70 Norton Front Shocks Question...

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Jul 1, 2008
Wonder if anyone else has the same issue.

When I push down on the handle bars and release fast, the compressed shocks expand and give a "clunk" noise.

I changed the oil in the forks and ensured that the top of the spring bolt is threaded into the cover bold that holds the gauges on so that is not the problem.

Is it normal to hear the clunk?

Not nice and bothers some people, but normal. Pull it up on the center stand and you will hear it too. Can be fixed, but only by changing some of the inside parts in the forks. Few bother to worry about it or invest in what needs to be done to get rid of the noise...but the Gurus will fill you in on how to do it ...for sure. :wink:
Dian said:
Is it normal to hear the clunk?

As Hewho says, if the clunk is happening when the forks are at full extension and you compress them by only a small amount, then they are likely to make that clunking noise as they spring back, and that is normal with the standard setup.
If you are hearing this clunk while riding, or if you keep hearing the noise when you pump the forks hard for a few seconds with the bike off the main stand, then you may need new fork damper caps and rods as they do wear out?
good responses, thanks all. This was actually posted to assist a buddy and he is sorted out now.

Thanks to the community.
So what exactly was "sorted out"? Is your buddy now living with the clunk or did he do something to solve it and if so, what was it?

Many of us like to know the final resolution on these tech questions just so that if it ever happens to us we'll know how to proceed.

The clunk was sounding only when on the centre stand and apply pressure and allowing it to come up.

Once off the centre stand and operational the clunk was not duplicated.

Sorted. Outstanding advice guys thanks.
Dian - Thanks for the follow-up. My '72 has done that from new. Every once in a while it will do it when "motocrossing" over railroad tracks or jumping small bridges too. (Unintentionally of course :lol: ) But it does not seem to detract from the operation of the forks if ridden normally.
That clunk is the valve assembly at the end of the dampener rod smacking the inside of the dampener cap at the top of the tube. That's how stock forks are controlled down to 4 1/2 inches of travel from the six possible. I have taken some apart that have the 2MM dowels folded right over look at the drawings in the workshop manual.
You wouldn't say I was not telling the truth about folded over 2MM dowels being found, at least I hope not.
So when you looked at the shop manual drawings to figure how this could happen I would have thought it you could have seen the chain of events that could led to this happening. It's about two out of ten bikes I find this way. There are always dowel marks on the steel cup(NM.14118B) on all stock bikes no matter.
I've bent them too but I'm light and mine'll do it over bad jointed concrete roads, let alone Belgian pavé
Perhaps thick oil to overcome wear elsewhere, weak, wrong steel pins? It's a strange one.

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