??? - front forks - metallic, metal to metal, banging sound

hope i'm explaining this correctly. just finished the caliper rebuild followed up by bleeding the front brakes. everything's fine - no issues. this is the first time since I got the bike i was able to do this, but when i lock the front wheel using the brakes, rocking the front end, thus compressing the fork tubes, i get this, metal to metal, metallic, banging or knocking sound. can't isolate it, but it sounds like it's coming from the upper fork assembly. doesn't sound right.

still a noob, and not enough experience to sort through this one, and not sure what to make of it, so WTF. i was extremely careful when i drained and refilled the fork tubes, and reassembled the upper fork nut to the inner spring assembly. torqued both upper fork nuts to upper fork yoke (torqued to 35 ft.lbs). since everything is finished on the front end, i dread the idea of tearing back into the fork tubes. hope it's not one of those "one step forward, two steps back" things. kind of puzzled....

Check more closely when it happens, there is a design flaw in Commando forks and when the forks extend the topping out hydraulic damper is not properly setup and instead the damper valve clatters against the damper body top. The fix is longer top fork bushes so oil is trapped between the fork bushes earlier.

Why no top out spring inside the damper unit ? (The reduced suspension travel if so would need to be addressed)

is this a related thread? is this what i am experiencing?

https://www.accessnorton.com/NortonCommando/front-fork-knock-help.3724/#post-35084

Yes but it is only normal in a not right sort of way.

Joe,
If that's your problem longer bushes will help, however often overlooked is the condition of the damper rods and especially damper body top caps. The bore of the the top cap is very tightly toleranced to the rod. As the bores wear the damping deteriorates slowly and unconsciously you adjust your riding to accommodate. Eventually you get the clonk.
RGM do a cast iron version of the top cap, I trialled a pair years ago, they are still fitted and since have never had that clonk or the any damping issues. Though there was a bit of stiffness in the fork action for a few miles.
Dave

thanks dave, and thanks everybody for the replies. sounds like it a somewhat normal issue. right now, just want to get the 74 running. if there is a problem with the forks, I live with it short term.

joe czech said:

this is the first time since I got the bike i was able to do this, but when i lock the front wheel using the brakes, rocking the front end, thus compressing the fork tubes, i get this, metal to metal, metallic, banging or knocking sound.

Click to expand...

Unless the clunk is often heard or you feel it through the handlebars when riding and depending on fork oil viscosity then there's probably no cause for concern, however, there are various 'cures' such as the RGM extended upper bushes or 'Covenant' sleeves etc.

https://www.rgmnorton.co.uk/buy/ext...s-topping-out-2-9-74mm-o-all-lgth-pr_2298.htm
https://www.rgmnorton.co.uk/buy/covenant-fork-damper-conversion-kit-improves-damping_2294.htm