5

My motorbike took a spectacularly violent trip into a gravel trap in Hockenheim. Long story short, I think my forks and/or triple clamps might be bent.

How do I go about accurately checking if forks and triple clamps are bent?

  • I'm sure there is a layman's way of discovering the voracity of the alignment, forks, and triple clamps. I'm wondering of @DucatiKiller might now how to do this. – Pᴀᴜʟsᴛᴇʀ2 Oct 20 '16 at 18:45
  • Why the downvote, people? – JoErNanO Oct 21 '16 at 15:25
  • What make and model of motorcycle is this? – Eric Urban Oct 26 '16 at 2:42
  • @EricUrban Ducati Hypermotard 1100. Why? – JoErNanO Oct 26 '16 at 12:08
  • 1
    @JoErNanO because your Ducati is a unique and beautiful snowflake. – DucatiKiller Oct 28 '16 at 1:41
2

The forks on a Ducati Hypermotard 1100 have 3 major components. The stanchion, the fork, and the boot. Damaging the stanchion is almost impossible, it is a thin section of aluminum that is well protected. The boot generally shows visible signs of damage, such as cracks or stripped fasteners.

The fork tubes are always of a steel construction. It's much easier to conclude they are bent than if they are straight. First you'll need to support the front and rear of the bike. For equipment to do so, look here:

http://www.pit-bull.com/category/motorcycle_stands.html

Once you have the front and rear supported, remove the front tire. Then attempt to reinstall it. If it is very difficult to reinstall, you have a major bend in the fork tubes.

Next, remove each fork from the motorcycle. You can use your body weight to move it through its travel. If it does not return freely, the fork tube is bent.

Next, you can remove the cap from the fork tube. On almost all forks, this allows the tube to move freely without the force of the spring on it. Move the tube within the stanchion. If at any point you feel significant drag or resistance, the fork tubes are likely bent.

This still doesn't mean the fork tubes are actually straight. To conclude they are straight you must remove the fork tubes from the stanchions. This is generally specific to the motorcycle, consult the factory service manual for information. Once out, place a straight edge along them to gauge if they aren't bent. If the straight edge does not sit flat on them, they are bent.

It is also possible you bent the triple clamp, but it is generally impossible to reinstall the forks into a bent triple clamp. They should reinstall easily without significant force.

| improve this answer | |
  • That's a good answer. He can also remove the slider and take the tubes and just roll them on a flat surface if a straight edge isn't available. A slight bend will show significantly. Thanks for the contribution! – DucatiKiller Oct 28 '16 at 1:39
  • Excellent. Could you please add a picture indicating which is the stanchion, fork and boot? Also, could you expand on how to test for bent triple clamps? – JoErNanO Oct 28 '16 at 8:18
1

Sounds like you'll need to have the fork legs checked for straightness, the best way to do this unfortunately involves removing the stanchions. And having an engineering shop test the forks on a surface plate. Some will say that just sliding a fork into and out of it's outer tubes is enough to check for straightness but its not, a leg can slide up and down in its tube and feel fine just fine, even though its still slightly bent! Best to have it done properly.

| improve this answer | |

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.