Author Topic: RD250c forks topping out  (Read 159 times)

0 Members and 1 Guest are viewing this topic.

Offline Leaking head gasket

  • Newcomer
  • Posts: 3
RD250c forks topping out
« on: June 17, 2021, 09:09:40 AM »
Hi all

Could anyone advise what is causing the “knocking “ of my forks when I run over something like a speed bump or a shallow pothole? They sound like they are topping out.

Quite a loud knock.
Any views on how to fix this or cause(s)

Thanks Pete

Offline tore

  • Club Member
  • Port Hacker
  • Posts: 1042
  • Location: On a two-wheeler
Re: RD250c forks topping out
« Reply #1 on: June 17, 2021, 09:30:16 AM »
Have you checked the preload of the springs?
Tore

Suzuki T20 1969
RD350B (Indonesia) 1975
BMW R1150GS Adv 2004
HVA Roulette 1957
NV 125 1955
https://www.youtube.com/watch?v=k85mRPqvMbE

Offline Astute Greaser

  • Club Member
  • Port Hacker
  • Posts: 888
  • Age: 64
  • Location: Bristol
Re: RD250c forks topping out
« Reply #2 on: June 17, 2021, 10:10:35 AM »
Check the castellated nut for preloading of the steering head bearings. Any slack will cause knocking. Easy to check by rolling the bike and suddenly applying the front brake. Do not tighten by using punch and hammer like some I've seen  :o :o, use a proper C hook spanner.
-Mike

Offline Leaking head gasket

  • Newcomer
  • Posts: 3
Re: RD250c forks topping out
« Reply #3 on: June 17, 2021, 03:53:04 PM »
I’ll check that, didn’t think of the head bearings being loose. Thanks for the advice 👍

Offline ajh

  • Club Member
  • Port Hacker
  • Posts: 580
  • Age: 55
  • Location: Chiswick, West London
  • theres always something bloody leaking!
Re: RD250c forks topping out
« Reply #4 on: June 17, 2021, 04:15:49 PM »
agree it could be head bearings play. Just to add though dont overtighten them if you adjust them up :)
in Chiswick, West London

77 RD250d, 80 DT175mx, 81 4L0 350LC

Offline Leaking head gasket

  • Newcomer
  • Posts: 3
Re: RD250c forks topping out
« Reply #5 on: June 17, 2021, 06:48:17 PM »
Cheers for that!


Offline Astute Greaser

  • Club Member
  • Port Hacker
  • Posts: 888
  • Age: 64
  • Location: Bristol
Re: RD250c forks topping out
« Reply #6 on: June 17, 2021, 06:58:15 PM »
Do come back and let us know when you resolve. Its nice to hear the end of the story  :)
-Mike

Offline stephen bailey

  • Club Member
  • Back Lane Scratcher
  • Posts: 375
  • Age: 56
  • Location: nottingham
Re: RD250c forks topping out
« Reply #7 on: July 02, 2021, 09:35:21 PM »
eBay item 265206522369 these have transformed my old forks
corky