Yz85 big wheel...

[wwillf01]

So what is the down fall if I pick this bike up with a 1 inch longer swing arm and put small wheels on it from a regular 85?

[gedakbx]

I think they are only 3/4 " I don't think it will affect any thing 

[CaptDan]

We did that swap on an RM85 with no ill effects. It was an RM85 "L" (big wheel) and we swapped to the smaller wheels for one season.

Just pay attention when setting up the suspension. ?

[wwillf01]

Just resetting the sag or more than that?

[Swappa]

1 hour ago, wwillf01 said:

Just resetting the sag or more than that?

I don't have specific knowledge of the big wheel (we have a small wheel) but you might find the spring rate is different (for a heavier average rider) and the compression and rebound shims may be different in the shock to cope with the additional leverage of the longer arm.

YZ85 parts are very inexpensive. Post a wanted ad for a small wheel shock or shock spring in the classifieds section or ebay if you run into trouble. It wouldn't be worth stripping the shock to re-shim it, if it were mine.

[gedakbx]

5 hours ago, Swappa said:

I don't have specific knowledge of the big wheel (we have a small wheel) but you might find the spring rate is different (for a heavier average rider) and the compression and rebound shims may be different in the shock to cope with the additional leverage of the longer arm.

YZ85 parts are very inexpensive. Post a wanted ad for a small wheel shock or shock spring in the classifieds section or ebay if you run into trouble. It wouldn't be worth stripping the shock to re-shim it, if it were mine.

We ran the exact same suspension and springs when we raced an 85 and a big wheel85 the same season 

[CaptDan]

Since both "small" wheels have a 1" smaller radius, you can lower the suspension at both ends by 1 inch.

This is done on the rear of the regular YZ85 with the shorter swingarm, and the forks are slid up in the triple clamps to the lower scribe line. (The scribe line on the upper fork tube is 1" down from the top; this is the "top" reference line for the small wheel bike. This means you can slide the fork tubes up in the triple clamp [lowering the bike] to that line and still have wheel clearance when bottomed out.)

Just remember that if you are running the long swingarm, lowering the front ALL the way to the scribe line may be too much.