Welcome to our resource for MG Car Information.
|
MG Midget and Sprite Technical - wire wheel hubs ok for vintage racing?
It seems to me from looking at photos of other cars that wire wheel hubs are undesirable for racing. Other than the fact that there are fewer wheels to chose from is there any safety or performance disadvantage? I like my wire wheel hubs (currently have mini-lite wheels). However, the front ones are a little worn and I am preparing to replace them. Is there anyone who has a really good reason why I would be sorry if I don't spend money converting to bolt on wheels or will I be ok with what I have (if I accept that there are fewer wheel choices). thanks, Rebecca |
R Harvey |
If your car has wire wheel hubs and you have fitted bolt on wheels using hub adaptors you car is carrying a significant weight penalty. Nothing wrong with wire wheels for racing, especially in a 5.5" rim designed for tubeless tyres. |
Daniel Thirteen-Twelve |
As Daniel said, except for the weight penality they are fine for vintage. If you start running slicks then you will put a lot of stress on them with that much traction, but for the spec tires allowed in vintage you should be fine. Your minilite type knock off wheels should be at least 5" wide, so plenty of width for most vintage tires. You can get wires made wider than the stock 4" if you prefer the look of those. There's a gentleman in England who races on 13" X 7" wires that has posted on this forum with photos of his car, really looks nice. |
B Young |
I currently have minilites. I have been having great difficulty getting my front nuts off (even if I only hand tighten then). I have been assuming that this is because the hub extensions are worn. I have been assuming that I won't have this problem after I replace them. Is this correct? I wanted to verify this before I commit to staying with the splined hubs. thanks, Rebecca |
R Harvey |
One obvious disadvantage of switching to bolt on wheels is that pit stops/wheel changes take longer due to removing/replacing four nuts compared to one per wheel. Trev |
T Mason |
Knock offs are self tightening by design, even with new splines there is some slight movement which will tend to tighten the wheel nut especially on the front as it is never subject to and forward thrust torque, just braking torque. It will be better with new spined hubs, but never totally eliminated which is really a good thing. You said nuts, I figure from that you have the hex style knock offs on your car, those are a pain in the butt to work with. You might consider changing over to a two ear knock off, will be much easier to tighten and remove with a lead hammer or as I personally like a plastic faced dead blow hammer. |
B Young |
B Young Hex nuts -- shame --octagon nuts just like the MG badge Rebecca Maybee you could get a wheelbrace made up using a MG nut tightening tool as the socket part. It might be a bit more wheel friendly than hammering away near them Minilites Just a thought Willy |
William Revit |
William, I hang my head in shame, I should have caught that error for sure. LOL My experience with the octaginal nuts is that the tool is very difficult to keep on the nut because of the smooth chrome surface and the slight taper most seem to have. For me the wrench kept slipping off as I was tightening or loosening the nut. They do look very clean when used with the Minilites though. Has anyone ever marketed a socket with some type of clip that would stay on the nut while you are removing or installing it? That combined with a good long handled ratchet wrench would really work great. |
B Young |
Bill - RD Enterprises in PA (www.rdent.com) sells a socket to suit the knock-on nuts on a Lotus Elan. I think they are the same size as the Spridget nuts, but I don't have any Lotus nuts to compare - my Lotus has the eared nuts. I agree with your assessment of the OEM wrench, very difficult to use. The eared nuts may not be much better, as the curve of the spokes bring them very close to the ears, and it's easy to whack the spokes when tightening the nuts. - Bill |
Bill Gavin |
Interesting comments. I have hit (and did chip it) one of my minilites and will try not to do it again. I had once tried to use the eared knockoffs but I like the way the octagon looks with the minilites. Also, with the octagon you can have more mechanical advantage (longer handle) if you whack on a tool). I will check out rdent.com. thanks, Rebecca |
R Harvey |
Rebecca - If you convert to bolt-on wheels you will incur the weight penalty of the standard front hubs which are quite a bit heavier than the wire wheel ones (unless you run to Huffaker alloy hubs at $$$$$). The car will be lighter at the back because of the centre-lock hub adapters, but only by 1.2Kg per side, and of course a little extra weight holding the back wheels down can help traction if you don't have an LSD. I suspect most people who change from wire wheels to bolt-on wheels actually end up with a heavier car, because they usually take advantage of being able to fit wider tyres and tyres really are heavy. So they get a slower-accelerating car which also has a lower top speed because of aerodynamic drag ... Tom |
Tom Coulthard |
Rebecca I'm running the same setup as you and am gathering the bits to convert to bolt-ons. I've weighed everything and expect to shed about 10kg. |
Mike Allen |
Mike - please do tell us how you arrive at this figure. |
Tom Coulthard |
ok. It is settled. I am keeping my wire wheel hubs and minilites. Pic shows a good look at them (before I started lowering experiments): http://www.pangalacticconsortium.com/cars/MG_midget//imgpages/image161.html Rebecca |
R Harvey |
