with it on, just put the tire on and let the jack down, and feel around. Have some heavy person bounce up and down on your bumper (be sure to remove hand first). You can also use washers on each stud for this kind of testing.

I think the ideal bearing would have the tire centerline centered over the bearing center. Didn't Porsche move more in that direction when it introduced the 964s, with the large offsets on the rims? I thought early Turbos did something along those lines - different front hubs? Maybe I am confusing that with the rear Turbo bananas.

But I am heartened to see so many thinking that it is a myth that spacers are bad, bad, bad in terms of bearing life. I've replaced both rear bearings on my SC, and one twice. Car has maybe 175 thousand miles on it, quite a lot of track hours in there. And only modest spacers used most of that time. Sooner or later you'll hear that noise.

Besides, if you get rims which have larger offsets, you can move the tire out that way, but it has the same effect on the bearings as spacers with lesser offsets - a longer lever arm either way.

I agree that spacers in front give you a less favorable scrub radius. I don't think it is a good idea to space the front out just for looks.

Front and rear, moving the tire centerline out (increasing the track with spacers) will have the effect of a smaller torsion bar or softer spring because of the lever arm bending or pushing is longer. I don't think that necessarily is a good thing. If it gives you a better roll center location, that might offset the greater roll? But "wider is better" is too simplistic a view from what I can tell.

While scrub radius will affect street driving, a slightly softer wheel rate is not going to be noticeable under those conditions, I would wager.