'89 YZ 80 Suspension upgrades?

[eastbayyz]

What type of upgrades can I do to modernize the suspension?

Front and rear is stock 1989 issue.

Will suspension from modern YZ85's? Fit?

The bike is a restore rider. I plan on just goofing off on it MX wise and some trail riding.

Nostalgia Trip...

X

I'm 5-8" 199

Any advice appreciated.

Edited January 17, 2016 by eastbayyz

[mlatour]

How tall are you and how much do you weigh?

and, what do you use the bike for : trail/off-road, motocross?

 

Have the current suspension components ever been refurbished since 1989 ?

(bushing, seals, fluid, nitrogen charge)

[mlatour]

Needless to say but at 5'8" / 199 lbs, you are WAY too tall and heavy for a YZ80.

 

Maybe for very slow trail riding but for MX'ing, the small ergononomic will have you sitting way farther

back than ideal (knees hitting the handlebars), greatly unbalancing the suspension and handling.

 

YZ80 & 85's are initialy designed around a shorter than 5'2", 100-120lbs riders,

a quick check on the Race Tech spring calculator and although infos on the 1989 are scarce,

I used a 1994 YZ as a comparative equivalent to enter the infos:

 

stock springs :

front: .29kg/mm  

rear: 4.8kg/mm

 

suggested for a 199lbs rider :

front: .39kg/mm (not even listed as available, .33 is the max)

rear: 6.7kg/mm

 

IMO the bike is physicaly too small to ever be comfortable no matter the type of riding you'll do,

and without the proper spring rates for a 199lbs rider would likely be unsafe to ride at speed / MX.

(bad handling, harsh suspension, bottom out too easily, etc.)

Edited January 18, 2016 by mlatour

[eastbayyz]

I should have been clearer in my original post.

I don't plan on doing any serious riding with it. Just the occasional hot lap around the block. Noodling around.

Overall I just wanted to see if I could improve the suspension from the 1989 design.

[mlatour]

Fully serviced (oil, bushings, nitrogen) and stiffer springs would likely feel like a major improvement.