Another wheel spacer question

I am having a hard time working out what size wheel spacers to order (mayB coz i iz fik)

Fronts are 17x9" 235/45/17 tyre and offset is 44, what size spacer can i use without rolling the arches.

Will find out what rears are in the morning.

Thanks.

Corneilious.

A 10mm spacer would extend the wheels out near the wheel arch, although clearance will be marginal, the lip may need slightly rolling depending on the make of the tyres you have fitted.

Personally I would not use spacers, but if you do, only use hubcentric spacers - see pic below - that bolt onto the hub and include a central spigot to support and centre the wheel (the lip you can see in the center that fits inside the wheel).

http://www.teamtorquesteer.co.uk/user/products/large/eibach%20rs%20st%20spacers.jpg

This can be the result of using a spacer that does not bolt onto the hub or include a central spigot. I've not posted this link for a while, definitely worth a read http://planetsoarer.com/offset/studs.htm

A 10mm spacer would extend the wheels out near the wheel arch, although clearance will be marginal, the lip may need slightly rolling depending on the make of the tyres you have fitted.

 

Personally I would not use spacers, but if you do, only use hubcentric spacers - see pic below - that bolt onto the hub and include a central spigot to support and centre the wheel (the lip you can see in the center that fits inside the wheel).

 

http://www.teamtorquesteer.co.uk/user/products/large/eibach%20rs%20st%20spacers.jpg

 

This can be the result of using a spacer that does not bolt onto the hub or include a central spigot. I've not posted this link for a while, definitely worth a read http://planetsoarer.com/offset/studs.htm

 

http://planetsoarer.com/offset/4686.jpg

That link is really inaccurate, the spigot is used to locate and centre the wheel (as if it's off centre the balance will be miles off and the angle will be wrong meaning the studs can shear easily). The wheel is held in place by friction created between the wheel face and the hub face.

If anyone thinks a 5mm lip on the hub will hold the weight of the car they are mental.

Don't worry I will use hubcentric spacers.

That link is really inaccurate, the spigot is used to locate and centre the wheel (as if it's off centre the balance will be miles off and the angle will be wrong meaning the studs can shear easily). The wheel is held in place by friction created between the wheel face and the hub face.

 

If anyone thinks a 5mm lip on the hub will hold the weight of the car they are mental.

Does that mean you would be quite happy driving the car around if all of the the spigot rings were magically removed after the wheels were fitted ?

Does that mean you would be quite happy driving the car around if all of the the spigot rings were magically removed after the wheels were fitted ?

Yes, 100% confident. As long as my wheels were centred I would be a happy bunny.

Think about it logically, look at the size of that spigot, and remember it has a chamfer. Think about it locating to the alloy wheel spigot bore, which also has a chamfer. The amount of material in contact is generally around 5-7mm. Putting any sort of weight onto 5-7mm of aluminium is going to see it deform VERY quickly. I hit alloy fixtures with a nylon mallet in work and dent them lol.

You don't need to trust me, you don't need to believe me, but this has been done to the death on here. It's the friction that holds the wheel in its axial position.

Reading all these threads makes me realise just how dumb and clueless I am.

Right just checked and rear is 17x10", 265/40/17 tyres with 41 offset.

Right just checked and rear is 17x10", 265/40/17 tyres with 41 offset.

Sounds ideal. The fronts sound ideal too so surprised you are looking at spacers.

Sounds ideal. The fronts sound ideal too so surprised you are looking at spacers.

Hmm, they seem to sit quite far in the arch, will find a pic for you.

Mine are 19x8.5 with a +35 offset. This would put yours in around 3mm further than mine, which isn't bad at all.

Granted you could push them out further if you really want. Are you absolutely certain on the sizes? Just in case there is a mixup that would explain the look.

Pics.

Mine are 19x8.5 with a +35 offset. This would put yours in around 3mm further than mine, which isn't bad at all.

 

Granted you could push them out further if you really want. Are you absolutely certain on the sizes? Just in case there is a mixup that would explain the look.

Double checked the front and it say 'of +44' i assume that is offset of 44.

If anyone thinks a 5mm lip on the hub will hold the weight of the car they are mental.

The 5mm of the lip doesn't relate to the weight bearing of that spigot feature though Scott - it wouldn't matter if it stuck into the wheel by 25mm, the shear area is the same.

the spigot is important on taking load off the studs, ive seen a guy in a paper weight mx5 sheer bolts under braking purley becease he had wheels with a larger bore and no spigot rings. bolts are shamferd and will centre up the wheel. there job is to hold the wheel in , and the spigot takes load

The 5mm of the lip doesn't relate to the weight bearing of that spigot feature though Scott - it wouldn't matter if it stuck into the wheel by 25mm, the shear area is the same.

