RD500 fork bottoms out
Moderator: rztom
RD500 fork bottoms out
Hi guys, Just got my 84 RD500 home and starting to go through it. First thing I noticed on test ride was forks very soft and bottom easily. Can this be fixed with just adding air or does it require new springs? Also, until I can track down a service manual, what is the pressure for a 250 lb rider? Any info greatly appreciated. Allan
Re: RD500 fork bottoms out
Current bikes -
RD 500 1984
KR1 250
Z1000 2010
VT 500 1984
XJ 600 2000
XL 125R 1984
XS 500 1977
FT 500 1982
previous bikes too many to list
RD 500 1984
KR1 250
Z1000 2010
VT 500 1984
XJ 600 2000
XL 125R 1984
XS 500 1977
FT 500 1982
previous bikes too many to list
Re: RD500 fork bottoms out
Thanks for that info, nick. I assumed it had to have air pressure, because it bottoms so easily. Wrong! No provision for that on this bike, d'oh! And I've got an 80.00 Progressive fork servicing pump on the way. Got a little ahead of myself there... I knew this bike would be a learning experience. My suspension guy tells me new (custom made) springs and overhaul is the fix for me. I'm trying to keep it stock.
Re: RD500 fork bottoms out
PDQ in the UK will provide springs according to your weight - get Racetech emulators for the damping as well - they make a massive difference - a new shock such as Nitron or Hagon for your weight will also help the handling.
Cheers
Paul
Cheers
Paul
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- Posts: 43
- Joined: Fri Oct 29, 2021 4:45 am
Re: RD500 fork bottoms out
Serviced my RZV forks and had the same issue on the first ride.
I reckon it must have cleared some crap from the internals whilst 'pumping' the forks to clear all the oil.
Went to 10wt oil and double the amount and it stopped
We have to remember these bikes were built and test road by lightweights
Years on use old farts are probably double their weight
In the RZV forks I have cut down Hagon RD500 springs.
I also fitted a Nitro shock
Both mods helped no end
I reckon it must have cleared some crap from the internals whilst 'pumping' the forks to clear all the oil.
Went to 10wt oil and double the amount and it stopped
We have to remember these bikes were built and test road by lightweights
Years on use old farts are probably double their weight
In the RZV forks I have cut down Hagon RD500 springs.
I also fitted a Nitro shock
Both mods helped no end
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- Posts: 336
- Joined: Wed Jul 03, 2019 1:46 pm
Re: RD500 fork bottoms out
Order the proper spring for the bike. You need to realize if it bottoms out under a panic braking situation or a hard bump you are going down most likely. A good shop should know what is needed for the bike, your weight, and gear etc. Do not cut springs because you change their design. Proper spring and then be sure you have the appropriate spacer in the fork. Normally you will have 10 MM of preload. The springs are most likely worn out and too light. You never know. They could have been changed in the past for a lighter rider. I agree with new springs, Race Tech Gold Valves, proper spacer per Race Tech instructions, then proper oil level and viscosity. Sound to me that you need to go to a good race suspension shop and have the work done. The Gold valves, spring, and spacers are engineered to work together. Do not use some local bike shop that says they can do it. It is not their butt in the seat. Repeat race shop.