| Author | Message | ||
     S3thunder |
I had a really stupid accident today and now I would like to have some input on how to check my forks for damage. I was in line to turn right at a busy intersection, the car in front pulled out onto the roadway and I watched left for an opening. When I saw it I took off and almost instantly went SPLAT! I was getting up trying to figure out what happened when I realized I had run into the back of a new Volvo that had pulled out and stopped. I couldn't believe I hadn't looked that way...stupid assumption they were gone... Damage so far seems to be a broken brake lever, broken right turn signal, and some more dents on my exhaust header. Damage to me is a strained Achilles and sprained foot, none of which I remember happening. So, I had some help getting my bike up and started it and finished riding to work, a little late. I also rode my bike home and had no trouble with it. All this leads up to my question....How do I check the forks for possible damage as I hit the car a pretty good whack. I am only looking for technical assistance...I know how stupid I was. Thanks. | ||
| Blake |
Perform first the easiest checks for the most obvious indications of damage, then work your way to progressively more exacting, more sensitive diagnostic procedures. Put a straight edge on the front and/or back face up as high as the fork geometry will allow to visually check straightness of outer tubes. Of course this only applies to areas of the tubes that are constant diameter. Then do likewise for sliders (inner tubes) with the forks fully extended. If those cursory checks don't indicate a problem, then you should next verify that suspension action remains smooth and without undue stiction/binding at any point in the front end travel. If working the front suspension fails to indicate a problem, then remove the front wheel and fork springs, set damping to minimum settings (fully unscrewed to the CCW stops) and work each fork leg by hand to check for any binding. Then with forks fully extended, rotate/spin the inner slider tubes within the outer fork leg tubes and check carefully for any off-axis movement. Use a hard reference similar to the gauge a wheel truer used wrt the wheel rim to help indicate any excessive runout. If you note a wobble (runout) as you turn the either of the sliders, you have identified a bent fork tube. The good news is that they are repairable.  If none of the above indicate a problem, you are likely good to go. Inverted forks are darn stout and pretty tough to bend. The frame might even begin to yield before the forks. Certainly the prudent approach would be to have an expert check it over if you are not sure. Glad you are relatively unscathed. (Message edited by blake on October 21, 2005) | ||
| Reepicheep |
I've done that once (in a car) to somebody else, and I have had it done to me three times (also in the car). Stupid? Probably, I felt pretty stupid when I did it, but not at all an uncommon mistake. Hope the forks are OK and that you heal quickly... | ||
| S3thunder |
Thank you for the info Blake, it sounds like a lot and armed with my repair manual it will be one more learning experience. I have come to know this bike pretty well through several of these DIY projects. I appreciate the assistance. Also thanks to Reepicheep for your kind comments. I am stunned I didn't look first and will have to pay the damages to learn that lesson too. | ||
| Henrik |
What sometimes happens is that the front axle can twist in it's mount, which in turn can twist the forks. If it seems like things don't line up, you can loosen the axle pinch bolts as well as the front axle and then bounce the front end to loosen everything up and get it lined up. Then re-tighten the front axle and pinch bolts. Henrik | ||
| Wyckedflesh |
A very good suggestion is to actually pull the front axle and check to make certain it is straight. Rolling it on a smooth flat surface with the head side hanging off will give you a good indication. If the axle itself is bent, its a very good indication that a fork tube somewhere is bent. It turns out the lower forkleg of my XB forks ended up being bent. Doing all of Blakes above tests didn't yeild enough data (not saying he left anything out its just where my forks are bent is out of the range that shows in his tests.) The bent axle when in place kept everything aligned enough, but when a straight axle was put in, the bend in the forks showed right up. |
