SImons Anti-cavitation fork internals?

DirtDgr
Profile picture for user DirtDgr
Posts
394
Joined
2/15/2009
Location
Lakeport, CA, USA
DirtDgr
Edited Date/Time 1/27/2012 7:29am
Looking for ways to improve the forks on my 1981 YZ 250.

I can get Simons fork internals but I dont know what they actually do and if its worth the trouble?






Thanks guys.
|
CamP
Profile picture for user CamP
Posts
6826
Joined
8/16/2006
Location
Colleyville, TX, USA
CamP 10/19/2009 10:23pm
10/19/2009 10:23pm
I had a set installed in my '85 KX250 forks, back in the day. They made a noticeable improvement to the forks. I don't know if they are better than Race Tech Emulator valves though. I have a set of the RT valves in the '84 RM forks I have and they work great.
DirtDgr
Profile picture for user DirtDgr
Posts
394
Joined
2/15/2009
Location
Lakeport, CA, USA
DirtDgr 10/19/2009 10:34pm
10/19/2009 10:34pm Edited Date/Time 4/17/2016 2:50am
I forgot about the Race Tech Emulators.

Well that is another option. Could they be used together?

Opinions?

Thanks again!
lumpy790
Profile picture for user lumpy790
Posts
11646
Joined
9/18/2007
Location
York, SC, USA
lumpy790 10/20/2009 7:26am
10/20/2009 7:26am
Probably the same thing but also look into Terry fork kits. I ran the Terry rods in my 78 YZ125 and they made a big difference.

Basically they revalve the forks action by moving the oil holes around and change the flow pattern.
CamP
Profile picture for user CamP
Posts
6826
Joined
8/16/2006
Location
Colleyville, TX, USA
CamP 10/20/2009 10:02am
10/20/2009 10:02am
DirtDgr wrote:
I forgot about the Race Tech Emulators.

Well that is another option. Could they be used together?

Opinions?

Thanks again!
I don't think you can use them together. With the RT valves, you drill out the compression orifices in the damper rod, then the RT valve sits on top of the damper rod and becomes the restriction on compression. A spring inside the valve allows the orifice size to vary depending on the volume of oil flowing through it. This is similar to how a modern shim stack works.

Based on my experience with both, I would install a set of Emulators. Also, make sure you get the proper spring rates for your shock and forks while you are at it.

The Shop

See All »
lumpy790
Profile picture for user lumpy790
Posts
11646
Joined
9/18/2007
Location
York, SC, USA
lumpy790 10/20/2009 1:32pm
10/20/2009 1:32pm
Basic suspension set up sure has come a long way since then......did they even offer heavier springs..... back in the day?
CamP
Profile picture for user CamP
Posts
6826
Joined
8/16/2006
Location
Colleyville, TX, USA
CamP 10/20/2009 2:04pm
10/20/2009 2:04pm
lumpy790 wrote:
Basic suspension set up sure has come a long way since then......did they even offer heavier springs..... back in the day?
Most bikes had optional heavier/lighter springs available by the early 80's.
project racer 10/20/2009 2:16pm
10/20/2009 2:16pm
Yamaha offered optional heavy springs for the YZ250/400's as far back as '79 for the shock. For heavier fork springs, I had to go with White Brothers . I had an unused WB kit for the '80 model 250/465 that I never installed for years. I pitched it out in '92 before the Evo bike craze hit.Unsure
DirtDgr
Profile picture for user DirtDgr
Posts
394
Joined
2/15/2009
Location
Lakeport, CA, USA
DirtDgr 10/20/2009 8:32pm
10/20/2009 8:32pm
Well sounds like the I will have to give the Emulators a try. I can put them in my 465 and 250 for a little more than one set of the Simons stuff.

Thanks for the words of wisdom!
captmoto
Profile picture for user captmoto
Posts
5889
Joined
4/22/2009
Location
Rancho Cucamonga, CA, USA
captmoto 10/20/2009 10:06pm
10/20/2009 10:06pm
DirtDgr wrote:
Well sounds like the I will have to give the Emulators a try. I can put them in my 465 and 250 for a little more...
Well sounds like the I will have to give the Emulators a try. I can put them in my 465 and 250 for a little more than one set of the Simons stuff.

Thanks for the words of wisdom!
Check out the Race Tech website on the YZ465. They really did their homework. All the guesswork is gone. Call and talk to Bill Rohde, he was involved in the testing. Tell him Steve referred you. (my bike)
DirtDgr
Profile picture for user DirtDgr
Posts
394
Joined
2/15/2009
Location
Lakeport, CA, USA
DirtDgr 10/22/2009 9:22pm
10/22/2009 9:22pm
DirtDgr wrote:
Well sounds like the I will have to give the Emulators a try. I can put them in my 465 and 250 for a little more...
Well sounds like the I will have to give the Emulators a try. I can put them in my 465 and 250 for a little more than one set of the Simons stuff.

Thanks for the words of wisdom!
captmoto wrote:
Check out the Race Tech website on the YZ465. They really did their homework. All the guesswork is gone. Call and talk to Bill Rohde, he...
Check out the Race Tech website on the YZ465. They really did their homework. All the guesswork is gone. Call and talk to Bill Rohde, he was involved in the testing. Tell him Steve referred you. (my bike)
Wow! I havent been to their site in a long time. I had no idea they did all that now.

I just had Back in the Day MX do my shock and am very happy with it so far. I have only one race on it.

I just had a good sunday of racing with Sterlyn Rigsby. He is from Socal. Do you know him?
FreshTopEnd
Profile picture for user FreshTopEnd
Posts
13293
Joined
8/16/2006
Location
Sacramento, CA, USA
FreshTopEnd 10/23/2009 10:10pm
10/23/2009 10:10pm Edited Date/Time 10/23/2009 10:11pm
You could probably sell those on ebay for a bucket of dough, more than the RT emulators cost. Do you ride Oasis? We go by there on the way to Arcata and I'm curious what the track is like.
DirtDgr
Profile picture for user DirtDgr
Posts
394
Joined
2/15/2009
Location
Lakeport, CA, USA
DirtDgr 10/24/2009 8:35am
10/24/2009 8:35am Edited Date/Time 4/17/2016 2:55am
FreshTopEnd wrote:
You could probably sell those on ebay for a bucket of dough, more than the RT emulators cost. Do you ride Oasis? We go by there...
You could probably sell those on ebay for a bucket of dough, more than the RT emulators cost. Do you ride Oasis? We go by there on the way to Arcata and I'm curious what the track is like.
Raced the Oasis last weekend. AVDRA National. We had that rain so traction was perfect.

Its a good layout and the Mann family are good people and giving it all they have.

Heres a couple blurry pics from the race.







Very short vid
http://s72.photobucket.com/albums/i172/DirtDgr/?action=view&current=089…
DirtDgr
Profile picture for user DirtDgr
Posts
394
Joined
2/15/2009
Location
Lakeport, CA, USA
DirtDgr 10/24/2009 8:38am
10/24/2009 8:38am
The middle pic is Dave Coupe. Dude is amazing!

Post a reply to: SImons Anti-cavitation fork internals?