Re: Steering Wheel Shimmy
Hopefully got to the bottom of the wheel shimmy, I put on my old alloys back on the front complete with 205 tyres, no shimmy, it felt so much better on the road. My conclusion is that 225 profile tyres are too wide and have an detrimental impact on the steering.
David
Re: Steering Wheel Shimmy
An Update on the wheel shimmy problem I have suffering from at 60 mph and above. I have finally got this irritation sorted with some help from Chris Jarvis. Basically the centre of the wheel must match the diameter of the hub. In my case the centre of the Minilite measured 66.6mm, the hub diameter measured 57.6.
In order to make up the difference SPIGOT RINGS are available in a variety of sizes in tough plastic or aluminium. BINGO the problem has now been resolved no more wheel shimmy at 60 plus mph.
If any one else is suffering from a similar problem it would well worth checking that the centre of the wheel matches the diameter of the hub.
David
Re: Steering Wheel Shimmy
So what you're saying, if I understand it correctly, is that the mating surface of the inside of the wheel that contacts the hub must be the same size as the hub mating surface, or you get shimmy. Bloody L. I'd never have thought such a thing could make a difference, and in fact it's not even something I'd ever considered that could affect...er....anything!
I'm trying to work out why this would happen, but I'm coming up blank. But it must be a known issue if you can get something to eliminate it! Congrats to you both for sussing it! - although it seems to have taken you 7 years :)
Re: Steering Wheel Shimmy
I'm struggling to understand the physics of this too. You're saying that the shimmy is not coming up the shaft from the wheels, but is due to a possible eccentricity in the steering wheel to hub join?
Ignore this, I misread the post and got hold of the wrong end of the column completely!
Re: Steering Wheel Shimmy
Are you saying that the wheel bolts/studs were not securing the wheels in a truly central position on the hub, and therefore allowing the wheel to be slightly off balance?
Re: Steering Wheel Shimmy
The centre bore on all production car road wheels is centred to the the spigot on the hub/flange.
The weight of the car shouldn't be taken by the wheel bolts/studs alone.
It's an important engineering feature.
For David's sake, I wish I'd had that in mind when I ordered the Minilites for him.
Having said all that, David's classic 5 spoke Revolutions (which the Minilites replaced) have sleeve bolts with no taper, and no spigot feature at all.
That type of sleeved bolt/stud is not typical though.
It seems that some aftermarket wheels are supplied with spigot rings, rather than having the wheels machined to specific centre bores.
Re: Steering Wheel Shimmy
My original thinking on this matter was that the wheels would automatically be centred on the hub by means of the matching tapers on the wheels and bolts, this is not the case. The wheel has to be centred first on the hub ( the hub is baring the weight of the wheel) This only achieved when the diameter of the hole in the centre of the wheel is sliding fit over the hub. You will find that all production cars have matching diameters.
It is amazing that it has taken me so long to get this problem sorted out, I was completely unaware that this mismatch between wheel and hub could cause the problem I have encountered all these years.
The original wheels on my car were Revolutions which were secured by wide shanked bolts (no tapers) directly on to the hubs. I did not experience any shimmy which those wheels. The hub to wheel alignment must have been absolutely accurate using this method.
Re: Steering Wheel Shimmy
Just think David, you have had 7 years of vibrio hand massage, that you wouldn’t have had with the old wheels. Be positive, keeps any ailments of stiffness at bay!
Re: Steering Wheel Shimmy
The first run in the car with the spigot rings in place was a revelation, at 60 and above the steering wheel remained still. No more vibrio hand massage. I was like a dog with two c**ks.
Re: Steering Wheel Shimmy
So basically, the wheels were off-centre to the hubs which caused the vibration. I'm sure I've come across cars without a hub spigot though, although I can't remember which ones...as you say, you'd think the tapers in the wheel bolt/stud holes would self-align with the tapered bolts/nuts.