Loud Cluck - front forks

[CB4ME]

I've been experiencing a loud clunk when I brake very hard or hit a pot hole hard. In other words when the front forks compress beyond a certain point, a sharp solid clunk is heard. The noise sometimes occurs after I release the brake, sometimes while braking, and always when hitting bumps hard.

What should I be checking for? My bike is lowered 15mm in the back and 12 mm in the front but I don't think that is contributing to the issue.

 

[Old Can Ride]

Sounds like your slider is bottoming out. Take your suspension back to stock setting, too see if the noise continues. I saw a lowering kit recently on this forum. You might try that kit.

http://nc700-forum.com/forum/bikes-parts-for-sale/10248-nc700-lowering-kit-kick-stand.html

 

[670cc]

So let me get this straight, is it a cluck or a clunk?

Did the problem begin in coincidence with a mod, or just out of the blue? Lowering a half inch in the front should not be an interference issue unless you've mounted an accessory, such as an aux light, under the beak.

I would go through the external hardware and confirm no bolts are loose, i.e. the caliper mounts, axle, pinch bolts, fork tube clamps, fender hardware. I would also check things on the bars, like the bar end weights. I once had a loose bar end weight on my Goldwing that made the bars clunk when I hit bumps.

 

[DirtFlier]

[...My bike is lowered 15mm in the back and 12 mm in the front...]

Just out of curiosity, how did you lower the back by 15 mm. That's such a small amount that it would be hardly noticeable.

In ref to your clunk from the forks, I'd make sure the oil level is where it should be.

 

[Deleted member 1183]

After lowering the front I would check that none of the brake lines are hitting anything. I also concur with the observations of 670cc. One other aspect to consider is stem head bearings that are getting slightly out of adjustment. Unless the fork oil has been changed I cannot see these forks bottoming out internally. Their very high resistance to high speed compression is my reason for thinking that. Just my thoughts for now.

 

[MZ5]

My forks clunk noticeably under hard braking, too, and have for about as long as I can remember. More specifically, they clunk when I _release_ the brake lever. I wouldn't call it loud, exactly, but it's clear and noticeable even with my ear plugs in. It's _not_ a matter of bottoming out on mine. I just kind of ignore it. Maybe one day I'll have them off and apart, and look for something. ...or maybe not...

 

[CB4ME]

I appreciate all the suggestions and will check them out . I'll raise the front too, since I can't remember when the chunks started,

"Over Racing" a Japanese accessories company, has 15mm lowering kits. You still need a shorter side stand. I got a 20mm shorter one from Kimja. Tried a foot pad with it, but the bike was too near upright for comfort.

 

[Whiteyez]

You need to check the steering stem bearing nut. Mine was a bit loose when I bought the NC, and as I would come on the brakes I would get a little thud/thunk that could actually be felt just a little. Re-torque the steering stem nut. You are not bottoming out the suspension unless the zip tie on your fork really indicates you are doing so (you all do this right?).

Mine got loose too after 40000km and have the same clunk noise, tighten the nut and problem solved.

 

[CB4ME]

I found the culprit.

I have a Plot skid plate and fender extender shown here:



I added an extension to the extender to keep mud away from the catalytic converter:



The middle bolt on the homemade extension was hitting the top tab on the skid plate when the folks compressed, making the sound I heard:



I removed the skid plate to bend that tab out of the way and discovered a nasty surprise:



I checked the bike and found one bolt missing and another bolt half way out of the bottom of the alternator cover! Oil had been leaking from the cover!!

Fortunately I had a spare bolt and tightened everything up. I also checked the oil level and it was within spec.

I had never touched those 2 bolts before today. I also found 2 more alternator bolts on either side along the bottom that weren't tight. I'll keep an eye on that area but hopefully found and fixed the leak.

 

[mreric]

loctite is your friend.... get some on those bolts!