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Old 09-03-2008, 10:51 AM   #1
StromBoni OP
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How Easy Should Forks Twist?

I have seen write ups before were, after a get off, someone had to stand in front of the bike with the wheel between his knees and straighten the handle bars because the forks had twisted.

This happened to me this past weekend, but it seemed to happen way too easy, and I had never had it happen before on other bikes.

Stock DR650 in an off road situation, I came down a low hill and attempted to make a right hand turn in some sand, but I lost the front end and crashed at less than 8mph. Got up and tried to drive off, but the handlebars were about 15 degrees off perpendicularly with the forks. I was able to easily fix it with the above described method.

When I got home I tried to tighten up the clamps, but there were already tight, I couldn't get any of them to budge.

Is this normal?
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Old 09-04-2008, 02:49 PM   #2
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62 views and no replies. I have a feeling that I did not state my question clearly.

1. Should forks twist in a low speed, non-contorting fall in sand?

2. Is there any way to test how much force it takes to twist forks, and is there a standard?

3. Is there anything that can happen to a tripple tree, other than bolts loosening, to allow forks to twist easily?
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Old 09-04-2008, 02:59 PM   #3
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Tighten the triple clamp bolts to the factory spec torque. Do not over-tighten them. They are supposed to twist during a crash. This is what keeps the forks from bending.

Make sure that when you get home you do the proper sequence of tightening the bolts so that the forks do not bind under compression.

What I do is get the front end off the ground and loosen all the triple clamp bolts. Loosen the clamp bolts on the axle. Leave the axel tight. Make sure that one fork leg is the correct height in the clamp, then snug up the top clamp on that fork. You now need to get the forks straight. One way is to spin the front wheel and slam on the front brake. This will usually cause the forks to find thier happy place. Then tighten everything up.

This is one area that I always use the proper torque required.
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Old 09-06-2008, 04:00 PM   #4
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My friend had the forks on his Suzuki RF 900 get twisted from a tank slapper, so I wouldn't freak out too bad if falling down caused it. It's better than something breaking, right?
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Old 09-06-2008, 06:06 PM   #5
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I've twisted the forks on my DR650 maybe three times, all from minor biffs.
I'm glad they turned and nothing else 'twisted'.
A curb or post can set them right.
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Old 09-07-2008, 02:33 PM   #6
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Like previously stated having them twist isn't a big deal, it helps keep them from breaking stuff. You may also double check the steering head. There is a nut that tightens down the top triple clamp onto the nut that sets the bearing preload. Make sure these are both torqued correctly. I have an old honda xl600 and had my forks do the exact same thing yours did. I checked the clamp bolts and they were tight. I loosened them anyway and retorqued them and the twist happened again from a very minor spill. After retorquing and checking everything from the axle up to the handlebars i figured what the heck and checked the triple clamp nut. it was a little loose. hope this helps.
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Old 09-08-2008, 07:22 AM   #7
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Excellent, thank you all.

It sounds like everything is normal, but I think I will open everything up this weekend, break out the torque wrench, and snug everything down to spec just to make sure.
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Old 09-08-2008, 08:51 AM   #8
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It could be a case of falling just right to make the forks twist. Or it could be something like bent triple clamps or forks. I had this issue with my 640 A from the first day I had it. I wadded it up in a sandwash and twisted the forks pretty good. They did seem to twist easy for the type of crash though. I fixed it up with the right torque values and alignment and everytime I fell the forks would twist. No matter how small the fall. The forks never naturally seeked the correct position either. The bars were always slightly twisted.

New clamps top and bottom fixed it up.
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Old 09-08-2008, 09:31 AM   #9
meat popsicle
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Quote:
Originally Posted by StromBoni
Excellent, thank you all.

It sounds like everything is normal, but I think I will open everything up this weekend, break out the torque wrench, and snug everything down to spec just to make sure.
If you have trouble setting the torque values, or they still "twist" too easily for your liking, then perhaps your fasteners have fatigued. Ever replaced your triple clamp pinch bolts? How many times have they been tightened/loosened? They have a lifespan, remember metal fatigues, and then they will not work like the factory intended.

Just one of my random thoughts, but it is a sound one I think.
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Old 09-08-2008, 02:17 PM   #10
skeptic
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Is it smart or dumb to put on a fork brace? I have 1983 XL600R and do not really know if it would change the handling, and I'm not complaining about it. I would think it would make steering more precise, and would strengthen the front, but would possibly result in bending of the tubes in event I hit something pretty hard.

BTW, since I dont go off road much, I'd like to put something like a rain type fender which conforms to and is pretty close to the front tire with a smaller than stock higher fender jutting straight out, like a motobike. Anyone know where such items are available?
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