CX Wheel Weights

[jamesnoble]

So heres a frustrating problem...

I am very very fussy about wheel balancing. Few tyre fitters do it well and when you drive a franch classic who's smothness is a major part of the pleasure of ownership, getting the wheels balanced spot on is essential.

The citroen CX had two factory alloy wheel designs in its production life. One design was fitted or optional on everything except the GTi Turbo and the other design was fitted exclusively to the GTi Turbo.

The non turbo design was available in 14" and metric 390 size
The 14" was fitted with 195/70 R14 H tyres
The metric 390 was fitted with 190/65 HR 390 Michelin TRX tryres

The turbo design was only available in metric 390 size and fitted with 210/55 VR 390 Michelin TRX tyres
However....
The Turbo Design is, according to James Walshe at Practical Classics, available in recently remanufactured form from Germany in 16" size

My CX Estate runs the 14" size alloy wheel; I prefer this style wheel on the estate, its angular design suiting the roof profile well. However my post is about balancing; not which wheel design is better or you prefer so lets keep any discussion to balancing

Balancing these wheels

Originally the non turbo design in both its metric and non metric sizes was balanced using clip on weights. These clip on weights are of different profile to standard steel or alloy wheel clip on weights and I haven't found a supply.

If you are running metric wheels of either design balancing is easy. Stick on weights work just fine (as they will for the new 16" wheel) but you will be spending a small fortune on tyres which I just can't afford to do. Tyre cost is solved by the new 16" turbo wheel but a set is over £1000 - although clearly a one of off cost!

But...

If like me you are ruynning the 14" alloys you will hit a problem. From my limited understanding balancing a wheel is done in 2 parts; a static and then dynamic balance. The static balance is (I beleive) acheived with weights on the inner edge (hub side). Here stick on weights work just fine.
The dynamic balance is acheived with weights on the outer edge (face side). Here is the problem...

This dynamic balance can be acheived with clip on weights on the outer face or stick on weights placed visbly on the outer rim or just the other side of the face out of sight. The problem with the 14" wheel is there is very limited clearence between the break caliper and the place inside the wheel that you can acheive a dynamic balance. You are therefore limited to the very ugly placing of stick on weights visibly on the outer rim. In theory clip on weights would be the perfect solution but I can't find them in the right profile for the rim!


Things Ive considered and ruled out:

Static only balance: Not balanced enough for a totaly smooth drive!
Fitting metric wheels of the non turbo design (clearence inside the wheel for dynamic balancing using stick on weights is not an issue due to larger wheel diameter): Tyres just way too expensive
Fitting Turbo wheels: as above and I don't think the dessign looks right on the estate
Fitting the new 16" Turbo wheel: I can't afford it and I don't think the design looks right on the estate
Fitting 14" steel wheels with clip on weights: I like the Alloys!!!
Fitting Alfa Romeo wheels: JUST NO!
Fitting an aftermarket wheel: REALLY??? When Citroen got the designs so right???

So the question is has anybody else overcome this problem?
Does anyone know where to get the right clip on weights? or does anyone know of a very low profile stick on weight that would clear the brake caliper?

[white exec]

Hi James,

Could you post a drawing/sketch, with dimensions, of the profile of the rim edge where the weights would clip on to your 14" alloys?

One more bonus of the 14" rims is that they carry relatively high-profile tyres, which is the first line of comfort on hpn suspension. Have found Michelin Energy+ provide a great ride, although not the cheapest tyre out there.

[jamesnoble]

Here is a picture of the profile with some measurements. And of my rims wearing ugly stick on weights!

[white exec]

Was interested to compare with the alloys here on the XM.
You look to have much the same "double right angle" arrangement, where clip-on weights would sit.

Ours here:

Never had a problem in UK (or here) with clip-ons being fitted. The fitter usually adjusts the clip a little to fit the outer rim, then clouts on. For very long weights, the body of the weight is sometimes bedded down with a couple of mallet blows.

[Paul-R]

The problem with clip-on weights and alloy wheels is that an electrolytic reaction can be set up between the wheel and the weight. The weights used to be lead and this could cause a lump of the wheel to literally fall away. Adhesive weights are insulated by the adhesive so this couldn't happen.

Lead isn't used any more I believe but there would still be a reaction between the steel of the clip and the wheel under certain circumstances.

[jamesnoble]

Was interested to compare with the alloys here on the XM.
You look to have much the same "double right angle" arrangement, where clip-on weights would sit.

Ours here:


Never had a problem in UK (or here) with clip-ons being fitted. The fitter usually adjusts the clip a little to fit the outer rim, then clouts on. For very long weights, the body of the weight is sometimes bedded down with a couple of mallet blows.

Hi Chris

You have standard alloy wheel weights and yes they do work on the majority of alloys with a lip. They sadly will not stay on a CX alloy! The Rim is much deeper (8.5mm compared to 5mm on yours) and the recess much shallower. Hence my problem...

If you have a look at the weight on the crusty metric in the picture you will see their is a marked difference between your weight and the one on the CX alloy. Its interesting isn't it?


Thanks for looking

[xantia_v6]

I think that your understanding of how static and dynamic balancing work is incomplete.

Static balancing corrects for the uneven distribution of weight around the overall circumference of the wheel. Static weights could theoretically be placed in any plane through the wheel (where the plane is perpendicular to the axle), abdd at any distance form the axle.

Dynamic balancing corrects for the uneven distribution of weight difference across the width of the wheel.

To achieve static balance, the weights can bee placed anywhere across the width of the rim, and for static balance, the balance weights can always be grouped together (you don't need multiple weights at different positions of the wheel to achieve static balance).

