ALL ABOUT RUST
Ever since iron was invented rust has been a continuing problem particularly in the case of steel car rims. All early rims are prone one way or another. Referring to Collins dictionary, rust is a reddish brown oxide coating on iron or steel by the action of oxygen and moisture - both of which you have in abundance in car rims. Especially after every journey when your tyres have heated up during the run and on stopping, the hot tyre cools down and creates moisture. This is the problem as rust forms on leading edges.
In the case of beaded edge rims, the leading edge is particularly prone. The leading edge is originally rolled to fit up against the flat on top of the bead. There are measurements for the different size tyres. When the motorist in his wisdom grinds the leading edge back to get rid of the offending sharp edge, this fixes the sharpness but creates another problem. The rim edge is no longer is pressed in the flat above the bead. The more you grind the more the bead is unloaded eventually getting into roll off country. As tyres are getting more expensive the economics of a new rim starts to make sense. Rust never stops and beaded edge rims are the most vulnerable.
The rim makers never envisaged that they would still be used up to 100 years later. Crystallisation is now a problem with age – in other words they become very brittle especially when welded. The safety of your car relies heavily on your tyres and rims. Good rims are essential for safe motoring. Tyre pressures should be checked regularly as the recommended pressure is vital. The bead being held only by tyre pressure.
Early manufacturers of beaded edge tyres all made their own individual sizes. They soon realised that this was going to cause problems - so in England in 1911 a standard was formed which all manufacturers used. One exception was a continental company whose tyres had a large bead – a trap to look for.
We were lucky to acquire an original set of Dunlop gauges which was supplied to garages. If a car came in with a puncture and the rim had been damaged hence the need for these gauges. With regard to the fitting of beaded edge tyres rust bands are recommended as chafing can occur particularly in the case of wire wheels.
Some new tubes are being produced with a reinforced inner side as they would have been made originally so rust bands might not be needed.
Being in the business of manufacturing old car rims, we have come across lock rings that have rusted well beyond their safe use. The beak on the inside of the ring where it touches the tyre is generally rusted off. If it gets too bad the tyre is no longer capable of holding the ring in place and on hard cornering releases and possibly files off.
Lock ring material has a higher carbon content than the rim and is more prone to rusting.
Henry Ford was one of the earliest car makers to use the lock ring rims in 1924 on his AA trucks and also several other cars came out with them. Firestone was the earliest to introduce the use of lock ring type rims. 3mm was used for narrow tyres but when balloon tyres became popular 4mm being a higher profile was needed.
The early tyres had a higher content of cotton in the beading and this accelerated the rusting process on all rims being used at the time.
Rolled edge rims also have a rust problem that is not so visible. The inside of the bead is where rust forms. Heat and moisture come into play eventually rusting the whole bead from the inside. We have adapted 4 different shapes and sizes to match the tyre bead as they vary according to the tyre size.
MG tyres generally use 3.50 to 4.00 – the beads on these are vertical in shape.
Model A tyres generally use 4.40 up to 4.75 – the angle of the bead is more pronounced.
Jaguar type rims have the biggest angles to match the bigger tyres.
Bentley rims – the beads go back to a more straight angle to match tyres of the bigger size.
The names we have adopted are only an indication relating mainly to car sizes not car makes.
The way we make rims is by rotary rollformed and great attention has been made to not thin the corners. We can supply samples of the rim sections showing no distortion of wall thickness. After all rims are sized and turned with precision making it easy for spoking. All these rims have been stress relieved.
We have been making rims since 1980 and after years of experimenting and lots of determination and persistence and cost of course, we have succeeded in making the best rims that are available and will continue making improvement in production.
Our range consists of 48 different types and over 110 different diameters in the range.