Absolutely not a chance. In order for that to be true the force would have to be exactly paralell and perpendicular to the hub face at all times, which obviously it isn't. If that hub lip was 25mm wide I could then be convinced that it is infact there to take the weight of the car, it would need to be FAR heavier than it is at the moment though. As it stands, if it was 25mm+ it would shear off in no time as 25mm out the force pusing down would break the hub lip off at an angle far easier than it will at 5mm.

As it stands at 5mm the alloy wouldn't take the sort of punishment that driving and hitting potholes would put onto it, the inner hub of the alloy would be worn and dented and dinged. It isn't.... that;s because the weight is held by the friction between the wheel face and the hub. Factor into that the fact that wheels are sent with plastic spigot rings that would crack in an instant if 2 ton of car cracked into a pothole at 30mph and you will see that they are only there to hold the wheel central while fasteners are put in place.

I don't really follow what you're on about there Scott.

I just wanted to point out that increasing the length of a spigot on the hub does not increase the shear area - your post could easily confuse people into thinking that was the case.

I don't really follow what you're on about there Scott.

 

I just wanted to point out that increasing the length of a spigot on the hub does not increase the shear area - your post could easily confuse people into thinking that was the case.

It doesn't increase the shear area but it increases the force that will be on the said shear area. Force x Distance rule and all that

Engineer vs Engineer

It doesn't increase the shear area but it increases the force that will be on the said shear area. Force x Distance rule and all that

But now you are talking about bending loads rather than shear....

I'm headed home now and have no internet there but I'll try to post somethng useful back up here tomorrow morning.

But now you are talking about bending loads rather than shear....

 

I'm headed home now and have no internet there but I'll try to post somethng useful back up here tomorrow morning.

Yes, but I'm trying to keep it all simple. The technical reference of things doesn't really matter much as the outcome is very very easy to understand if you look at it properly.

The spigot isn't interference fit, therefor the end point of the spigot is where the load would end up being. Even if it was interference fit the load would still increase the further out from the hub face you went along the spigot as alloy is very soft and will bend/move. This means that the very edge of the spigot would be seeing the majority of the force from the corner weight of the car, not to mention any extra load put on from hitting bumps etc. If this was indeed the case if you took your alloy off you would have a nice big dug in, bashed spigot bore where the spigot ring had been digging in. There isn't though, the only reason those areas would have a mark on them is if the wheel nuts weren't properly tightened.

I'm not really sure how else to put any of this. I can understand people who don't know about this sort of thing being unsure but to anyone with any sort of engineering background I would have thought this would have been cut and dry.

A good test would be to get a set of open ended shallow nuts and another set of nuts to lock against them. Put very little load onto the wheel nut and then put the locking nut on top of it to stop it from pulling back out. Do this with all of them. In this instance there won't be anywhere near the required friction force on the hub, but the wheel will still be held firm against the hub. The spigot bore of the alloy would be wrecked in no time.

Yes, but I'm trying to keep it all simple.

That may be so, but talking about shear loads and bending loads as interchangeable is wrong. You could easily confuse people who don't know any better.

I'm not really sure how else to put any of this. I can understand people who don't know about this sort of thing being unsure but to anyone with any sort of engineering background I would have thought this would have been cut and dry.

Don't get the wrong impression - I understand the loadings in this example perfectly. All I said was that the length of the spigot is not related to its shear area...I've said nothing about the relevance or irrelevance of that shear area.

Edit: I really am going home now

That may be so, but talking about shear loads and bending loads as interchangeable is wrong. You could easily confuse people who don't know any better.

 

 

 

Don't get the wrong impression - I understand the loadings in this example perfectly. All I said was that the length of the spigot is not related to its shear area...I've said nothing about the relevance or irrelevance of that shear area.

 

Edit: I really am going home now

Ahh, fair enough. I took it out of context thinking you meant the spigot wouldn't see any increased load if it was extended. I know where you're coming from now.... it just wouldn't see any difference in the shear stress, apologies

Now you ladies have put your hand bags away please tell me what spacers i can get away with

Now you ladies have put your hand bags away please tell me what spacers i can get away with

Are you keeping the height the same? I would say 10mm easy, possibly 15mm.

I still don't get why yours sit in so much further than mine, especially considering I have the front overfenders on.