To achieve dynamic balance, you generally need a second set of weights, which are usually placed opposite (across the circumference from) the static weights, but these must be in a different plane to the static weights, nearer or further from the centre-line of the car. Adding the weights to achieve dynamic balance changes the static balance so more wight is also required at the place where the static weights were applied.

The thing that many people (including some tyre fitters) don't seem to understand is that the balancing weights can be added at any place across the width of the wheel, they don't need to be right at the bead of the tyre, as long as the dynamic balancing weights are in a different plane to the static weights, and that the size of the weights is correctly calculated for the planes where they are fitted.

The further apart the planes are, the less overall balancing mass is required to achieve perfect balance. So the most efficient (in use of lead) is to have the wights clipped on at the inside and outside of the tyre beads. But this is not necessary.

It is also possible to balance a wheel with stick-on weights which are entirely placed on the inside of the wheel, with some near the inner edge of the rim and some on or past the centre-line towards the outside of the rim, but still inside of the normally visible face of the rim.

My XJ-S has it original GKN Kent alloys,

and these are another wheel that will not accept clip-on weights (they just fly off the first time you exceed the speed limit). You have to tell the tyre fitter that you must have stick-on weights, and that you want them all fitted on the hidden side of the rim. This does mean that he needs to set his balancing machine to know the correct plane for each set of weights, but the machines can all do it.

[jamesnoble]

It is also possible to balance a wheel with stick-on weights which are entirely placed on the inside of the wheel, with some near the inner edge of the rim and some on or past the centre-line towards the outside of the rim, but still inside of the normally visible face of the rim.

My XJ-S has it original GKN Kent alloys,

and these are another wheel that will not accept clip-on weights (they just fly off the first time you exceed the speed limit). You have to tell the tyre fitter that you must have stick-on weights, and that you want them all fitted on the hidden side of the rim. This does mean that he needs to set his balancing machine to know the correct plane for each set of weights, but the machines can all do it.

Thats hugely helpful and had given me a much deeper understanding. My excellent fitter tried the solution you have found for the GKN XJS Rim but thisd is where we hit the problem of clearence. One set of weights at the rear of the wheel face fowled the brake caliper at the front...

[white exec]

That's a really clear explanation, Mike, and very instructive. Learned new things there.
Presumably modern balancing machines simultaneously calculate the mass and positions of the static and dynamic weights, in the course of a single spin-up. This (I guess) automatically deducts the mass of the dynamic weight from the static one, and comes up with the correct figure. Clever!

Where I have seen the whole kaboodle go wrong (just once) is in the case of a tyre that was out-of-round, and the stupid fitter added a load of weight to achieve balance. He did, and the machine read the required 0–0, but didn't stop the car lolloping along the road on its oval tyre! After this idiotic episode, and with good tyres at the price they are, I always take a shuftie under the balancing hood at the perimeter of the tread, to make sure it is spinning true, radially and axially. Have rejected one brand new tyre, and had another one re-fitted because of this.

[xantia_v6]

Thats hugely helpful and had given me a much deeper understanding. My excellent fitter tried the solution you have found for the GKN XJS Rim but thisd is where we hit the problem of clearence. One set of weights at the rear of the wheel face fowled the brake caliper at the front...

I suppose that with 14" rims, there can't be much clearance for the brake calipers.

Even with the 15" rims of my XM, I had them balanced (the fitter mumbling in French under his breath about the difficulty of balancing Citroen centre-less wheels), and then while driving the car off the ramps the rear brake dust shields wiped the inner stick-on weights off of the rims. It was possible to find a different plane to re-balance and fit the weights in this case, but you may not be so lucky.

Another thing to remember is that most of the imbalance is in the tyre, so reversing the tyres on the rim should swap the major balance weight between the inner and outer face of the wheel, it that helps cosmetically. A new set of high quality tyres will often require a lot less balance weights than cheaper tyres.

[white exec]

Some tyres have specified inner and outer faces, so flipping might not always be possible.

[Stickyfinger]

I always insist on stick on weights. Press on types are horrible, by either damaging the paint of rotting the alloy itself.

[jamesnoble]

So Stick on weights are the answer; except when you can see them the look awful (see the picture of my wheel with grotty stick ons)!

So I continue my quest for the original spec clip on weight; they can't have been unique to Citroen... Anyone any ideas?

[white exec]

Try contacting/researching the manufacturers of balancing weights and machinery. Should throw up something.

[bobins]

Most modern tyre balancing machines have a program for allowing positioning of weights in various places. A common setting would be to use stick-on weights hidden behind the spokes of a wheel - this may mean using more weights to achieve a balance, but leaves no weights visible from the outside. It all depends on whether the tyre fitter has actually read the manual for the machine and knows what those settings mean ! On a lot of slightly older machines it can take 2 or 3 balancing passes on the machine before the machine thinks the wheel is balanced i.e. spin it up - apply the desired weights, spin it up again and check / adjust, spin it up again and check / adjust. If you've got a tame wheel fitter, it'd be beneficial to ask them to de-mount and remount the wheel on the machine and check the balance after the first successful balancing session. Another issue is whether the machine is properly calibrated - I bought a 100g calibration weight for mine, and when I checked it on the scales, found it was only 96g
Low profile wheel weights are available - Google should bring up some sources, though you may have to be persistent. Have a look at Hofmann Power Weight balance weights and see if they'll be thin enough - a decent tyre fitter would have no problem with you bringing your own weights to the party
Also - have a look at the Trax Professional range of wheel weights as they claim to be only 4.2mm high : https://www.youngautomotivedirect.co.uk ... ofessional
And Trax Premium at only 2.8mm high (allegedly !) https://www.youngautomotivedirect.co.uk ... m/620C-040

Trax Premium available in small quantities from eBay: https://www.ebay.co.uk/itm/Trax-Premium ... 3966105751