How to change the sideplates and maintain a discus
This 'How to...' video is essential viewing for any discus-thrower who wants to keep their equipment in perfect condition. I'm sure you all know that you should clean and wipe-down your discus after every use, and oil the metal parts periodically. But often we don't have the time and grime builds up, particularly in clubs with lots of throwers, so take this opportunity to spruce up your kit.
This video also covers changing the side-plates if they are damaged by hitting the cage or landing on a stone.
How to change the side plates on a discus and general discus maintenance
Tools for the job:
- an old discus (Our demonstration discus was provided by our friends at Plymouth Athletics Club, so our thanks to them)
- a scourer. You can buy these at the supermarket or hardware shop, just be very careful to buy the kind with no soap
- fine grade sandpaper (optional, depending on the level of maintenance required)
- 2 allen keys. Each discus takes a different diameter of allen key, so you will need to try out which size fits your discus. Note: There are imperial and decimal sets of allen keys, so if you struggle to find a correct fit, you may need to try a different set.
- light machine oil and a dry cloth or paper towel
- furniture polish and a dry cloth
Steps to maintain your discus:
Take it apart. Put one allen key in either side of the bolt hole in the centre and simply If your discus has never been taken apart before it will be very tight and will take some strength to ‘unclick’ the first turn. Your discus will come apart into a rim, two side plates, a centre weight block and two bolts.
Unscrew the centre weight block and the discus is ready for cleaning.
Clean the rim. Most of the discus weight is in the rim. A low spin discus will have a slightly thinner rim and a larger centre weight block, whereas a high-spin discus has the vast majority of the weight in the rim so the rim is even heavier with a small centre weight block. Use the scourer pad with not too much pressure. Work round the discus rim and get the rough areas off. Feel around the rim with your fingers. If there are rougher areas which do not respond to the scourer, take the very fine grade sandpaper and very lightly rub the area to remove any catches. These areas may be caused by the discus hitting small stones when landing, for example. Feel with your hand to check it is quite smooth, then brush off with a clean cloth to remove any dirt.
Clean the plates. Use a soft cloth to remove dirt built up inside the discus and on the side plates. You can use the scourer very lightly to clean any rougher areas on the plates, but be gentle and do not damage the surface. If the side-plates are cracked, you will need to replace them with new ones (see point 7).
Lightly rub the centre weight block to remove surface dirt, but do not scrub or use sandpaper.
Oil the centre weight. Take a pad of paper and a small amount of light machine oil. Apply oil to the centre weight block (this will remove any loose surface rust) to protect the surface with a light coat of oil to protect it against further corrosion.
Put the discus back together. Put the first side plate on the rim of the discus, put the first bolt through and screw the oiled centre weight loosely onto the bolt. Place the second sideplate on and insert the bolt loosely by hand. Position one allen key in each bolt and tighten the bolts.
- Oil the discus rim and centre bolt. This is to protect the metal and prevent corrosion. The metal will darken very slightly when oiled, so you can see where you have worked. It is very important that the discus is not oily as this will cause it to slip from your hand when throwing.
- Use a very small amount of oil
Let the oil soak in overnight before throwing the discus
Polish the discus (optional). There is a school of thought that polishing the upper surface of the discus improves aerodynamics and lift. Choose the smoothest surface of the discus to be the upper surface. Spray a tiny amount of standard furniture polish onto the discus and work it in with a soft cloth. It is important to let the polish soak in overnight before throwing it to reduce the risk of the discus slipping when thrown.
Note: Now that you have broken the manufacturer’s seal on the discus, it is possible that the bolt will loosen over time. Therefore we recommend that you check the bolts with two allen keys periodically (e.g. monthly) to ensure they are secure.
Your discus is now clean, maintained and ready to be re-used.
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