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The Little Things

Tech Note 001

Just when I was sitting down thinking what to write in the first article for the Tech Notes series, unexpected inspiration arrived in the form of a customer dropping by with a bike that he purchased online. He was complaining that he thought it had been in a crash and wanted my opinion as to what was bent and how much it would cost to make it right.

I had a look at the bike and it didn't have any obvious signs of crash damage, in fact it looked very clean and well cared for. I started looking over the bike and my first check is always front stiction. The bike had about 30 mm of stiction, which is way too much; 8 mm or more usually indicates a problem. The cause of the stiction was simple to find, when the new front tyre had been fitted, the technique to reinstall the front wheel was not ideal and the forks were pinched together, causing the forks to bind in the lower part of the stroke and of course made the forks very harsh. With that little problem taken care of, I checked the forks to make sure that they were indeed set parallel in the triple clamps; they were close but could be improved, so a small adjustment was made there as well. While doing this I noticed that the steering head bearings were loose, not a whole lot but enough to matter and these were re-adjusted and checked for smoothness of movement, which was in this case fine. Sometimes when steering head bearings have been too loose for too long and / or have been subjected to large impacts, the races can become indented and make the steering quite "notchy" and replacement of the upper and lower bearings is the only cure.

Then we moved to the rear end and the bike, unusually, had a lot of rear stiction. On inspection, we found that a lower linkage bearing was seized and not moving freely, also the lower shock bearing was dry and binding. The linkage bearing was dry and rusty, so as a temporary measure while new bearings are sourced the bearing was lubricated with a good quality waterproof chassis grease. The lower bearing on the shock was replaced as it was worn beyond service limits and starting to collapse, again dry and rusty. Both of these items were very likely caused by the over-zealous use of a pressure cleaner!

With the bike now having both ends working smoothly and not exhibiting excessive stiction the front and rear sags were set. The rear sag was way too much, probably in an effort to adjust round the problems caused by the poor rear suspension action. The rear rebound damping was also slowed down, again it seems logical to assume that this was sped up to compensate for the failing bearings. This particular machine only has rear rebound damping, so other adjustments were not possible to make externally. A quick inspection of the chain and sprocket showed some wear, which is often a sign of the rear wheel not being set in the swing arm correctly. This was set using a string line and the accuracy of the OEM alignment marks checked, a few strokes with a file on the adjuster pieces and now the marks were accurate.

With the basics done, my attention turned to the front brake, it felt awful! The culprit was soon found, a dry and corroded lever pivot, this was cleaned up and again lubricated with some quality grease, a small dab of grease was also put on the lever, where it bears on the master cylinder piston to ease the sliding component of its normal operation. The clutch lever got the same treatment, resulting in a significant improvement in clutch action, read considerable reduction in force and an improvement in smoothness of action. My suspicions of the insidious damage that pressure washing motorcycles can cause, led me to inspect the rear brake lever, again it was dry and corroded, as was the gear shift lever pivot, and main and passenger foot-peg pivots, all of which got a quick clean up and lubrication.

Next I sat on the bike and it was, well, horrible. The rear brake lever was too high so that I had to lift my foot off the foot-peg to get my foot on the lever. This was quickly adjusted to suit the owner, who, after thinking about it, agreed that he found it un-natural to use. Both the clutch and brake levers were set too high, making using either of them quite a stretch, and the handle bars were pulled back at an odd angle, so these were normalized and lever positions set to a more natural angle, again the owner had just accepted that it was the way it was. I believe it is much better to make the bike fit the rider rather than trying to fit yourself to the bike!

The owner was sent out for a quick test ride; some 90 minutes later he returned, much to my relief! The bike was all he had hoped for and more, he loved it and had just kept riding. All the things he had been disappointed with, the grabby clutch, poor front brake, and handling all resolved in just over an hour and a few cents worth of lubricant! The bike is now booked in for replacement linkage bearings, and a check and lubricate of the steering head and swing arm bearings, and given the amount of dry and corroded pivots, it seems likely that both these other areas may be in need of attention or preventative maintenance.

Anyhow, this all too familiar "adventure" has reminded me again just what a big effect having the basics right can make on the enjoyment and safety of a motorcycle. If you are mechanically minded, many of these tasks you can take care of yourself; you will be amazed at just how much a little bit of the correct lubricant in the right places can do to improve you ride. Of course if you have any doubt as to your own abilities or the correct products for the job, seek the services of a suitably experienced person to do this work for you, after all reliable primary controls especially brakes are required for safe operation of your vehicle on the roads. With the proliferation of low cost water blasters, many bike owners are seeing these as a less labour intensive route to keeping their bike clean, especially in those hard to reach places. Just keep in mind that it is so very easy to drive high pressure water past the seals on many suspension pivots and once in there, it can't escape. Trapped water is definitely not the friend of precision bearings made from high carbon steel. Once that water is in there, it's only a matter of time till somehing goes badly.  Some cleaning fluids are very aggressive and over quite a short period of time can strip out the small quantities of grease that keep all of those little pivots that we never think about, that all of the controls of a motorcycle rely on for smooth operation. The degradation of these control actions is slow, and as such, we likely never notice reduction in control feel on a day to day basis, so the next time you get on your bike, take the time to make sure it fits you, and that you are not bending yourself awkwardly to fit it. Slowly exercise the controls, if you notice any difficulty binding or loss of smoothness of operation, it's likely all thats required to return it to its as new feel is a little time and the right lubricant.

Remember to make sure that the little things are right before you go chasing the big things!

Kerry Dukie

Dukic Performance

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