Rebecca How did you end up with the spring/twist saga Willy |
William Revit |
Tom - I don't do much with wire wheels, but I always thought the wire wheel stuff was all heavier than the corresponding bolt-on stuff. Your comments got me to dig out some parts and weigh them. I was surprised to find that the bare w/w hub weighed only 3lb 4oz to the b/o hub's 4lb 1oz: not earth-shaking but surprising. With the k/o nuts, however, the w/w weight went up to 4lb 11oz for the eared nut, 4lb 7oz for the octagonal nut. The w/w brake rotor should be a bit lighter than the b/o rotor, but I didn't have any handy to weigh. It looks like it's pretty much a wash, not considering wheels, since Rebecca would be using alloy wheels in either case. The k/o wheel should be heavier due to the steel insert, but I don't have any numbers for them. As you note, the rear is significantly heavier. A b/o axle weighs 5lb 8oz, a w/w axle weighs 10lb with an eared nut - it would be a few oz lighter with the octagonal nut. I wonder if Mike was counting the weight of a set of wire wheels? BTW in the USA, the stock car industry can supply alloy hubs fairly cheaply if approached properly. The hubs for small modifieds are pretty close in size, needing to be machined for the Sprite bearings and the 4x4" bolt circle. One of my friends had such hubs on his Miata. - Bill |
Bill Gavin |
Bill - many thanks for those weights, which are fascinating. My w/w hubs are all attached to brake discs and my only set of bolt-on hubs are on the Midget. The trouble is, we all have bits in various states of assembly and it's actually quite difficult to compare individual items - before even getting to what applies to which set-up. The bolt-on brake rotor is 3/4" deeper in the 'top hat' spacer section which makes it quite a bit heavier, it being a 3/4" chunk of cast iron. The w/w set-up also does without 4 wheel nuts at the front - only 80g but it should all be counted (apologies for Napoleonic units). At the rear, I was forgetting the added weight of the spinners - lovely lumps of manganese bronze, but not light. The axles/halfshafts I was not including, as I was thinking of the Sebring w/w spec. But in fact, a competition halfshaft (with its large nut to try to keep the flange on) must be heavier than standard, whereas the competition w/w halfshaft only needs better steel. All of which does not amount to a whole bag of beans, perhaps, but it does confirm that the w/w set-up is not vastly heavier. As to the wheels themselves - the only wire wheel I have to hand without a tyre is a rare period Dunlop 4.5J (so heavier than the 'standard' Spridget 4" wire wheel, but probably comparable to the Dayton) which tips the scales at 6.6 Kg. For comparison, an (even rarer) original Dunlop 5.5J frogeye steel wheel is 5.6Kg and a Superlite 5.5J Minilite replica alloy is advertised to be 5.3Kg(www.superlite-wheels.com/technical.html). Rebecca - nice car, and I don't want to worry you, but why are so much of your chassis legs visible below the front valence? Is it possible that someone has 'corrected' the kick-up in the chassis rails, as sometimes happens if the car has been in a shunt? Apologies if this has been the subject of previous postings I may have missed. Tom |
Tom Coulthard |
Tom I looked up my weight savings notes hoping there'd be enough data to support my claim. Nothing for the hubs, axles and discs, but my splined Minators weigh 8kg, and the VTO's I'm replacing them with weigh 5kg. That's enough to convince me. Plus I find it a pain flogging away at those ears to loosen the wheels. cheers Mike |
Mike Allen |
Which picture are you referring to. I have not noticed this problem. Rebecca |
R Harvey |
I had to cut a socket down: http://www.pangalacticconsortium.com/cars/MG_Midget//imgpages/image110.html In order to get good clearance to remove the bolts that connect the wire wheel hub extension to the front disk: http://www.pangalacticconsortium.com/cars/MG_Midget//imgpages/image110.html You can see the wear in the ww hub extension in that picture (not acceptable). Rebecca |
R Harvey |
If you look at them the chassis rails are slightly bent up. I don't know if they are bent up as much as they should be. they are not horrizontal or bent down. In some of the pictures that I have I am practically lying on the ground when the pic was taken: http://www.pangalacticconsortium.com/cars/MG_Midget//imgpages/image258.html such as that one. However, as soon as I can get the door of my hangar open (hopelessly blocked by ice and snow at the top and the bottom right now) I am going to take the car to a body shop down the road and they are going to help me make some proper vertical alignment measurements. Rebecca |
R Harvey |
It was this pic, but as you say it's most likely just the low angle. It's a problem on a shell I have, so I'm probably a bit paranoid about it - it's going to take some rectification! Hope you get a thaw soon ... Tom |
Tom Coulthard |
Rebecca Just looking through your pics. Is that a stain or a crack down from the centre headstud nut on the sparkplug side. Willy |
William Revit |
Tom/Rebecca The end of the rails always hangs out the bottom like that,probably because it's white it shows a bit, usually you can see the cross bolts without having to get down very low and you can also see the hole in the end of the rail easilly, looks normal to me. I made a towing hook to bolt on the side of the rail using the existing hardware to secure it and it came out under the nose easily. Willy |
William Revit |
This thread was discussed between 29/01/2011 and 04/02/2011
MG Midget and Sprite Technical index
This thread is from the archive. The Live MG Midget and Sprite Technical BBS is active now.