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- One of the problems we can have when performing alignments and making changes to corner weights are the inconsistencies that can creep in as a result of the wheels and tyres fitted to the car.
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It only takes one rim to be slightly bent or one tyre to have some pick up on it from the racetrack or piece of gravel stuck to it to affect the alignment and the corner weights that you're measuring..
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00:22 |
Even the tyre pressures can have an effect on the accuracy of our results.
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00:26 |
A good way to demonstrate this is to measure the circumference of the tyre with a flexible measuring tape.
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00:32 |
Where you measure the tyre, whether it's the inner edge or the outer edge, will most likely give you a very slightly different measurement.
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00:39 |
Likewise, if you measure the front left tyre and the front right tyre, depending how they're worn, you'll also again get a different measurement.
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00:47 |
While the differences admittedly are likely to be small, they will ultimately affect the accuracy of your corner weights.
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00:54 |
A technique used in high end motorsport to avoid these problems is the use of setup hubs.
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01:00 |
Setup hubs usually consist of a CNC machined alloy plate that bolts to the vehicle's hubs in place of the wheels.
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01:07 |
They're designed in such a way that they mimic the wheel and tyre size and use a set of rollers where they sit on top of the scales.
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01:14 |
The rollers prevent issues with the suspension binding up when the car is jacked up and lowered into the scales and they also allow for the camber to be adjusted without affecting the way the setup hub sits on the scales.
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01:26 |
Setup hubs also include convenient reference points that replicate the width of the rim and these can be measured relative to the strings in order to measure the toe on each corner of the car.
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01:36 |
Another benefit of using setup hubs is that it makes it easier to access all of the suspension components and make adjustments without needing to lift the car off the scales.
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01:46 |
Having the car sitting on the scales during the full alignment and corner weighting process makes it much easier to get repeatability and consistency.
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01:55 |
There are many different design options when it comes to setup hubs and all of the designs will vary depending on the car and the wheel hub design.
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02:04 |
For example, you'll need a different style of setup hub for cars running studs compared to one that runs a centre lock.
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02:11 |
In general though, it's fair to say that setup hubs are expensive with prices starting at around $1000 USD for a simple setup hub design, up to $20,000 USD or more for a complete full vehicle alignment and setup system.
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02:25 |
For many top racing teams, setup hubs are an essential piece of kit when making the alignment and corner weight adjustment.
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02:32 |
The argument here is that people think that not having the wheels on the car will affect the corner weight of the car and this actually isn't the case.
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02:40 |
While the total weight of the car will of course be different, the wheels are what is referred to as unsprung weight which means it does not affect the way in which the car is balanced.
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