Balancing Lotus Alloy Road Wheels

[Bainford]

Has anyone had trouble having Lotus alloy wheels balanced?

At various times since I've had the car I feel like the wheels are not well balanced. And in a 1600 lbs car its not hard to tell. When I picked up the last set of rear tires I had mounted last summer, they had huge gobs of weight on them. I knew that wasn't right, and sure enough the car was jumping all over the place. So I called around to find a tire shop to do the job with care, and stood by while the technician mounted them. After several tries using various mounting methods, he could not get them mounted true. We examined the wheels and found that the centre wheel hole from the back side is tapered and has an 'as cast' surface, which cannot be assumed true centre relative to the wheel rim. The large array of adaptors he had at his disposal just would not mount those wheels to the machine properly.

He told me that some wheels have bespoke mounting adaptors that can be purchased (he cited certain Volvo and Triumph wheels) and wondered if Lotus had the same. Has anyone heard of this?

I am thinking of having the centre hole area of the backside of the wheels machined to accept conventional mounting adaptors, but first wondered if others have had this problem and devised a solution.

[4129R]

I had 12 wheels completely re-furbished, and they balanced them with no problems.

I even had the silver bits diamond polished. Few can do that, (7 in the UK), but it was worth doing as they came out better than 2 new ones I bought recently.

http://www.ba-wheels.co.uk/

Alex in Norfolk

[BDA]

It's been a long time since I dealt with the stock wheels, but I don't remember taking them anywhere special for tires nor do I remember that any special accommodation was needed, but then, that was long before the fancy computer balancing equipment we have today. I also don't recall anybody mentioning this difficulty before either here or on the yahoo group either.

The thing I know about those wheels is that the holes for the logs can get wallowed out, but even if that had happened to your wheels, that doesn't seem like your problem.

I wonder if you can find somebody with a bubble balancer to balance your wheels. When I was racing, that's all they did and we never had any problems. It may not be technically as good, but it seemed good enough back then.

[Bainford]

Yes, I think modern computer balancers, and their mounting arrangements designed for modern wheels, are part of the problem.

Bubble balancing can do a good job of establishing a static balance, but can't account for a dynamic balance. However, given it is a 13" alloy wheel, it might get close enough.

[BDA]

Like I said, back in the '70s, all club race wheels were balanced with a bubble ballance. From Corvettes, to Formula Fords, they all worked with no discernable problems. Light Formula Atlantics which weighed less than 1300 lbs and went over 150 mph ran without issues.

[Rosco5000]

It sounds like the tire shop doesn't have a small enough centering cone for their balancing machine.  I know my dad had to make a centering cone for his friends 1930's Aston Martin.  The owner just keeps the cone and brings it to shops so they have the right bit to do the balancing, I think his was the reverse though needed a bigger cone or a very specific taper so that the center lock wheels would fit on the machine.  It is hard to tell with out seeing the problem, did you take any pictures?  You may just have to have a custom cone machined so that it centers properly. 
Ross

[Bainford]

Interesting info BDA. When doing this, is all added weight added to one side of the wheel (inside or outside of the wheel)? Or is it evenly distributed between both sides? Just curious about how this was done.

[Bainford]

It sounds like the tire shop doesn't have a small enough centering cone for their balancing machine.  I know my dad had to make a centering cone for his friends 1930's Aston Martin.  The owner just keeps the cone and brings it to shops so they have the right bit to do the balancing, I think his was the reverse though needed a bigger cone or a very specific taper so that the center lock wheels would fit on the machine.  It is hard to tell with out seeing the problem, did you take any pictures?  You may just have to have a custom cone machined so that it centers properly. 
Ross

The problem seems to be that the hole in the centre of the wheel is a cast surface, not machined. It is therefore not a true centre. He did try positioning a small cone from the outside of the wheel and a steady plate from the inside, but couldn't make it work.

[Rosco5000]

The problem seems to be that the hole in the centre of the wheel is a cast surface, not machined. It is therefore not a true centre. He did try positioning a small cone from the outside of the wheel and a steady plate from the inside, but couldn't make it work.
[/quote]
Ah I see, the wheel is in rough casting form I reread your first post sorry I missed the rough cast part.  That would be a problem.  I guess if it wasn't hub centric mounting they weren't concerned with truing up the center hole. That is a PITA. 
I think your solution suggested to get the inner hole machined is what I would look into. Then they will never be a problem again.  The only think I can think that could be an issue is to make sure you don't machine all the way through as your center caps won't fit anymore if you have to make the bore bigger all the way through the center of the wheel.
Ross

[BDA]

Interesting info BDA. When doing this, is all added weight added to one side of the wheel (inside or outside of the wheel)? Or is it evenly distributed between both sides? Just curious about how this was done.

If memory serves, the weights were generally put on the inside rim about in the center. Usually, the inside had the greatest offset so there was room put duct tape over the weights as insurance. I might expect that they were looking for the center of the entire wheel, but I don't think I ever asked about that. That's not to say that they never put them on the outside and it's certainly not to say that my memory is infallible! It was quite a while ago! I just know that they used a simple bubble balancer. No spinning the wheel and no computers.

Machining the hub would probably be the "best" solution, but it might be an interesting exercise to see how well a simple bubble balance works (if you can find one).

[Roger]

Harbor Freight sell a bubble balancer.

[jbcollier]

I can't comment on whether the centre hole is actually centred, but, if it is not machined, it isn't.  I would have them lightly machined myself.

Also, use two tapered lug nuts to centre the wheel first before fitting the regular lug nuts.

[Bainford]

Thanks for the replies, guys. I think the balancing guy worked it out, though I have yet to road test the job. There is less than a third of the original quantity of weight on the rear wheels, which looked so wrong before. He spent two hours trying to get them right, and modified a couple of his adaptors to make it work. He seems to be a technician who cares, and took the time to sort the issue. The icing on the cake is when I showed up at the end of the day to pick up the wheels, the counter guy had already closed off the till, and so charged me nothing for the job. If the job is done well, this guy is getting a coffee card and an 'atta boy' call to his supervisor.

I think the next time I have all four tires removed from the wheels, I will have some minor machining done to the centre hole on the back side of the wheels, and make a hardened steel adaptor specifically to fit. However, the balancing guy has marked his modified adaptors for the next time I come in.

[BDA]

Glad you got it squared away!

[3929R]

Trevor, Are you using tapered lug nuts to center the wheel first before fitting the regular lug nuts as JB suggested? Of course this would only seem to help if they can be balanced on the machine in the first place. But I'm wondering if this could be an additional problem? (Buying tapered lug nuts is on my to do list for tomorrow.)