For those who are interested, here’s Colin Quilter’s comprehensive summary.
1) Tire pressure. Old-school ACTA riders like me have long believed that hard tires are happy tires, and that soft tires cause increased rolling resistance. However Benny argued that most of us are riding on tires that are pumped up too hard. For an explanation of this theory see:
According to this view softer tires are faster, safer and more comfortable. The soft tire school contends that the tire inflation pressures written on the tire sidewall (eg.”55 – 85psi”) are meaningless, and that you should calculate your personal tire pressures using a calculator such as:
For a tire manufacturer’s opinion on inflation pressures you could read:
2) Tubeless tires. There’s a move towards using tubeless tires for both mountain and road bikes. A white, latex-based solution is added into the airspace inside the tire, and this makes most punctures self-sealing. While riding, you probably won’t realise that you’ve punctured because the sealant has instantly done its job. For an explanation see:
An advantage of tubeless tires is that they can be run safely at low pressure (on gravel or off-road for example) without the risk of pinch flats (“snake bites”) which occur when an inner tube gets pinched between the tire bead and the wheel rim.
The disadvantage of tubeless tires is that if the puncture is too large for the sealant to block, you will be on the roadside with a deflated, damaged tire lined with sticky white goo. The tire and the wheel rim will have to be cleaned before you can fit an inner tube as a temporary measure to get you home. Benny warned that in this case you should check the tire carefully for pieces of glass or wire embedded in it. They represent past punctures which self-sealed and so you were unaware of them; but if not found and removed now, they will immediately puncture the new tube.
3) Removing difficult tires. Some modern bikes are sold with “tubeless-ready” wheel rims. They often have a very tight fit between the tire bead and the wheel rim. Of course this feature remains even if you choose to fit inner tubes in the conventional way. It probably explains why, on some ACTA rides, we’ve had extreme difficulty removing a tire after a puncture. According to Benny there’s no solution for this except for big, strong, thumbs.
4) Chain lubrication. Broadly, there are two types of lubricants.
A “Dry” lube is wax dissolved in a solvent. You apply it liberally to the chain and the solvent evaporates leaving a film of wax which acts as a lubricant. The advantage is that the chain remains clean and dry, and won’t transfer black oil onto your hands and clothes. The disadvantage is that the wax quickly washes out in the rain. Benny recommends dry lubes only in the summer.
“Wet” lubes are synthetic oil. They are more resistant to washing out, and therefore best for the winter months. To minimise the buildup of black, sticky oil on the chain after you’ve oiled it, wipe the chain clean after your first wide with a rag or paper towel. Then do it again after your second ride. That will remove most of the surplus oil, leaving it where it needs to be inside the bearing surfaces of the links. Two wipes will be enough.
5) Chain life. As you cycle, the moving parts of the chain links become worn where they rub against each other. The joints become very slightly “sloppy”. When you pull a worn chain out straight it seems to have lengthened (“stretched”) because all of the tiny amounts of wear add together. If the chain has lengthened by 0.75% it is appreciably worn; if it has lengthened by 1% it should be replaced. Riding with a worn chain will cause accelerated wear on chain-wheels and on cogs in the rear cassette, which are much more expensive to replace than the chain.
The life of a chain depends on how often it is lubricated, and how much dirt and road grit it encounters. On my bike each chain lasts about 8,000km. Benny replaces chains more frequently. I guess that most ACTA riders would cover 6,000 – 10,000km per year so as a rule of thumb we should be changing our chains at least every year. To measure chain wear yourself, buy a chain measuring tool (about $25).
Our two-hour session with Benny covered more than I’ve recounted, but that’s probably enough for now. My impression was that Benny really knows bikes, and his shop and workshop are well equipped. I wouldn’t hesitate to take a bike to him for repairs, which is worth knowing since good cycle mechanics are not easily found. (Benny’s Bike Shop, 78 Upper Queen St. 09 5585483).