In this episode: Pete dismantles the rear end of his KTM 950, which he rode through a salt lake in South America; while Trent sets to work cleaning and greasing an all-too-neglected part of any bike: the swingarm bearings. Trent ‘breaks the bead’ on Waz’s front tyre and removes the tyre and tube, giving advice along the way on how to find and fix a puncture at the roadside.
Swingarm bearings come in two main varieties: plain or needle roller. A plain bearing is essentially a tube of metal, sometimes bronze, that is pressed into the suspension parts involved. Running inside these bearings are the various shafts or bushes that are the pivot points of the suspension.
Needle roller bearings are far superior – they consist of a tubular metal casing that houses thin cylindrical rollers. In this episode Trent gives a great demonstration of how to pack them with fresh, clean grease, and the best kind of grease to use.
These bearings are often ‘caged’ to keep the needle rollers in place. That’s how Pete’s KTM and Richard’s BMW are set up, but unfortunately in my Cagiva Elefant the rollers are loose, and held in place only by the shafts and bushes running through them. When dismantling the suspension, the little buggers are prone to falling out everywhere. When removing, lubricating and reinstalling they must be meticulously counted out and counted back in.
One big problem with the loose kind is that once you’ve lubed them and stuck them all back into place with grease, you’ve got to reinstall whatever shaft or bush runs inside them. When you insert this into the bearing, it dislodges the needles and pushes them out the other side! You end up picking those precious needle rollers out of a gob of grease lying on the ground beneath your bike.
My trick is to find a socket of suitable length that is small enough in diameter to push into the bearing without dislodging the needles, but large enough that it holds them in place. Then you slowly insert the suspension shaft/bush from one side and it pushes the socket out the other.
There are usually seals sitting outside the bearings, and these can often be sourced as a generic item from a bearing supply shop, rather than paying for genuine parts from your bike dealer. Same goes for the bearings themselves, but check and compare prices, because sometimes the bike dealer will be cheaper. Both the seals and bearings will hopefully be marked with a universal part number and perhaps the name of a bearing manufacturer, such as SKF. Any good bearing shop can look this stuff up.
That said, the seals usually don’t do much good anyway. Any heavily used bike will probably have dry bearings, and whatever grease is left inside will be filthy. Clean them out with a solvent, check that both the rollers and the bearing casing itself are OK (not flattened, misshapen, or heavily scored, notched or corroded, and if caged, that the cage is not broken or distorted) and pack with waterproof grease. Watch the video – Trent shows you how.
Bearings need replacing? Then you will have to get them out first. Consult the workshop manual for your bike, but you can sometimes put the swingarm or suspension linkage in a vice (holding it in place with aluminium or wooden ‘soft jaws’), place a socket against the bearing and hammer the socket to drive out the bearing. Once again, the socket should be big enough in diameter for the job but small enough that it doesn’t get stuck where the bearing was.
If you are flash enough to have access to such things, you could use a suitably sized brass drift or piece of PVC rod. Or you can use your vice as a press with two sockets – the ‘pushing’ socket on one side of the suspension part, and a much larger ‘receiving’ one in the same position on the other side to act as a spacer, allowing the bearing to slide out. This ‘receiving’ socket should have a big enough internal diameter that the bearing can slide into it.
If you can’t puzzle out a way of doing this, or the bearing just won’t budge, have a bike shop, engineering works or mechanic friend press it out it for you.
Also in this episode, Trent shows how to ‘break the bead’ on a motorcycle tyre and gives tips on finding and repairing a puncture. Watch, listen and learn!
One more thing: Richard and Pete’s London-to-India/Singapore travelogue. We have decided to break this out into separate videos for the moment, and they will probably be posted at our Beer Fridge side-blog. There will still be plenty of travel tales thrown into the main episodes, like Pete’s account of his Salar de Uyuni trip, but we want to keep the main show a manageable length. So coming soon will be part 2 of Richard and Pete’s “Singdia” travelogue (see what I did there? Singapore+India=Singdia).