Penton Owners Group

General Discussion => Penton Talk => Topic started by: 70MXer on June 13, 2021, 06:22:07 PM

Title: Knocking noise frt hub
Post by: 70MXer on June 13, 2021, 06:22:07 PM
Hello POG , I hope all is well. I have a 1976 MC5 250 and just started noticing a loud knocking noise in my front hub when I apply the brake. (e.g. standing still I hold the the front brake on and compress the front suspension and that's when I hear the knock in the frt hub) Has anyone ever experienced this issue? I disassembled the frt hub and everything looks in tack.  Thank you
Title: Knocking noise frt hub
Post by: Paul Danik on June 13, 2021, 07:16:52 PM
I realize you said it is in the front hub, but "back in the day" when applying the front break if I heard/felt a noise or thud it usually meant the steering head bearing needed tightened. Place your hand where the lower triple tree meets the steering stem and apply the front brake and rock the bike forward and backward and see if you feel any movement.

Hope this helps and in the words of the late Doug Wilford, "Have fun" !

Paul
Title: Knocking noise frt hub
Post by: 70MXer on June 13, 2021, 08:30:04 PM
Thanks Paul I appreciate your suggestion to try. Actually that was the first thing I checked and the steering head adjustment was okay. The knock only happens when I hold the front brake and rock the suspension up and down. I pushed the front wheel against my wall and compressed the suspension WITHOUT holding the brake and NO knock happened. So that leads me to believe it has something to do with the brake or hub. Thanks again!
Title: Knocking noise frt hub
Post by: Paul Danik on June 13, 2021, 09:42:32 PM
Couple of thoughts.

 I am sure you have checked the brake stay arm to make sure it is tight on both ends.

I have seen where the brakes are worn just enough that when you hold the brake on and compress the forks the wheel will actually turn just a tad before the brakes lock it up, causing a noise of sorts. Possibly have someone watch the front wheel for a tad of movement when you do the static test. Maybe take the brakes out of the hub and reverse them, making the leading one the trailing one, if nothing else seems to work.

Could the noise he coming from a loose fork leg?

Paul

Title: Knocking noise frt hub
Post by: 70MXer on June 13, 2021, 09:58:08 PM
I will try your additional recommendations . Couple good options to try. Thanks again Paul
Title: Knocking noise frt hub
Post by: Carl Hill on June 14, 2021, 05:37:20 AM
I've seen those front axles worn so bad they will let the wheel move slightly.
Title: Knocking noise frt hub
Post by: 70MXer on June 14, 2021, 08:26:35 AM
Thanks Carl, appreciate the help.