Hub flange

[meb]

10mm wheel spacers are not available for the current model Mini Cooper. If I look at the hub design, which is pretty much standard fair across run of the mill rigs, a 10mm spacer does not work because it removes the function of the flange. Now, I'm no engineer, but I assume that the flange is responsible for resisting some load generated by the tires as wll as centering the wheel - hubcentric.

I ask because I just ran into an entire group of folks whom have layerd two 5mm spcaers together. To my way of thinking, the studs should not bare all the load. It's madness to my brain!

The hub flange on this car is 10mm.

[trikesrule]

Madness or inexperience on their behalf? Anyone who runs speedway will tell of stories of having a wheel go by cause there was no flange to help carry the load. This was always caused by human error in design of the spacer. Spacers must be a snug fit to the centre of the wheel and be snug on the hub. Thats it in a nut shell or pay the price...........trikes

[Notso Swift]

You will be able to get a locl engineering shop do this for you , as Trikes said it is critical that it is done right. Especially during hard cornering, I would assume BMW would engineer a fair safety margin for the road, but if you are pushing....

[meb]

Thanks. I thought I might check my intuition.

[Dave Brand]

Originally Posted by meb

10mm wheel spacers are not available for the current model Mini Cooper. If I look at the hub design, which is pretty much standard fair across run of the mill rigs, a 10mm spacer does not work because it removes the function of the flange. Now, I'm no engineer, but I assume that the flange is responsible for resisting some load generated by the tires as wll as centering the wheel - hubcentric.

I assume that by 'flange' you mean the centre spigot? It does, as you say, both locate the wheel & take some of the load.

In theory, if the wheel bolts are torqued up correctly I'd assume (& it's only an assumption!) that the clamping pressure between wheel & hub face should be sufficient to resist the applied loads.....however, in the real world, I wouldn't rely on it! No way would I drive a car with the wheels not firmly located on the spigot.

That spigot is there for a purpose - it would be a few pence cheaper to manufacture the hub without it; believe me, if they could get away with it, they would - multiply those few pence by a few million & you've got a big saving.

[greenamex2]

Originally Posted by meb

I ask because I just ran into an entire group of folks whom have layerd two 5mm spcaers together. To my way of thinking, the studs should not bare all the load. It's madness to my brain!

They would get thrown out of scrutineering in the UK.

[meb]

A lot of folks like me, though not engineers, really get into cars. With what little time we have as parents and husbands, we study and ask questions and in general have a great time at the track. But some of these instances are down right scary...and dare I write, one need not be an engineer to at least 'reason' some of these details out.

I certainly hope the tech folks know what to look for...

[dtype38]

I'd personally agree with the general sentiment that wheels should have a spigot (flange) location onto the hub, and I do on my car. But I was surprised to find my friend with a nearly identical car was running his rear wheels without a spigot. When I voiced my concern he said that in several years of racing he'd never had any problem with it mechanically, except that it was a bugger getting the sleeve nuts on the studs. Not only that, but more recently he's moved to taper nuts, and still hasn't had a problem.

Maybe if the hub face area is large enough, and there are sufficient studs of big enough size, then a spiggot isn't always needed, even for racing.

[trikesrule]

Hi dtype your friend will only get away with that set up for so long. It's like they say 'u took a long time to leave me loose wheel'. His car would have a hard time passing scrutineering here in aus at any circuit. In speedway he'd be putting her on the trailer. If he races in your class you'd do him and you an enormous favour if u got on his case about setting it up correctly. The advantages for him, the other competitors and spectators from an errant wheel cannot be impressed upon him enough. If all else fails dob him in to the officials and sleep well. I recently worked on a customer car and his external 'kill' switch was unable to be turned off. He just shrugged his shoulders said he didn't give a stuff. He was the first to complain when at the next race meet the Scrutiners checked the entire fields kill switch..........trikes

[dtype38]

Can't say I've ever seen anything in the Blue Book about wheel mounting flanges, so I'm not sure on what basis a scrutineer would object.

Either way, I'm not going to criticise my mate's car when I've come close to loosing a wheel myself, and nothing to do with spiggots. I was distracted during a wheel change and ended up going out for practice with the nuts on one wheel only nipped up rather than properly torqued. Near the end of the session something didn't feel right so I returned to the paddock to find that the nuts on that wheel were all within two or three threads of falling off.

Can't say I've seen scrutineers checking wheel nut torques either. How far do you take it?

[meb]

Perhaps, and only perhaps, it might be possible with some wheel designs to fasten the spacer to the wheel. Then...perhaps...the flange retains its function??? This, of course, may or may not appeal to officials.

[dtype38]

Odd you should say that... it's exactly what I do on my wet tyre rims because they're quite narrow and don't clear the calipers. I only use three small screws though, so it's only really to centre the wheel, not take any radial load. I'm happy to rely only on the sleeve nuts and face friction though, because my hubs were designed for 1800kg car and mine is less than 1000kg. And in keeping with the thread, they also happen to be 10mm ones and have never given me any trouble even on a dry track.

[ian.stewart]

If you look at modern aftermarket wheel fitments, TUV approved, you will find that it seems to be a "one size fits all" situation, the wheel makers offer a couple of generic PCDs and bore the wheel to the largest spigot size that is generally used, when you buy one of the wheel sets and have a hub that has smaller spigots you are sold plastic aligning rings, which are designed to do just that align the wheel while you bolt it up, so I assume the spigots have very little to do with wheel fixing but a lot to do with holding the wheel in position for bolting up, and the clamping pressure applied by the bolts are adequate to retain the wheel and the taper nuts or sleve nuts are safely locating the wheel in its correct rotational position.
Ian

[retro_msport]

(the phone rang while i was typing this so Ian beat my post ....)

Got me thinking , and yes i like the spacers to have a spigot and recess for the hub's spigot, but..........

The loads on the wheel.. braking is a torque force around the hub, so without the wheel studs the wheel would spin around the spigots ...

Acceleration loads are the same..

side loads.. take the studs out and push the wheel at the bottom and pull the top... the wheel would fall off the spigot.

so perhaps the spigot will only support the weight of the car on a wind free day and as long as no one breathed on the car.

So, which is more important for security, the studs or the spigot ?
personally ..Both

I would say that the spigot is on there for the centralising of the wheel, some steel wheels have a hollow behind the nut/stud, (perhaps a form of spring washer?) and if one stud is done up tight before the other 3/4 then without the spigot the wheel could be pulled over/out of square. Perhaps thats the reason manufactures dont delete the spigot and save a few million.
I belive that the sleeve nut became the spigot on aftermarket wheels, which quite a few has hole centers much larger than the hubs spigot.

One other thing with wheel nuts/ wheel bolts... change them every year. They are normally softer than the studs/hubs so wear is confined to the nut/bolts, not the studs/hubs, and half a thread left in a nut is easier to strip than a full thread. ('specially if you havnt got a spigot ;-)