Trials Bikes For Dummies

By Ron Milam

This is Part 3 of suspension basics. It may take a few more issues to complete this topic, but then we’ve got plenty of time, right? Anyway, I’ve got a lot to say about springs and oils and damping, etc., but I know that the season is moving by quickly and that every one of you is waiting in anticipation for my advice before you touch anything. Sure, I believe that. Well in case at least one of you is waiting, I want to say a few things before you start adjusting.

First of all, and very important, is to make a record of what settings you currently have. Measure your spring preload settings with the most accurate method you have. If you have Paoli or other forks with an externally accessible preload screw, screw it all the way in and count the turns required to bottom out the adjuster. Write this number down and if you need to return to these settings later, you just screw it all the way to the bottom again and back out the number of turns you wrote down. You can do the same with the damping adjustment. This sounds pretty basic, but many people think they are just going to make a little change here or there, and pretty soon things are all messed up and they don’t know how to get it back to its former, less messed up state. On the rear, things are a little more difficult for a couple of reasons. First, access is very restricted unless you do some disassembly. Second, the spring is very stiff, so even a small movement of the preload adjustment causes a considerable change in the spring force. Be very accurate in your measurement. A good trick if you can gain visual access is to count the number of threads showing under the adjustment nuts. Then put a witness mark such as a punch or chisel mark in a place that lines up with some stationary part of the bike or maybe just in visual alignment with the mounting bolts. If you use a magic marker, the marks may be gone when you come back to them later. Magic marker marks are good however, for temporary marks such as when you are making the adjustment. Later, if after making several adjustments and deciding that the original setting wasn’t so bad after all, you can use the thread count for the rough adjustment and then bring the witness marks into alignment. This will get you so close to the original setting, Dougie couldn’t tell the difference.

I know that everybody reading this is a dedicated and responsible mechanic who always uses the right tool for the job and hasn’t used a pair of channel locks in years. Of course as the original trials bike dummy, this is how I try to conduct myself. However- there is a limit to this and on most bikes adjusting the rear shock spring is just on the far side of that limit. I own a complete set of hook spanners and I use them if the shock is off of the bike. But they won’t fit if the shock is on the bike. And to make an adjustment I am notta-gonna spend an hour or more taking the shock off to make a trial adjustment that is probably going to be too much or too little anyway. I just use a long punch and a hammer. If the punch is soft, it will not hurt the nut much anyway. Now that I have publicly made this confession, the 99.999% of the rest of you that do the same can stop feeling guilty.

The next thing to consider is that any adjustment you make will affect more than just bottoming out or making it easier to hop. This will be the subject of next month’s column.

Ron