Terry@rigdenage

Practical bicycle tribology

Tribology is the posh word for lubrication so this isn't a piece on how cyclists separate into mutually suspicious groups. Bikes will accept a lot of neglect, but lubricating it properly will make it easier to ride and last longer.

You may be thinking I don't need to do all this my bikes brand new !! DON'T YOU believe it, almost every new bike I've had or looked at has had at least one dry bearing. A friend in the trade tells me that 2 out of 3 bikes delivered to his shop even from "reputable" manufacturers were misassembled or had dry bearings. One thing to ask the shop when you buy your next bike is what sort of pre delivery inspection do they do?

For the wheel, headset, freewheel and pedal bearings ordinary car grease is fine. But for the bottom bracket white waterproof grease is better as it gets quite wet down there. The bearings should be stripped, cleaned, checked for wear and repacked with grease at least twice a year if you use the bike for commuting, less if you are a fair weather tootler, more if you go mud plugging.

The brake and gear levers, brake pivots, and derailier joints need a shot of a PTFE loaded dry lube such as GT85 etc. every 3 months or so.

Derailier jockey wheels should be cleaned, stripped and re-greased about twice a year. If you really want to cut friction you might want to replace the ordinary plain bearing type with ball raced ones, but they're expensive.

I usually grease cables on installation and thereafter give a squirt of the dry lubricant about twice a year. HOWEVER don't do this if you have PTFE coated cable outers because the oil makes the outer swell which leads to all sorts of grief. Pay special attention to where the gear cables pass under the bottom bracket and give them a regular clean and a dose of a heavier oil. The back brake cable on some ladies bikes is especially vulnerable the end of the cable points upwards (great design) so water runs down inside corrodes the cable and lo and behold no back brake.

I've tried a variety of lubricants on the chain and they all have their drawbacks. Ordinary oil degenerates into a filthy oily mess as road dirt sticks to it making a grinding paste. The dry lubricants wash off in the rain and need to be redone every month or so even in dry weather. Paraffin wax is a palaver to put on but tends to get pushed out of the chain. I've tried some of the expensive specialist chain lubes but haven't found one with any significant advantage. I currently use paraffin wax backed up with a dry lube, at least its less messy than oil.

This might sound daft but lubricating the inside of the frame is also a good idea. If you look carefully at the ends of the forks and rear drop outs etc. you will see some small holes. These are put in by the manufactures to let water inside the frame to ensure that it rusts from the inside and you have to buy a new bike. The best way to combat this is to poke the tube that comes with the aerosol dry lube into the hole and spray some oil up inside the tubing. Likewise take out the saddle stem and spray inside the crossbar & seat tube. You can get at the down tube and the front of the drop outs when you strip the bottom bracket for re-greasing.